Milk intake and incident stroke and CHD in populations of European descent: a Mendelian randomisation study

Higher milk intake has been associated with a lower stroke risk, but not with risk of CHD. Residual confounding or reverse causation cannot be excluded. Therefore, we estimated the causal association of milk consumption with stroke and CHD risk through instrumental variable (IV) and gene-outcome analyses. IV analysis included 29 328 participants (4611 stroke; 9828 CHD) of the European Prospective Investigation into Cancer and Nutrition (EPIC)-CVD (eight European countries) and European Prospective Investigation into Cancer and Nutrition-Netherlands (EPIC-NL) case-cohort studies. rs4988235, a lactase persistence (LP) SNP which enables digestion of lactose in adulthood was used as genetic instrument. Intake of milk was first regressed on rs4988235 in a linear regression model. Next, associations of genetically predicted milk consumption with stroke and CHD were estimated using Prentice-weighted Cox regression. Gene-outcome analysis included 777 024 participants (50 804 cases) from MEGASTROKE (including EPIC-CVD), UK Biobank and EPIC-NL for stroke, and 483 966 participants (61 612 cases) from CARDIoGRAM, UK Biobank, EPIC-CVD and EPIC-NL for CHD. In IV analyses, each additional LP allele was associated with a higher intake of milk in EPIC-CVD (β = 13·7 g/d; 95 % CI 8·4, 19·1) and EPIC-NL (36·8 g/d; 95 % CI 20·0, 53·5). Genetically predicted milk intake was not associated with stroke (HR per 25 g/d 1·05; 95 % CI 0·94, 1·16) or CHD (1·02; 95 % CI 0·96, 1·08). In gene-outcome analyses, there was no association of rs4988235 with risk of stroke (OR 1·02; 95 % CI 0·99, 1·05) or CHD (OR 0·99; 95 % CI 0·95, 1·03). Current Mendelian randomisation analysis does not provide evidence for a causal inverse relationship between milk consumption and stroke or CHD risk.

Substitution among milk and yogurt products and the risk of incident type 2 diabetes in the EPIC-NL cohort

Background

Higher dairy consumption has been associated with lower type 2 diabetes (T2D) risk, whereas dairy product subtypes appear to differ in their T2D risk association. We investigated whether replacing one type of milk or yogurt product with another is associated with T2D incidence.

Methods

Participants of the European Prospective Investigation into Cancer and Nutrition‐Netherlands (EPIC‐NL) cohort (n = 35 982) were included in the present study. Information on milk and yogurt consumption at baseline was obtained by a validated food frequency questionnaire. T2D cases were identified by self‐report or linkage to the hospital discharge registry, and validated by consulting the general practitioner. Multivariable Cox proportional hazard models were used to estimate associations.

Results

During a mean of 15 years of follow‐up, 1467 indecent T2D cases were validated. Median total milk and yogurt intake was 1.5 servings (25th percentile to 75th percentile: 0.8–2.4). After adjustment for demographic and cardiovascular risk factors, replacement of one serving (200 g) of whole‐fat milk [hazard ratio (HR) = 0.93, 95% confidence interval (CI) = 0.60–1.44], buttermilk (HR = 0.88, 95% CI = 0.58‐1.34), skimmed milk (HR = 0.87, 95% CI = 0.57–1.32) or skimmed fermented milk (HR = 0.99, 95% CI = 0.63–1.54) with whole‐fat yogurt was not associated with T2D risk. Substitutions among other milk and yogurt products were also not associated with T2D risk. Sensitivity analysis investigating T2D risk halfway follow‐up suggested a lower risk for substitutions with whole‐fat yogurt.

Conclusions

No evidence was found for the association between substitutions among milk and yogurt products and the risk of incident T2D, although we cannot exclude possible attenuation of results as a result of dietary changes over time. This analysis should be repeated in a population with a wider consumption range of whole‐fat yogurt.

