Consumption of meat is associated with higher fasting glucose and insulin concentrations regardless of glucose and insulin genetic risk scores: a meta-analysis of 50,345 Caucasians

The burden of type 2 diabetes attributable to dietary risks in China: Insights from the global burden of disease study 2021

OBJECTIVES

This study aims to comprehensively assess how dietary risk factors have influenced the prevalence of Type 2 Diabetes Mellitus (T2DM) in China from 1990 to 2021. The study seeks to provide robust data and scientific evidence essential for formulating effective preventive and control strategies to combat T2DM in China.

STUDY DESIGN

This cross-sectional study conducted secondary analyses using data from the Global Burden of Disease 2021 (GBD 2021) to assess the burden of T2DM in China attributable to dietary risks.

METHODS

The study analyzed age-adjusted metrics related to T2DM, including death counts, Disability-Adjusted Life Years (DALYs), and Age-Standardized Rates (ASRs), using GBD 2021 data, stratified by age and sex. Additionally, Estimated Annual Percentage Changes (EAPCs) were employed to track trends over time.

RESULTS

In 2021, the results show that 21.43 % of T2DM-related deaths and 23.51 % of DALYs were attributable to dietary risk factors, notably a diet low in whole grains and high in red and processed meats. Over the period from 1990 to 2021, there has been an increasing trend in the EAPCs of death rates and DALYs associated with dietary risks in China, suggesting a substantial impact of dietary factors on the burden of T2DM in the country.

CONCLUSION

This study highlights the urgent need for targeted public health interventions to promote dietary changes and reduce the burden of T2DM in China.

Healthy dietary pattern is associated with lower glycemia independently of the genetic risk of type 2 diabetes: a cross-sectional study in Finnish men

PURPOSE

Hyperglycemia is affected by lifestyle and genetic factors. We investigated if dietary patterns associate with glycemia in individuals with high or low genetic risk for type 2 diabetes (T2D).

METHODS

Men (n = 1577, 51-81 years) without T2D from the Metabolic Syndrome in Men (METSIM) cohort filled a food-frequency questionnaire and participated in a 2-hour oral glucose tolerance test. Polygenetic risk score (PRS) including 76 genetic variants was used to stratify participants into low or high T2D risk groups. We established two data-driven dietary patterns, termed healthy and unhealthy, and investigated their association with plasma glucose concentrations and hyperglycemia risk.

RESULTS

Healthy dietary pattern was associated with lower fasting and 2-hour plasma glucose, glucose area under the curve, and better insulin sensitivity (Matsuda insulin sensitivity index) and insulin secretion (disposition index) in unadjusted and adjusted models, whereas the unhealthy pattern was not. No interaction was observed between the patterns and PRS on glycemic measures. Healthy dietary pattern was negatively associated with the risk for hyperglycemia in an adjusted model (OR 0.69, 95% CI 0.51-0.95, in the highest tertile), whereas unhealthy pattern was not (OR 1.08, 95% CI 0.79-1.47, in the highest tertile). No interaction was found between diet and PRS on the risk for hyperglycemia (p = 0.69 for healthy diet, p = 0.54 for unhealthy diet).

CONCLUSION

Our findings suggest that healthy diet is associated with lower glucose concentrations and lower risk for hyperglycemia in men with no interaction with the genetic risk.

Association between processed red meat intake and cardiovascular risk factors in patients with type 2 diabetes: a cross-sectional study from China

Aim

To explore the association between Processed red meat (PRM) consumption and cardiovascular risk factors in Chinese adults with type 2 diabetes mellitus (T2DM).

Methods

Dietary survey, physical measurement, and blood biochemical examination were conducted on 316 patients with type 2 diabetes in Bengbu, China from May to July 2019. Possible confounding factors were identified by comparing between-group variability in the baseline table. To eliminate the effect of confounding factors, subgroup analysis was used to explore whether there were differences in the correlation between PRM intake status and the indicators in cardiovascular disease risk factors. A logistic regression model was used to analyze the association between PRM and the risk of abnormal levels of cardiovascular risk factors in T2DM patients. Restricted cubic spline plots were used to analyze the dose-response relationship between PRM intake and the indicators of cardiovascular disease risk factors.

Results

A total of 316 subjects were included in the study, of whom 139 (44.0%) were male and 177 (56.0%) were female. In the multiplicative interaction, there was an effect modifier for smoking (Pinteraction = 0.033) on the association between PRM intake and the risk of substandard FPG level control; sex (Pinteraction = 0.035), smoking status (Pinteraction = 0.017), and alcohol consumption (Pinteraction = 0.046) had effect modifying effects on the association between PRM intake and risk of abnormal systolic blood pressure. Sex (Pinteraction = 0.045) had an effect modifier on the association of PRM intake status with the risk of diastolic blood pressure abnormality. In addition, age had an effect modifier on the association of PRM intake status with risk of abnormal triglyceride index (Pinteraction = 0.004) and risk of abnormal HDL index (Pinteraction = 0.018). After adjusting for potential confounding variables, logistic regression showed that the OR for substandard HbA1c control in patients in the highest PRM intake group, T3 (3.4 ~ 57.2 g/d), was 1.620-fold higher than in the lowest intake, i.e., the no-intake group, T1 (0.0 ~ 0.0 g/d; OR = 2.620; 95% CI 1.198 ~ 5.732; p = 0.016). Whereas the OR for abnormal control of systolic blood pressure levels was 1.025 times higher (OR = 2.025; 95% CI 1.033 ~ 3.968; p = 0.040) in patients in the PRM low intake group T2 (0.1 ~ 3.3 g/d) than in the non-intake group T1 (0.0 ~ 0.0 g/d), the OR for substandard control of systolic blood pressure in patients in the highest group T3 (3.4 ~ 57.2 g/d) was 1.166 times higher than in the no-intake group T1 (OR = 2.166; 95% CI 1.007 ~ 4.660; p = 0.048). The OR for abnormal TG levels in patients in the highest PRM intake group T3 (3.4 ~ 57.2 g/d) was 1.095 times higher than in the no-intake group T1 (OR = 2.095; 95% CI 1.076 ~ 4.078; p = 0.030). Restricted cubic spline plots presented a nonlinear dose-response relationship between PRM intake and risk of substandard HbA1c and SBP control (P nonlinear <0.05), and an atypical inverted U-shaped association between PRM intake and TC and LDL-C levels (P nonlinear <0.05). The strength of the associations between PRM intake and the control levels of FPG, DBP, HDL-C, and TG were not statistically significant (p > 0.05).

Conclusion

PRM intake was generally low in patients with T2DM, but a nonlinear dose-response relationship between PRM intake and the risk of suboptimal control of HbA1c and SBP, with an atypical inverted U-shaped association with TC and LDL-C levels, was observed. Appropriate control of PRM intake may be important for tertiary prevention of T2DM and cardiovascular disease prevention. We need to better understand these relationships to promote improved cardiometabolism and global health.

Nutrition at the Intersection between Gut Microbiota Eubiosis and Effective Management of Type 2 Diabetes

Nutrition is one of the most influential environmental factors in both taxonomical shifts in gut microbiota as well as in the development of type 2 diabetes mellitus (T2DM). Emerging evidence has shown that the effects of nutrition on both these parameters is not mutually exclusive and that changes in gut microbiota and related metabolites such as short-chain fatty acids (SCFAs) and branched-chain amino acids (BCAAs) may influence systemic inflammation and signaling pathways that contribute to pathophysiological processes associated with T2DM. With this background, our review highlights the effects of macronutrients, carbohydrates, proteins, and lipids, as well as micronutrients, vitamins, and minerals, on T2DM, specifically through their alterations in gut microbiota and the metabolites they produce. Additionally, we describe the influences of common food groups, which incorporate varying combinations of these macronutrients and micronutrients, on both microbiota and metabolic parameters in the context of diabetes mellitus. Overall, nutrition is one of the first line modifiable therapies in the management of T2DM and a better understanding of the mechanisms by which gut microbiota influence its pathophysiology provides opportunities for optimizing dietary interventions.

The Global Burden of Type 2 Diabetes Attributable to Dietary Risks: Insights from the Global Burden of Disease Study 2019

The Global Burden of Disease Study (GBD) 2019 reveals an increasing prevalence of Type 2 Diabetes Mellitus (T2DM) from 1990 to 2019. This study delves into the role of dietary risk factors across different demographic and socioeconomic groups. Utilizing data from the GBD 2019, it analyzes age-adjusted T2DM metrics-death counts, Disability-Adjusted Life Years (DALYs), and Age-Standardized Rates (ASRs)-stratified by age, sex, and region. The study employed Estimated Annual Percentage Changes (EAPCs) to track trends over time. The results show that in 2019, 26.07% of T2DM mortality and 27.08% of T2DM DALYs were attributable to poor diets, particularly those low in fruits and high in red and processed meats. There was a marked increase in both the death rate and DALY rate associated with dietary risks over this period, indicating the significant impact of dietary factors on the global T2DM landscape. Geographic variations in T2DM trends were significant, with regions like Southern Sub-Saharan Africa and Central Asia experiencing the most substantial increases in Age-Standardized Mortality Rate (ASMR) and Age-Standardized DALY Rate (ASDR). A positive correlation was noted between Socio-Demographic Index (SDI) and T2DM burden due to dietary risk factors. The study concludes that targeted public health initiatives promoting dietary changes could substantially reduce the global T2DM burden.

