Relationship of three different types of low-carbohydrate diet to cardiometabolic risk factors in a Japanese population: the INTERMAP/INTERLIPID Study

The effect of a nurse-led low carbohydrate regimen on anthropometric and laboratory parameters of patients with metabolic syndrome: a quasi-experimental study

Introduction

Metabolic syndrome is a global health concern. It is a condition that includes a cluster of various risk factors for type 2 diabetes and cardiovascular disease. This quasi-experimental study investigates the effect of a nurse-led low-carbohydrate regimen on anthropometric and laboratory parameters in metabolic syndrome patients.

Methods

The study used a quasi-experimental design conducted at the University of Mosul; 128 participants meeting the metabolic syndrome criteria were recruited and divided into the intervention and control groups. The intervention group received personalized counseling and support in implementing a low-carb regime, while the control group received standard advice. The study participants were assessed by anthropometry, and laboratory parameters were evaluated pre- and post-intervention. Statistical data analysis was conducted using IBM-SPSS 27, including chi-square, Fisher's exact test, t-tests, and the Mcnemar test, which were performed to compare the changes within and between groups.

Results

The mean age of the participants in the intervention and control groups was 50.72 ± 6.43 years and 49.14 ± 6.89 years, respectively. Compared to the control group, the intervention group experienced a significant positive reduction in anthropometric measures and laboratory parameters, including weight, body mass index (BMI), waist circumference, lipid profiles, and HbA1c.

Conclusion

A tangible effect of nurse-led interventions based on low-carbohydrate regimens in managing metabolic syndrome was empirically authenticated. Positive changes were observed in the intervention group regarding anthropometric measures and laboratory parameters. However, future research may require a larger sample size and a longer follow-up to confirm these effects and evaluate long-term metabolic impacts.

The relationship between the dietary index based Meiji nutritional profiling system for adults and lifestyle-related diseases: a predictive validity study from the National Institute for Longevity Sciences-Longitudinal Study of Aging

Background

Nutritional profiling system (NPS) holds promise as a public health tool for companies to measure product healthiness and for individuals in making healthier food choices. The Meiji NPS for adults specifically targets lifestyle-related diseases prevalent among Japan's adult population, including overweight/obesity, hypertension, diabetes, and dyslipidemia. This study examined the cross-sectional association between the Meiji NPS for adults Dietary Index (MNfA-DI) and indicators of lifestyle-related diseases in a population.

Methods

The study comprised 1,272 middle-aged individuals (40-64 years, 50.1% male) who participated in the seventh wave (2010-2012) of the National Institute for Longevity Sciences-Longitudinal Study of Aging project, with no missing data on three-day dietary records. The MNfA-DI was computed at the individual diet level (accounting for the whole diet) using arithmetic energy-weighted means. A higher MNfA-DI indicated a greater nutritional quality of an individual's overall diet. Lifestyle-related disease indicators included body mass index (BMI, kg/m2), body fat (%), systolic and diastolic blood pressure (mmHg), fasting plasma glucose (mg/dL), HbA1c (%), triglyceride levels (mg/dL), LDL, and HDL cholesterol levels (mg/dL). A multiple regression model was used to assess the association between the MNfA-DI and lifestyle-related disease indicators, adjusting for demographics, socioeconomic status, lifestyle factors, disease history, and energy intake as covariates, depending on the outcome.

Results

The median (interquartile range) age and MNfA-DI were 53.0 (46.0, 59.0) years and 10.1 (6.0, 14.0) points, respectively. MNfA-DI was negatively associated with body fat [partial regression coefficient (95% confidence interval) -0.04 (-0.07, -0.01)], diastolic blood pressure [-0.08 (-0.17, -0.002)], fasting plasma glucose [-0.18 (-0.33, -0.01)], and triglyceride [-1.36 (-2.16, -0.55)]. Additionally, MNfA-DI was also associated with almost indicators (except for LDL and HDL cholesterol) among participants with a BMI between 18.5 and 24.9 kg/m2.

Conclusion

These findings suggest that the Meiji NPS for adults could be associated with a lower risk of lifestyle-related diseases. In addition, from a public health nutrition perspective, the Meiji NPS for adults may be useful to assess the food healthiness of the adult population.

Overall, plant-based, or animal-based low carbohydrate diets and all-cause and cause-specific mortality: A systematic review and dose-response meta-analysis of prospective cohort studies

INTRODUCTION

In this study, we sought to summarize the associations between overall, plant-, and animal-based low carbohydrate diet (LCD) scores and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality from prospective cohort studies.

