Phylloquinone intake as a marker for coronary heart disease risk but not stroke in women

OBJECTIVE: To examine the feasibility of using phylloquinone intake as a marker for coronary heart disease (CHD) and stroke risk in women. DESIGN AND SETTING: Nurses' Health Study, a prospective cohort study during 1984-2000. Dietary data were collected in 1984, 1986, 1990, and 1994 using a validated semiquantitative food frequency questionnaire. SUBJECTS: A total of 72 874 female nurses, aged 38-65 y, without previously diagnosed angina, myocardial infarction (MI), stroke, or cancer at baseline. MAIN OUTCOME MEASURES: Incidence of nonfatal MI, CHD deaths, total CHD events, ischemic, and total strokes. RESULTS: There were 1679 CHD events (1201 nonfatal) and 1009 strokes (567 ischemic). After adjustment for age and lifestyle factors associated with cardiovascular disease risk, the multivariate relative risks (RR) (95% CI) of total CHD from the lowest to the highest quintile category of phylloquinone intake were 1 (reference), 0.80 (0.69-0.94), 0.86 (0.74-1.00), 0.77 (0.66-0.99), and 0.79 (0.68-0.92), P for trend=0.01. Further adjustment for dietary intakes of saturated fat, polyunsaturated fat, trans fatty acids, eicosapentaenoic, and docosahexaenoic acids, cereal fiber, and folate attenuated the association (RR comparing extreme quintiles 0.84 [0.71-1.00], P for trend=0.12). Incidence rates of total or ischemic strokes were not associated with phylloquinone intake. CONCLUSION: The data suggest that high phylloquinone intake may be a marker for low CHD risk. Dietary and lifestyle patterns associated with phylloquinone intakes, rather than intake of the nutrient itself, might account for all or part of the weak association. .     

Dietary folate intake, alcohol, and risk of breast cancer in a prospective study of postmenopausal women.

Low B-vitamin intake may increase risk of breast cancer through decreased DNA repair capacity. Alcohol intake increases risk for breast cancer, with evidence from prospective studies of an interaction between alcohol and folate. We explored dietary intake of folate and other B vitamins with risk of breast cancer in a cohort study of 34,387 postmenopausal women. To measure diet, we mailed a food frequency questionnaire; we estimated nutrient intakes and categorized them into four levels: <10th, 11th-30th, 31st-50th, and >50th percentiles. Through 12 years of follow-up, we identified 1,586 cases of breast cancer in the cohort at risk. We estimated relative risks (RRs) and 95% confidence intervals (CIs) through Cox regression models adjusted for age, energy, and other risk factors. Women in the lowest 10th percentile of folate intake from diet alone were at modestly increased risk of breast cancer relative to those above the 50th percentile: RR = 1.21 (95% CI = 0.91--1.61). We examined the joint association of folate intake and alcohol use on risk of breast cancer, with the reference group defined as women with high folate (>50th percentile) and no alcohol use. The RRs of breast cancer associated with low dietary folate intake were 1.08 (95% CI = 0.78--1.49) among nondrinkers, 1.33 (95% CI = 0.86--2.05) among drinkers of < or = 4 gm per day, and 1.59 (95% CI = 1.05--2.41) among drinkers of > 4 gm per day. These results suggest that the risks of postmenopausal breast cancer may be increased among women with low intakes of folate if they consume alcohol-containing beverages.     

Transient exposure to coffee as a trigger of a first nonfatal myocardial infarction

