The evidence linking low-carbohydrate diets (LCD) to CVD is controversial, and results from epidemiological studies are inconsistent. We aimed to assess the relationship between LCD patterns and coronary artery Ca (CAC) scores from computed tomography in the Multi-Ethnic Study of Atherosclerosis cohort. Our sample included 5614 men and women free of clinical CVD at baseline (2000–2002), who had a FFQ, a baseline measure and ≥1 measure of CAC during follow-up. We excluded those with implausible energy intake or daily physical activity. The overall, animal-based and plant-based LCD scores were calculated based on intakes of macronutrients. Relative risk regression and robust regression models were used to examine the cross-sectional and longitudinal relationship between LCD score quintile and CAC outcomes, after adjustment for multiple cardiovascular risk factors. The mean age of participants was 63 years. The median intakes of total carbohydrate, fat and protein were 53·7, 30·5 and 15·6 % energy/d, respectively. Among 2892 participants with zero CAC scores at baseline, 264 developed positive scores during 2·4-year follow-up (11–59 months). Among those with positive scores at baseline, the median increase in CAC was 47 units over the course of follow-up. The overall, the animal-based and the plant-based LCD scores were not associated with CAC prevalence, incidence and progression. In conclusion, diets low in carbohydrate and high in fat and/or protein, regardless of the sources of protein and fat, were not associated with higher levels of CAC, a validated predictor of cardiovascular events, in this large multi-ethnic cohort.

The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.

The Mediterranean diet has been reported to be inversely associated with incident metabolic syndrome (MetSyn) among older adults; however, this association has not been studied in young African American and white adults. The objective of the present study was to evaluate the association of a modified Mediterranean diet (mMedDiet) score with the 25-year incidence of the MetSyn in 4713 African American and white adults enrolled in the Coronary Artery Risk Development in Young Adults (CARDIA) study. A diet history questionnaire was used to assess dietary intake at baseline, year 7 and year 20 and a mMedDiet score was created. Cardiovascular risk factors were measured at multiple examinations over 25 years. The MetSyn was defined according to the National Cholesterol Education Program Adult Treatment Panel III (ATP III) criteria. Cox proportional-hazards regression analysis was use to evaluate associations for incident MetSyn across the mMedDiet score categories adjusting for demographic characteristics, lifestyle factors and BMI. Higher mMedDiet scores represented adherence to a dietary pattern rich in fruit, vegetables, whole grains, nuts and fish, but poor in red and processed meat and snack foods. The incidence of MetSyn components (abdominal obesity, elevated TAG concentrations and low HDL-cholesterol concentrations) was lower in those with higher mMedDiet scores than in those with lower scores. Furthermore, the incidence of the MetSyn was lower across the five mMedDiet score categories; the hazard ratios and 95 % CI from category 1 to category 5 were 1·0; 0·94 (0·76, 1·15); 0·84 (0·68, 1·04); 0·73 (0·58, 0·92); and 0·72 (0·54, 0·96), respectively (Ptrend= 0·005). These findings suggest that the risk of developing the MetSyn is lower when consuming a diet rich in fruit, vegetables, whole grains, nuts and fish.

Dietary protein has been shown to increase urinary Ca excretion in randomised controlled trials, and diets high in protein may have detrimental effects on bone health; however, studies examining the relationship between dietary protein and bone health have conflicting results. In the present study, we examined the relationship between dietary protein (total, animal and vegetable protein) and lumbar spine trabecular volumetric bone mineral density (vBMD) among participants enrolled in the Multi-Ethnic Study of Atherosclerosis (n 1658). Protein intake was assessed using a FFQ obtained at baseline examination (2000–2). Lumbar spine vBMD was measured using quantitative computed tomography (2002–5), on average 3 years later. Multivariable linear and robust regression techniques were used to examine the associations between dietary protein and vBMD. Sex and race/ethnicity jointly modified the association of dietary protein with vBMD (P for interaction = 0·03). Among white women, higher vegetable protein intake was associated with higher vBMD (P for trend = 0·03), after adjustment for age, BMI, physical activity, alcohol consumption, current smoking, educational level, hormone therapy use, menopause and additional dietary factors. There were no consistently significant associations for total and animal protein intakes among white women or other sex and racial/ethnic groups. In conclusion, data from the present large, multi-ethnic, population-based study suggest that a higher level of protein intake, when substituted for fat, is not associated with poor bone health. Differences in the relationship between protein source and race/ethnicity of study populations may in part explain the inconsistent findings reported previously.