METHODS

We searched PubMed, Scopus, and Web of Science up to January 2022. We included prospective cohort studies that investigated the relationship between LCD-score and risk of overall, CVD, or cancer mortality. Two investigators assessed the studies for eligibility and extracted the data. Summary hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using a random-effects model.

RESULTS

Ten studies, with 421022 participants, were included in the analysis. In the high-versus-low meta-analysis, overall (HR:1.05,95%CI:0.97, 1.13, I2 =72.0%) and animal-based LCD-scores (HR: 1.08, 95% CI: 0.97-1.21; I2 = 88.0%) were not associated with all-cause mortality, but plant-based LCD-score was associated with a risk reduction (HR:0.87, 95%CI:0.78,0.97; I2 = 88.4%). CVD mortality was not associated with overall, plant-, or animal-based LCD-scores. Overall (HR:1.14, 95%CI:1.05,1.24; I2 = 37.4%) and animal-based LCD scores (HR:1.16,95%CI:1.02,1.31; I2 = 73.7%) were associated with a higher risk of cancer mortality, while plant-based LCD-score was not. A U-shaped relationship was revealed between overall LCD-score and all-cause and CVD mortality. The shape of relationship between LCD and cancer mortality was a linear dose-response.

CONCLUSION

In conclusion, diets with a moderate carbohydrate content were associated with the lowest risk of all-cause and CVD mortality. If the sources of macronutrients that replaced carbohydrates were plant-based, the risk of all-cause mortality was reduced linearly with lower carbohydrate content. The risk of cancer mortality increased linearly with the increase in carbohydrate content. Considering the low certainty of evidence, more robust prospective cohort studies are suggested.

Beneficial effects of monounsaturated fatty acid-rich blended oils with an appropriate polyunsaturated/saturated fatty acid ratio and a low n-6/n-3 fatty acid ratio on the health of rats

BACKGROUND

The effects of dietary fat on health are influenced by its fatty acid profile. We aimed to determine the effects of monounsaturated fatty acid (MUFA)-rich blended oils (BO) containing a balance of polyunsaturated fatty acids (PUFAs) and saturated fatty acids (SFAs) and with a low n-6/n-3 PUFA ratio on the health of rats fed normal or high-fat diets. The BO was obtained by mixing red palm oil, rice bran oil (RO), tea seed oil and flaxseed oil in appropriate proportions.

RESULTS

BO consumption reduced the serum low-density lipoprotein cholesterol (LDL-C), non-esterified fatty acid (NEFA), insulin (INS), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), interleukin-1 (IL-1), high-sensitivity C-reactive protein (hs-CRP), malondialdehyde (MDA), lipid peroxide (LPO) and oxidized LDL (ox-LDL) concentrations and the homeostasis model assessment of insulin resistance (HOMA-IR); it increased the high-density lipoprotein cholesterol (HDL-C), glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) concentrations, and the bone mineral density (BMD) versus control oil-containing normal and high-fat diets. BO also reduced the triglyceride (TG), hs-CRP, MDA, ox-LDL and reactive oxygen species (ROS) concentrations; and increased the serum HDL-C and SOD, and BMD versus RO-containing high-fat diets. Finally, BO reduced the glucose (GLU) and INS, and HOMA-IR; it increased HDL-C, SOD, femoral weight and BMD versus RO-containing normal diets.

CONCLUSION

BOs with an appropriate fatty acid profile have beneficial effects on the glucolipid metabolism, inflammation, oxidative stress and bone quality of rats when included in both normal and high-fat diets. © 2022 Society of Chemical Industry.

A genome-wide association study on adherence to low-carbohydrate diets in Japanese

BACKGROUND/OBJECTIVES

Low-carbohydrate diets (LCD) are useful for weight reduction, and 50-55% carbohydrate consumption is associated with minimal risk. Genetic differences were related to nutritional consumption, food preferences, and dietary patterns, but whether particular genetic differences in individuals influence LCD adherence is unknown.

SUBJECTS/METHODS

We conducted a GWAS on adherence to LCD utilizing 14,076 participants from the Japan Multi-Institutional Collaborative Cohort study. We used a previously validated semiquantitative food frequency questionnaire to estimate food consumption. Association of the imputed variants with the LCD score by Halton et al. we used linear regression analysis adjusting for sex, age, total dietary energy consumption, and components 1 to 10 by principal component analysis. We repeated the analysis with adjustment for alcohol consumption (g/day) in addition to the above-described variables.

RESULTS

Men and women combined analysis without adjustment for alcohol consumption; we found 395 variants on chromosome 12 associated with the LCD score having P values <5 × 10^-8. A conditional analysis with the addition of the dosage data of rs671 on chromosome 12 as a covariate, P values for all 395 SNPs on chromosome 12 turned out to be insignificant. In the analysis with additional adjustment for alcohol consumption, we did not identify any SNPs associated with the LCD score.

