Low-carbohydrate diets and cardiovascular and total mortality in Japanese: a 29-year follow-up of NIPPON DATA80

Association between dietary patterns and cardiovascular diseases: A review

Cardiovascular disease (CVD), especially atherosclerosis, is the primary cause of global deaths. It accounts for millions of deaths annually. Even a small reduction in CVD through preventive treatment can have a substantial impact. Dietary patterns and substances are strongly linked to chronic diseases such as atherosclerosis, hypertension, heart failure, and type 2 diabetes. An unhealthy diet could lead to traditional risk factors such as LDL levels, TG levels, diabetes, and high blood pressure while accelerating atherosclerosis progression. Recent research has shown the potential of dietary interventions to prevent and treat cardiovascular disease, particularly through healthy dietary patterns such as the Mediterranean diet or DASH. In 2016, the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) launched a new initiative aimed at enhancing the prevention and control of cardiovascular disease (CVD) by improving the management of CVD in primary care, including the optimization of dietary patterns. Here, this review summarizes several large cohort researches about the effects of dietary patterns on atherosclerosis, refines dietary components, and outlines some typical anti-atherosclerosis dietary agents. Finally, this review discusses recent mechanisms by which dietary interventions affect atherosclerosis progression.

Restricted carbohydrate diets below 45% energy are not associated with risk of mortality in the National Health and Nutrition Examination Survey, 1999-2018

Introduction

Cardiometabolic diseases (CMD) are the leading causes of death for people living in the United States. Dietary strategies, such as restricting carbohydrate intake, are becoming popular strategies for improving health status. However, there is limited and often contradictory evidence on whether restricting carbohydrate intake is related to all-cause, CMD, or cardiovascular disease (CVD) mortality.

Methods

The objective of the present study was to evaluate the association between restricted carbohydrate diets (<45%en) and mortality from all-causes, CMD, and CVD, stratified by fat amount and class. Data were acquired using the National Health and Nutrition Examination Survey (1999-2018) linked with mortality follow-up until December 31, 2019 from the Public-use Linked Mortality Files. Multivariable survey-weighted Cox proportional hazards models estimated hazard ratios for 7,958 adults (≥20 y) that consumed <45%en from carbohydrates and 27,930 adults that consumed 45-65%en from carbohydrates.

Results

During the study period a total of 3,780 deaths occurred, including 1,048 from CMD and 1,007 from CVD, during a mean follow-up of 10.2 y. Compared to individuals that met carbohydrate recommendations (45-65%en), those that consumed carbohydrate restricted diets (<45%en) did not have significantly altered risk of mortality from all-causes (HR: 0.98; 95% CI: 0.87, 1.11), CMD (1.18; 0.95, 1.46), or CVD (1.20; 0.96, 1.49). These findings were maintained when the restricted carbohydrate diet group was stratified by intake of total fat, saturated fat (SFA), monounsaturated fat (MUFA), and polyunsaturated fat (PUFA).

Discussion

Carbohydrate restriction (<45%en) was not associated with mortality from all-causes, CVD, or CMD. Greater efforts are needed to characterize the risk of mortality associated with varied degrees of carbohydrate restriction, e.g., low (<26%en) and high (>65%en) carbohydrate diets separately.

Low-carbohydrate diet and risk of cardiovascular disease, cardiovascular and all-cause mortality: a systematic review and meta-analysis of cohort studies

Background: Evidence for the long-term health effect of low-carbohydrate diets (LCDs) is inconsistent. Herein, we aimed to examine the associations of LCDs with cardiovascular disease (CVD) and all-cause and cause-specific mortality. Methods: We searched PubMed, EMBASE, and the Web of Science up to 26 July 2023 for eligible publications. Random-effect models were used to pool the summary relative risks (RRs) and 95% confidence intervals (CIs). Results: A total of 44 studies (17 articles) were included in the systematic review and 38 in the meta-analysis, including 223 657 all-cause deaths (771 609 participants), 14 046 cardiovascular deaths (274 807 participants), 18 264 CVD cases (405 631 participants), and 3634 coronary heart disease (CHD) cases (151 023 participants). Subsequently, the highest LCD score was compared with the lowest one and the pooled RRs (95% CIs) were 1.05 (0.96, 1.14; I2 = 65.1%; n = 13) for CVD, 1.43 (1.18, 1.72; I2 = 25.4%; n = 3) for CHD, 0.93 (0.81, 1.06; I2 = 0.0%; n = 2) for stroke, 1.03 (0.96, 1.10; I2 = 86.6%; n = 13) for all-cause mortality and 1.09 (0.99, 1.19; I2 = 65.1%; n = 10) for cardiovascular mortality. Conclusion: Our analysis showed positive associations of LCDs with CHD. Thus, vigilance is recommended for long-term adherence to this dietary pattern.

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.

Dietary Carbohydrate and Fat Intakes and Risk of Mortality in the Japanese Population: the Japan Multi-Institutional Collaborative Cohort Study

BACKGROUND

Previous cohort studies have yielded contradictory findings regarding the associations of dietary carbohydrate and fat intakes with risks of mortality.

OBJECTIVES

We examined long-term associations of carbohydrate and fat intakes with mortality.

METHODS

In this cohort study, 34,893 men and 46,440 women aged 35-69 y (mean body mass index of 23.7 and 22.2 kg/m2, respectively) were followed up from the baseline survey (2004-2014) to the end of 2017 or 2018. Intakes of carbohydrate, fat, and total energy were estimated using a food frequency questionnaire. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated for all-cause and cause-specific mortality according to percentage of energy intakes of carbohydrate and fat.

RESULTS

During a mean 8.9-y follow-up, we identified 2783 deaths (1838 men and 945 women). Compared with men who consumed 50% to <55% of energy from carbohydrate, those who consumed <40% carbohydrate energy experienced a significantly higher risk of all-cause mortality (the multivariable-adjusted HR: 1.59; 95% CI: 1.19-2.12; P-trend = 0.002). Among women with 5 y or longer of follow-up, women with high-carbohydrate intake recorded a higher risk of all-cause mortality; the multivariable-adjusted HR (95% CI) was 1.71 (0.93-3.13) for ≥65% of energy from carbohydrate compared with that for 50% to <55% (P-trend = 0.005). Men with high fat intake had a higher risk of cancer-related mortality; the multivariable-adjusted HR (95% CI) for ≥35% was 1.79 (1.11-2.90) compared with that for 20% to <25%. Fat intake was marginally inversely associated with risk of all-cause and cancer-related mortality in women (P-trend = 0.054 and 0.058, respectively).

CONCLUSIONS

An unfavorable association with mortality is observed for low-carbohydrate intake in men and for high-carbohydrate intake in women. High fat intake can be associated with a lower mortality risk in women among Japanese adults with a relatively high-carbohydrate intake.

Low-carbohydrate diets containing plant-derived fat but not animal-derived fat ameliorate heart failure

Cardiovascular disease (CVD) is a global health burden in the world. Although low-carbohydrate diets (LCDs) have beneficial effects on CVD risk, their preventive effects remain elusive. We investigated whether LCDs ameliorate heart failure (HF) using a murine model of pressure overload. LCD with plant-derived fat (LCD-P) ameliorated HF progression, whereas LCD with animal-derived fat (LCD-A) aggravated inflammation and cardiac dysfunction. In the hearts of LCD-P-fed mice but not LCD-A, fatty acid oxidation-related genes were highly expressed, and peroxisome proliferator-activated receptor α (PPARα), which regulates lipid metabolism and inflammation, was activated. Loss- and gain-of-function experiments indicated the critical roles of PPARα in preventing HF progression. Stearic acid, which was more abundant in the serum and heart of LCD-P-fed mice, activated PPARα in cultured cardiomyocytes. We highlight the importance of fat sources substituted for reduced carbohydrates in LCDs and suggest that the LCD-P-stearic acid-PPARα pathway as a therapeutic target for HF.