Association of diet quality during pregnancy with maternal glucose metabolism in Chinese women

Overall diet quality during pregnancy has played an important role on maternal glucose metabolism. However, evidence based on the adherence to the dietary guideline is limited, especially for Asian populations. We aimed to examine the association between adherence to the Chinese dietary guideline measured by the Diet Balance Index for Pregnancy (DBI-P) and maternal glucose metabolism, including gestational diabetes mellitus (GDM) status, fasting and 2-h plasma glucose. Data were obtained from the baseline survey of the Yuexiu birth cohort. We recruited 942 pregnant women at 20-28 weeks of gestation in 2017-2018. Dietary intakes during the past month were collected using a validated semi-quantitative FFQ. The scores of DBI-P were calculated to assess dietary quality. Lower absolute values of the scores indicate higher adherence to the Chinese dietary guidelines. All participants underwent a 75 g of oral glucose tolerance test (OGTT). Multiple linear regression and logistic regression were conducted. The Benjamini-Hochberg method was used to adjust multiple comparisons across DBI-P food components. The value of high bound score indicator, reflecting excessive total food intake, was positively associated with OGTT-2h glucose levels (β = 0·037, P = 0·029). After adjustment for multiple comparisons, the score of animal food intake was positively associated with OGTT-2 h glucose levels (β = 0·045, P = 0·045) and risk of GDM (OR = 1·105, P = 0·030). In conclusion, excessive total food intake was associated with higher postprandial glucose in pregnant women. Lower compliance with the dietary guideline for animal food was associated with both higher postprandial glucose and increased risk of GDM during pregnancy.

Adherence to the 2015-2020 Dietary Guidelines for Americans Compared with the Mediterranean Diet in Relation to Risk of Prediabetes: Results from NHANES 2007-2016

Prediabetes presents a high-risk state for the development of various diseases and is reversible by adhering to a healthy lifestyle. We conducted this analysis to explore the associations of the Healthy Eating Index-2015 (HEI-2015) and the Alternate Mediterranean Diet Index (aMed index) with the risk of prediabetes. The data were derived from the National Health and Nutrition Examination Survey, including 20,844 participants. Multivariable-adjusted odds ratios (OR) of prediabetes and 95% confidence intervals (CI) by tertile of diet quality scores were estimated using a weighted logistic regression. Compared to those in the lowest tertile, the multivariable-adjusted OR of prediabetes for the highest tertile was 0.82 (95% CI: 0.72, 0.94; p for trend = 0.005) for HEI-2015 and 0.87 (95% CI: 0.76, 0.98; p for trend = 0.02) for the aMed index. After mutual adjustment, the association for HEI-2015 (p for trend = 0.03) but not for the aMed index (p for trend = 0.59) remained significant. Among the component food groups and nutrients, higher intakes of red and processed meat, sodium, and total saturated fatty acids were associated with a higher risk of prediabetes, while moderate alcohol consumption was associated with a lower risk. In conclusion, adherence to the 2015-2020 Dietary Guidelines for Americans, as compared with the Mediterranean Diet, appeared to be more strongly associated with a lower risk of prediabetes among adults in the United States.

TT Genotype of TLR4 rs1928295 Is a Risk Factor of Overweight/Obesity in Han Chinese Children Aged 7-12 Years and Can Interact with Dietary Patterns to Affect the Incidence of Central Obesity and Lipid Profile, Systolic Blood Pressure Levels

Previous studies have found that TLR4 rs1928295 polymorphism is associated with Body Mass Index in European and American Indian adults. This study evaluates the relationship between this locus polymorphism, obesity-related parameters and dietary patterns in Chinese Han Children. A total of 798 children aged 7-12 years were included in this cross-sectional study. An improved Multiple Ligase Detection Reaction was used for genotyping. Dietary patterns were identified by principal component factor analysis. The overweight/obesity rate of the TT genotype was greater than those of the CC/CT genotype (p = 0.032 and 0.048 in boys and girls, respectively). Boys of the TT genotype could interact with protein and cholesterol intake to increase low density lipoprotein (LDL) levels (p = 0.02, 0.015, respectively), while girls of the TT genotype could interact with total energy intake to increase triglyceride (TG) (p = 0.018) levels. Boys predisposed to a healthy balance dietary pattern (HBDP) and girls predisposed to an egg/fruit/fish dietary pattern (EFDP) were significantly associated with lower rates of central obesity (p = 0.045, 0.028). Boys carrying the TT genotype and predisposed to animal food dietary pattern (AFDP) had a higher level of low-density lipoprotein (p = 0.017) and systolic pressure (p = 0.044). Our results indicated that the TT genotype of TLR4 rs1928295 is a potential risk factor for obesity in Chinese Han children and is associated with dietary patterns.

Fake meat or meat with benefits? How Dutch consumers perceive health and nutritional value of plant-based meat alternatives

Animal agriculture has a large impact on the environment. Hence, there is an increasing demand for meat alternatives - more sustainably produced plant-based products that replace meat as meal component. Demands for meat alternatives also seem to be fuelled by consumers' belief that meat alternatives are healthier than meat products. In an online questionnaire study, we examined whether consumers indeed perceived meat alternatives to be healthier, to what degree consumers adequately estimated the nutritional value of meat (alternatives), and whether a nutrition claim could misguide consumers. In a panel of 120 Dutch consumers, it was found that meat alternatives were generally perceived as being healthier than meat products. According to supermarket data, meat alternatives contained less protein and saturated fat, higher levels of fibre and salt compared to meat. Consumers were found to overestimate the protein content of meat alternatives relative to meat products, especially when meat alternatives carry a 'high in protein' claim. The current beliefs about the healthiness and nutritional content of meat and meat alternatives are precarious and a fair, transparent, and understandable environment should be created for the conscious consumer.

Fecal Microbiota Composition, Their Interactions, and Metagenome Function in US Adults with Type 2 Diabetes According to Enterotypes

T2DM etiology differs among Asians and Caucasians and may be associated with gut microbiota influenced by different diet patterns. However, the association between fecal bacterial composition, enterotypes, and T2DM susceptibility remained controversial. We investigated the fecal bacterial composition, co-abundance network, and metagenome function in US adults with T2DM compared to healthy adults based on enterotypes. We analyzed 1911 fecal bacterial files of 1039 T2DM and 872 healthy US adults from the Human Microbiome Projects. Operational taxonomic units were obtained after filtering and cleaning the files using Qiime2 tools. Machine learning and network analysis identified primary bacteria and their interactions influencing T2DM incidence, clustered into enterotypes, Bacteroidaceae (ET-B), Lachnospiraceae (ET-L), and Prevotellaceae (ET-P). ET-B showed higher T2DM incidence. Alpha-diversity was significantly lower in T2DM in ET-L and ET-P (p < 0.0001), but not in ET-B. Beta-diversity revealed a distinct separation between T2DM and healthy groups across all enterotypes (p < 0.0001). The XGBoost model exhibited high accuracy and sensitivity. Enterocloster bolteae, Facalicatena fissicatena, Clostridium symbiosum, and Facalibacterium prausnitizii were more abundant in the T2DM group than in the healthy group. Bacteroides koreensis, Oscillibacter ruminantium, Bacteroides uniformis, and Blautia wexlerae were lower in the T2DM than in the healthy group regardless of the enterotypes in the XGBoost model (p < 0.0001). However, the patterns of microbial interactions varied among different enterotypes affecting T2DM risk. The interaction between fecal bacteria was more tightly regulated in the ET-L than in the ET-B and ET-P groups (p < 0.001). Metagenomic analysis revealed an inverse association between bacteria abundance in T2DM, energy utility, butanoate and propanoate metabolism, and the insulin signaling pathway (p < 0.0001). In conclusion, fecal bacteria play a role in T2DM pathogenesis, particularly within different enterotypes, providing valuable insights into the link between gut microbiota and T2DM in the US population.

The Association between Plant-Based Diets and Dietary Patterns with Cardiometabolic Risk in a Sample of Commercial Taxi Drivers in South Africa

The consumption of unhealthy foods and a sedentary lifestyle predispose individuals to non-communicable diseases. This study investigated the distribution and the association of plant-based diets (PBDs) and dietary patterns in relation to the cardiometabolic risks in commercial taxi drivers. A cross-sectional analysis was conducted among males (≥19 years) who consumed street foods sold by vendors in the Cape Metropole. A validated questionnaire was administered, including a quantified 24 h dietary recall, and fasting blood samples were collected for biochemical analyses. Statistical analyses were performed to investigate the association between dietary habits and cardiometabolic risks, while adjusting for confounding variables. The analytic sample consisted of 189 males with a median age of 38 years. The taxi drivers who ranked in the top-third of the healthy plant-based diet index (hPDI) had a 1–4% lower likelihood of having raised triglycerides (TG). Furthermore, consumption patterns including refined grains and meat conferred a 33% lower likelihood of dysglycaemia (p = 0.049), while fish/seafood, potatoes, and vegetables conferred a 43% greater likelihood of low high-density lipoprotein cholesterol (HDL-C) (p = 0.026) and 44% greater probability of raised low-density lipoprotein cholesterol (LDL-C) (p = 0.027). Consumption patterns, including sugar-sweetened beverages and eggs, conferred a 37% greater probability of hypertension (p = 0.047) and 53% greater likelihood of subclinical inflammation (p = 0.017). These preliminary findings require larger and more elaborate studies to explore the associations between PBDs and dietary patterns in at-risk African populations, with or without sedentary lifestyles, and exposure to unhealthy food environments.