The relation between healthy lifestyle changes and decrease in systemic inflammation in patients with stable cardiovascular disease

BACKGROUND AND AIMS

Pharmacological lowering of inflammation has proven effective in reducing recurrent cardiovascular event rates. Aim of the current study is to evaluate lifestyle changes (smoking cessation, weight loss, physical activity level increase, alcohol moderation, and a summary lifestyle improvement score) in relation to change in plasma C-reactive protein (CRP) concentration in patients with established cardiovascular disease.

METHODS

In total, 1794 patients from the UCC-SMART cohort with stable cardiovascular disease and CRP levels ≤10 mg/L, who returned for a follow-up study visit after median 9.9 years (IQR 5.4-10.8), were included. The relation between changes in smoking status, weight, physical activity, alcohol consumption, a summary lifestyle improvement score and change in plasma CRP concentration was evaluated with linear regression analyses.

RESULTS

Smoking cessation was related to a 0.40 mg/L decline in CRP concentration (β-coefficient -0.40; 95%CI -0.73,-0.07). Weight loss (per 1SD = 6.4 kg) and increase in physical activity (per 1 SD = 48 MET hours per week) were related to a decrease in CRP concentration (β-coefficients -0.25; 95%CI -0.33,-0.16 and -0.09; 95%CI -0.17,-0.01 per SD). Change in alcohol consumption was not related to CRP difference. Every point higher in the summary lifestyle improvement score was related to a decrease in CRP concentration of 0.17 mg/L (β-coefficient -0.17; 95%CI -0.26,-0.07).

CONCLUSIONS

Smoking cessation, increase in physical activity, and weight loss are related to a decrease in CRP concentration in patients with stable cardiovascular disease. Patients with the highest summary lifestyle improvement score have the most decrease in CRP concentration. These results may indicate that healthy lifestyle changes contribute to lowering systemic inflammation, potentially leading to a lower cardiovascular risk in patients with established cardiovascular disease.

Association of leukocyte DNA methylation changes with dietary folate and alcohol intake in the EPIC study

Background

There is increasing evidence that folate, an important component of one-carbon metabolism, modulates the epigenome. Alcohol, which can disrupt folate absorption, is also known to affect the epigenome. We investigated the association of dietary folate and alcohol intake on leukocyte DNA methylation levels in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Leukocyte genome-wide DNA methylation profiles on approximately 450,000 CpG sites were acquired with Illumina HumanMethylation 450K BeadChip measured among 450 women control participants of a case-control study on breast cancer nested within the EPIC cohort. After data preprocessing using surrogate variable analysis to reduce systematic variation, associations of DNA methylation with dietary folate and alcohol intake, assessed with dietary questionnaires, were investigated using CpG site-specific linear models. Specific regions of the methylome were explored using differentially methylated region (DMR) analysis and fused lasso (FL) regressions. The DMR analysis combined results from the feature-specific analysis for a specific chromosome and using distances between features as weights whereas FL regression combined two penalties to encourage sparsity of single features and the difference between two consecutive features.

Results

After correction for multiple testing, intake of dietary folate was not associated with methylation level at any DNA methylation site, while weak associations were observed between alcohol intake and methylation level at CpG sites cg03199996 and cg07382687, with q_val = 0.029 and q_val = 0.048, respectively. Interestingly, the DMR analysis revealed a total of 24 and 90 regions associated with dietary folate and alcohol, respectively. For alcohol intake, 6 of the 15 most significant DMRs were identified through FL.

Conclusions

Alcohol intake was associated with methylation levels at two CpG sites. Evidence from DMR and FL analyses indicated that dietary folate and alcohol intake may be associated with genomic regions with tumor suppressor activity such as the GSDMD and HOXA5 genes. These results were in line with the hypothesis that epigenetic mechanisms play a role in the association between folate and alcohol, although further studies are warranted to clarify the importance of these mechanisms in cancer.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0637-x) contains supplementary material, which is available to authorized users.