BACKGROUND: The effects of coffee on myocardial infarction are uncertain. We hypothesize that coffee in the presence of predisposing factors can induce a cascade of events that, through sympathetic nervous activation, can induce the onset of myocardial infarction. METHODS: We recruited 503 incident cases of nonfatal myocardial infarction between 1994 and 1998 in Costa Rica. We used a case-crossover design to calculate relative risks (RRs) and 95% confidence intervals (95% CIs). RESULTS: The RR of myocardial infarction in the hour after coffee intake was 1.49 (95% CI = 1.17-1.89). Occasional coffee drinkers (< or =1 cup/day, n = 103) had a RR of myocardial infarction of 4.14 (2.03-8.42), moderate coffee drinkers (2-3 cups/day, n = 280) had a RR of 1.60 (1.16-2.21), and heavy coffee drinkers (> or =4 cups/d, n = 120) had a RR of 1.06 (0.69-1.63; P = 0.006, test of homogeneity). Patients with 3 or more risk factors (n = 101) had a RR of myocardial infarction of 2.10 (1.30-3.39), whereas patients with fewer than 3 risk factors (n = 396) had a RR of 1.39 (1.04-1.82; P = 0.15, test of homogeneity); and RR was 1.72 (1.30-2.30) among sedentary patients compared with 1.07 (0.66-1.72) among nonsedentary (P = 0.10, test of homogeneity). CONCLUSIONS: The findings indicate that coffee intake may trigger myocardial infarction. The association is particularly strong among people with light/occasional intake of coffee (< or =1 cup/day), with sedentary lifestyle, or with 3 or more risk factors for coronary heart disease.     

Folate intake and pancreatic cancer risk: an overall and dose–response meta-analysis

Objective

Inconsistent findings of association between supplemental folate consumption and pancreatic cancer risk have been observed in the literature. This study aims to summarize the relationship between folate intake and risk of pancreatic cancer.

Study design

Pertinent studies published before November 2011 were identified by searching PubMed and Embase and by reviewing the reference lists of retrieved articles. The summary relative risks were estimated by the random effects model. A linear regression analysis of the natural logarithm of the relative risk (RR) was carried out to assess a possible dose–response relationship between folate intake and pancreatic cancer risk.

Results

Ten studies on dietary and supplemental folate intake and pancreatic cancer (4 case–control and 6 cohort studies) were included in the meta-analysis. The pooled RRs of pancreatic cancer for the highest vs lowest categories of dietary folate intake and supplemental folate intake were 0.66 (95% CI: 0.49–0.88) and 1.08 (95% CI, 0.82–1.41), respectively. The dose–response meta-analysis indicated that a 100 μg/day increment in dietary folate intake conferred a RR of 0.93 (95% CI: 0.90–0.97). These findings support the hypothesis that dietary folate may play a protective role in carcinogenesis of pancreatic cancer.     

Dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease among women

BACKGROUND: Experimental studies in laboratory animals and humans suggest that alpha-linolenic acid (18:3n-3) may reduce the risk of arrhythmia. OBJECTIVE: The objective was to examine the association between dietary intake of alpha-linolenic acid and risk of fatal ischemic heart disease (IHD). DESIGN: This was a prospective cohort study. The intake of alpha-linolenic acid was derived from a 116-item food-frequency questionnaire completed in 1984 by 76283 women without previously diagnosed cancer or cardiovascular disease. RESULTS: During 10 y of follow-up, we documented 232 cases of fatal IHD and 597 cases of nonfatal myocardial infarction. After adjustment for age, standard coronary risk factors, and dietary intake of linoleic acid and other nutrients, a higher intake of alpha-linolenic acid was associated with a lower relative risk (RR) of fatal IHD; the RRs from the lowest to highest quintiles were 1.0, 0.99, 0.90, 0.67, and 0.55 (95% CI: 0.32, 0.94; P for trend = 0.01). For nonfatal myocardial infarction there was only a modest, nonsignificant trend toward a reduced risk when extreme quintiles were compared (RR: 0.85; 95% CI: 0.61, 1.19; P for trend = 0.50). A higher intake of oil and vinegar salad dressing, an important source of alpha-linolenic acid, was associated with reduced risk of fatal IHD when women who consumed this food > or =5-6 times/wk were compared with those who rarely consumed this food (RR: 0.46; 95% CI: 0.27, 0.76; P for trend = 0.001). CONCLUSIONS: This study supports the hypothesis that a higher intake of alpha-linolenic acid is protective against fatal IHD. Higher consumption of foods such as oil-based salad dressing that provide polyunsaturated fats, including alpha-linolenic acid, may reduce the risk of fatal IHD.     