Incident type 2 diabetes attributable to suboptimal diet in 184 countries

The global burden of diet-attributable type 2 diabetes (T2D) is not well established. This risk assessment model estimated T2D incidence among adults attributable to direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.8-14.4 million) incident T2D cases, representing 70.3% (68.8-71.8%) of new cases globally. Largest T2D burdens were attributable to insufficient whole-grain intake (26.1% (25.0-27.1%)), excess refined rice and wheat intake (24.6% (22.3-27.2%)) and excess processed meat intake (20.3% (18.3-23.5%)). Across regions, highest proportional burdens were in central and eastern Europe and central Asia (85.6% (83.4-87.7%)) and Latin America and the Caribbean (81.8% (80.1-83.4%)); and lowest proportional burdens were in South Asia (55.4% (52.1-60.7%)). Proportions of diet-attributable T2D were generally larger in men than in women and were inversely correlated with age. Diet-attributable T2D was generally larger among urban versus rural residents and higher versus lower educated individuals, except in high-income countries, central and eastern Europe and central Asia, where burdens were larger in rural residents and in lower educated individuals. Compared with 1990, global diet-attributable T2D increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variation in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve dietary quality and reduce T2D globally.

[Meat consumption by adults and the elderly in a city colonized by Germans in the south of Brazil: a population-based study]

Excessive meat consumption, especially red and processed meats, is associated with increased morbidity and mortality. The pattern of meat consumption varies in Brazil and is influenced by economic and cultural factors in the world. The study aimed to analyze the consumption of meat by adults and the elderly in a city colonized by Germans in the south of Brazil. It involved a cross-sectional population study. Sociodemographic and meat consumption data were collected using a previously validated Food Frequency Questionnaire. Frequencies and amounts were analyzed by type of meat and processing. The association between excessive meat consumption and the study variables was estimated by Prevalence Ratio. Among the 1,941 participants, the average amount of meat consumed was 250 g/day, the most consumed being white unprocessed meat (138 g/day), especially poultry (80 g/day). The prevalence of excessive consumption of red and processed meat (more than 500 g/week) was 63%, mainly among men (PR=1.6; 95%CI 1.5-1.8), aged 20 to 29 years (PR=1.4; 95%CI 1.2-1.5), and higher economic class (PR=1.2; 95%CI 1.0-1.3). Excessive consumption of red and processed meat among young men of upper economic class should be the target of public health actions for the adequacy of food consumption.

MetS Prevalence and Its Association with Dietary Patterns among Chinese Middle-Aged and Elderly Population: Results from a National Cross-Sectional Study

The prevalence of metabolic syndrome (MetS) increased dramatically over the past years among adults in a separate province in China; little is known about newly diagnosed MetS in middle-aged and above residents nationwide. We investigated the prevalence of MetS and its components, the dietary patterns, and their relationship among the middle-aged and above population of China by using data from a national cross-sectional survey. General information involving lifestyles and health stations was collected, and dietary intake using a 3-day 24 h dietary recall and weighing method for edible oil and condiments was conducted. Height, weight, waist circumference, and blood pressure were measured, and fasting serum lipids and glucose were tested by trained clinical staff. Dietary patterns were derived from 23 food categories by using cluster analysis, and a multivariate logistic regression model was used to evaluate the odd ratio of MetS and its component across obtained dietary patterns. The estimated prevalence of MetS was 37.1% among 40,909 middle-aged and older participants in the study. Participants were classified into diversity pattern, northern pattern, and southern pattern that, respectively, accounted for 9.8%, 47.2%, and 43.0% of the total. Compared with those inclined to the northern pattern, participants prone to the southern pattern decreased the risk of MetS (OR = 0.81, 95%CI: 0.75- 0.87; p < 0.001), central obesity (OR = 0.70, 95%CI: 0.65−0.76; p < 0.001), and HDL-C (OR = 0.82, 95%CI: 0.76−0.89; p < 0.001), and elevated BP (OR = 0.86, 95%CI: 0.79−0.93; p < 0.001) respectively. However, participants of the southern pattern tended to have a higher risk of elevated glucose; the OR (95%CI) was 1.13 (1.05, 1.22; p = 0.002) after adjusting for potential confounding factors. Greater adherence to diverse dietary patterns was negatively related to the risk of central obesity and elevated blood pressure with an OR (95%CI) of 0.82 (0.71, 0.94; p = 0.005) and 0.77 (0.67, 0.88; p < 0.001), respectively. We concluded that dietary improvement and health promotion for MetS should be based on the district-specific nutritional status of the Chinese middle-aged and elderly population.

Food proteins in the regulation of blood glucose control

Food proteins, depending on their origin, possess unique characteristics that regulate blood glucose via multiple physiological mechanisms, including the insulinotropic effects of amino acids, the activation of incretins, and slowing gastric emptying rate. The strategies aimed at curbing high blood glucose are important in preventing impaired blood glucose control, including insulin resistance, prediabetes and diabetes. The effect of proteins on blood glucose control can be achieved with high-protein foods short-term, and high-protein diets long-term using foods that are naturally high in protein, such as dairy, meat, soy and pulses, or by formulating high-protein functional food products using protein concentrates and isolates, or blended mixtures of proteins from different sources. Commercial sources of protein powders are represented by proteins and hydrolysates of caseins, whey proteins and their fractions, egg whites, soy, yellow pea and hemp which will be reviewed in this chapter. The effective doses of food protein that are capable of reducing postprandial glycemia start from 7 to 10g and higher per serving; however, the origin of protein, and macronutrient composition of a meal will determine the magnitude and duration of their effect on glycemia. The theoretical and methodological framework to evaluate the effect of foods, including food proteins, on postprandial glycemia for substantiation of health claims on food has been proposed in Canada and is discussed in the context of global efforts to harmonize the international food regulation and labeling.

Eating Habits in Patients with Familial Hypercholesterolemia from North-Eastern Romania

(1) Background: Familial hypercholesterolemia (FH) is a genetic autosomal dominant disorder characterized by elevated levels of low-density lipoprotein cholesterol (LDL) that develops deposits of lipids in the arterial wall. Since it is underdiagnosed and undertreated, the disease has a high risk of premature cardiovascular disease and death. Patients are not always aware of the changes they should make in their diet. Thus, our study aimed to evaluate through a food frequency questionnaire their eating habits. (2) Methods: We included 70 patients with FH and 20 subjects in a control group that were evaluated through a physical examination and blood tests. They also completed a food frequency questionnaire. (3) Results: Throughout our study, we observed several aspects: regardless of age, patients with FH had higher carbohydrate intakes compared to the control group; from the same group, a positive correlation was observed between salami intake and the levels of glucose and glycated hemoglobin. Moreover, the sour cream preference was associated with higher liver function tests. In the control group, we observed a higher intake of pasta and fast food and fewer fruit portions. (4) Conclusions: As far as we know, this is the first study from Romania that evaluated the eating habits of patients diagnosed with FH. Our study reveals that, although patients with FH avoid junk food, they still have a high intake of carbohydrates when compared to the control group. Further research is needed in order to get a comprehensive nutritional evaluation of these patients.

Non-Pharmacological Treatments for Insulin Resistance: Effective Intervention of Plant-Based Diets—A Critical Review

Plant-based diets are becoming increasingly popular. Vegetarian diets are better for the environment and exhibit health benefits. A correctly balanced plant-based diet is appropriate at every stage of life. Compared to omnivores, vegetarians consume more fruits and vegetables, more fibre, vitamins C and E, magnesium and less saturated fats. In general, they have better nutrition knowledge, and they are slimmer, healthier and live longer than omnivores. It also seems that following a plant-based diet prevents the onset of chronic diseases such as cardiovascular diseases, hypertension, type 2 diabetes, obesity and some cancers. Food intake has a key influence on insulin resistance. Consumption of calorie-rich and highly processed foods, meats and sweetened beverages is a characteristic element of Western diets. They promote and elevate insulin resistance and type 2 diabetes. In contrast, intake of pulses and exclusion of meats as well as animal products bring significant benefits to vegetarian diets. According to studies, vegetarians and vegans have better blood parameters, including better glucose, insulin, total cholesterol, and LDL cholesterol levels. Their homeostatic model assessment for insulin resistance (HOMA-IR) test results are also better. More plant-based foods and fewer animal foods in a diet result in lower insulin resistance and a lower risk of prediabetes and type 2 diabetes. The aim of the study was to investigate the effect of plant-based diets on insulin resistance. In this review, we focused on presenting the positive effects of vegetarian and vegan diets on insulin resistance while showing possible clinical applications of plant-based diets in the treatment and prevention of modern-age diseases. Current and reliable publications meeting the requirements of Evidence-Based Medicine (EBM) were taken into account in this review.

Dietary Patterns Associated with Diabetes in an Older Population from Southern Italy Using an Unsupervised Learning Approach

Dietary behaviour is a core element in diabetes self-management. There are no remarkable differences between nutritional guidelines for people with type 2 diabetes and healthy eating recommendations for the general public. This study aimed to evaluate dietary differences between subjects with and without diabetes and to describe any emerging dietary patterns characterizing diabetic subjects. In this cross-sectional study conducted on older adults from Southern Italy, eating habits in the “Diabetic” and “Not Diabetic” groups were assessed with FFQ, and dietary patterns were derived using an unsupervised learning algorithm: principal component analysis. Diabetic subjects (n = 187) were more likely to be male, slightly older, and with a slightly lower level of education than subjects without diabetes. The diet of diabetic subjects reflected a high-frequency intake of dairy products, eggs, vegetables and greens, fresh fruit and nuts, and olive oil. On the other hand, the consumption of sweets and sugary foods was reduced compared to non-diabetics (23.74 ± 35.81 vs. 16.52 ± 22.87; 11.08 ± 21.85 vs. 7.22 ± 15.96). The subjects without diabetes had a higher consumption of red meat, processed meat, ready-to-eat dishes, alcoholic drinks, and lower vegetable consumption. The present study demonstrated that, in areas around the Mediterranean Sea, older subjects with diabetes had a healthier diet than their non-diabetic counterparts.