Dietary carbohydrate quantity and quality and risk of cardiovascular disease, all-cause, cardiovascular and cancer mortality: A systematic review and meta-analysis

BACKGROUND & AIMS

Evidence remains conflicted on the association between dietary carbohydrate quantity and quality and risk of cardiovascular disease, all-cause, cardiovascular and cancer mortality, and such meta-analyses are lacking. The study aimed to conduct a systematic review and meta-analysis to synthesize the knowledge about their associations and to explore the dose-response relations.

METHODS

We comprehensively searched PubMed, EMBASE, and Web of Science up to March 2022 for observational studies investigating the associations in adults. Random effect model was used to estimate the summary relative risks (RRs) and 95% confidence intervals (CIs) and the dose-response association was explored by restricted cubic splines.

RESULTS

We obtained the data from 41 eligible studies. Compared with participants with lowest dietary carbohydrate intake, those with highest intake had an RR of 1.10 (95% CI 1.03-1.17, I2 = 52.8%) for cardiovascular disease, 1.10 (0.98-1.24, I2 = 65.5%) for coronary heart disease (CHD), 1.20 (1.08-1.34, I2 = 0) for stroke, 1.07 (1.00-1.14, I2 = 61.9%) for all-cause mortality, 1.02 (0.92-1.14, I2 = 51.3%) for cardiovascular mortality, and 1.01 (0.89-1.13, I2 = 56.7%) for cancer mortality. For each 5 %E increase in dietary carbohydrate intake, the summary RR was 1.02 (1.00-1.04, I2 = 66.8%) for cardiovascular disease, 1.04 (1.01-1.06, I2 = 0) for stroke but not significant for other outcomes. Restricted cubic splines showed linear associations with risk of cardiovascular disease (Pnon-linearity = 0.143), CHD (Pnon-linearity = 0.508), stroke (Pnon-linearity = 0.654) and non-linear associations with all-cause mortality (Pnon-linearity = 0.008) and cardiovascular mortality (Pnon-linearity = 0.055). Limited studies were found on the association of cardiovascular disease and mortality with dietary carbohydrate quality using a multidimensional and integrated indicator.

CONCLUSIONS

Increased consumption of dietary carbohydrate intake is associated with increased risk of cardiovascular disease, stroke, and all-cause mortality. Linear relation was found for cardiovascular disease and stroke but non-linear relation for all-cause mortality. More studies are warranted to investigate the association of dietary carbohydrate quality using a combined indicator and cardiovascular disease and mortality.

Trends in Dietary Carbohydrates, Protein, and Fat Intake and Diet Quality Among Chinese Adults, 1991-2015: Results from the China Health and Nutrition Survey

OBJECTIVE

Dietary transitions in China have undergone rapid changes in over the last three decades. The purpose of this study to describe trends in the macronutrient consumption, the sources of those nutrients, and the diet quality among Chinese adults.

DESIGN

Longitudinal China Health and Nutrition Survey (CHNS) cohort analysis. Main outcomes are dietary energy intake from total carbohydrate, protein and fat and their subtypes, as well as food sources of carbohydrates, protein, and fat, and the China Dietary Guidelines Index 2018 (CDGI-2018).

SETTING

CHNS (1991, 2000, 2009, 2015).

PARTICIPANTS

Data from the longitudinal 1991, 2000, 2009, and 2015 China Health and Nutrition Survey (CHNS) of adults aged 18 years or older, who had complete demographic information.

RESULTS

The estimated mean energy intake from total carbohydrate decreased from 62.6% to 50.6% between 1991 and 2015, while the mean energy intake from total protein increased from 12.6% to just 13.1% and the mean energy intake from total fat significantly increased from 24.0% to 35.8% (P < 0.001 for trend). Decreases were observed in evaluated mean energy from low-quality carbohydrates (from 53.6% to 41.7%) and incomplete protein (from 9.3% to 7.5%), while increases were seen in estimated mean energy from high-quality protein (from 3.3% to 5.5%), high-quality fat (from 9.1% to 16.7 %), and low-quality fat (from 14.9% to 19.0%). Low-quality carbohydrates, primarily those derived from refined grains, decreased from 52.2% to 36.2%. The diet quality as measured by CDGI-2018 improved, with the estimated mean increasing from 41.7 to 52.4 (P < 0.01 for trend).

CONCLUSION

For Chinese adults, there was a significant change in the macronutrient composition over the previous few decades. The percentage of energy consumed from carbohydrates significantly decreased, however the percentage of energy consumed from total fat significantly increased. Additionally, the diet quality remains suboptimal.

Racial and Ethnic Differences in the Association of Low-Carbohydrate Diet With Mortality in the Multi-Ethnic Study of Atherosclerosis

IMPORTANCE

Evidence linking low-carbohydrate diets (LCDs) to mortality is limited among multiethnic populations.

OBJECTIVE

To evaluate the association between LCDs and mortality by race and ethnicity.

DESIGN, SETTING, AND PARTICIPANTS

The Multi-Ethnic Study of Atherosclerosis is a large, population-based prospective cohort study of adults aged 45 to 84 years recruited from 6 US communities. A total of 6109 participants without baseline cardiovascular disease were included in this analysis. Baseline data were collected from July 2000 to August 2002, with follow-up completed by December 2017. The data were analyzed between May 2021 and April 2022.

EXPOSURES

Food frequency questionnaires were used to assess dietary intake. From these data, overall LCD scores were calculated from the percentages of energy intake from carbohydrates, fats, and proteins. Animal-based (emphasizing saturated fat and animal protein) and vegetable-based (emphasizing monounsaturated fat and vegetable protein) LCD scores were also calculated.

MAIN OUTCOMES AND MEASURES

All-cause and cause-specific mortality over a median follow-up of 15.9 years (IQR, 14.3-16.6 years).

RESULTS

Among the 6109 participants (mean [SD] age, 62.3 [10.3] years; 3190 women [52.2%]; 1623 African American [26.6%], 701 Chinese American [11.5%], 1350 Hispanic [22.1%], and 2435 non-Hispanic White [39.8%]), there were 1391 deaths. Overall, LCD scores were not associated with mortality, but when analyses were stratified by race and ethnicity, a lower risk of all-cause and non-CV mortality was observed among Hispanic participants with moderate carbohydrate intake. Specifically, the hazard ratios for total mortality for overall LCD scores were 0.58 (95% CI, 0.40-0.84) for quintile 2, 0.67 (95% CI, 0.45-0.98) for quintile 3, 0.60 (95% CI, 0.41-0.87) for quintile 4, and 0.83 (95% CI, 0.57-1.21) for quintile 5, with quintile 1 as the reference group. A similar association was observed for animal-based (but not vegetable-based) LCD scores. In contrast, no significant associations were found between LCD scores and mortality risk in the other racial and ethnic groups.

CONCLUSIONS AND RELEVANCE

In this cohort study of multiethnic US adults, LCD score was not associated with mortality in the whole population. However, moderate carbohydrate intake was associated with a lower risk of mortality among Hispanic participants. These findings suggest that the association between carbohydrate intake and mortality may differ according to race and ethnicity. Dietary guidelines considering these differences may be necessary.

Dietary patterns and predicted 10-year cardiovascular disease risk in a multiethnic Asian population

BACKGROUND AND AIMS

Studies examining associations between dietary patterns and Framingham risk score (FRS) and predicted 10-year cardiovascular diseases (CVD) risk in an Asian population are lacking. This study aimed to identify a posteriori dietary patterns across three major ethnic groups in Singapore and ascertain their associations with locally modified FRS and predicted 10-year CVD risk.

METHODS AND RESULTS

This cross-sectional study included 8594 Singapore residents (aged 21-75 years) from the Singapore Multi-Ethnic Cohort. Data on sociodemographic and lifestyle factors were collected via questionnaires. Food consumption was assessed using a validated Food Frequency Questionnaire. Dietary patterns were identified using principal component analysis and associations with CVD risk factors, FRS and predicted CVD risk (%) were analysed using multiple linear and logistic regression. Four dietary patterns emerged that explained 25.6% of variance. The 'processed food and sugar-sweetened beverages' pattern was significantly associated with higher FRS (β: 0.13; 95% CI: 0.04, 0.23), while the 'ethnic breads, legumes and nuts' (β: 0.13; 95% CI: 0.22, -0.04) and 'whole grains, fruit and dairy' (β: 0.17; 95% CI: 0.24, -0.10) patterns were significantly associated with lower FRS. The 'meat and vegetables' pattern was not significantly associated with FRS. Increased adherence to the 'whole grains, fruit and dairy' pattern was associated with lower odds of having predicted CVD risk of ≥10% (p-trend: 0.03).