Inverse association of tea and flavonoid intakes with incident myocardial infarction: the Rotterdam Study

BACKGROUND: Dietary flavonoids may protect against cardiovascular disease, but evidence is still conflicting. Tea is the major source of flavonoids in Western populations. OBJECTIVE: The association of tea and flavonoid intake with incident myocardial infarction was examined in the general Dutch population. DESIGN: A longitudinal analysis was performed with the use of data from the Rotterdam Study-a population-based study of men and women aged >or=55 y. Diet was assessed at baseline (1990-1993) with a validated semiquantitative food-frequency questionnaire. The analysis included 4807 subjects with no history of myocardial infarction, who were followed until 31 December 1997. Data were analyzed in a Cox regression model, with adjustment for age, sex, body mass index, smoking status, pack-years of cigarette smoking, education level, and daily intakes of alcohol, coffee, polyunsaturated fat, saturated fat, fiber, vitamin E, and total energy. RESULTS: During 5.6 y of follow-up, a total of 146 first myocardial infarctions occurred, 30 of which were fatal. The relative risk (RR) of incident myocardial infarction was lower in tea drinkers with a daily intake >375 mL (RR: 0.57; 95% CI: 0.33, 0.98) than in nontea drinkers. The inverse association with tea drinking was stronger for fatal events (0.30; 0.09, 0.94) than for nonfatal events (0.68; 0.37, 1.26). The intake of dietary flavonoids (quercetin + kaempferol + myricetin) was significantly inversely associated only with fatal myocardial infarction (0.35; 0.13, 0.98) in upper compared with lower tertiles of intake. CONCLUSIONS: An increased intake of tea and flavonoids may contribute to the primary prevention of ischemic heart disease.     

Dietary fat and cholesterol and the risk of cardiovascular disease among women with type 2 diabetes

BACKGROUND: Nutritional therapy is a cornerstone of diabetes management, but no epidemiologic studies have investigated the relation between specific dietary fatty acids and cholesterol and cardiovascular disease (CVD) risk among diabetic patients. OBJECTIVE: This study assessed the relation between specific dietary fatty acids and cholesterol and CVD risk among women with type 2 diabetes. DESIGN: Among 5672 women with type 2 diabetes from the Nurses' Health Study, diet was assessed prospectively and updated periodically. Relative risks of CVD were estimated from Cox proportional hazards analysis after adjustment for potential confounders. RESULTS: Between 1980 and 1998, we identified 619 new cases of CVD (nonfatal myocardial infarction, fatal coronary heart disease, and stroke). The relative risk (RR) of CVD for an increase of 200 mg cholesterol/1000 kcal was 1.37 (95% CI: 1.12, 1.68; P = 0.003). Each 5% of energy intake from saturated fat, as compared with equivalent energy from carbohydrates, was associated with a 29% greater risk of CVD (RR: 1.29; 95% CI: 1.02, 1.63; P = 0.04). The ratio of polyunsaturated to saturated fat (P:S) was inversely associated with the risk of fatal CVD. We estimated that replacement of 5% of energy from saturated fat with equivalent energy from carbohydrates or monounsaturated fat was associated with a 22% or 37% lower risk of CVD, respectively. CONCLUSIONS: A higher intake of cholesterol and saturated fat and a low P:S were related to increased CVD risk among women with type 2 diabetes. Among diabetic persons, replacement of saturated fat with monounsaturated fat may be more effective in lowering CVD risk than is replacement with carbohydrates.     

Soy food consumption is associated with lower risk of coronary heart disease in Chinese women