Red meat consumption, obesity, and the risk of nonalcoholic fatty liver disease among women: Evidence from mediation analysis

BACKGROUND

Previous studies have suggested consumption of red meat may be associated with an increased risk of developing nonalcoholic fatty liver disease (NAFLD). However, large-scale, prospective data regarding red meat consumption in relation to the incidence of NAFLD are lacking, nor is it known whether any association is mediated by obesity.

OBJECTIVE

We aimed to evaluate the relationship between red meat consumption and the subsequent risk of developing NAFLD.

DESIGN

This prospective cohort study included 77,795 women in the Nurses' Health Study II cohort without NAFLD at baseline (in 1995), who provided detailed, validated information regarding diet, including consumption of red meat, every 4 years, followed through 2015. Lifestyle factors, clinical comorbidities and body mass index (BMI), were updated biennially. Cox proportional hazard models were used to estimate multivariable adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over 1,444,637 person years of follow-up, we documented 3130 cases of incident NAFLD. Compared to women who consumed ≤1 serving/week of red meat, the multivariable-adjusted HRs of incident NAFLD were 1.20 (95% CI: 0.97, 1.50) for 2-4 servings/week; 1.31 (95% CI: 1.06, 1.61) for 5-6 servings/week; 1.41 (95% CI: 1.13, 1.75) for 1 serving/day; and 1.52 (95% CI: 1.23, 1.89) for ≥2 servings/day. However, after further adjustment for BMI, all associations for red meat, including unprocessed and processed red meat, were attenuated and not statistically significant (all P-trend>0.05). BMI was estimated to mediate 66.1% (95% CI: 41.8%, 84.2%; P < 0.0001) of the association between red meat consumption and NAFLD risk.

CONCLUSIONS

Red meat consumption, including both unprocessed and processed red meat, was associated with significantly increased risk of developing NAFLD. This association was mediated largely by obesity.

Mediterranean Diet and Fatty Liver Risk in a Population of Overweight Older Italians: A Propensity Score-Matched Case-Cohort Study

Hepatic steatosis, often known as fatty liver, is the most common hepatic disease in Western countries. The latest guidelines for the treatment of nonalcoholic fatty liver disease emphasize lifestyle measures, such as changing unhealthy eating patterns. Using a propensity score-matching approach, this study investigated the effect of adhering to a Mediterranean diet (MedDiet) on fatty liver risk in an older population (≥65 years) from Southern Italy. We recruited 1.403 subjects (53.6% men, ≥65 years) who completed a food frequency questionnaire (FFQ) and underwent clinical assessment between 2015 and 2018. For the assessment of the liver fat content, we applied the Fatty Liver Index (FLI). To evaluate the treatment effect of the MedDiet, propensity score matching was performed on patients with and without FLI > 60. After propensity score-matching with the MedDiet pattern as treatment, we found a higher consumption of red meat (p = 0.04) and wine (p = 0.04) in subjects with FLI > 60. Based on the FLI, the inverse association shown between adherence to the MedDiet and the risk of hepatic steatosis shows that the MedDiet can help to prevent hepatic steatosis. Consuming less red and processed meat, as well as alcoholic beverages, may be part of these healthy lifestyle recommendations.

Association of maternal pre-pregnancy dietary intake with adverse maternal and neonatal outcomes: A systematic review and meta-analysis of prospective studies

This study aimed to summarize the evidence regarding the effects of dietary intake before conception on pregnancy outcomes by performing a systematic review and meta-analysis of prospective studies. Electronic databases were searched from inception up to August 2021. Overall, 65 studies involving 831 798 participants were included and 38 studies were quantitatively pooled. With regard to maternal outcomes, pre-pregnancy intake of fried food, fast food, red and processed meat, heme iron and a low-carbohydrate dietary pattern was positively associated with the risk of gestational diabetes mellitus (GDM) (all P < 0.05). However, a high dietary fiber intake and folic acid supplementation were negatively associated with GDM risk (both P < 0.05). With regard to neonatal outcomes, maternal caffeine intake before pregnancy significantly increased the risk of spontaneous abortion, while folic acid supplementation had protective effects on total adverse neonatal outcomes, preterm birth, and small-for-gestational age (SGA, all P < 0.05). However, no significant associations were found between adverse pregnancy outcomes (i.e., GDM and SGA) and the pre-pregnancy dietary intake of sugar-sweetened beverages, potato, fish, and carbohydrates and the Healthy Eating Index. Our study suggests that maintaining a healthy diet before conception has significant beneficial effects on pregnancy outcomes.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.1989658.

Lower Dietary Intake of Plant Protein Is Associated with Genetic Risk of Diabetes-Related Traits in Urban Asian Indian Adults

The increasing prevalence of type 2 diabetes among South Asians is caused by a complex interplay between environmental and genetic factors. We aimed to examine the impact of dietary and genetic factors on metabolic traits in 1062 Asian Indians. Dietary assessment was performed using a validated semi-quantitative food frequency questionnaire. Seven single nucleotide polymorphisms (SNPs) from the Transcription factor 7-like 2 and fat mass and obesity-associated genes were used to construct two metabolic genetic risk scores (GRS): 7-SNP and 3-SNP GRSs. Both 7-SNP GRS and 3-SNP GRS were associated with a higher risk of T2D (p = 0.0000134 and 0.008, respectively). The 3-SNP GRS was associated with higher waist circumference (p = 0.010), fasting plasma glucose (FPG) (p = 0.002) and glycated haemoglobin (HbA1c) (p = 0.000066). There were significant interactions between 3-SNP GRS and protein intake (% of total energy intake) on FPG (Pinteraction = 0.011) and HbA1c (Pinteraction = 0.007), where among individuals with lower plant protein intake (<39 g/day) and those with >1 risk allele had higher FPG (p = 0.001) and HbA1c (p = 0.00006) than individuals with ≤1 risk allele. Our findings suggest that lower plant protein intake may be a contributor to the increased ethnic susceptibility to diabetes described in Asian Indians. Randomised clinical trials with increased plant protein in the diets of this population are needed to see whether the reduction of diabetes risk occurs in individuals with prediabetes.

Dietary Treatment for NAFLD: New Clinical and Epidemiological Evidence and Updated Recommendations

The key factor in preventing and treating nonalcoholic fatty liver disease (NAFLD) is a holistic lifestyle modification approach, encompassing diet based on healthy eating patterns of unprocessed foods, exercise, balanced drinking, and smoking habits. The Mediterranean diet and other healthy dietary patterns can reduce liver fat and may be related with lower disease progression. The type of diet should be tailored to the patient's cultural and personal preferences. Changing dietary composition without reducing caloric intake may offer an additional and sometimes more feasible alternative, so that the nutritional treatment incorporates, but is not focused on, weight reduction goals. The growing global consumption of ultra-processed foods, which is the polar opposite of the Mediterranean diet and its concept of home-based cooking, poses a great challenge in the prevention of NAFLD and probably hepatocellular carcinoma.This review will cover the most updated clinical and epidemiological evidence for lifestyle treatment in NAFLD and provide practical treatment tools.

Interventions to reduce meat consumption by appealing to animal welfare: Meta-analysis and evidence-based recommendations

Reducing meat consumption may improve human health, curb environmental damage, and limit the large-scale suffering of animals raised in factory farms. Most attention to reducing consumption has focused on restructuring environments where foods are chosen or on making health or environmental appeals. However, psychological theory suggests that interventions appealing to animal welfare concerns might operate on distinct, potent pathways. We conducted a systematic review and meta-analysis evaluating the effectiveness of these interventions. We searched eight academic databases and extensively searched grey literature. We meta-analyzed 100 studies assessing interventions designed to reduce meat consumption or purchase by mentioning or portraying farm animals, that measured behavioral or self-reported outcomes related to meat consumption, purchase, or related intentions, and that had a control condition. The interventions consistently reduced meat consumption, purchase, or related intentions at least in the short term with meaningfully large effects (meta-analytic mean risk ratio [RR] = 1.22; 95% CI: [1.13, 1.33]). We estimated that a large majority of population effect sizes (71%; 95% CI: [59%, 80%]) were stronger than RR = 1.1 and that few were in the unintended direction. Via meta-regression, we identified some specific characteristics of studies and interventions that were associated with effect size. Risk-of-bias assessments identified both methodological strengths and limitations of this literature; however, results did not differ meaningfully in sensitivity analyses retaining only studies at the lowest risk of bias. Evidence of publication bias was not apparent. In conclusion, animal welfare interventions preliminarily appear effective in these typically short-term studies of primarily self-reported outcomes. Future research should use direct behavioral outcomes that minimize the potential for social desirability bias and are measured over long-term follow-up.

Meet the Meat Alternatives: The Value of Alternative Protein Sources

PURPOSE OF REVIEW

Meat alternatives are non-animal-based proteins with chemical characteristics and aesthetic qualities comparable to meat. The global increase in meat consumption is associated with the adverse environmental impacts such as increased greenhouse gas emissions contributing to global warming and higher water/land use. In this review, we focus on the development, availability, and nutritional value of various meat alternatives and their impact on meat consumption.

RECENT FINDINGS

Changing dietary patterns and drive for environmental conservation contribute to the recent increase in the consumption of environmental friendly sources of proteins such as plant-based and mycoprotein-based meat alternatives. Perceived lack of naturalness and poor cultural acceptance present as roadblocks for widespread societal acceptance for meat alternatives. Continued research and efforts are needed to make the meat alternatives more aesthetically appealing with improved nutritive value.