CONCLUSION

Adherence to the 'ethnic breads, legumes and nuts' and 'whole grains, fruit and dairy' patterns was associated with a lower predicted CVD risk, and an inverse association for the 'processed food and sugar-sweetened beverages' pattern in an Asian population. These findings can inform the development of culturally sensitive dietary interventions to prevent CVD.

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.

Habitual- and Meal-Specific Carbohydrate Quality Index and Their Relation to Metabolic Syndrome in a Sample of Iranian Adults

Aim

Most studies on diet quality have focused on the habitual and overall intake of foods without considering intakes at specific eating occasions. This study aimed to assess the association between habitual- and meal-specific carbohydrate quality index (CQI) and metabolic syndrome (MetS) in Iranian adults.

Methods

In this cross-sectional study, data from 850 participants were analyzed. Dietary information was obtained from a 3-day nonconsecutive 24 h recall. CQI was calculated from three criteria: dietary fiber, glycemic index, and solid carbohydrate/total carbohydrate ratio. The association between CQI and MetS was assessed by logistic regression.

Results

The prevalences of MetS in the lowest and highest tertile of CQI were 30.1 and 33.7, respectively (P = 0.6). In habitual diet and all the three meals, we failed to find any significant association between tertiles of CQI and MetS either before or after adjustment for covariates. However, in the habitual meals [odds ratio (OR): 0.69, 95% CI: 0.47–0.96] and lunch meals (OR: 0.66; 95% CI: 0.47–0.94), the highest CQI in comparison to the lowest one, significantly decreased the low high-density lipoprotein (HDL). In addition, the trend of low-HDL with CQI in habitual meal and lunch meal was statistically significant.

Conclusion

The results of this study showed that CQI was not associated with MetS and its components. Further investigations into the mechanisms underlying the role of carbohydrate quality in developing metabolic disorders are warranted.

Replacing dietary carbohydrates and refined grains with different alternatives and risk of cardiovascular diseases in a multi-ethnic Asian population

BACKGROUND

Cardiovascular diseases (CVDs) are a major cause of deaths worldwide, but prospective data on dietary risk factors for CVD in South and Southeast Asian populations are sparse.

OBJECTIVE

We aimed to evaluate the relation between macronutrient and food intakes and incidence of major adverse cardiovascular events (MACEs) in a multi-ethnic Asian population.

METHODS

We used data from the Singapore Multi-Ethnic Cohort (n = 12,408), a prospective cohort of ethnic Chinese, Malay, and Indian adults aged 21‒65 y recruited between 2004 and 2010. Dietary intakes were assessed using a validated food-frequency questionnaire, and the incidence of MACEs was ascertained through data linkage with national registries. A Cox proportional hazards model was used to evaluate the associations between dietary intakes and MACE risk.

RESULTS

Over a mean (SD) follow-up of 10.1 (2.3) y, 746 incident cases of MACEs were documented. We observed a direct association between carbohydrate intake and MACE risk (highest vs. lowest quartile, HR: 1.35; 95% CI: 1.07, 1.71; P-trend = 0.001). Replacing 5% of energy from carbohydrate with polyunsaturated fat (HR: 0.79; 95% CI: 0.69, 0.91) but not saturated fat (HR: 0.95; 95% CI: 0.84, 1.09) was significantly associated with a lower MACE risk. In terms of food groups, replacing 1 serving/d of refined grains with fruit (HR: 0.93; 95% CI: 0.87, 0.99), vegetables (HR: 0.92; 95% CI: 0.85, 1.00), and dairy (HR: 0.90; 95% CI: 0.82, 0.98) was associated with lower MACE risk. Cholesterol intake was associated with a higher MACE risk in ethnic Indians (highest vs. lowest quartile, HR: 2.40; 95% CI: 1.53, 3.75; P-trend < 0.001) but not in ethnic Malay or Chinese (P-interaction = 0.015).

CONCLUSIONS

Moderating carbohydrate intakes by increasing polyunsaturated fat intake and replacing refined grains with fruits, vegetables, and dairy was associated with lower MACE risk in Asian populations.

Why and How the Indo-Mediterranean Diet May Be Superior to Other Diets: The Role of Antioxidants in the Diet

The Seven Countries Study showed that traditional Japanese and Mediterranean diets are protective against cardiovascular diseases (CVDs). The Japanese diet is considered the healthiest because it provides Japanese populations with the highest longevity and health. DASH and Mediterranean-style diets are also considered healthy diets, although the Indo-Mediterranean-style diet may provide better protective effects among patients with CVDs compared to other diets. The concept of the Indo-Mediterranean type of diet was developed after examining its role in the prevention of CVDs in India, the value of which was confirmed by a landmark study from France: the Lyon Heart Study. These workers found that consuming an alpha-linolenic acid-rich Mediterranean-style diet can cause a significant decline in CVDs and all-cause mortality. Later in 2018, the PREDIMED study from Spain also reported that a modified Mediterranean-style diet can cause a significant decline in CVDs, type 2 diabetes mellitus (T2DM), and cancer. The Indo-Mediterranean diet may be superior to DASH and Mediterranean diets because it contains millets, porridge, and beans, as well as spices such as turmeric, cumin, fenugreek, and coriander, which may have better anti-inflammatory and cardioprotective effects. These foods are rich sources of nutrients, flavonoids, calcium, and iron, as well as proteins, which are useful in the prevention of under- and overnutrition and related diseases. It is known that DASH and Mediterranean-style diets have a similar influence on CVDs. However, the Indo-Mediterranean-style diet may be as good as the Japanese diet due to improved food diversity and the high content of antioxidants.

Dietary carbohydrate and the risk of type 2 diabetes: an updated systematic review and dose-response meta-analysis of prospective cohort studies

We did this study to clarify the association between carbohydrate intake and the risk of type 2 diabetes (T2D) and potential effect modification by geographical location. PubMed, Scopus and Web of Science were searched to find prospective cohort studies of dietary carbohydrate intake and T2D risk. A random-effects dose–response meta-analysis was performed to calculate the summary hazard ratios (HRs) and 95%CIs. The quality of cohort studies and the certainty of evidence was rated using the Newcastle–Ottawa Scale and GRADE tool, respectively. Eighteen prospective cohort studies with 29,229 cases among 607,882 participants were included. Thirteen studies were rated to have high quality, and five as moderate quality. The HR for the highest compared with the lowest category of carbohydrate intake was 1.02 (95%CI: 0.91, 1.15; I² = 67%, GRADE = low certainty). The HRs were 0.93 (95%CI: 0.82, 1.05; I² = 58%, n = 7) and 1.26 (95%CI: 1.11, 1.44; I² = 6%, n = 6) in Western and Asian countries, respectively. Dose–response analysis indicated a J shaped association, with the lowest risk at 50% carbohydrate intake (HR_50%: 0.95, 95%CI: 0.90, 0.99) and with risk increasing significantly at 70% carbohydrate intake (HR_70%: 1.18, 95%CI: 1.03, 1.35). There was no association between low carbohydrate diet score and the risk of T2D (HR: 1.14, 95%CI: 0.89, 1.47; I² = 90%, n = 5). Carbohydrate intake within the recommended 45–65% of calorie intake was not associated with an increased risk of T2D. Carbohydrate intake more than 70% calorie intake might be associated with a higher risk.

