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

PURPOSE: Low-carbohydrate diets (LCD) are a popular dietary strategy for weight reduction. The effects of LCD on long-term outcome vary depending on type of LCD, possibly due to the fact that effects on cardiometabolic risk factors may vary with different types of LCD. Accordingly, we studied these relations. METHODS: We assessed serum concentrations of high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), high-sensitivity C-reactive protein (CRP), total cholesterol, glycated hemoglobin, and uric acid, and nutrient intakes by standardized methods in men and women ages 40-59 years from four population samples of Japanese in Japan (553 men and 544 women, combined). For people consuming usual, animal-based, and plant-based LCDs, we calculated LCD scores, based on relative level of fat, protein, and carbohydrate, by modifying the methods of Halton et al. Instead of calculating scores based on animal or vegetable fat, we used saturated fatty acids (SFA) or monounsaturated fatty acids (MUFA) + polyunsaturated fatty acids (PUFA). RESULTS: In multivariate regression analyses with adjustment for site, age, sex, BMI, smoking, alcohol intake, physical activity, and years of education, all three LCD scores were significantly positively related to HDLc (all P < 0.001), but not to LDLc. The plant-based LCD score was significantly inversely related to log CRP (coefficient = -0.010, P = 0.018). CONCLUSIONS: All three LCD scores were significantly positively related to HDLc. The plant-based LCD score was significantly inversely related to CRP. Carbohydrate intake below 50 % of total energy with higher intakes of vegetable protein and MUFA + PUFA, and lower intakes of SFA may be favorable for reducing cardiometabolic risk factors.

High long-chain n-3 fatty acid intake attenuates the effect of high resting heart rate on cardiovascular mortality risk: a 24-year follow-up of Japanese general population.

BACKGROUND: Increased resting heart rate (RHR) independently predicts cardiovascular mortality. Meanwhile, long-chain n-3 fatty acids (LCn3FAs) have a cardioprotective effect. Our aim was to evaluate whether higher LCn3FAs intake attenuates the elevated risk of cardiovascular mortality associated with increased RHR. METHODS: We conducted a population-based 24-year prospective cohort study of Japanese, whose LCn3FAs intake is relatively high. Study participants included 8807 individuals aged 30-95 years from randomly selected areas across Japan without cardiovascular diseases and anti-hypertensive drugs at baseline. The primary endpoint was cardiovascular mortality, and the secondary endpoints were cardiac and stroke mortality during 24 years of follow-up. Individual dietary LCn3FAs intake was estimated from household-based 3-day weighed food records. RHR was obtained from 3 consecutive R-wave intervals on 12-lead electrocardiography. Cox models were used to estimate the multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) adjusting for possible confounders. RESULTS: During the follow-up period, 617 cardiovascular deaths were observed. The median daily intake of LCn3FAs was 0.37% kcal (0.86g/day). The interaction between dietary LCn3FAs intake and RHR in the risk of cardiovascular mortality was statistically significant (p=0.033). The risk of cardiovascular mortality was significantly higher in the low-intake group (<0.37%kcal) with an RHR >85beats/min (bpm) [hazard ratio (HR), 1.67; 95% confidence interval (CI), 1.15-2.43], but not in the high-intake group (≥0.37%kcal) with an RHR >85bpm (HR, 0.92; 95% CI, 0.61-1.38), compared with those in the high-intake group with an RHR <70bpm. Similar results were observed with stroke mortality, but not with cardiac mortality. CONCLUSIONS: The risk of cardiovascular mortality associated with increased RHR is elevated in participants with low dietary LCn3FAs intake, but not in participants with high dietary LCn3FAs intake in a representative Japanese general population. These results suggest that high dietary LCn3FAs intake may prevent cardiovascular mortality associated with increased RHR.

Long-chain n-3 polyunsaturated fatty acids intake and cardiovascular disease mortality risk in Japanese: a 24-year follow-up of NIPPON DATA80.