Effect of the intake of dietary protein on insulin resistance in subjects with obesity: a randomized controlled clinical trial

PURPOSE

We compared the effect of diets with different amounts and sources of dietary protein on insulin sensitivity (IS) in subjects with obesity and insulin resistance (IR).

METHODS

Eighty subjects with obesity (BMI ≥ 30 kg/m²) and IR (Matsuda index < 4.3 and HOMA-IR ≥ 2.5) over 18 years old were randomized to four groups for a one-month period: a normal protein diet (< 20%) with a predominance of animal protein (Animal NP) or vegetable protein (Vegetable NP) and a high-protein diet (25-30%) with a predominance of animal protein (Animal HP) or vegetable protein (Vegetable HP). Baseline and final measurements of body weight, body composition, biochemical parameters, blood pressure (BP), resting energy expenditure and plasma amino acid profiles were performed.

RESULTS

Body weight, BMI and waist circumference decreased in all groups. Interestingly, the IS improved more in the Animal HP (Matsuda index; 1.39 vs 2.58, P = 0.003) and in the Vegetable HP groups (Matsuda index; 1.44 vs 3.14, P < 0.0001) after one month. The fat mass, triglyceride levels, C-reactive protein levels and the leptin/adiponectin index decreased; while, the skeletal muscle mass increased in the Animal and Vegetable HP groups. The BP decreased in all groups except the Animal NP group.

CONCLUSION

Our study demonstrates that a high-protein hypocaloric diets improves IS by 60-90% after one month in subjects with obesity and IR, regardless of weight loss and the source of protein, either animal or vegetable.

TRIAL REGISTRATION

The trial is registered at clinicaltrials.gov (NCT03627104), August 13, 2018.

Cultural Adaptation, Validation, and Primary Application of a Questionnaire to Assess Intentions to Eat Low-Glycemic Index Foods among Rural Chinese Women

Different lines of evidence indicate that knowledge of low-glycemic index (GI) foods and the practice of eating them play important roles in blood glucose management and preventing T2DM in women with prior gestational diabetes mellitus (GDM). According to the theory of planned behavior (TPB), intention is a critical factor in complying with health-related behaviors. However, an instrument for assessing the intention to eat low-GI foods is lacking in China. We aimed to (1) adapt and validate a Chinese version of the intentions to eat low-GI foods questionnaire (CIELQ) and (2) apply the CIELQ among rural Chinese women to explore the associations between CIELQ scores and glycemic status. A cross-sectional study was conducted on 417 nondiabetic, nonpregnant participants with a history of GDM in Hunan, China. After cultural adaptation and validation, the CIELQ was applied in a target population. Glycemic status, anthropometric variables, dietary intake, and physical activity were measured; a self-developed, standard questionnaire was applied to collect relevant information. The CIELQ showed good internal consistency; model fitness was acceptable based on the confirmatory factor analysis results. Awareness of the glycemic index was low among the study population. TPB factors were found to be associated with each other; education level and parents’ diabetes history were associated with specific factors. The score for instrumental attitude showed a positive association with the risk for a high level of the 2-h 75-g oral glucose tolerance test (odds ratio, OR = 1.330), while the score for perceived behavior control (PBC) showed a negative association with the risk for a high level (OR = 0.793). The CIELQ was determined to be a valid instrument for assessing the intention to eat a low-GI diet among the study population. The awareness of the GI was poor among the study population. The score for instrumental attitude showed a positive association with the risk of a high level on the 2-h 75-g oral glucose tolerance test (OGTT), and the score for PBC showed a negative association with the risk for a high level on OGTT.

Body mass index mediates the association between meat intake and insulin sensitivity

The purpose of this study was to examine the possible inverse relationship between total meat intake and processed meat intake and insulin sensitivity as mediated by body mass index (BMI). The Quantitative Insulin Sensitivity Check Index (QUICKI) was used to assess participants' insulin sensitivity: decreased insulin sensitivity indicated at a score of <0.36. Cross-sectional data were used from Visit 1 of the Atherosclerosis Risk in Communities (ARIC) cohort. Mediation analysis was conducted using the PROCESS macro for SPSS. The mean BMI was 27.3 ± 5.0 kg/m², total meat intake was 1.76 ± 0.89 servings per day, processed meat intake was 0.44 ± 0.46 servings per day, and the mean QUICKI score was 0.34 ± 0.039. This suggested decreased insulin sensitivity was prevalent in this population. As hypothesized and previously shown, both total meat intake and processed meat were inversely and significantly associated with insulin sensitivity after adjusting for key covariates including BMI. In mediation analysis, the significant inverse direct association model between total meat and QUICKI was -0.0017 (95% CI: -0.0026, -0.0008). BMI had a significant indirect association with QUICKI of -0.0028 (95% CI: -0.0033, -0.0023) which accounted for 62% of the association between total meat intake and insulin sensitivity. In the processed meat intake and QUICKI mediation model, BMI accounted for a significant 43% of the relationship. Our results suggest that the association between total meat and processed meat intake and insulin sensitivity is mediated by BMI.

Effects of Aging and Diet on Cardioprotection and Cardiometabolic Risk Markers

The prevalence of several diseases increases by age, including cardiovascular diseases, which are the leading cause of morbidity and mortality worldwide. Aging, as a complex process characterized by senescence, triggers various pathways, such as oxidative stress, systemic inflammation, metabolism dysfunction, telomere shortening, mitochondrial dysfunction and deregulated autophagy. A better understanding of the mechanisms underlying senescence may lead to the development of new therapeutic targets and strategies for age-related pathologies and extend the healthy lifespan. Modulating lifestyle risk factors and adopting healthy dietary patterns remain significant tools in delaying the aging process, decreasing age-associated comorbidities and mortality, increasing life expectancy and consequently, preventing the development of cardiovascular disease. Furthermore, such a strategy represents the most cost-effective approach, and the quality of life of the subjects may be significantly improved. An integrated, personalized approach targeting cardiometabolic aging and frailty is suggested in daily clinical practice. However, it should be initiated from an early age. Moreover, there is a need for further well designed and controlled studies in order to elucidate a link between the time of feeding, longevity and cardiovascular prevention. In the future, it is expected that the pharmacological treatment in cardioprotective management will be necessary, accompanied by equally important lifestyle interventions and adjunctive exercise.

Reducing meat consumption by appealing to animal welfare: protocol for a meta-analysis and theoretical review

BACKGROUND

Reducing meat consumption may improve human health, curb environmental damage and greenhouse gas emissions, and limit the large-scale suffering of animals raised in factory farms. Previous work has begun to develop interventions to reduce individual meat consumption, often by appealing directly to individual health motivations. However, research on nutritional behavior change suggests that interventions additionally linking behavior to ethical values, identity formation, and existing social movements may be particularly effective and longer-lasting. Regarding meat consumption, preliminary evidence and psychological theory suggest that appeals related to animal welfare may have considerable potential to effectively leverage these elements of human psychology. We aim to conduct a systematic review and quantitative meta-analysis evaluating the effectiveness of animal welfare-related appeals on actual or intended meat consumption or purchasing. Our investigation will critically synthesize the current state of knowledge regarding psychological mechanisms of intervening on individual meat consumption and empirically identify the psychological characteristics underlying the most effective animal welfare-based interventions.

METHODS

We will systematically search eight academic databases and extensively search unpublished grey literature. We will include studies that assess interventions intended to reduce meat consumption or purchase through the mention or portrayal of animal welfare, that measure outcomes related to meat consumption or purchase, and that have a control condition. Eligible studies may recruit from any human population, be written in any language, and be published or released any time. We will meta-analyze the studies, reporting the pooled point estimate and additional metrics that describe the distribution of potentially heterogeneous effects. We will assess studies' risk of bias and conduct sensitivity analyses for publication bias. We describe possible follow-up analyses to investigate hypothesized moderators of intervention effectiveness.

DISCUSSION

The findings of the proposed systematic review and meta-analysis, including any identified methodological limitations of the existing literature, could inform the design of successful evidence-based interventions with broad potential to improve human, animal, and environmental well-being.

SYSTEMATIC REVIEW REGISTRATION

The protocol was preregistered via the Open Science Framework (https://osf.io/d3y56/registrations).

Dietary Protein Consumption and the Risk of Type 2 Diabetes: ADose-Response Meta-Analysis of Prospective Studies

The relationship between dietary protein consumption and the risk of type 2 diabetes (T2D) has been inconsistent. The aim of this meta-analysis was to explore the relations between dietary protein consumption and the risk of T2D. We conducted systematic retrieval of prospective studies in PubMed, Embase, and Web of Science. Summary relative risks were compiled with a fixed effects model or a random effects model, and a restricted cubic spline regression model and generalized least squares analysis were used to evaluate the diet–T2D incidence relationship. T2D risk increased with increasing consumption of total protein and animal protein, red meat, processed meat, milk, and eggs, respectively, while plant protein and yogurt had an inverse relationship. A non-linear association with the risk for T2D was found for the consumption of plant protein, processed meat, milk, yogurt, and soy. This meta-analysis suggests that substitution of plant protein and yogurt for animal protein, especially red meat and processed meat, can reduce the risk for T2D.

Role of diet in type 2 diabetes incidence: umbrella review of meta-analyses of prospective observational studies

OBJECTIVE

To summarise the evidence of associations between dietary factors and incidence of type 2 diabetes and to evaluate the strength and validity of these associations.

DESIGN

Umbrella review of systematic reviews with meta-analyses of prospective observational studies.