Soy food intake has been shown to have beneficial effects on cardiovascular disease risk factors. Data directly linking soy food intake to clinical outcomes of cardiovascular disease, however, are sparse. We examined the relationship between soy food intake and incidence of coronary heart disease (CHD) among participants in the Shanghai Women's Health Study, a population-based prospective cohort study of approximately 75000 Chinese women aged 40-70 y at the baseline survey that was conducted from 1997 to 2000. Included in this study were 64915 women without previously diagnosed CHD, stroke, cancer and diabetes at baseline. Information on usual intake of soy foods was obtained at baseline through an in-person interview using a validated food-frequency questionnaire. Cohort members were followed biennially through in-person interviews. After a mean of 2.5 y (162277 person-years) of follow-up, 62 incident cases of CHD (43 nonfatal myocardial infarctions and 19 CHD deaths) were documented. There was a clear monotonic dose-response relationship between soy food intake and risk of total CHD (P for trend = 0.003) with an adjusted relative risk (RR) of 0.25 (95% CI, 0.10-0.63) observed for women in the highest vs. the lowest quartile of total soy protein intake. The inverse association was more pronounced for nonfatal myocardial infarction (RR = 0.14; 95% CI, 0.04-0.48 for the highest vs. the lowest quartile of intake; P for trend = 0.001). This study provides, for the first time, direct evidence that soy food consumption may reduce the risk of CHD in women.     

Fruit and vegetable intake and risk of cardiovascular disease: the Women's Health Study

BACKGROUND: Prospective data relating fruit and vegetable intake to cardiovascular disease (CVD) risk are sparse, particularly for women. OBJECTIVE: In a large, prospective cohort of women, we examined the hypothesis that higher fruit and vegetable intake reduces CVD risk. DESIGN: In 1993 we assessed fruit and vegetable intake among 39876 female health professionals with no previous history of CVD or cancer by use of a detailed food-frequency questionnaire. We subsequently followed these women for an average of 5 y for incidence of nonfatal myocardial infarction (MI), stroke, percutaneous transluminal coronary angioplasty, coronary artery bypass graft, or death due to CVD. RESULTS: During 195647 person-years of follow-up, we documented 418 incident cases of CVD including 126 MIs. After adjustment for age, randomized treatment status, and smoking, we observed a significant inverse association between fruit and vegetable intake and CVD risk. For increasing quintiles of total fruit and vegetable intake (median servings/d: 2. 6, 4.1, 5.5, 7.1, and 10.2), the corresponding relative risks (RRs) were 1.0 (reference), 0.78, 0.72, 0.68, and 0.68 (95% CI comparing the 2 extreme quintiles: 0.51, 0.92; P: for trend = 0.01). An inverse, though not statistically significant, trend remained after additional adjustment for other known CVD risk factors, with RRs of 1.0, 0.75, 0.83, 0.80, and 0.85 (95% CI for extreme quintiles: 0.61, 1.17). After excluding participants with a self-reported history of diabetes, hypertension, or high cholesterol at baseline, the multivariate-adjusted RR was 0.45 when extreme quintiles were compared (95% CI: 0.22, 0.91; P: for trend = 0.09). Higher fruit and vegetable intake was also associated with a lower risk of MI, with an adjusted RR of 0.62 for extreme quintiles (95% CI: 0.37, 1.04; P: for trend = 0.07). CONCLUSION: These data suggest that higher intake of fruit and vegetables may be protective against CVD and support current dietary guidelines to increase fruit and vegetable intake.     

Whole-grain consumption and risk of coronary heart disease: results from the Nurses' Health Study.

BACKGROUND: Although current dietary guidelines for Americans recommend increased intake of grain products to prevent coronary heart disease (CHD), epidemiologic data relating whole-grain intake to the risk of CHD are sparse. OBJECTIVE: Our objective was to evaluate whether high whole-grain intake reduces risk of CHD in women. DESIGN: In 1984, 75521 women aged 38-63 y with no previous history of cardiovascular disease or diabetes completed a detailed, semiquantitative food-frequency questionnaire (SFFQ) and were followed for 10 y, completing SFFQs in 1986 and 1990. We used pooled logistic regression with 2-y intervals to model the incidence of CHD in relation to the cumulative average diet from all 3 cycles of SFFQs. RESULTS: During 729472 person-years of follow-up, we documented 761 cases of CHD (208 of fatal CHD and 553 of nonfatal myocardial infarction). After adjustment for age and smoking, increased whole-grain intake was associated with decreased risk of CHD. For increasing quintiles of intake, the corresponding relative risks (RRs) were 1.0 (reference), 0.86, 0.82, 0.72, and 0.67 (95% CI comparing 2 extreme quintiles: 0.54, 0.84; P for trend < 0.001). After additional adjustment for body mass index, postmenopausal hormone use, alcohol intake, multivitamin use, vitamin E supplement use, aspirin use, physical activity, and types of fat intake, these RRs were 1.0, 0.92, 0.93, 0.83, and 0.75 (95% CI: 0.59, 0.95; P for trend = 0.01). The inverse relation between whole-grain intake and CHD risk was even stronger in the subgroup of never smokers (RR = 0. 49 for extreme quintiles; 95% CI: 0.30, 0.79; P for trend = 0.003). The lower risk associated with higher whole-grain intake was not fully explained by its contribution to intakes of dietary fiber, folate, vitamin B-6, and vitamin E. CONCLUSIONS: Increased intake of whole grains may protect against CHD.     