The intake of the mainly plant-derived n-3 PUFA α-linolenic acid (ALA) has been reported to be associated with a lower risk of CHD. However, the results have been inconsistent. Therefore, the objective of the present study was to examine the association between the intake of ALA and the risk of CHD. Potential effect modification by the intake of long-chain n-3 PUFA (n-3 LCPUFA) was also investigated. Data from eight American and European prospective cohort studies including 148 675 women and 80 368 men were used. The outcome measure was incident CHD (CHD event and death). During 4–10 years of follow-up, 4493 CHD events and 1751 CHD deaths occurred. Among men, an inverse association (not significant) between the intake of ALA and the risk of CHD events and deaths was observed. For each additional gram of ALA consumed, a 15 % lower risk of CHD events (hazard ratios (HR) 0·85, 95 % CI 0·72, 1·01) and a 23 % lower risk of CHD deaths (HR 0·77, 95 % CI 0·58, 1·01) were observed. No consistent association was observed among women. No effect modification by the intake of n-3 LCPUFA was observed.

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is an independent risk factor for CVD and has been proposed as a marker of vascular inflammation. Polyunsaturated n-3 fatty acids (FA) and several n-6 FA are known to suppress inflammation and may influence Lp-PLA2 mass and activity. The associations of n-3 and n-6 plasma FA with Lp-PLA2 mass and activity were analysed using linear regression analysis in 2246 participants of the Multi-Ethnic Study of Atherosclerosis; statistical adjustments were made to control for body mass, inflammation, lipids, diabetes, and additional clinical and demographic factors. Lp-PLA2 mass and activity were significantly lower in participants with the higher n-3 FA EPA (β = − 4·72, P< 0·001; β = − 1·53; P= 0·023) and DHA levels (β = − 4·47, β = − 1·87; both P< 0·001). Those in the highest quintiles of plasma EPA and DHA showed 12·71 and 19·15 ng/ml lower Lp-PLA2 mass and 5·7 and 8·90 nmol/min per ml lower Lp-PLA2 activity than those in the first quintiles, respectively. In addition, lower Lp-PLA2 mass and activity were associated with higher levels of n-6 arachidonic acid (β = − 1·63, β = − 1·30; both P< 0·001), while γ-linolenic acid was negatively associated with activity (β = − 27·7, P= 0·027). Lp-PLA2 mass was significantly higher in participants with greater plasma levels of n-6 linoleic (β = 0·828, P= 0·011) and dihomo-γ-linolenic acids (β = 4·17, P= 0·002). Based on their independent associations with Lp-PLA2 mass and activity, certain n-3 and n-6 FA may have additional influences on CVD risk. Intervention studies are warranted to assess whether these macronutrients may directly influence Lp-PLA2 expression or activity.

Type 2 diabetes (T2D) is a highly prevalent but preventable disorder. We assessed the association between an a priori Mediterranean diet (MeDiet) score and fasting glucose and insulin at baseline and incident T2D after a 6-year follow-up in the Multi-Ethnic Study of Atherosclerosis. Dietary intake was measured at baseline using a 127-item FFQ in 5390 men and women aged 45–84 years free of prevalent diabetes and clinical CVD. A MeDiet score was created based on the intake of ten food components: vegetables; whole grains; nuts; legumes; fruits; ratio of monounsaturated:saturated fat; red and processed meat; dairy products; fish; alcohol. Multivariable linear and proportional hazards models were used to estimate the association of the MeDiet, categorised in quintiles, with baseline insulin and glucose, and incident diabetes, respectively. The models were adjusted for demographic, physiological and behavioural characteristics. After multivariable adjustment, individuals with a higher MeDiet score had lower baseline mean insulin levels (Q1: 5·8 (95 % CI 5·6, 6·0) μmol/l; Q5: 4·8 (95 % CI 4·6, 5·0) μmol/l; P for trend < 0·0001). A higher MeDiet score was also associated with significantly lower glucose levels after basic adjustment, but was attenuated after adjustment for waist circumference. During the follow-up, 412 incident diabetes events accrued. The MeDiet was not significantly related to the risk of incident diabetes (P for trend = 0·64). In summary, greater consistency with a Mediterranean-style diet, reflected by a higher a priori MeDiet score, was cross-sectionally associated with lower insulin levels among non-diabetics, and with lower blood glucose before adjustment for obesity, but not with a lower incidence of diabetes.

An inverse association between alcohol consumption and risk of CHD in diverse populations has been reported in over forty prospective studies(1).