Fish consumption and risk of stroke, coronary heart disease, and cardiovascular mortality in a Dutch population with low fish intake

BACKGROUND/OBJECTIVES

Fish consumption of at least 1 portion/week is related to lower cardiovascular disease (CVD) risk. It is uncertain whether a less frequent intake is also beneficial and whether the type of fish matters. We investigated associations of very low intakes of total, fatty, and lean fish, compared with no fish intake, with 18-year incidences of stroke, coronary heart disease (CHD), and CVD mortality.

METHODS

Data were used from 34,033 participants, aged 20-70 years, of the EPIC-Netherlands cohort. Baseline (1993-1997) fish consumption was estimated using a food frequency questionnaire. We compared any fish consumption, <1 portion/week (<100 g) and ≥1 portion/week to non-fish consumption.

RESULTS

During 18 follow-up years, 753 stroke events, 2134 CHD events, and 540 CVD deaths occurred. Among the fish consumers (~92%) median intakes of total, lean, and fatty fish were 57.9, 32.9, and 10.7 g/week, respectively. Any fish consumption compared with non-consumption was not associated with incidences of stroke, CHD, MI, and CVD mortality. Furthermore, consumption of <1 portion/week of total, fatty, or lean fish was not associated with any CVD outcome, as compared with non-consumption. Consumption of ≥1 portion/week of lean fish (HR: 0.70, 95% CI: 0.57-0.86) and of fatty fish (HR: 0.63, 95% CI: 0.39-1.02) were associated with lower incidence of ischaemic stroke.

CONCLUSIONS

Baseline fish consumption of <1 portion/week, regardless of the type of fish, was unrelated to incidences of stroke, CHD, and CVD mortality in this Dutch cohort. Consumption of ≥1 portion/week of fatty or of lean fish reduced the incidence of ischaemic stroke.

Fluidity of the dietary fatty acid profile and risk of coronary heart disease and ischemic stroke: Results from the EPIC-Netherlands cohort study

BACKGROUND AND AIMS

The fluidity of dietary fatty acids consumed has been suggested to inversely affect coronary heart disease (CHD) risk. Lipophilic index (LI) represents overall fluidity of the dietary fatty acid profile. Lipophilic load (LL) represents a combination of overall fluidity and absolute intake of dietary fatty acids. We investigated the relations of dietary LI and LL with risk of CHD and ischemic stroke (iStroke).

METHODS AND RESULTS

We used data from the prospective EPIC-NL study, including 36,520 participants aged 20-70 years. LI and LL were calculated using dietary intake data estimated with a validated FFQ. Incident CHD (n = 2348) and iStroke (n = 479) cases were obtained through linkage to national registers during 15 years follow-up. LI and LL were not associated with CHD risk (HRs_{highest-versus-lowest-quartiles}: 0.93 [95%CI: 0.83, 1.04], and 0.92 [95%CI: 0.79, 1.07], respectively), and neither with iStroke risk (HRs 1.15 (95%CI: 0.89, 1.48), and 0.98 (95%CI: 0.70, 1.38), respectively). Original fatty acid classes (SFA, MUFA and PUFA), and LI and LL stratified by these fatty acid classes, were overall not related to CHD and ischemic stroke either.

CONCLUSIONS

In this Dutch population, neither the overall fluidity of the dietary fatty acid profile (LI), nor the combined fluidity and amount of fatty acids consumed (LL) were related to CHD or iStroke risk. Dietary LI and LL may have limited added value above original fatty acid classes and food sources in establishing the relation of fatty acid consumption with CVD.

Dietary intake of carotenoids and risk of type 2 diabetes

BACKGROUND AND AIMS

Carotenoids may reduce diabetes risk, due to their antioxidant properties. However, the association between dietary carotenoids intake and type 2 diabetes risk is still unclear. Therefore, the objective of this study was to examine whether higher dietary carotenoid intakes associate with reduced type 2 diabetes risk.