Effects of Dietary Fat to Carbohydrate Ratio on Obesity Risk Depending on Genotypes of Circadian Genes

Although the impacts of macronutrients and the circadian clock on obesity have been reported, the interactions between macronutrient distribution and circadian genes are unclear. The aim of this study was to explore macronutrient intake patterns in the Korean population and associations between the patterns and circadian gene variants and obesity. After applying the criteria, 5343 subjects (51.6% male, mean age 49.4 ± 7.3 years) from the Korean Genome and Epidemiology Study data and nine variants in seven circadian genes were analyzed. We defined macronutrient intake patterns by tertiles of the fat to carbohydrate ratio (FC). The very low FC (VLFC) was associated with a higher risk of obesity than the optimal FC (OFC). After stratification by the genotypes of nine variants, the obesity risk according to the patterns differed by the variants. In the female VLFC, the major homozygous allele of CLOCK rs11932595 and CRY1 rs3741892 had a higher abdominal obesity risk than those in the OFC. The GG genotype of PER2 rs2304672 in the VLFC showed greater risks for obesity and abdominal obesity. In conclusion, these findings suggest that macronutrient intake patterns were associated with obesity susceptibility, and the associations were different depending on the circadian clock genotypes of the CLOCK, PER2, and CRY1 loci.

Low-Carbohydrate-Diet Score and Mortality in Adults With and Without Chronic Kidney Disease: Results From the Third National Health and Nutrition Examination Survey

OBJECTIVE

The long-term safety of consuming low-carbohydrate diets (LCDs) remains controversial. As high protein and high fat might accelerate chronic kidney disease (CKD) progression, the impact of LCD on mortality might be different in subjects with CKD and subjects without CKD. Therefore, the objective of this study was to assess the association of LCD with mortality among individuals with and without CKD.

METHODS

Data from 1158 subjects with CKD and 9523 subjects without CKD in the Third National Health and Nutrition Examination Survey were analyzed. The LCD score was calculated based on a 24-hour dietary recall interview. Mortality was from baseline until 31 December 2015. Cox proportional hazards regression models were fitted to estimate multivariable-adjusted hazard ratios and 95% confidence intervals.

RESULTS

During the median follow-up of 24 years, 751 (65%) deaths and 2624 (28%) deaths were recorded in the CKD group and the non-CKD group, respectively. The multivariable-adjusted hazard ratio for all-cause mortality comparing the highest versus lowest quarters of LCD score was 1.51 (95% confidence interval, 1.01-2.25, P for trend = 0.045) in the CKD group. However, there were no association between the LCD score and all-cause mortality in the non-CKD group.

CONCLUSIONS

The LCD scores were found significantly positively associated with all-cause mortality in adults with CKD, but not in adults without CKD.

Macronutrient Intake and Risk of Dementia in Community-Dwelling Older Adults: A Nine-Year Follow-Up Cohort Study

BACKGROUND

Little is known about the association between macronutrient intake and incident dementia.

OBJECTIVE

To identify an optimal range of macronutrient intake associated with reduced risk of dementia.

METHODS

Our analysis included 93,389 adults aged 60-75 years from the UK Biobank. Diet was assessed using a web-based 24-h recall questionnaire between 2009-2012. Dementia was ascertained using hospital inpatient, death records, and self-reported data up to January 2021. We calculated a macronutrient score based on associations between an individual's macronutrient intake and incident dementia.

RESULTS

During a median follow-up of 8.7 years, 1,171 incident dementia cases were documented. We found U-shape relationships for carbohydrate, fat, and protein intake with incident dementia. Compared to individuals with optimal carbohydrate intake, those with high intake (HR (95%CI): 1.48(1.15-1.91)) but not low intake (1.19(0.89-1.57)) had a higher risk of dementia. In the multivariable analysis, a low-fat intake (HR (95%CI): 1.42(1.11-1.82)) was associated with a higher risk of all-cause dementia. After adjustment for covariates, a high (HR (95%CI): 1.41(1.09-1.83)) but not low protein intake (1.22(0.94-1.57)) was associated with an increased risk of dementia. Individuals in quintiles 3-5 of optimal macronutrient score had a lower risk of dementia compared with those in quintile 1 (HR (95%CI): 0.76(0.64-0.91) for quintile 3, 0.71(0.60-0.85) for quintile 4, 0.74(0.61-0.91) for quintile 5). The association between macronutrient score and incident dementia was significant across subgroups of age, gender, education, and smoking.

CONCLUSION

Moderate intakes of carbohydrate, fat, and protein were associated with the lowest risk of incident dementia.

Alternative Dietary Patterns for Americans: Low-Carbohydrate Diets

The decades-long dietary experiment embodied in the Dietary Guidelines for Americans (DGA) focused on limiting fat, especially saturated fat, and higher carbohydrate intake has coincided with rapidly escalating epidemics of obesity and type 2 diabetes (T2D) that are contributing to the progression of cardiovascular disease (CVD) and other diet-related chronic diseases. Moreover, the lack of flexibility in the DGA as it pertains to low carbohydrate approaches does not align with the contemporary trend toward precision nutrition. We argue that personalizing the level of dietary carbohydrate should be a high priority based on evidence that Americans have a wide spectrum of metabolic variability in their tolerance to high carbohydrate loads. Obesity, metabolic syndrome, and T2D are conditions strongly associated with insulin resistance, a condition exacerbated by increased dietary carbohydrate and improved by restricting carbohydrate. Low-carbohydrate diets are grounded across the time-span of human evolution, have well-established biochemical principles, and are now supported by multiple clinical trials in humans that demonstrate consistent improvements in multiple established risk factors associated with insulin resistance and cardiovascular disease. The American Diabetes Association (ADA) recently recognized a low carbohydrate eating pattern as an effective approach for patients with diabetes. Despite this evidence base, low-carbohydrate diets are not reflected in the DGA. As the DGA Dietary Patterns have not been demonstrated to be universally effective in addressing the needs of many Americans and recognizing the lack of widely available treatments for obesity, metabolic syndrome, and T2D that are safe, effective, and sustainable, the argument for an alternative, low-carbohydrate Dietary Pattern is all the more compelling.

Evaluation of Disparities in Adults' Macronutrient Intake Status: Results from the China Health and Nutrition 2011 Survey

Little is known about the macronutrient intake status of adult Chinese people. This cross-sectional study assessed the macronutrient intake status of adults (aged ≥20 years) by comparing their intake level of macronutrients against the Dietary Reference Intakes (DRI). It further explored the associations between macronutrient intake status and age groups, genders, education levels, smoking status, drinking frequency, social classes, knowledge of Chinese Dietary Guidelines 2016 (CDGs), healthy diet priorities, and areas (urban and rural) within two regions (northern and southern). The analysis includes the dietary intake data of 7860 Chinese adults, with complete data entries in the China Health and Nutrition 2011 survey. Dietary data were obtained through the 24 h recall method. More than half had carbohydrate intake below the recommended level of intake, and more than half had fat intake above the recommended level of intake. There were significant associations between three macronutrient intakes and education levels, social classes, healthy diet priorities, areas, and regions. Disparities in macronutrient consumptions revealed geographical and socioeconomic variations in dietary patterns, as well as risks for many different noncommunicable diseases. Public health and nutrition interventions should take notice of regional differences in dietary intake and place more emphasis on vulnerable populations including women, rural residents, and people with lower education level.

Evaluation of Dietary Patterns and All-Cause Mortality: A Systematic Review

Importance

The 2020 Dietary Guidelines Advisory Committee conducted a systematic review of existing research on diet and health to inform the current Dietary Guidelines for Americans. The committee answered this public health question: what is the association between dietary patterns consumed and all-cause mortality (ACM)?

Objective

To ascertain the association between dietary patterns consumed and ACM.

Evidence Review

Guided by an analytical framework and predefined inclusion and exclusion criteria developed by the committee, the US Department of Agriculture's Nutrition Evidence Systematic Review (NESR) team searched PubMed, the Cochrane Central Register of Controlled Trials, and Embase and dual-screened the results to identify articles that were published between January 1, 2000, and October 4, 2019. These studies evaluated dietary patterns and ACM in participants aged 2 years and older. The NESR team extracted data from and assessed risk of bias in included studies. Committee members synthesized the evidence, developed conclusion statements, and graded the strength of the evidence supporting the conclusion statements.