BACKGROUND: Dietary intake of long-chain n-3 PUFA (LCn3FA) among Japanese is generally higher than that in Western populations. However, little is known whether an inverse association of LCn3FA with cardiovascular disease (CVD) risk exists in a population with higher LCn3FA intake. OBJECTIVE: To investigate the association between LCn3FA intake and the long-term risk of CVDs in a Japanese general population. METHODS: We followed-up a total of 9190 individuals (56.2% women, mean age 50.0 years) randomly selected from 300 areas across Japan and free from CVDs at baseline. Dietary LCn3FA intake was estimated using household weighed food records. Cox models were used to calculate multivariate-adjusted hazard ratios (HR) and confidence intervals (CI) according to sex specific quartiles of LCn3FA intake. RESULTS: During 24-year follow-up (192,897 person-years), 879 cardiovascular deaths were observed. The median daily intake of LCn3FA was 0.37% kcal (0.86 g/day). Adjusted HR for CVD mortality was lower in the highest quartile of LCn3FA intake (HR 0.80; 95% CI 0.66-0.96) compared with the lowest quartile, and the trend was statistically significant (P = 0.038). The similar but statistically non-significant trends were observed for coronary heart disease death and stroke death. In analyses by age groups, the inverse associations of LCn3FA intake with the risk of total CVD death and stroke death were significant in younger individuals (30-59 years at baseline). CONCLUSION: LCn3FA intake was inversely and independently associated the long-term risk of total CVD mortality in a representative sample of Japanese with high LCn3FA intake.

Interaction between dietary marine-derived n-3 fatty acids intake and J-point elevation on the risk of cardiac death: a 24-year follow-up of Japanese men.

OBJECTIVE: Higher marine-derived n-3 fatty acids (MDn3FAs) intake reduces the risk of sudden cardiac death via antiarrhythmic effects. The article evaluates whether MDn3FAs intake attenuates the increased risk of cardiac death associated with J-point elevation (JPE), characterised by an elevation of QRS-ST junction (J-point) ≥0.1 mV on electrocardiography. DESIGN: A prospective population-based cohort study. SETTING: The National Survey on Circulatory Disorders and the National Nutrition Survey of Japan. PARTICIPANTS: A total of 4348 community-dwelling men (mean age 49.3 years), without cardiovascular diseases at baseline, from randomly selected areas across Japan. MAIN OUTCOME MEASURES: Cardiac death (200 men) during the 24-year follow-up. RESULTS: Dietary MDn3FAs intake was assessed using a dietary method to estimate individual intake of household-based weighed food records for 3 days. Cox models were used to calculate HRs and 95% CIs adjusted for possible confounding factors. JPE was present in 340 participants (7.8%). The median daily intake of MDn3FAs was 0.35%kcal (0.92 g/day). The risk of cardiac death was significantly higher in participants with JPE than in those without JPE in the low intake group (<0.35%kcal; adjusted HR 3.51; 95% CI 1.84 to 6.73; p<0.001), but not in the high intake group (≥0.35%kcal; adjusted HR 1.09; 95% CI 0.56 to 2.16; p=0.795). The interaction between dietary MDn3FAs intake and JPE on the risk of cardiac death was statistically significant (p=0.006). CONCLUSIONS: The increased risk of cardiac death associated with JPE may be attenuated by higher dietary MDn3FAs intake.

Relationship of dietary monounsaturated fatty acids to blood pressure: the International Study of Macro/Micronutrients and Blood Pressure.

OBJECTIVE: In short-term feeding trials, replacement of other macronutrients with monounsaturated fatty acid reduces blood pressure. However, observational studies have not clearly demonstrated a relationship between monounsaturated fatty acid intake and blood pressure. We report associations of monounsaturated fatty acid intake of individuals with blood pressure in a cross-sectional study. METHODS: The International Study of Macro/Micronutrients and Blood Pressure is a cross-sectional epidemiologic study of 4680 men and women ages 40-59 years from 17 population samples in China, Japan, UK and USA. Nutrient intake data were based on four in-depth multipass 24-h dietary recalls/person and two-timed 24-h urine collections/person. Blood pressure was measured eight times at four visits. RESULTS: Mean monounsaturated fatty acid intake ranged from 8.1%kcal (China) to 12.2%kcal (USA). With sequential models to control for possible confounders (dietary, other), linear regression analyses showed significant inverse relationship of total monounsaturated fatty acid intake with DBP for all participants; for 2238 'nonintervened' individuals, the relationship was stronger. Estimated DBP differences with 2-SD higher monounsaturated fatty acids (5.35%kcal) were -0.82 mmHg (P < 0.05) for all participants and -1.70 mmHg (P < 0.01) for nonintervened individuals. Inverse associations of dietary total oleic acid (main monounsaturated) with blood pressure in nonintervened individuals were not significant, but those of oleic acid from vegetable sources were stronger and significant (P < 0.05). CONCLUSION: Dietary monounsaturated fatty acid intake, especially oleic acid from vegetable sources, may contribute to prevention and control of adverse blood pressure levels in general populations.

Distribution of vitamin E intake among Japanese dietary supplement and fortified food users: a secondary analysis from the National Health and Nutrition Survey, 2003-2009.