METHODS AND RESULTS

Data from 37,846 participants of the European Prospective Investigation into Cancer and Nutrition- Netherlands study were analyzed. Dietary intakes of β-carotene, α-carotene, β-cryptoxanthin, lycopene, lutein & zeaxanthin and the sum of these carotenoids were assessed using a validated food frequency questionnaire. Incident type 2 diabetes was mainly self-reported, and verified against general practitioner information. Mean ±SD total carotenoid intake was 10 ± 4 mg/day. During a mean ±SD follow-up of 10 ± 2 years, 915 incident cases of type 2 diabetes were ascertained. After adjustment for age, sex, diabetes risk factors, dietary intake, waist circumference and BMI, higher β-carotene intakes associated inversely with diabetes risk [Hazard Ratio quartile 4 versus quartile 1 (HR(Q4)): 0.78 (95%CI:0.64,0.95), P-linear trend 0.01]. For α-carotene, a borderline significant reduced risk was observed, with a HR(Q4) of 0.85 (95%CI:0.70,1.03), and P-linear trend 0.05. β-cryptoxanthin, lycopene, lutein & zeaxanthin, and the sum of all carotenoids did not associate with diabetes risk.

CONCLUSIONS

This study shows that diets high in β-carotene and α-carotene are associated with reduced type 2 diabetes in generally healthy men and women.

Consumption of fatty foods and incident type 2 diabetes in populations from eight European countries

BACKGROUND/OBJECTIVES

Diets high in saturated and trans fat and low in unsaturated fat may increase type 2 diabetes (T2D) risk, but studies on foods high in fat per unit weight are sparse. We assessed whether the intake of vegetable oil, butter, margarine, nuts and seeds and cakes and cookies is related to incident T2D.

SUBJECTS/METHODS

A case-cohort study was conducted, nested within eight countries of the European Prospective Investigation into Cancer (EPIC), with 12,403 incident T2D cases and a subcohort of 16,835 people, identified from a cohort of 340,234 people. Diet was assessed at baseline (1991-1999) by country-specific questionnaires. Country-specific hazard ratios (HRs) across four categories of fatty foods (nonconsumers and tertiles among consumers) were combined with random-effects meta-analysis.

RESULTS

After adjustment not including body mass index (BMI), nonconsumers of butter, nuts and seeds and cakes and cookies were at higher T2D risk compared with the middle tertile of consumption. Among consumers, cakes and cookies were inversely related to T2D (HRs across increasing tertiles 1.14, 1.00 and 0.92, respectively; P-trend <0.0001). All these associations attenuated upon adjustment for BMI, except the higher risk of nonconsumers of cakes and cookies (HR 1.57). Higher consumption of margarine became positively associated after BMI adjustment (HRs across increasing consumption tertiles: 0.93, 1.00 and 1.12; P-trend 0.03). Within consumers, vegetable oil, butter and nuts and seeds were unrelated to T2D.

CONCLUSIONS

Fatty foods were generally not associated with T2D, apart from weak positive association for margarine. The higher risk among nonconsumers of cakes and cookies needs further explanation.

Association between dietary meat consumption and incident type 2 diabetes: the EPIC-InterAct study

AIMS/HYPOTHESIS

A diet rich in meat has been reported to contribute to the risk of type 2 diabetes. The present study aims to investigate the association between meat consumption and incident type 2 diabetes in the EPIC-InterAct study, a large prospective case-cohort study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

METHODS

During 11.7 years of follow-up, 12,403 incident cases of type 2 diabetes were identified among 340,234 adults from eight European countries. A centre-stratified random subsample of 16,835 individuals was selected in order to perform a case-cohort design. Prentice-weighted Cox regression analyses were used to estimate HR and 95% CI for incident diabetes according to meat consumption.