DATA SOURCES

PubMed, Web of Science, and Embase, searched up to August 2018.

ELIGIBILITY CRITERIA

Systematic reviews with meta-analyses reporting summary risk estimates for the associations between incidence of type 2 diabetes and dietary behaviours or diet quality indices, food groups, foods, beverages, alcoholic beverages, macronutrients, and micronutrients.

RESULTS

53 publications were included, with 153 adjusted summary hazard ratios on dietary behaviours or diet quality indices (n=12), food groups and foods (n=56), beverages (n=10), alcoholic beverages (n=12), macronutrients (n=32), and micronutrients (n=31), regarding incidence of type 2 diabetes. Methodological quality was high for 75% (n=115) of meta-analyses, moderate for 23% (n=35), and low for 2% (n=3). Quality of evidence was rated high for an inverse association for type 2 diabetes incidence with increased intake of whole grains (for an increment of 30 g/day, adjusted summary hazard ratio 0.87 (95% confidence interval 0.82 to 0.93)) and cereal fibre (for an increment of 10 g/day, 0.75 (0.65 to 0.86)), as well as for moderate intake of total alcohol (for an intake of 12-24 g/day v no consumption, 0.75 (0.67 to 0.83)). Quality of evidence was also high for the association for increased incidence of type 2 diabetes with higher intake of red meat (for an increment of 100 g/day, 1.17 (1.08 to 1.26)), processed meat (for an increment of 50 g/day, 1.37 (1.22 to 1.54)), bacon (per two slices/day, 2.07 (1.40 to 3.05)), and sugar sweetened beverages (for an increase of one serving/day, 1.26 (1.11 to 1.43)).

CONCLUSIONS

Overall, the association between dietary factors and type 2 diabetes has been extensively studied, but few of the associations were graded as high quality of evidence. Further factors are likely to be important in type 2 diabetes prevention; thus, more well conducted research, with more detailed assessment of diet, is needed.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018088106.

Effect of diet composition on insulin sensitivity in humans

Diet composition has a marked impact on the risk of developing type 2 diabetes and cardiovascular disease. Prospective studies show that dietary patterns with elevated amount of animal products and low quantity of vegetable food items raise the risk of these diseases. In healthy subjects, animal protein intake intensifies insulin resistance whereas plant-based foods enhance insulin sensitivity. Similar effects have been documented in patients with diabetes. Accordingly, pre-pregnancy intake of meat (processed and unprocessed) has been strongly associated with a higher risk of gestational diabetes whereas greater pre-pregnancy vegetable protein consumption is associated with a lower risk of gestational diabetes. Population groups that modify their traditional dietary habit increasing the amount of animal products while reducing plant-based foods experience a remarkable rise in the frequency of type 2 diabetes. The association of animal protein intake with insulin resistance is independent of body mass index. In obese individuals that consume high animal protein diets, insulin sensitivity does not improve following weight loss. Diets aimed to lose weight that encourage restriction of carbohydrates and elevated consumption of animal protein intensify insulin resistance increasing the risk of developing type 2 diabetes and cardiovascular disease. The effect of dietary components on insulin sensitivity may contribute to explain the striking impact of eating habits on the risk of type 2 diabetes and cardiovascular disease. Insulin resistance predisposes to type 2 diabetes in healthy subjects and deteriorates metabolic control in patients with diabetes. In nondiabetic and diabetic individuals, insulin resistance is a major cardiovascular risk factor.

Insulin-like growth factor I, binding proteins -1 and -3, risk of type 2 diabetes and macronutrient intakes in men

The insulin-like growth factor (IGF) axis may be involved in the development of type 2 diabetes. We examined the associations of IGF-I and IGF binding proteins (IGFBP)-1 and -3 with diabetes risk and evaluated macronutrient intakes related to the observed associations. In a nested case-control study of the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study of Finnish male smokers aged 50-69 years, the IGF variables were measured from baseline serum samples for a random sample of 310 men with diabetes diagnosed during a 12-year follow-up and for 310 controls matched by age, recruitment day and intervention group. Diet at baseline was assessed using a validated FFQ. The associations of IGF proteins with diabetes risk were estimated using conditional logistic regression and the associations with macronutrient intakes using linear regression. IGF-I and IGFBP-3 were not associated with the incidence of diabetes. Higher IGFBP-1 was associated with lower diabetes risk in an unadjusted crude model (OR 0·25; 95 % CI 0·15, 0·42 in the highest quartile compared with the lowest), but not after adjustment for BMI (corresponding OR 0·76; 95 % CI 0·41, 1·40). Intakes of carbohydrates, plant protein and milk protein associated positively and intake of meat protein and fat negatively with IGFBP-1 (P&lt;0·005). IGFBP-1 was inversely associated with diabetes risk, but the association was substantially dependent on BMI. The associations between macronutrient intakes and IGFBP-1 may reflect influences of nutrients or foods on insulin concentrations.

Vegetarian diets and risk of hospitalisation or death with diabetes in British adults: results from the EPIC-Oxford study

BACKGROUND

The global prevalence of diabetes is high and rapidly increasing. Some previous studies have found that vegetarians might have a lower risk of diabetes than non-vegetarians.

OBJECTIVE

We examined the association between vegetarianism and risk of hospitalisation or death with diabetes in a large, prospective cohort study of British adults.

METHODS

The analysed cohort included participants from the European Prospective Investigation into Cancer and Nutrition (EPIC)-Oxford study who were diabetes free at recruitment (1993-2001), with available dietary intake data at baseline, and linked hospital admissions and death data for diabetes over follow-up (n = 45,314). Participants were categorised as regular meat eaters (≥50 g per day: n = 15,181); low meat eaters (<50 g of meat per day: n = 7615); fish eaters (ate no meat but consumed fish: n = 7092); and vegetarians (ate no meat or fish, including vegans: n = 15,426). We used multivariable Cox proportional hazards models to assess associations between diet group and risk of diabetes.

RESULTS

Over a mean of 17.6 years of follow-up, 1224 incident cases of diabetes were recorded. Compared with regular meat eaters, the low meat eaters, fish eaters, and vegetarians were less likely to develop diabetes (hazard ratio (HR) = 0.63, 95% confidence interval (CI) 0.54-0.75; HR = 0.47, 95% CI 0.38-0.59; and HR = 0.63, 95% CI 0.54-0.74, respectively). These associations were substantially attenuated after adjusting for body mass index (BMI) (low meat eaters: HR = 0.78, 95% CI 0.66-0.92; fish eaters: HR = 0.64, 95% CI 0.51-0.80; and vegetarians: HR = 0.89, 95% CI 0.76-1.05).

CONCLUSIONS

Low meat and non-meat eaters had a lower risk of diabetes, in part because of a lower BMI.

Effects of processed red meat consumption on the risk of type 2 diabetes and cardiovascular diseases among Korean adults: the Korean Genome and Epidemiology Study

PURPOSE

Few studies have evaluated the effects of processed red meat (PRM) consumption on chronic disease risk, especially among low average PRM consumption populations. This study examined association between PRM intake and type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD) incidences in Korea.

METHODS

Participants (n = 10,030; aged 40-69 years) were recruited from the Ansan-Ansung cohort study, a subset of Korean Genome Epidemiology Study. Validated 103-item semi-quantitative food frequency questionnaire was used to assess dietary information, at baseline (2001-2002) and at second follow-up (2005-2006). T2DM and CVD incidences were identified using biennial questionnaire-based interview during a 10-year follow-up period. Cox proportional hazards regression analysis was used to calculate multivariable-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Over the 10-year follow-up period, 668 and 493 incident cases of T2DM (62,130 person-years) and CVD (63,150 person-years), respectively, were documented. In crude models, comparing the highest and lowest levels of PRM intake, no significant association occurred with incident T2DM [HR, 95% CI (0.94, 0.76-1.17)], while significant association occurred with incident CVD (0.67, 0.51-0.88). However, in adjusted models, this association was no longer significant, showing HRs (95% CI) of PRM intake for T2DM and CVD of 1.07 (0.85-1.35) and 1.14 (0.85-1.55), respectively.

CONCLUSIONS

PRM intake did not affect T2DM and CVD incidences among Korean middle-aged adults, although extremely low average consumption of PRM may explain the finding. Therefore, limiting PRM intake may not be a top priority for the prevention of chronic diseases in Korean population.

High red and processed meat consumption is associated with non-alcoholic fatty liver disease and insulin resistance

BACKGROUND & AIMS

High red and processed meat consumption is related to type 2 diabetes. In addition, cooking meat at high temperatures for a long duration forms heterocyclic amines (HCAs), which are related to oxidative stress. However, the association between meat consumption and non-alcoholic fatty liver disease (NAFLD) is yet to be thoroughly tested. Therefore, we aimed to test the association of meat type and cooking method with NAFLD and insulin resistance (IR).

METHODS

This was a cross-sectional study in individuals who were 40-70 years old and underwent screening colonoscopy between 2013 and 2015 in a single center in Israel. NAFLD and IR were evaluated by ultrasonography and homeostasis model assessment. Meat type and cooking method were measured by a food frequency questionnaire (FFQ) and a detailed meat questionnaire. Unhealthy cooking methods were considered as frying and grilling to a level of well done and very well done. Dietary HCA intake was calculated.