Findings

A total of 1 randomized clinical trial and 152 observational studies were included in the review. Studies enrolled adults and older adults (aged 17-84 years at baseline) from 28 countries with high or very high Human Development Index; 53 studies originated from the US. Most studies were well designed, used rigorous methods, and had low or moderate risks of bias. Precision, directness, and generalizability were demonstrated across the body of evidence. Results across studies were highly consistent. Evidence suggested that dietary patterns in adults and older adults that involved higher consumption of vegetables, fruits, legumes, nuts, whole grains, unsaturated vegetable oils, fish, and lean meat or poultry (when meat was included) were associated with a decreased risk of ACM. These healthy patterns were also relatively low in red and processed meat, high-fat dairy, and refined carbohydrates or sweets. Some of these dietary patterns also included intake of alcoholic beverages in moderation. Results based on additional analyses with confounding factors generally confirmed the robustness of main findings.

Conclusions and Relevance

In this systematic review, consuming a nutrient-dense dietary pattern was associated with reduced risk of death from all causes.

Low carbohydrate diet and all cause and cause-specific mortality

BACKGROUND

Evidence is limited regarding the association between low-carbohydrate diet (LCD) score and mortality among Asians, a population that consumes a large amount of carbohydrates.

OBJECTIVE

The present study examined the association between low-carbohydrate diet (LCD) score (based on percentage of energy as carbohydrate, fat, and protein) and the risk of total and cause-specific mortality among Asians.

DESIGN

This study was a prospective cohort study in Japan with follow-up for a median of 16.9 years involving 43008 men and 50646 women aged 45-75 years. Association of LCD score, LCD score based on animal sources of protein and fat, and LCD score based on plant sources of protein and fat with risk of mortality was assessed using Cox proportional hazards model.

RESULTS

A U-shaped association was observed between LCD score and total mortality: the multivariable-adjusted hazard ratios (HRs) (95% CI) of total mortality for lowest through highest scores were 1.00, 0.95 (0.91, 1.01), 0.93 (0.88, 0.98), 0.93 (0.88, 0.98), and 1.01 (0.95, 1.07) (P-non-linearity <0.01). A similar association was found for mortality from cardiovascular disease (CVD) and heart disease. LCD score based on carbohydrate, animal protein, and animal fat also showed a U-shaped association for total mortality (P-non-linearity <0.01). In contrast, LCD score based on carbohydrate, plant protein, and plant fat was linearly associated with lower total (HR, 0.89; 95% CI: 0.83, 0.94 for highest versus lowest quintile), CVD [0.82 (0.73, 0.92)], heart disease [0.83 (0.71, 0.98)], and cerebrovascular disease [0.75 (0.62, 0.91) mortality.

CONCLUSIONS

Both LCD with high animal protein and fat and high-carbohydrate diet with low animal protein and fat were associated with higher risk of mortality. Meanwhile, LCD high in plant-based sources of protein and fat was associated with a lower risk of total and CVD mortality.

Dietary Macronutrient Intakes and Mortality among Patients with Type 2 Diabetes

The best macronutrient percentages of dietary intake supporting longevity remains unclear. The strength of association between dietary intake and mortality in patients with type 2 diabetes (T2DM) should be quantified as a basis for dietary recommendations. Our study cohort consisted of 15,289 type 2 diabetic patients aged 30 years and older in Taiwan during 2001-2014 and was followed up through 2016. Percentages of macronutrient intakes were calculated as dietary energy intake contributed by carbohydrate, protein, and fat, divided by the total energy intake using a 24 h food diary recall approach. Cox proportional hazard models were applied to examine the temporal relation of macronutrient intakes with all-cause and cause-specific mortality. The average follow-up time was 7.4 years, during which 2,784 adults with T2DM died. After multivariable adjustment, people with fourth and fifth quintiles of total energy, second and third quintiles of carbohydrate, and fourth quintiles of protein intakes were likely to have lower risks of all-cause and expanded cardiovascular disease (CVD) mortality. People with fifth quintiles of total energy intake were likely to have decreased non-expanded CVD mortality. We found a significant interaction between gender and fat intake on all-cause and expanded CVD mortality. Fat intake was associated with all-cause, expanded and non-expanded CVD mortality among males with T2DM. Total energy, carbohydrate, and protein intakes were associated with lower risks of all-cause and expanded CVD mortality, with minimal risks observed at ≥1673 Kcal total energy, 43-52% carbohydrate intake, and 15-16% protein intake among people with T2DM.

Cardio-metabolic consequences of dietary carbohydrates: reconciling contradictions using nutritional geometry

Carbohydrates are the major source of dietary energy, but their role in health and disease remains controversial. Recent epidemiological evidence suggests that the increased consumption of carbohydrates is associated with obesity and increased risk of mortality and dietary trials show that carbohydrate restriction leads to weight loss and improved glycaemic status in obese and diabetic subjects. In contrast, the diets of populations with long and healthy lifespans (e.g. traditional Okinawans from Japan) are high in carbohydrate and low in protein, and several clinical and preclinical studies have linked low-carbohydrate-high-protein diets with increased mortality risk. In this paper we attempt to reconcile these contradictory findings by moving beyond traditional single-nutrient analyses to consider the interactions between nutrients on health outcomes. We do so using the Geometric Framework (GF), a nutritional modelling platform that explicitly considers the main and interactive effects of multiple nutrients on phenotypic characteristics. Analysis of human data by GF shows that weight loss and improved cardio-metabolic outcomes under carbohydrate restriction derive at least in part from reduced caloric intake due to the concomitantly increased proportion of protein in the diet. This is because, as in many animals, a specific appetite for protein is a major driver of food intake in humans. Conversely, dilution of protein in the diet leverages excess food intake through compensatory feeding for protein ('protein leverage'). When protein is diluted in the diet by readily digestible carbohydrates and fats, as is the case in modern ultra-processed foods, protein leverage results in excess calorie intake, leading to rising levels of obesity and metabolic disease. However, when protein is diluted in the diet by increased quantities of less readily digestible forms of carbohydrate and fibre, energy balance is maintained and health benefits accrue, especially during middle age and early late-life. We argue that other controversies in carbohydrate research can be resolved using the GF methodology in dietary studies.

Low-carbohydrate diet and cardiovascular diseases in Iranian population: Tehran Lipid and Glucose Study

BACKGROUND AND AIMS

Studies indicated that the risk of cardiovascular disease (CVD) in association to greater adherence to low-carbohydrate diet (LCD) differs in various populations. In this study, we aimed to assess the association of LCD score with the risk of CVD events in a prospective population-based study.

METHODS AND RESULTS

CVD-free participants (n = 2188) were recruited from the Tehran Lipid and Glucose Study (2006-2008) and followed for a mean of 6.7 years. Using a valid and reliable 168 item semi-quantitative food frequency questionnaire, the LCD score was determined based on the percentage of energy as carbohydrate, protein, and fat, which ranged from 0 to 12. Cox proportional hazard regression models, adjusted for potential confounders, were used to estimate the hazard ratios (HRs) and 95% confidence interval (CI) of CVD across tertiles of LCD score in women and men. Mean ± SD age of participants (44.8% male) was 38.8 ± 13.0 years, and median (25-75, interquartile range) of the LCD score was 6 (4-8) at baseline. During follow-up, 77 (3.5%) new cases of CVD were identified. After adjustment for sex, age, body mass index, physical activity, smoking, energy intake, diabetes, and hypertension, there was no association between the LCD score and risk of CVD outcomes in all participants (HR = 0.93; 95% CI: 0.86-1.02) and women (HR = 1.13; 95% CI: 0.94-1.36); however, the LCD score was associated with an 11% reduced incidence of CVD events in men (HR = 0.89; 95% CI: 0.80-0.98), (P for trend: 0.028).

CONCLUSION

Findings showed that higher adherence to LCD may be associated with a lower risk of CVD outcomes in men but not in women.

"Japan Diet" and Health-The Present and Future

Japan achieved remarkable economic development after World War II, which has led remarkable changes in risk factors of atherosclerotic diseases and led to epidemiological transition in Japan. Nowadays, obesity is pandemic around world, which is same case in Japan. BMI of Japanese population, especially young adult men increased gradually since the 1960s associated with increase in intake of fat as well as decrease in intake of rice, which has been revealed by the annual report of the Ministry of Health, Labour and Welfare. Such changes suggest the change of dietary habit from Japanese style to westernized style. In recent years such changes in lifestyle has been accompanied by a gradual increase in serum cholesterol in the Japanese population, which is associated with increase in the incidence of cardiovascular diseases (CVD). Japanese guidelines recommend "The Japan diet" to prevent CVD, because there are several epidemiological data to show the cardio-preventive effect of fish, soy bean, and vegetables, which are the major component of "The Japan Diet". It is very important to recognize the diet habit is one of culture and that rice plays a pivotal role in "The Japan Diet".