RESULTS

Overall, multivariate analyses showed significant positive associations with incident type 2 diabetes for increasing consumption of total meat (50 g increments: HR 1.08; 95% CI 1.05, 1.12), red meat (HR 1.08; 95% CI 1.03, 1.13) and processed meat (HR 1.12; 95% CI 1.05, 1.19), and a borderline positive association with meat iron intake. Effect modifications by sex and class of BMI were observed. In men, the results of the overall analyses were confirmed. In women, the association with total and red meat persisted, although attenuated, while an association with poultry consumption also emerged (HR 1.20; 95% CI 1.07, 1.34). These associations were not evident among obese participants.

CONCLUSIONS/INTERPRETATION

This prospective study confirms a positive association between high consumption of total and red meat and incident type 2 diabetes in a large cohort of European adults.

Fruit and vegetable intake and type 2 diabetes: EPIC-InterAct prospective study and meta-analysis

Fruit and vegetable intake (FVI) may reduce the risk of type 2 diabetes (T2D), but the epidemiological evidence is inconclusive. The aim of this study is to examine the prospective association of FVI with T2D and conduct an updated meta-analysis. In the European Prospective Investigation into Cancer-InterAct (EPIC-InterAct) prospective case-cohort study nested within eight European countries, a representative sample of 16,154 participants and 12,403 incident cases of T2D were identified from 340,234 individuals with 3.99 million person-years of follow-up. For the meta-analysis we identified prospective studies on FVI and T2D risk by systematic searches of MEDLINE and EMBASE until April 2011. In EPIC-InterAct, estimated FVI by dietary questionnaires varied more than twofold between countries. In adjusted analyses the hazard ratio (95% confidence interval) comparing the highest with lowest quartile of reported intake was 0.90 (0.80-1.01) for FVI; 0.89 (0.76-1.04) for fruit and 0.94 (0.84-1.05) for vegetables. Among FV subtypes, only root vegetables were inversely associated with diabetes 0.87 (0.77-0.99). In meta-analysis using pooled data from five studies including EPIC-InterAct, comparing the highest with lowest category for FVI was associated with a lower relative risk of diabetes (0.93 (0.87-1.00)). Fruit or vegetables separately were not associated with diabetes. Among FV subtypes, only green leafy vegetable (GLV) intake (relative risk: 0.84 (0.74-0.94)) was inversely associated with diabetes. Subtypes of vegetables, such as root vegetables or GLVs may be beneficial for the prevention of diabetes, while total FVI may exert a weaker overall effect.

Design and cohort description of the InterAct Project: an examination of the interaction of genetic and lifestyle factors on the incidence of type 2 diabetes in the EPIC Study

AIMS/HYPOTHESIS

Studying gene-lifestyle interaction may help to identify lifestyle factors that modify genetic susceptibility and uncover genetic loci exerting important subgroup effects. Adequately powered studies with prospective, unbiased, standardised assessment of key behavioural factors for gene-lifestyle studies are lacking. This case-cohort study aims to investigate how genetic and potentially modifiable lifestyle and behavioural factors, particularly diet and physical activity, interact in their influence on the risk of developing type 2 diabetes.

METHODS

Incident cases of type 2 diabetes occurring in European Prospective Investigation into Cancer and Nutrition (EPIC) cohorts between 1991 and 2007 from eight of the ten EPIC countries were ascertained and verified. Prentice-weighted Cox regression and random-effects meta-analyses were used to investigate differences in diabetes incidence by age and sex.