RESULTS

A total of 789 individuals had a valid FFQ and 357 had a valid meat questionnaire. High consumption of total meat (portions/day above the median) (odds ratio [OR] 1.49; 95% CI 1.05-2.13; p = 0.028; OR 1.63; 1.12-2.37; p = 0.011), red and/or processed meat (OR1.47; 95% CI 1.04-2.09; p = 0.031; OR1.55; 1.07-2.23; p = 0.020) was independently associated with higher odds of NAFLD and IR, respectively, when adjusted for: body mass index, physical activity, smoking, alcohol, energy, saturated fat and cholesterol intake. High intake of meat cooked using unhealthy methods (OR1.92; 95% CI 1.12-3.30; p = 0.018) and HCAs (OR2.22; 95% CI 1.28-3.86; p = 0.005) were independently associated with higher odds of IR.

CONCLUSION

High consumption of red and/or processed meat is associated with both NAFLD and IR. High HCA intake is associated with IR. If confirmed in prospective studies, limiting the consumption of unhealthy meat types and improving preparation methods may be considered as part of NAFLD lifestyle treatment.

LAY SUMMARY

High red and processed meat consumption is related to several diseases. In addition, cooking meat at high temperatures for a long duration forms heterocyclic amines, which have harmful health effects. Non-alcoholic fatty liver disease is a significant public health burden and its formation is strongly related to insulin resistance. In this study, both were found to be more frequent in people who consume relatively high quantities of red and processed meat. In addition, a high intake of heterocyclic amines was associated with insulin resistance.

Dietary and genetic risk scores and incidence of type 2 diabetes

Background

Both lifestyle and genetic predisposition determine the development of type 2 diabetes (T2D), and studies have indicated interactions between specific dietary components and individual genetic variants. However, it is unclear whether the importance of overall dietary habits, including T2D-related food intakes, differs depending on genetic predisposition to T2D. We examined interaction between a genetic risk score for T2D, constructed from 48 single nucleotide polymorphisms identified in genome-wide association studies, and a diet risk score of four foods consistently associated with T2D in epidemiological studies (processed meat, sugar-sweetened beverages, whole grain and coffee). In total, 25,069 individuals aged 45–74 years with genotype information and without prevalent diabetes from the Malmö Diet and Cancer cohort (1991–1996) were included. Diet data were collected with a modified diet history method.

Results

During 17-year follow-up, 3588 incident T2D cases were identified. Both the diet risk score (HR in the highest risk category 1.40; 95% CI 1.26, 1.58; P trend = 6 × 10⁻¹⁰) and the genetic risk score (HR in the highest tertile of the genetic risk score 1.67; 95% CI 1.54, 1.81; P trend = 7 × 10⁻³⁵) were associated with increased incidence of T2D. No significant interaction between the genetic risk score and the diet risk score (P = 0.83) or its food components was observed. The highest risk was seen among the 6% of the individuals with both high genetic and dietary risk scores (HR 2.49; 95% CI 2.06, 3.01).

Conclusions

The findings thus show that both genetic heredity and dietary habits previously associated with T2D add to the risk of T2D, but they seem to act in an independent fashion, with the consequence that all individuals, whether at high or low genetic risk, would benefit from favourable food choices.

Electronic supplementary material

The online version of this article (10.1186/s12263-018-0599-1) contains supplementary material, which is available to authorized users.

Dietary Patterns in Relation to Metabolic Syndrome among Adults in Poland: A Cross-Sectional Study

In several populations the associations between diet and the risk of metabolic syndrome have not been fully examined yet. The aim of the study is to identify the main dietary patterns among Polish adults and the evaluation of the relationships of these patterns with metabolic syndrome and its components. The study was conducted on a group of 7997 participants, aged between 37 and 66 years old. Dietary patterns were identified by factor analysis. Metabolic syndrome was defined according to the International Diabetes Federation. Three dietary patterns were identified and designated as: "Healthy", "Westernized" and "Traditional-carbohydrate". In the adjusted model, a higher score in the "Westernized" pattern aligns with a higher risk of abnormal glucose concentration (p_trend = 0.000), but with a lower risk of abnormal High-Density Lipoprotein Cholesterol HDL-cholesterol concentration (p_trend = 0.024). Higher scores in the "Traditional-carbohydrate" pattern were connected with the risk of abdominal obesity (p_trend = 0.001) and increased triglycerides concentration (p_trend = 0.050). Our results suggest that adherence to the "Traditional-carbohydrate" dietary pattern, characterized by higher intakes of refined grains, potatoes, sugar and sweets is associated with a higher risk of abdominal obesity and triglyceridemia. A "Westernized" dietary pattern on the other hand, is related to hyperglycemia. The study results can be used for community-based health promotion and intervention programs to prevent or better manage chronic diseases.

Association between microbiota-dependent metabolite trimethylamine-N-oxide and type 2 diabetes

Background: The association of trimethylamine-N-oxide (TMAO), a microbiota-dependent metabolite from dietary choline and carnitine, with type 2 diabetes was inconsistent.Objective: We evaluated the association of plasma TMAO with newly diagnosed type 2 diabetes and the potential modification of TMAO-generating enzyme flavin monooxygenase 3 (FMO3) polymorphisms.Design: This was an age- and sex-matched case-control study of 2694 participants: 1346 newly diagnosed cases of type 2 diabetes and 1348 controls. Concentrations of plasma TMAO were measured, and FMO3 E158K polymorphisms (rs2266782) were genotyped.Results: Medians (IQRs) of plasma TMAO concentration were 1.47 μmol/L (0.81-2.20 μmol/L) for controls and 1.77 μmol/L (1.09-2.80 μmol/L) for type 2 diabetes cases. From the lowest to the highest quartiles of plasma TMAO, the multivariable adjusted ORs of type 2 diabetes were 1.00 (reference), 1.38 (95% CI: 1.08, 1.77), 1.64 (95% CI: 1.28, 2.09), and 2.55 (95% CI: 1.99, 3.28) (P-trend < 0.001); each SD of ln-transformed plasma TMAO was associated with a 38% (95% CI: 26%, 51%) increment in ORs of type 2 diabetes. The FMO3 rs2266782 polymorphism was not associated with type 2 diabetes. The positive association between plasma TMAO and type 2 diabetes was consistent in each rs2266782 genotype group, and no significant interaction was observed (P = 0.093).Conclusions: Our results suggested that higher plasma TMAO was associated with increased odds of newly diagnosed type 2 diabetes and that this association was not modified by the FMO3 rs2266782 polymorphism. This study was registered at clinicaltrials.gov as NCT03130894.

Processed red meat contribution to dietary patterns and the associated cardio-metabolic outcomes

Evidence suggests that processed red meat consumption is a risk factor for CVD and type 2 diabetes (T2D). This analysis investigates the association between dietary patterns, their processed red meat contributions, and association with blood biomarkers of CVD and T2D, in 786 Irish adults (18–90 years) using cross-sectional data from a 2011 national food consumption survey. All meat-containing foods consumed were assigned to four food groups (n 502) on the basis of whether they contained red or white meat and whether they were processed or unprocessed. The remaining foods (n 2050) were assigned to twenty-nine food groups. Two-step and k-means cluster analyses were applied to derive dietary patterns. Nutrient intakes, plasma fatty acids and biomarkers of CVD and T2D were assessed. A total of four dietary patterns were derived. In comparison with the pattern with lower contributions from processed red meat, the dietary pattern with greater processed red meat intakes presented a poorer Alternate Healthy Eating Index (21·2 (sd 7·7)), a greater proportion of smokers (29 %) and lower plasma EPA (1·34 (sd 0·72) %) and DHA (2·21 (sd 0·84) %) levels (P<0·001). There were no differences in classical biomarkers of CVD and T2D, including serum cholesterol and insulin, across dietary patterns. This suggests that the consideration of processed red meat consumption as a risk factor for CVD and T2D may need to be re-assessed.

Breakfast quality and cardiometabolic risk profiles in an upper middle-aged German population

Background/Objectives:

Little is known about relation of overall breakfast quality with cardiometabolic risk factors. Therefore, this study aimed to explore sex-specific associations between breakfast quality and cardiometabolic risk profiles in a sample of an upper middle-aged German population.

Subjects/Methods:

Cardiometabolic profiles of 339 men and 329 women were cross-sectionally assessed using an overall biomarker score (BScore), glycated hemoglobin (HbA1_c), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), triglycerides (TG), blood pressure, body mass index (BMI) and waist circumference (WC). Overall breakfast quality was assessed by using (i) an a-priori defined breakfast quality score (BQS) and (ii) data-driven breakfast patterns based on principal component analysis (PCA). Multiple linear regression models for association of breakfast quality with all outcomes were adjusted for all potential confounders including overall diet quality.

Results:

After adjustment for all potential confounders the BQS was inversely associated with the BScore (regression beta with 95% Confidence Interval: −0.29 (052−0.06)) and HbA1c (−0.12 (−0.21, −0.04)) in men; whereas no such associations were observed in women. Four breakfast (B) patterns were identified: B-processed-food pattern, B-cereal pattern, B-high fat pattern and B-dairy & cereal pattern. The B-processed-food pattern was positively associated with HbA1c (0.09(0.01, 0.18)), BMI (0.16 (0.06, 0.26)), and WC (0.17 (0.8, 0.26)) in men, and BMI (0.13 (0.1, 0.25)) and WC (0.11(0.01.0.22)) in women. The B-cereal pattern was inversely associated with BScore (−0.23 (−0.45, −0.01)) and BMI (-0.11 (−0.20, −0.01)) in men and WC(−0.16 (−0.27, −0.05)) in women. The B-dairy & cereal pattern was also inversely associated with BScore (−0.26 (−0.48, −0.04)) in men but not in women.

Conclusions:

The overall breakfast quality was cross-sectionally associated with a healthier cardiometabolic profile, especially in upper-middle age men, independent of overall dietary quality. Such analyses should be supplemented by studies investigating the circadian sequence of food intake and metabolic consequences including hard disease endpoints.

Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies

The aim of this systematic review and meta-analysis was to synthesize the knowledge about the relation between intake of 12 major food groups and risk of type 2 diabetes (T2D). We conducted a systematic search in PubMed, Embase, Medline (Ovid), Cochrane Central, and Google Scholar for prospective studies investigating the association between whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSB) on risk of T2D. Summary relative risks were estimated using a random effects model by contrasting categories, and for linear and non-linear dose–response relationships. Six out of the 12 food-groups showed a significant relation with risk of T2D, three of them a decrease of risk with increasing consumption (whole grains, fruits, and dairy), and three an increase of risk with increasing consumption (red meat, processed meat, and SSB) in the linear dose–response meta-analysis. There was evidence of a non-linear relationship between fruits, vegetables, processed meat, whole grains, and SSB and T2D risk. Optimal consumption of risk-decreasing foods resulted in a 42% reduction, and consumption of risk-increasing foods was associated with a threefold T2D risk, compared to non-consumption. The meta-evidence was graded “low” for legumes and nuts; “moderate” for refined grains, vegetables, fruit, eggs, dairy, and fish; and “high” for processed meat, red meat, whole grains, and SSB. Among the investigated food groups, selecting specific optimal intakes can lead to a considerable change in risk of T2D.

Utilizing nutritional genomics to tailor diets for the prevention of cardiovascular disease: a guide for upcoming studies and implementations

INTRODUCTION

Personalized diets based on an individual's genome to optimize the success of dietary intervention and reduce genetic cardiovascular disease (CVD) risk, is one of the challenges most frequently discussed in the scientific community. Areas covered: The authors gathered literature-based evidence on nutritional genomics and CVD phenotypes, our own results and research experience to provide a critical overview of the current situation of using nutritional genomics to tailor diets for CVD prevention and to propose guidelines for future studies and implementations. Expert commentary: Hundreds of studies on gene-diet interactions determining CVD intermediate (plasma lipids, hypertension, etc.) and final phenotypes (stroke, etc.) have furnished top-level scientific evidence for claiming that the genetic effect in cardiovascular risk is not deterministic, but can be modified by diet. However, despite the many results obtained, there are still gaps in practically applying a personalized diet design to specific genotypes. Hence, a better systemization and methodological improvement of new studies is required to obtain top-level evidence that will allow their application in the future precision nutrition/medicine. The authors propose several recommendations for tackling new approaches and applications.

Associations between hepatic miRNA expression, liver triacylglycerols and gut microbiota during metabolic adaptation to high-fat diet in mice

AIMS/HYPOTHESIS

Despite the current pandemic of metabolic diseases, our understanding of the diverse nature of the development of metabolic alterations in people who eat a high-fat diet (HFD) is still poor. We recently demonstrated a cardio-metabolic adaptation in mice fed an HFD, which was characterised by a specific gut and periodontal microbiota profile. Since the severity of hepatic disease is characterised by specific microRNA (miRNA) signatures and the gut microbiota is a key driver of both hepatic disease and miRNA expression, we analysed the expression of three hepatic miRNA and studied their correlation with hepatic triacylglycerol content and gut microbiota.

METHODS

Two cohorts of C57BL/6 4-week-old wild-type (WT) male mice (n = 62 and n = 96) were fed an HFD for 3 months to provide a model of metabolic adaptation. Additionally 8-week-old C57BL/6 mice, either WT or of different genotypes, with diverse gut microbiota (ob/ob, Nod1, Cd14 knockout [Cd14KO] and Nod2) or without gut microbiota (axenic mice) were fed a normal chow diet. Following which, glycaemic index, body weight, blood glucose levels and hepatic triacylglycerol levels were measured. Gut (caecum) microbiota taxa were analysed by pyrosequencing. To analyse hepatic miRNA expression, real-time PCR was performed on total extracted miRNA samples. Data were analysed using two-way ANOVA followed by the Dunnett's post hoc test, or by the unpaired Student's t test. A cluster analysis and multivariate analyses were also performed.

RESULTS

Our results demonstrated that the expression of miR-181a, miR-666 and miR-21 in primary murine hepatocytes is controlled by lipopolysaccharide in a dose-dependent manner. Of the gut microbiota, Firmicutes were positively correlated and Proteobacteria and Bacteroides acidifaciens were negatively correlated with liver triacylglycerol levels. Furthermore, the relative abundance of Firmicutes was negatively correlated with hepatic expression of miR-666 and miR-21. In contrast, the relative abundance of B. acidifaciens was positively correlated with miR-21.

CONCLUSIONS/INTERPRETATION

We propose the involvement of hepatic miRNA, liver triacylglycerols and gut microbiota as a new triad that underlies the molecular mechanisms by which gut microbiota governs hepatic pathophysiology during metabolic adaptation to HFD.

Potential health hazards of eating red meat

Red meat (beef, veal, pork, lamb and mutton) consumption contributes several important nutrients to the diet, for example essential amino acids, vitamins (including B12) and minerals (including iron and zinc). Processed red meat (ham, sausages, bacon, frankfurters, salami, etc.) undergoes treatment (curing, smoking, salting or the use of chemical preservatives and additives) to improve its shelf life and/or taste. During recent decades, consumption of red meat has been increasing globally, especially in developing countries. At the same time, there has been growing evidence that high consumption of red meat, especially of processed meat, may be associated with an increased risk of several major chronic diseases. Here, a comprehensive summary is provided of the accumulated evidence based on prospective cohort studies regarding the potential adverse health effects of red meat consumption on major chronic diseases, such as diabetes, coronary heart disease, heart failure, stroke and cancer at several sites, and mortality. Risk estimates from pooled analyses and meta-analyses are presented together with recently published findings. Based on at least six cohorts, summary results for the consumption of unprocessed red meat of 100 g day^-1 varied from nonsignificant to statistically significantly increased risk (11% for stroke and for breast cancer, 15% for cardiovascular mortality, 17% for colorectal and 19% for advanced prostate cancer); for the consumption of 50 g day^-1 processed meat, the risks were statistically significantly increased for most of the studied diseases (4% for total prostate cancer, 8% for cancer mortality, 9% for breast, 18% for colorectal and 19% for pancreatic cancer, 13% for stroke, 22% for total and 24% for cardiovascular mortality and 32% for diabetes). Potential biological mechanisms underlying the observed risks and the environmental impact of red meat production are also discussed. The evidence-based integrated message is that it is plausible to conclude that high consumption of red meat, and especially processed meat, is associated with an increased risk of several major chronic diseases and preterm mortality. Production of red meat involves an environmental burden. Therefore, some European countries have already integrated these two issues, human health and the 'health of the planet', into new dietary guidelines and recommended limiting consumption of red meat.

Differentially expressed genes selection via Laplacian regularized low-rank representation method

With the rapid development of DNA microarray technology and next-generation technology, a large number of genomic data were generated. So how to extract more differentially expressed genes from genomic data has become a matter of urgency. Because Low-Rank Representation (LRR) has the high performance in studying low-dimensional subspace structures, it has attracted a chunk of attention in recent years. However, it does not take into consideration the intrinsic geometric structures in data. In this paper, a new method named Laplacian regularized Low-Rank Representation (LLRR) has been proposed and applied on genomic data, which introduces graph regularization into LRR. By taking full advantages of the graph regularization, LLRR method can capture the intrinsic non-linear geometric information among the data. The LLRR method can decomposes the observation matrix of genomic data into a low rank matrix and a sparse matrix through solving an optimization problem. Because the significant genes can be considered as sparse signals, the differentially expressed genes are viewed as the sparse perturbation signals. Therefore, the differentially expressed genes can be selected according to the sparse matrix. Finally, we use the GO tool to analyze the selected genes and compare the P-values with other methods. The results on the simulation data and two real genomic data illustrate that this method outperforms some other methods: in differentially expressed gene selection.

Trimethylamine-N-oxide and its biological variations in vegetarians

PURPOSE

Restriction of animal foods and choline may affect plasma trimethylamine-N-oxide (TMAO). In vegetarians, we investigated the association between TMAO concentrations and the strictness of the diet or sex. We also studied the biological variations of TMAO in vegans.

METHODS

Concentrations of plasma TMAO and choline metabolites were measured in 38 vegans and 67 lacto-ovo-vegetarians (group 1: mean age ± SD = 50 ± 15 years). Group 2 consisted of 66 vegans (29.2 ± 7.3 years) that was tested twice within 3 months of intervention with vitamin B12 or a placebo.

RESULTS

In group 1, plasma TMAO did not differ according to the strictness of the diet (both means 3.7 µmol/L). In lacto-ovo-vegetarians, men had higher TMAO and betaine, but lower trimethylamine than women. In group 2, the intervention with vitamin B12 had no effect on plasma TMAO or choline metabolites. The mean within-subject change of TMAO within 3 months was -0.3 (95 % confidence intervals = -0.7-0.1 µmol/L). TMAO increased after 3 months (mean 1.7 to 2.8 µmol/L) in vegans with a lower baseline dimethylglycine (2.2 µmol/L), while it declined (from 2.7 to 1.9 µmol/L) in vegans with a higher dimethylglycine (3.1 µmol/L). The intra-class correlation coefficients were 0.819 for TMAO, 0.885 for betaine and 0.860 for dimethylglycine.

CONCLUSIONS

Plasma TMAO was not related to the strictness of the vegetarian diet. Metabolisms of TMAO and dimethylglycine are interrelated. Intra-individual variations of TMAO are low in vegans. Changes of fasting plasma TMAO >80 % upon retesting are likely to exceed the biological variations.