Carbohydrate intake and risk of metabolic syndrome: A dose-response meta-analysis of observational studies

BACKGROUND AND AIMS

Epidemiological association studies have reported inconsistent findings on the relationship between carbohydrate intake and risk of metabolic syndrome (MetS). Therefore, we aimed to conduct the first dose-response meta-analysis to investigate this effect.

METHODS AND RESULTS

A systematic search in PubMed and Web of Science databases from their inception to June 01, 2019, together with relevant literature scrutiny, was performed to identify related studies for inclusion into the meta-analysis. We calculated the odds ratios (ORs) with 95% confidence intervals (CIs) using a random effects model. Furthermore, subgroup, sensitivity, heterogeneity, and publication bias analyses were performed. This meta-analysis included 14 cross-sectional and four cohort studies, totaling 284,638 participants and 69,554 MetS cases. The highest versus the lowest carbohydrate intake values were associated with an increased risk of MetS (OR: 1.253, 95% CI: 1.147-1.368), with moderate heterogeneity (I² = 54.5%). Using dose-response analysis, we found a linear association between carbohydrate consumption and MetS risk with a corresponding OR of 1.026 (95% CI, 1.004-1.048) and with significant heterogeneity (I² = 82.0%) at 5% energy intake from carbohydrates. We have found similar results using subgroup analyses for major study characteristics and adjustment for confounders. Sensitivity analysis further enhanced the robustness of the results, and no publication bias was detected.

CONCLUSION

Carbohydrate intake is associated with an increased risk of developing MetS. Therefore, additional large prospective cohort studies are warranted to confirm our findings.

Lower carbohydrate diets and all-cause and cause-specific mortality: a population-based cohort study and pooling of prospective studies

Aims

Little is known about the long-term association between low-carbohydrate diets (LCDs) and mortality. We evaluated the link between LCD and overall or cause-specific mortality using both individual data and pooled prospective studies.

Methods and results

Data on diets from the National Health and Nutrition Examination Survey (NHANES; 1999–2010) were analysed. Multivariable Cox proportional hazards were applied to determine the hazard ratios and 95% confidence intervals (CIs) for mortality for each quartile of the LCD score, with the lowest quartile (Q1—with the highest carbohydrates intake) used as reference. We used adjusted Cox regression to determine the risk ratio (RR) and 95% CI, as well as random effects models and generic inverse variance methods to synthesize quantitative and pooled data, followed by a leave-one-out method for sensitivity analysis. Overall, 24 825 participants from NHANES study were included (mean follow-up 6.4 years). After adjustment, participants with the lowest carbohydrates intake (quartile 4 of LCD) had the highest risk of overall (32%), cardiovascular disease (CVD) (50%), cerebrovascular (51%), and cancer (36%) mortality. In the same model, the association between LCD and overall mortality was stronger in the non-obese (48%) than in the obese (19%) participants. Findings on pooled data of nine prospective cohort studies with 462 934 participants (mean follow-up 16.1 years) indicated a positive association between LCD and overall (RR 1.22, 95% CI 1.06–1.39, P < 0.001, I2 = 8.6), CVD (RR 1.13, 95% CI 1.02–1.24, P < 0.001, I2 = 11.2), and cancer mortality (RR 1.08, 95% CI 1.01–1.14, P = 0.02, I2 = 10.3). These findings were robust in sensitivity analyses.

Conclusion

Our study suggests a potentially unfavourable association of LCD with overall and cause-specific mortality, based on both new analyses of an established cohort and by pooling previous cohort studies. Given the nature of the study, causality cannot be proven; we cannot rule out residual bias. Nevertheless, further studies are needed to extend these important findings, which if confirmed, may suggest a need to rethink recommendations for LCD in clinical practice.

Relationship between carbohydrate and dietary fibre intake and the risk of cardiovascular disease mortality in Japanese: 24-year follow-up of NIPPON DATA80

BACKGROUND/OBJECTIVES

The association between carbohydrate intake and cardiovascular disease (CVD) risk has been investigated, but whether the quality of carbohydrate is more important than its amount is not known. We examined the associations between intake of dietary fibre (DF), carbohydrate, available carbohydrate, and starch with long-term CVD mortality in a Japanese population.

SUBJECTS/METHODS

We prospectively followed 8925 participants (3916 men and 5009 women) aged 30-79 years without CVD at baseline who participated in the National Nutrition Survey in Japan. Cox proportional hazards models were used to estimate multivariable-adjusted hazard ratios (HRs) and their 95% confidence intervals (CIs) for CVD mortality by quartiles of exposure variables.

RESULTS

During 24 years of follow-up, 823 CVD deaths were observed. In men, the multivariable-adjusted HR for CVD mortality was lower in the highest quartile of DF intake (HR: 0.64; 95% CI: 0.47-0.87; P_trend = 0.007) compared with the lowest quartile. This association was not significant in women. Multivariable-adjusted HR for total stroke mortality was lower in the highest quartile of DF intake (HR: 0.61; 95% CI: 0.38-0.98; P_trend = 0.046) compared with the lowest quartile in women. Carbohydrate, available carbohydrate, and starch intake were not associated with CVD mortality.

CONCLUSIONS

Higher intake of DF was associated significantly with a lower risk of CVD mortality in men and lower risk of stroke mortality in women. Intake of carbohydrate, available carbohydrate, and starch were not associated with the risk of CVD mortality in men or women.

Long-term incidence and risk factors of cardiovascular events in Asian populations: systematic review and meta-analysis of population-based cohort studies

BACKGROUND

Scientific studies on cardiovascular disease (CVD) burden and risk factors are predominantly based on short-term risk in Westerner populations, and such information may not be applicable to Asian populations, especially over the longer term. This review aims to estimate the long-term (>10 years) CVD burden, including coronary heart disease (CHD) and stroke, as well as associated risk factors in Asian populations.

METHODS

PubMed, Embase and Web of Science were systematically searched, and hits screened on: Asian adults, free of CVD at baseline; cohort study design (follow-up >10 years). Primary outcomes were fatal and non-fatal CVD events. Pooled estimates and between-study heterogeneity were calculated using random effects models, Q and I² statistics.

RESULTS

Overall, 32 studies were eligible for inclusion (follow-up: 11-29 years). The average long-term rate of fatal CVD is 3.68 per 1000 person-years (95% CI 2.84-4.53), the long-term cumulative risk 6.35% (95% CI 4.69%-8.01%, mean 20.13 years) and the cumulative fatal stroke/CHD risk ratio 1.5:1. Important risk factors for long-term fatal CVD (RR, 95% CI) were male gender (1.49, 1.36-1.64), age over 60/65 years (7.55, 5.59-10.19) and current smoking (1.68, 1.26-2.24). High non-HDL-c, and β- and γ-tocopherol serum were associated only with CHD (HR 2.46 [95% CI 1.29-4.71] and 2.47 [1.10-5.61] respectively), while stage 1 and 2 hypertensions were associated only with fatal stroke (2.02 [1.19-3.44] and 2.89 [1.68-4.96] respectively).

CONCLUSIONS

Over a 10 year + follow-up period Asian subjects had a higher risk of stroke than CHD. Contrary to CVD prevention in Western countries, strategies should also consider stroke instead of CHD only.

Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis

BACKGROUND

Low carbohydrate diets, which restrict carbohydrate in favour of increased protein or fat intake, or both, are a popular weight-loss strategy. However, the long-term effect of carbohydrate restriction on mortality is controversial and could depend on whether dietary carbohydrate is replaced by plant-based or animal-based fat and protein. We aimed to investigate the association between carbohydrate intake and mortality.