Certain dietary patterns may be related to the risk of CVD. We hypothesised that a plant-centred dietary pattern would be associated with a reduced risk of first myocardial infarction (MI). A case–control study of Norwegian men and postmenopausal women (age 45–75 years) was performed. A FFQ was administered, generally within 3 d after incident MI (n 106 cases). Controls (n 105) were frequency matched on sex, age and geographic location. On the FFQ, 190 items were categorised into thirty-five food groups and an a priori healthy diet pattern score was created. We estimated OR using logistic regression with adjustment for energy intake, family history of heart disease, marital status, current smoking, education and age. Among food groups, the risk of MI was significantly higher per sd of butter and margarine (OR 1·66 (95 % CI 1·12, 2·46)), and lower per sd of tomatoes (OR 0·53 (95 % CI 0·35, 0·79)), high-fat fish (OR 0·57 (95 % CI 0·38, 0·86)), wine (OR 0·58 (95 % CI 0·41, 0·83)), salad (OR 0·59 (95 % CI 0·40, 0·87)), wholegrain breakfast cereals (OR 0·64 (95 % CI 0·45, 0·90)), cruciferous vegetables (OR 0·66 (95 % CI 0·47, 0·93)) and non-hydrogenated vegetable oil (OR 0·68 (95 % CI 0·49, 0·95)). An abundance of cases were found to have a low a priori healthy diet pattern score. A dietary pattern emphasising nutrient-rich plant foods and high-fat fish and low in trans fatty acids was associated with decreased risk of MI among Norwegians.

We examined the relationship between whole grain intake and obesity, insulin resistance, inflammation, diabetes and subclinical CVD using baseline data from the Multi-Ethnic Study of Atherosclerosis. Whole grain intake was measured by a 127-item FFQ in 5496 men and women free of CHD and previously known diabetes. Mean whole grain intake was 0·5 (sd 0·5) servings per d; biochemical measures reflect fasting levels. After adjustment for demographic and health behaviour variables, mean differences for the highest quintile of whole grain intake minus the lowest quintile of intake were 0·6 kg/m2 for BMI, 0·36 mg/l for C-reactive protein, 0·82 μmol/l for homocysteine, 0·15 mU/l*mmol/l for homeostasis model assessment (HOMA), 0·48 mU/l for serum insulin, 2·0 mg/dl for glucose and 5·7 % for prevalence of newly diagnosed impaired fasting glucose (glucose ≥ 100 mg/dl or diabetes medication). These differences represent 11–13 % of a standard deviation of BMI, HOMA, glucose and impaired fasting glucose, but 23 %, 52 % and 80 % of a standard deviation of homocysteine, C-reactive protein and insulin, respectively. An inverse association between whole grains and urine albumin excretion was suggested but retained statistical significance after adjustment only in Chinese and Hispanic participants. No associations were observed between whole grain intake and two subclinical disease measures: carotid intima-media thickness and coronary artery calcification. Concordant with previous research, whole grain intake was inversely associated with obesity, insulin resistance, inflammation and elevated fasting glucose or newly diagnosed diabetes. Counter to hypothesis, however, whole grain intake was unrelated to subclinical CVD.

The epidemic of type 2 diabetes among children, adolescents and adults is increasing along with the increasing prevalence of overweight and obesity. Overweight is the most powerful modifiable risk factor for type 2 diabetes. Intake of whole-grain foods may reduce diabetes risk. Three prospective studies in 160 000 men and women examined the relationship of whole-grain or cereal-fibre intake with the risk of type 2 diabetes. Each study used a mailed Willett food-frequency questionnaire and similar methods of quantifying whole-grain foods and cereal fibre. The self-reported incident diabetes outcome was more reliably determined in the two studies of health-care professionals than in the study of Iowa women. Risk for incident type 2 diabetes was 21–27% lower for those in the highest quintile of whole-grain intake, and 30–36% lower in the highest quintile of cereal-fibre intake, each compared with the lowest quintile. Risk reduction persisted after adjustment for the healthier lifestyle found among habitual whole-grain consumers. Observations in non-diabetic individuals support an inverse relationship between whole-grain consumption and fasting insulin levels. In feeding studies in non-diabetic individuals insulin resistance was reduced using whole grains or diets rich in whole grains. Glucose control improved with diets rich in whole grains in feeding studies of subjects with type 2 diabetes. There is accumulating evidence to support the hypothesis that whole-grain consumption is associated with a reduced risk of incident type 2 diabetes; it may also improve glucose control in diabetic individuals.