CONCLUSION

We found rs671 was inversely associated with adherence to LCD, but that was strongly confounded by alcohol consumption.

Associations of Moderate Low-Carbohydrate Diets With Mortality Among Patients With Type 2 Diabetes: A Prospective Cohort Study

CONTEXT

A statement of context for the abstract was added in Objective as follows: Lower-carbohydrate-diet (LCD) has been reported to have beneficial effects on cardiovascular risk factor profile in general population. However, whether adherence to an LCD could benefit long-term survival among individuals with diabetes is unclear.

OBJECTIVE

This work aimed to investigate the associations of different types of lower-carbohydrate diets with mortality among individuals with type 2 diabetes (T2D).

METHODS

This prospective study included 5677 patients with T2D. The overall, unhealthy, and healthy lower-carbohydrate-diet (LCD) scores were calculated based on the percentage of energy from total and subtypes of carbohydrate, protein, and fat. Deaths were determined via linkage to the National Death Index records until December 31, 2015. Cox proportional hazards models were used to estimate the hazard ratios (HRs) and 95% CIs of mortality.

RESULTS

During a median of 6.3 years of follow-up (39 401 person-years), 1432 deaths were documented. After multivariable adjustment including lifestyle factors, diabetes duration, and glycated hemoglobin A1c, patients in the third quartile of overall LCD score had the lowest risk of mortality (HR: 0.65; 95% CI, 0.50-0.85), compared with the first quartile. The multivariable-adjusted HRs (95% CIs) of mortality across quartiles of healthy lower-carbohydrate-diet score were 1.00 (reference), 0.78 (0.64-0.96), 0.73 (0.58-0.91), and 0.74 (0.58-0.95) (Ptrend = .01). Isocalorically replacing 2% of energy from carbohydrates with plant-based protein or polyunsaturated fatty acids was associated with 23% to approximately 37% lower total mortality. Similar results were observed when analyses were stratified by age, sex, race/ethnicity, smoking status, body mass index, physical activity, and diabetes duration.

CONCLUSION

Healthy LCD score was significantly associated with a lower risk of mortality in adults with T2D. Adherence to a well-balanced moderate lower-carbohydrate diet that emphasizes healthy carbohydrates, plant-based protein, and polyunsaturated fat may prevent premature death among patients with T2D.

The association between low carbohydrate diet scores and cardiometabolic risk factors in Chinese adults

Epidemiological studies on the association between the low carbohydrate diet (LCD) score and cardiovascular disease risk factors have limited and inconsistent results. Data are from the baseline survey of Community-based Cohort Study on Nervous System Diseases. A total of 4609 adults aged ≥18 years were included in the study. Dietary data were assessed using a validated semi-quantitative Food Frequency Questionnaire. Multivariable logistic regression analyses were used to estimate relationships of three LCD scores with low high-density lipoprotein cholesterol (HDL-C), high low-density lipoprotein cholesterol (LDL-C), hypercholesterolemia, hypertriglyceridemia, impaired fasting glucose (IFG), high blood pressure, and hyperuricemia after adjusting for potential confounders. A higher LCD score was negatively associated with low HDL-C [OR (95%CI): 0.65 (0.50, 0.83), P=0.0001] and IFG [OR (95%CI): 0.65 (0.51, 0.81), P=0.001] after the final adjustment. However, there are gender differences in this result. Males in the highest quintile of the animal-based or plant-based LCD scores showed a decreased risk of low HDL-C, and females in the highest quintile of the animal-based or plant-based LCD scores showed a decreased risk of IFG than those in the lowest quintile of the LCD scores. These results suggest that gender differences should be considered when using LCD to treat dyslipidemia and reduce fasting blood glucose.

The association between low-carbohydrate diet score and metabolic syndrome among Iranian adults

OBJECTIVE

Assessing the relationship between low-carbohydrate diet (LCD) score and metabolic syndrome (Mets) in Iranian adults.

DESIGN

Cross-sectional study.

SETTING

Yazd Health Study and Taghzieh Mardom-e-Yazd study.

PARTICIPANTS

Data of 2074 participants were used. Dietary intakes were assessed by a validated semi-quantitative FFQ. LCD score was calculated for each person by summing up the assigned scores to deciles of energy percentages from macronutrients. Mets was evaluated using National Cholesterol Education Program Adult Treatment Panel III. Eventually, association between LCD score and Mets was examined using logistic regression.