METHODS

We studied 15 428 adults aged 45-64 years, in four US communities, who completed a dietary questionnaire at enrolment in the Atherosclerosis Risk in Communities (ARIC) study (between 1987 and 1989), and who did not report extreme caloric intake (<600 kcal or >4200 kcal per day for men and <500 kcal or >3600 kcal per day for women). The primary outcome was all-cause mortality. We investigated the association between the percentage of energy from carbohydrate intake and all-cause mortality, accounting for possible non-linear relationships in this cohort. We further examined this association, combining ARIC data with data for carbohydrate intake reported from seven multinational prospective studies in a meta-analysis. Finally, we assessed whether the substitution of animal or plant sources of fat and protein for carbohydrate affected mortality.

FINDINGS

During a median follow-up of 25 years there were 6283 deaths in the ARIC cohort, and there were 40 181 deaths across all cohort studies. In the ARIC cohort, after multivariable adjustment, there was a U-shaped association between the percentage of energy consumed from carbohydrate (mean 48·9%, SD 9·4) and mortality: a percentage of 50-55% energy from carbohydrate was associated with the lowest risk of mortality. In the meta-analysis of all cohorts (432 179 participants), both low carbohydrate consumption (<40%) and high carbohydrate consumption (>70%) conferred greater mortality risk than did moderate intake, which was consistent with a U-shaped association (pooled hazard ratio 1·20, 95% CI 1·09-1·32 for low carbohydrate consumption; 1·23, 1·11-1·36 for high carbohydrate consumption). However, results varied by the source of macronutrients: mortality increased when carbohydrates were exchanged for animal-derived fat or protein (1·18, 1·08-1·29) and mortality decreased when the substitutions were plant-based (0·82, 0·78-0·87).

INTERPRETATION

Both high and low percentages of carbohydrate diets were associated with increased mortality, with minimal risk observed at 50-55% carbohydrate intake. Low carbohydrate dietary patterns favouring animal-derived protein and fat sources, from sources such as lamb, beef, pork, and chicken, were associated with higher mortality, whereas those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality, suggesting that the source of food notably modifies the association between carbohydrate intake and mortality.

FUNDING

National Institutes of Health.

Dietary Approaches for Japanese Patients with Diabetes: A Systematic Review

This study aimed to elucidate the effect of an energy restricted and carbohydrate restricted diet on the management of Japanese diabetes patients. Several databases including MEDLINE, EMBASE, and the Japan Medical Abstracts Society were searched for relevant articles published prior to June 2017. The articles identified were systematically reviewed. We identified 286 articles on an energy restricted diet, assessed seven and included two studies in our review. On a carbohydrate restricted diet, 75 articles were extracted, seven articles assessed and three included in the review, of which two were the studies that were selected for the energy restricted diet group, since they compared energy restricted diets with carbohydrate restricted diets. All selected studies were on Japanese patients with type 2 diabetes. No studies for type 1 diabetes were found in our search. Two randomized controlled trials on an energy restricted diet were also included in the three studies for a carbohydrate restricted diet. All the three randomized controlled trials showed better glucose management with the carbohydrate restricted diet. Our study revealed that there is very little evidence on diets, particularly in Japanese patients with diabetes, and that the energy restricted diet, which has been recommended by the Japan Diabetes Society in the sole dietary management approach, is not supported by any scientific evidence. Our findings suggest that the carbohydrate restricted diet, but not the energy restricted diet, might have short term benefits for the management of diabetes in Japanese patients. However, since our analysis was based on a limited number of small randomized controlled trials, large scale and/or long term trials examining the dietary approaches in these patients are needed to confirm our findings.

The Japanese food score and risk of all-cause, CVD and cancer mortality: the Japan Collaborative Cohort Study

Few studies have reported the association between the Japanese diet as food score and mortality. This study aimed to investigate adherence to the Japanese food score associated with all-cause, CVD and cancer mortality. A total of 58,767 (23,162 men and 35,605 women) Japanese participants aged 40-79 years, who enrolled in the Japan Collaborative Cohort Study between 1988 and 1990, were included. The Japanese food score was derived from the components of seven food groups (beans and bean products, fresh fishes, vegetables, Japanese pickles, fungi, seaweeds and fruits) based on the FFQ. The total score ranged from 0 to 7, and participants were divided into five categories based on scores (0-2, 3, 4, 5 and 6-7). Hazard ratios (HR) and 95 % CI for all-cause, CVD and cancer mortality based on sex were estimated using Cox proportional models. During the follow-up period until 2009, 11 692 participants with all-cause, 3408 with CVD and 4247 with cancer died. The multivariable HR in the 6-7 and 0-2 Japanese food score groups were 0·93 (95 % CI 0·86, 1·01) in men and 0·82 (95 % CI 0·75, 0·90) in women for all-cause mortality and 0·89 (95 % CI 0·76, 1·04) in men and 0·66 (95 % CI 0·56, 0·77) in women for CVD mortality. Our findings suggest that adherence to the Japanese food score consisting of food combinations characterised by a Japanese diet may help in preventing all-cause and CVD mortality, especially in women.

Intake of Carbohydrate to Fiber Ratio Is a Useful Marker for Metabolic Syndrome in Patients with Type 2 Diabetes: A Cross-Sectional Study

BACKGROUND/AIMS

The effect of low carbohydrate diet on human health is still controversial. Whole grain, which is carbohydrate rich in fiber, has protective effects on human health. Thus, we assumed that intake of carbohydrate to fiber ratio has an important role in human health.

METHODS

This is a post-hoc analysis of a cross-sectional study of 164 patients with type 2 diabetes. Habitual food and nutrient intake were assessed and estimated by a self-administered diet history questionnaire. Intake of carbohydrate to fiber ratio was defined as carbohydrate (g)/fiber intake (g). Logistic regression analyses were performed to reveal the association between intake of carbohydrate to fiber ratio and metabolic syndrome (MetS).

RESULTS

Intake of carbohydrate to fiber ratio has closely associated with metabolic parameters, including triglycerides (r = 0.21, p = 0.007) and high-density lipoprotein cholesterol (r = -0.23, p = 0.003). Intake of carbohydrate to fiber ratio was associated with MetS (OR 1.06 [95% CI 1.00-1.13], p = 0.047) after adjusting for covariates, whereas carbohydrate intake (1.00 [0.99-1.01], p = 0.752) or carbohydrate energy/total energy (1.00 [0.94-1.07], p = 0.962) was not associated with MetS.

CONCLUSIONS

Intake of carbohydrate to fiber ratio was associated with MetS, whereas carbohydrate intake was not.

Macronutrient Intake and Socioeconomic Status: NIPPON DATA2010

BACKGROUND

This study examined the relationships among household income, other SES indicators, and macronutrient intake in a cross-sectional study of a representative Japanese population.

METHODS

In 2010, we established a cohort of participants in the National Health and Nutrition Survey (NHNS) from 300 randomly selected areas throughout Japan. A total of 2,637 participants (1,145 men and 1,492 women) were included in the study. Data from NHNS2010 and the Comprehensive Survey of Living Conditions 2010 (CSCL2010) were merged, and relationships among macronutrient intake and SES were evaluated. Additionally, socioeconomic factors associated with a risk of a higher carbohydrate/lower fat intake beyond dietary recommendations were evaluated.

RESULTS

Household income was positively associated with fat intake (P = 0.001 for men and <0.001 for women) and inversely associated with carbohydrate intake (P = 0.003 for men and <0.001 for women) after adjustments for age and other SES variables. Similar relationships were observed between equivalent household expenditure (EHE) and macronutrient intake; however, these relationships were weaker than those of household income. Older age was the factor most strongly associated with a high carbohydrate/low fat intake, followed by household income, EHE, education levels, and occupation type.

CONCLUSIONS

Older age was the factor most strongly associated with a high carbohydrate/low fat intake, and some aspects of SES, such as household income, EHE, education levels, and occupation type, were independently associated with an imbalanced macronutrient intake. SES may affect the health status of individuals through the intake of macronutrients.