This study was performed to: (1) assess the prevalence of dietary supplement and fortified food use, (2) examine the differences in vitamin E intake with and without dietary supplementation and/or fortified food use, and (3) determine whether some individuals consume vitamin E above the tolerable upper intake level (UL). Data were obtained from 64,624 individuals (age, ≥1 y; 47.4% males) who completed a 1-d household dietary assessment that was part of the National Health and Nutrition Survey conducted in Japan, 2003-2009. The survey also obtained information on the brand or generic name of each dietary supplement or fortified food reported, including their ingredients, through dietary assessment. The prevalence of a potential risk of excess was estimated by the proportion of persons above the age-/sex-specific ULs provided by the Dietary Reference Intakes for Japanese 2010. Supplement use was reported by 5.8% of men and 7.7% of women, whereas fortified food consumption was reported by only 2.9% of men and 3.6% of women. Use of dietary supplements was most common among older women, whereas use of fortified foods was most common among younger women. Both dietary supplement and fortified food use accounted for maximum vitamin E intake; however, the use of dietary supplements and fortified foods had little effect on the median and 95th percentile intake values. None of the subjects consumed nutrients above the UL. The collected data confirm that the use of both dietary supplements and fortified foods contributes a small amount to nutrient intake in Japanese subjects.

Dietary intake of nutrients with adequate intake values in the dietary reference intakes for Japanese.

The Adequate Intake (AI) values in the Dietary Reference Intakes for Japanese (DRIs-J) 2010 were mainly determined based on the median intakes from 2 y of pooled data (2005-2006) from the National Health and Nutrition Survey-Japan (NHNS-J). However, it remains unclear whether 2 y of pooled data from the NHNS-J are appropriate for evaluating the intake of the population. To clarify the differences in nutrient intakes determined from 2 and 7 y of pooled data, we analyzed selected nutrient intake levels by sex and age groups using NHNS-J data. Intake data were obtained from 64,624 individuals (age: ≥1 y; 47.4% men) who completed a semi-weighed 1-d household dietary record that was part of the NHNS-J conducted annually in Japan from 2003 to 2009. There were no large differences between the median intakes calculated from 2 or 7 y of pooled data for n-6 or n-3 polyunsaturated fatty acids (PUFAs), vitamin D, pantothenic acid, potassium, or phosphorus. When the AI values and median intakes were compared, there was no large difference in the values for n-6 or n-3 PUFAs, pantothenic acid, or phosphorus. Conversely, the AI values for vitamin D and potassium differed from the median intakes of these nutrients for specific sex and age groups, because values were not based on NHNS-J data. Our results indicate that 2 y of pooled data from the NHNS-J adequately reflect the population's intake, and that the current system for determination of AI values will be applicable for future revisions.

Nutrient and food intakes of middle-aged adults at low risk of cardiovascular disease: the international study of macro-/micronutrients and blood pressure (INTERMAP).

PURPOSE: Individuals with favorable levels of readily measured cardiovascular disease (CVD) risk factors (low risk, LR) experience low long-term rates of CVD mortality and greater longevity. The purpose of the current study was to compare nutrient/food intakes of LR participants with participants not LR in the INTERMAP study. METHODS: Men and women (40-59 years) from 17 population samples in four countries (China, Japan, UK, US) provided four 24-h dietary recalls and two timed 24-h urine collections. LR was defined as meeting all of the following CVD risk criteria: systolic/diastolic blood pressure (BP) ≤ 120/ ≤ 80 mmHg; no drug treatment for high BP, hyperlipidemia, or CVD; non-smoking; BMI <25.0 kg/m(2) (US, UK) or <23.0 kg/m(2) (China, Japan); alcohol consumption <26.0 g/day (men)/<13.0 g/day (women); and no history of diabetes or CVD. Multivariate logistic regression was used to examine associations of nutrient/food intakes with LR. RESULTS: LR individuals reported higher intake of vegetable protein, fiber, magnesium, non-heme iron, potassium; lower energy intake; lower intake of cholesterol, saturated fatty acids, animal protein; and lower 24-h urinary sodium compared with individuals not LR. With regard to foods, LR individuals reported higher intake of fruits, vegetables, grains, pasta/rice, fish; lower intakes of meats, processed meats, high-fat dairy, and sugar-sweetened beverages than individuals not LR. CONCLUSIONS: Lower energy intake and differential intake of multiple specific nutrients and foods are characteristic of individuals at low risk for developing CVD. Identification of dietary habits associated with LR is important for further development of public health efforts aimed at reduction/prevention of CVD.

Relationship of the polyunsaturated to saturated fatty acid ratio to cardiovascular risk factors and metabolic syndrome in Japanese: the INTERLIPID study.