RESULTS

A total of 12,403 verified incident cases of type 2 diabetes occurred during 3.99 million person-years of follow-up of 340,234 EPIC participants eligible for InterAct. We defined a centre-stratified subcohort of 16,154 individuals for comparative analyses. Individuals with incident diabetes who were randomly selected into the subcohort (n = 778) were included as cases in the analyses. All prevalent diabetes cases were excluded from the study. InterAct cases were followed-up for an average of 6.9 years; 49.7% were men. Mean baseline age and age at diagnosis were 55.6 and 62.5 years, mean BMI and waist circumference values were 29.4 kg/m(2) and 102.7 cm in men, and 30.1 kg/m(2) and 92.8 cm in women, respectively. Risk of type 2 diabetes increased linearly with age, with an overall HR of 1.56 (95% CI 1.48-1.64) for a 10 year age difference, adjusted for sex. A male excess in the risk of incident diabetes was consistently observed across all countries, with a pooled HR of 1.51 (95% CI 1.39-1.64), adjusted for age.

CONCLUSIONS/INTERPRETATION

InterAct is a large, well-powered, prospective study that will inform our understanding of the interplay between genes and lifestyle factors on the risk of type 2 diabetes development.

Ascertainment and verification of diabetes in the EPIC-NL study

BACKGROUND

The objectives of this study were to describe in detail the ascertainment and verification of prevalent and incident diabetes in the Dutch contributor to the European Prospective Investigation into Cancer and Nutrition (EPIC-NL cohort) and to examine to what extent ascertained diabetes agreed with general practitioner (GP) and pharmacy records.

METHODS

In total, 40,011 adults, aged 21 to 70 years at baseline, were included. Diabetes was ascertained via self-report, linkage to registers of hospital discharge diagnoses (HDD) and a urinary glucose strip test. Ascertained diabetes cases were verified against GP or pharmacist information using mailed questionnaires.

RESULTS

At baseline, 795 (2.0%) diabetes cases were ascertained, and 1494 (3.7%) during a mean follow-up of ten years. The majority was ascertained via self-report only (56.7%), or self-report in combination with HDD (18.0%). After verification of ascertained diabetes cases, 1532 (66.9%) [corrected] were defined as having diabetes , 495 (21.6%) as non-diabetic individuals, and 262 (11.5%) as uncertain. Of the 1538 cases ascertained by self-report, 1350 (positive predictive value: 87.8%) were confirmed by GP or pharmacist. Cases ascertained via self-report in combination with HDD were most often confirmed (334 (positive predictive value: 96.0%)).

CONCLUSIONS

Two out of three ascertained diabetes cases were confirmed to have been diagnosed with diabetes by their GP or pharmacist. Diabetes cases ascertained via self-report in combination with HDD had the highest confirmation.

A high menaquinone intake reduces the incidence of coronary heart disease

BACKGROUND AND AIM

Vitamin K dependent proteins have been demonstrated to inhibit vascular calcification. Data on the effect of vitamin K intake on coronary heart disease (CHD) risk, however, are scarce. To examine the relationship between dietary vitamins K(1) and K(2) intake, and its subtypes, and the incidence of CHD.

METHODS AND RESULTS

We used data from the Prospect-EPIC cohort consisting of 16,057 women, enrolled between 1993 and 1997 and aged 49-70 years, who were free of cardiovascular diseases at baseline. Intake of vitamin K and other nutrients was estimated with a food frequency questionnaire. Multivariate Cox proportional hazards models were used to analyse the data. After a mean+/-SD follow-up of 8.1+/-1.6 years, we identified 480 incident cases of CHD. Mean vitamin K(1) intake was 211.7+/-100.3 microg/d and vitamin K(2) intake was 29.1+/-12.8 microg/d. After adjustment for traditional risk factors and dietary factors, we observed an inverse association between vitamin K(2) and risk of CHD with a Hazard Ratio (HR) of 0.91 [95% CI 0.85-1.00] per 10 microg/d vitamin K(2) intake. This association was mainly due to vitamin K(2) subtypes MK-7, MK-8 and MK-9. Vitamin K(1) intake was not significantly related to CHD.

CONCLUSIONS

A high intake of menoquinones, especially MK-7, MK-8 and MK-9, could protect against CHD. However, more research is necessary to define optimal intake levels of vitamin K intake for the prevention of CHD.