Novel Nutrition Profiling of New Zealanders' Varied Eating Patterns

There is increasing recognition that the relationship between nutrition and health is influenced by complex eating behaviors. The aims of this study were to develop novel nutrition profiles of New Zealanders and to describe the prevalence of these profiles. Observational, cross-sectional data from the Sovereign Wellbeing Index, 2014 was used to develop the profiles in an a-priori process. Descriptive prevalence for the total data (N = 10,012; 4797 males; 18+ years) and profiles were reported. Nutrition question responses were presented as: Includers (consumed few time a week or more), Avoiders (few time a month) and Limiters (not eaten). Fruit or non-starchy vegetables were Included (fruit: 83.4%, 95% confidence interval (CI: 82.7, 84.1); vegetables: 82.6% (81.8, 83.4)) by the majority of the sample. Also Included were confectionary (48.6% 95% CI (47.6, 49.6)) and full sugar drinks (34.3% (33.4, 35.2)). The derived nutrition profiles were: Junk Food (22.4% 95% CI (21.6, 23.3)), Moderator (43.0% (42.1, 44.0)), High-Carbohydrate (23.0% (22.2, 23.8)), Mediterranean (11.1% (10.5, 11.8)), Flexitarian (8.8% (8.2, 9.4)), and Low-Carbohydrate (5.4% (4.9, 5.8)). This study suggests that New Zealanders follow a number of different healthful eating patterns. Future work should consider how these alternate eating patterns impact on public health.

Effect of soy on metabolic syndrome and cardiovascular risk factors: a randomized controlled trial

BACKGROUND

Cardiovascular diseases are currently the commonest cause of death worldwide. Different strategies for their primary prevention have been planned, taking into account the main known risk factors, which include an atherogenic lipid profile and visceral fat excess.

METHODS

The study was designed as a randomized, parallel, single-center study with a nutritional intervention duration of 12 weeks. Whole soy foods corresponding to 30 g/day soy protein were given in substitution of animal foods containing the same protein amount.

RESULTS

Soy nutritional intervention resulted in a reduction in the number of MetS features in 13/26 subjects. Moreover, in the soy group we observed a significant improvement of median percentage changes for body weight (-1.5 %) and BMI (-1.5 %), as well as for atherogenic lipid markers, namely TC (-4.85 %), LDL-C (-5.25 %), non-HDL-C (-7.14 %) and apoB (-14.8 %). Since the majority of the studied variables were strongly correlated, three factors were identified which explained the majority (52 %) of the total variance in the whole data set. Among them, factor 1, which loaded lipid and adipose variables, explained the 22 % of total variance, showing a statistically significant difference between treatment arms (p = 0.002).

CONCLUSIONS

The inclusion of whole soy foods (corresponding to 30 g/day protein) in a lipid-lowering diet significantly improved a relevant set of biomarkers associated with cardiovascular risk.

Impact of low-carbohydrate diet on body composition: meta-analysis of randomized controlled studies

The effect of low-carbohydrate diet (LCD) on body composition, especially fat mass, in obese individuals remains to be elucidated. We performed a meta-analysis to provide quantitative summary estimates of the mean change of body weight (kg) and fat mass (kg) in LCD comparing to those in control diet. Literature searches were performed using EMBASE, MEDLINE and Cochrane Library until Dec 2014. Fourteen randomized controlled studies were included in this meta-analysis. Eight studies including very LCD (50 g carbohydrate or 10% calorie from carbohydrate) and seven studies including mild LCD (about 40% calorie from carbohydrate). Meta-analysis carried out on data of 1416 obese individuals, showed that LCD was associated with decrease in body weight (-0.70 kg [95% CI -1.07/-0.33]) or fat mass (-0.77 kg [-1.55/-0.32]). Subgroup meta-analysis of studies in over 12 months suggested that LCD was not associated with decrease in body weight (-0.44 kg [-0.94/0.07]), but LCD was associated with decrease in fat mass (-0.57 kg [-1.05/-0.09]). In addition, very LCD was associated with decrease in fat mass (-0.97 kg [-1.50/-0.44]), but mild LCD was not associated with decrease in fat mass (-0.43 kg [-1.15/0.33]). LCD, especially very LCD, might be effective for decrease in fat mass in obese individuals. © 2016 World Obesity.

Low carbohydrate diet-based intervention for obstructive sleep apnea and primary hypothyroidism in an obese Japanese man

BACKGROUND

Obesity is a major risk factor for obstructive sleep apnea (OSA), and weight loss is necessary in the overall management of obese patients with OSA. However, primary care physicians can provide only limited weight loss with lifestyle interventions, usually reducing a patient's body weight by only 2.5 kg or less after 6-18 months.

CASE PRESENTATION

A 45-year-old Japanese man was referred to our clinic owing to obesity, daytime sleepiness, and snoring during sleep. His weight was 130.7 kg and his body mass index (BMI) was 41.0 kg/m(2). He underwent polysomnography, which revealed OSA with an apnea-hypopnea index of 71.2 events/h (normal, <5 events/h). His laboratory results were as follows: thyroid stimulating hormone, >500 μIU/mL; free triiodothyronine, 1.4 pg/mL; free thyroxine, <0.15 ng/dL; thyroid peroxidase antibody, 10 IU/mL; thyroglobulin antibody, >4000 IU/mL; total cholesterol (TC), 335 mg/dL; high-density lipoprotein cholesterol, 45 mg/dL; triglycerides (TGs), 211 mg/dL; low-density lipoprotein cholesterol, 248 mg/dL; fasting blood sugar, 86 mg/dL; and glycated hemoglobin (HbA1c), 6.1 %. These results showed that he also had primary hypothyroidism (Hashimoto's disease). Continuous positive airway pressure (CPAP), levothyroxine replacement, and a low-carbohydrate diet (LCD) were initiated. CPAP use and a euthyroid condition induced by 175 μg/day levothyroxine allowed the patient to proactively reduce his body weight. After 18 months, the patient achieved a weight reduction of 32.4 kg (25 % of his initial weight) and a BMI reduction of 10.2 kg/m(2), as well as improved laboratory results, including an HbA1c level of 5.3 %, TC level of 194 mg/dL, and TG level of 89 mg/dL.

CONCLUSION

An LCD may be an effective intervention for weight loss in obese Japanese patients with OSA. Further studies are needed to investigate the weight loss effect of an LCD compared with a conventional calorie-restricted diet. Hopefully, this case report will help to improve the management of obese Asian patients with OSA who typically consume a higher amount of carbohydrates.

Low-carbohydrate diet and type 2 diabetes risk in Japanese men and women: the Japan Public Health Center-Based Prospective Study

Objective

Evidence is sparse and contradictory regarding the association between low-carbohydrate diet score and type 2 diabetes risk, and no prospective study examined the association among Asians, who consume greater amount of carbohydrate. We prospectively investigated the association of low-carbohydrate diet score with type 2 diabetes risk.

Methods

Participants were 27,799 men and 36,875 women aged 45–75 years who participated in the second survey of the Japan Public Health Center-Based Prospective Study and who had no history of diabetes. Dietary intake was ascertained by using a validated food-frequency questionnaire, and low-carbohydrate diet score was calculated from total carbohydrate, fat, and protein intake. The scores for high animal protein and fat or for high plant protein and fat were also calculated. Odds ratios of self-reported, physician-diagnosed type 2 diabetes over 5-year were estimated by using logistic regression.

Results

During the 5-year period, 1191 new cases of type 2 diabetes were self-reported. Low-carbohydrate diet score for high total protein and fat was significantly associated with a decreased risk of type 2 diabetes in women (P for trend <0.001); the multivariable-adjusted odds ratio of type 2 diabetes for the highest quintile of the score were 0.63 (95% confidence interval 0.46–0.84), compared with those for the lowest quintile. Additional adjustment for dietary glycemic load attenuated the association (odds ratio 0.75, 95% confidence interval 0.45–1.25). When the score separated for animal and for plant protein and fat, the score for high animal protein and fat was inversely associated with type 2 diabetes in women, whereas the score for high plant protein and fat was not associated in both men and women.

Discussion

Low-carbohydrate diet was associated with decreased risk of type 2 diabetes in Japanese women and this association may be partly attributable to high intake of white rice. The association for animal-based and plant-based low-carbohydrate diet warrants further investigation.