AIM: There have been few studies on the relationships of the dietary polyunsaturated to saturated fatty acid ratio (P/S) to cardiovascular risk factors and metabolic syndrome. We hypothesized that there would be favorable relationships. METHODS: Metabolic cardiovascular risk factors from dietary nutrient intake were investigated in 1,004 men and women aged 40-59 years from 4 population samples of Japanese. Multiple linear regression analysis was used to examine the relationship of the dietary P/S ratio to the following risk factors: hemoglobin A1c, blood pressure, serum triglycerides, LDL and total cholesterol, and HDL-cholesterol. Adjusted odds ratio of having metabolic syndrome was also calculated. RESULTS: The dietary P/S ratio was significantly and inversely related to serum total and LDL cholesterol with control for possible confounding variables. We did not find any significant relationship between the P/S ratio and single metabolic risk factors or the prevalence of metabolic syndrome. CONCLUSIONS: Managing the P/S ratio is important to control serum LDL-cholesterol; however, increasing the P/S ratio may not improve metabolic risk factors. Other countermeasures, such as weight control, greater physical activity, and smoking cessation should be recommended to prevent and control metabolic syndrome.

Fatty acids intakes and serum lipid profiles: NIPPON DATA90 and the national nutrition monitoring.

BACKGROUND: The National Nutritional Survey in Japan (NNSJ) was initiated in 1946. Using the majority of the participants for NNSJ, the National Survey on Circulatory Disorders (NSCD) has been conducted every 10 year since 1960. We compared fatty acids intakes obtained from NNSJ and serum lipid profiles from NSCD conducted in 1990. METHODS: A total of 8344 community residents (4856 women and 3488 men, age > or = 30) from 300 randomly selected districts participated in the both surveys in 1990. At baseline, history, physical, and blood biochemical measurement and a nutritional survey were performed. We estimated nutrient intakes of each household member by dividing household intake data proportionally using average intakes by sex and age groups calculated for NNSJ95. RESULTS: Total fat, saturated fatty acids (SFA), poly-unsaturated fatty acids (PUFA), dietary cholesterol, and Keys dietary lipid factor (KEYS) were inversely associated with age in both men and women (all Ps < 0.001). In women, age and body mass index (BMI) adjusted serum total cholesterol (TC), high-density lipoprotein cholesterol (HDLc), and low-density lipoprotein cholesterol (LDLc) were positively associated with SFA, total fat intakes (%kcal), and with KEYS (P < 0.001). In men, age-BMI adjusted HDLc was not associated with SFA, total fat intakes, and with KEYS factors unlike in women. Other associations were similar to those in women. CONCLUSIONS: The total fatty acids, SFA intakes, and KEYS lipid factor obtained from NNSJ were significantly associated with serum total and LDL cholesterol from the National Survey on Circulatory Disorders conducted in 1990.

Relation of long chain n-3 polyunsaturated fatty acid intake to serum high density lipoprotein cholesterol among Japanese men in Japan and Japanese-American men in Hawaii: the INTERLIPID study.

Epidemiologic evidence shows an inverse relationship between fish consumption and coronary heart disease (CHD) mortality. Associations between dietary intake of long chain n-3 polyunsaturated fatty acids (PUFA) and serum high density lipoprotein (HDL) cholesterol concentration are unknown. In this study, the association between n-3 PUFA (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) and docosapentaenoic acid (DPA)) intake and serum HDL cholesterol among Japanese men and women in Japan and Hawaii was examined. The study population consisted of Japanese ancestries from five research centers of the International Study of Macronutrients and Blood Pressure (INTERMAP) study, in Japan and Hawaii (672 men and 676 women), surveyed between 1996 and 1998. Four 24-h dietary recalls and one set of serum lipid measurements were performed. For men, n-3 PUFA intake and HDL cholesterol were higher in Japan than in Hawaii (n-3 PUFA: 1.32 g/day versus 0.47 g/day, p<0.001). For women, n-3 PUFA intake was higher in Japan than in Hawaii (p<0.001) but HDL cholesterol was not significantly different (p=0.752). After adjustment for age, body mass index, physical activity, number of cigarettes per day, alcohol intake, and hormone replacement therapy (for women), n-3 PUFA intake was positively associated with serum HDL cholesterol in men (4.6 mg/dl higher HDL cholesterol with 1%kcal higher n-3 PUFA intake, p=0.011). This association was not observed in women. This positive association of dietary n-3 PUFA with serum HDL cholesterol may partially explain the low mortality from CHD among Japanese men.