RESULTS

Total Mets prevalence was approximately 40·5 %. After adjustment for confounders, subjects in the higher quartile of LCD score had a significant lower chance of Mets than lower quartile among all participants (Q4 v. Q1: OR: 0·68, 95 % CI (0·50, 0·92)) and separately in men (Q4 v. Q1: OR: 0·54, 95 % CI (0·34, 0·86)) and women (Q2 v. Q1: OR: 0·53, 95 % CI (0·34, 0·82)). Furthermore, more LCD adherence in men reduced abdominal obesity by 47 % (Q3 v. Q1: OR: 0·53, 95 % CI (0·28, 0·99)). A significant inverse relation was also observed between low HDL cholesterol and LCD score in all participants (Q4 versus Q1 OR: 0·74, 95% CI: 0·56-0·99) and separately in men (Q4 versus Q1 OR: 0·63, 95% CI: 0·40-0·98).

CONCLUSIONS

More adherence to LCD might be related to lower chance of Mets and some of its components such as low HDL-cholesterol and abdominal obesity specially in men. Further studies are required to confirm the findings.

Association of the low-carbohydrate dietary pattern with postpartum weight retention in women

Low-carbohydrate diets (LCD) have been considered a popular dietary strategy for weight loss. However, the association of the low-carbohydrate dietary pattern with postpartum weight retention (PPWR) in women remains unknown. The present study involved 426 women from a prospective mother-infant cohort study. Overall, animal or plant LCD scores, which represent adherence to different low-carbohydrate dietary patterns, were calculated using diet intake information assessed by three consecutive 24 h dietary surveys. PPWR was assessed by the difference of weight at 1 year postpartum minus the pre-pregnancy weight. After adjusting for potential confounding variables, women in higher quartiles of total and animal-based LCD scores had a significantly lower body weight and weight retention at 1 year postpartum (P < 0.05). The multivariable-adjusted ORs of substantial PPWR (≥5 kg), comparing the highest with the lowest quartile, were 0.47 (95% confidence interval 0.23-0.96) for the total LCD score (P = 0.021 for trend) and 0.38 (95% confidence interval 0.19-0.77) for the animal-based LCD score (P = 0.019 for trend), while this association was significantly attenuated by rice, glycemic load, fish, poultry, animal fat and animal protein (P for trend <0.05). A high score for plant-based LCD was not significantly associated with the risk of PPWR (P > 0.05). The findings suggested that a low-carbohydrate dietary pattern, particularly with high protein and fat intake from animal-source foods, is associated with a decreased risk of weight retention at 1 year postpartum. This association was mainly due to low intake of glycemic load and high intake of fish and poultry.

The short- and long-term effects of dietary patterns on cardiometabolic health in adults aged 65 years or older: a systematic review

CONTEXT

Cardiometabolic diseases are leading causes of death and morbidity. Aging increases the risk of disease development. Diet has protective and causal effects on cardiometabolic health.

OBJECTIVE

To consolidate the current evidence on the short- and long-term effects of dietary patterns on cardiometabolic health in adults aged ≥ 65 years.

DATA SOURCES

The Medline, Embase, Cochrane Central Register of Controlled Trials, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, Cumulative Index to Nursing and Allied Health Literature, Web of Science, Scopus, Global Health, and Pre-Medline databases, along with ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform were searched.

DATA EXTRACTION

A total of 40 042 records were identified. Quality assessment involved using the revised Cochrane risk-of-bias tool for randomized trials and Joanna Briggs Institute checklists. The certainty of evidence was assessed using Grading of Recommendations, Assessment, Development, and Evaluation.

RESULTS

Thirteen articles were included (n = 5 cohort studies and n = 3 randomized controlled trials). The low-fat dietary pattern reduced adiposity; however, no effects were evident for hypertension incidence, composite coronary heart disease incidence (including myocardial infarction, coronary heart disease, and coronary revascularization), high-density lipoprotein cholesterol level, and increased blood pressure in the long term. The Mediterranean dietary pattern resulted in reduced triglyceride levels and systolic blood pressure, and had no effects on diastolic blood pressure and glucose in the short term. Other dietary patterns had inconclusive effects.

CONCLUSIONS

The Mediterranean dietary pattern showed the most benefits without harm on cardiometabolic health in older adults. The current body of evidence is small, indicating the need for more research to confirm these findings at a high certainty of evidence, and to include dietary patterns combined with other dietary components, subgroups with cardiometabolic disease or risk factors, longer follow-up, and outcomes that have not yet been investigated. Studies including these factors may help identify the most effective dietary pattern for cardiometabolic health benefits in older adults, to inform future guidelines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO registration no. CRD42020141400.

Low carbohydrate diet score and odds of neuromyelitis optica spectrum disorder: A case-control study

Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is a demyelinating inflammatory disease of The Central nervous system. We aimed to investigate the association between low carbohydrate diet (LCD) and NMOSD odds. Method: Seventy NMOSD patients with definite diagnosis and 164 hospital-based controls were enrolled in this case-control study. Dietary data was obtained using a validated 168-item food frequency questionnaire. To determine the LCD score, participants were stratified into 11 groups according to carbohydrate, protein, fat, animal fat, animal protein, vegetable fat and vegetable protein intakes. Higher intake of protein and fat, and lower intake of carbohydrate received a higher score between 0-10. Macronutrients scores were summed together and LCD scores calculated. The association between LCD scores and likelihood of being assigned to NMOSD group was investigated using multiple regression models. Results: Total LCD scores increased from the median of 21.00 in the first decile to 53.00 in the tenth decile of LCD score. After adjustment for confounding factors including age, gender, BMI, energy intake, cigarette smoking and alcohol consumption, an inverse association was detected between LCD scores and odds of NMOSD. The odds of suffering from NMOSD declined significantly about 78% (OR: 0.22; 95% CI: 0.05-0.87) and 76% (OR: 0.24; 95% CI: 0.06-0.93) in the fifth and sixth deciles of LCD score compared to the first decile. Conclusion: From the obtained results it can be speculated that higher carbohydrate and lower protein and fat intakes may be associate with the increased odds of NMOSD. However, further studies are needed to confirm these results.

Association between carbohydrate intake and body composition: The Korean National Health and Nutrition Examination Survey

OBJECTIVE

Several studies have investigated the effects of dietary carbohydrate intake on body composition. However, the results are controversial and few studies have been conducted on an Asian population. The aim of this study was to investigate whether dietary carbohydrate intake is associated with body composition in Korean adults.

METHODS

The present study used data from the Korean National Health and Nutrition Examination Survey, a cross-sectional survey of Korean civilians, conducted from 2008 to 2011. The study analyzed 9594 participants. Carbohydrate intake was defined as the proportion of energy consumed from carbohydrate. Waist circumference, body mass index, and lean and fat mass using a whole-body dual-energy x-ray absorptiometry scanner were measured as body composition parameters.

RESULTS

After adjusting for age, household income, smoking, alcohol consumption, physical activity, history of diabetes, hypertension, dyslipidemia, and intake of energy and fiber per day, the proportion of carbohydrate intake was positively correlated with total limb lean mass in men (β = 0.141, P = 0.046), and in women, the proportion of carbohydrate intake was positively associated with appendicular skeletal muscle mass index (β = 0804, P = 0.003) but negatively associated with trunk fat percentage (β = -0.075, P = 0.026). Total limb lean mass and appendicular skeletal muscle mass index in women showed an increasing trend as the proportion of carbohydrate intake increased.

CONCLUSIONS

No positive association was found between the proportion of carbohydrate intake and any measure of obesity or body fat mass in either men or women. Further studies are needed to evaluate the effects of quantity and quality of carbohydrate intake on body composition.

Low-carbohydrate diet and the risk of metabolic syndrome in Korean adults

BACKGROUND & AIMS

The association of low-carbohydrate diet with weight loss and the risk of cardiovascular diseases has recently been the focus of increasing research attention. However, studies on low-carbohydrate diet in the Asian population are limited. The present study was aimed to examine the association between low-carbohydrate diet and metabolic syndrome among Korean adults.

METHODS AND RESULTS

A total of 16,349 participants aged 30 years or older who participated in a 24-h dietary recall survey of the fifth and sixth Korea National Health and Nutrition Examination Survey were included in this study. Low-carbohydrate diet was evaluated using the low-carbohydrate-diet score, which was calculated based on the percentage of energy from carbohydrate, protein, and fat by sex. The association between the low-carbohydrate-diet score and metabolic syndrome was analyzed using multiple logistic regression analysis. A low-carbohydrate diet was not associated with metabolic syndrome and its components such as waist circumference, blood pressure, and triglyceride levels. However, women in the highest decile of the animal- or plant-based low-carbohydrate-diet score showed a decreased risk of reduced high-density lipoprotein (HDL)-cholesterol levels, and men in the highest decile of the animal-based low-carbohydrate-diet score showed a decreased risk of reduced HDL-cholesterol levels than those in the lowest decile of the low-carbohydrate-diet score.

CONCLUSION

These findings indicate that, in Korea, a low-carbohydrate diet did not increase the risk of metabolic syndrome among adults who typically consume a high-carbohydrate low-fat diet. However, it may moderately decrease the risk of reduced HDL-cholesterol levels.