Dietary factors of one-carbon metabolism and prostate cancer risk

BACKGROUND: Folate is hypothesized to be inversely associated with the risk of several cancers, but such a potential association has not been well studied for prostate cancer. Vitamin B-6, vitamin B-12, methionine, and alcohol can influence folate-related metabolism. OBJECTIVE: The objective was to investigate the associations between dietary factors of one-carbon metabolism and prostate cancer risk within the alpha-Tocopherol, beta-Carotene Cancer Prevention Study. DESIGN: Of the cohort's 27 111 Finnish male smokers aged 50-69 y who had complete dietary data, 1270 had a diagnosis of incident prostate cancer between 1985 and 2002. Folate, vitamin B-6, vitamin B-12, methionine, and alcohol intakes were estimated from a 276-item modified dietary history questionnaire. Cox proportional hazard models, adjusted for age and vitamin supplement use, estimated relative risks (RR) and 95% CIs. RESULTS: Vitamin B-6 intake was inversely associated with prostate cancer risk (RR for highest versus lowest quintile: 0.88; 95% CI: 0.72, 1.07; P for trend = 0.045), whereas vitamin B-12 intake was associated with significantly increased risk (RR = 1.36; 95% CI: 1.14, 1.96; P for trend = 0.01). No association between folate or alcohol intake and prostate cancer risk was observed. No differences were found in the above associations according to stage of disease or subgroups of several potential effect modifiers. CONCLUSIONS: We found no convincing evidence for a protective role of one-carbon metabolism against prostate cancer, although these observations can be generalized only to smokers. The possible modest protective association with vitamin B-6 and the significantly elevated risk with vitamin B-12 intake warrant further investigation.     

Folate intake, serum homocysteine and methylenetetrahydrofolate reductase (MTHFR) C677T genotype are not associated with oral cancer risk in Puerto Rico

We examined the relationships between folate and methionine intake, serum homocysteine levels (as a biomarker for folate metabolism), and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism genotype and risk of oral cancer in a population-based, case-control study in Puerto Rico. Structured questionnaires were used to collect information on demographic factors, usual adult diet, and tobacco and alcohol use. Oral epithelial cells and blood samples were collected from a subset of subjects. Analyses were conducted by logistic regression, adjusting for age, sex, lifetime smoking and lifetime alcohol intake, with the following numbers of cases/controls, respectively: dietary data (341/521); MTHFR genotype (148/149); and homocysteine (60/90). Although increased folate intake was associated with decreased oral cancer risk [adjusted odds ratio (OR) in highest vs. lowest quartile = 0.6, 95% confidence interval (CI): 0.4, 1.0, P(trend) = 0.05)], this finding was due almost entirely to folate intake from fruit (adjusted OR = 0.4, 95% CI: 0.2, 0.6; P(trend) = 0.0001), whereas other dietary folate sources showed no clear association. Methionine intake and serum homocysteine levels were not associated with oral cancer risk. Subjects with the MTHFR C677T homozygous variant (TT) genotype had a nonsignificantly lower risk, and risk patterns tended to differ by level of folate, methionine, alcohol intake and smoking, although the power to detect significant associations in subgroups of these variables was low. Risks for oral cancer are not folate specific; preventive recommendations for this disease should emphasize the importance of a healthy diet, including substantial intake of fruits.     

Dietary intake of B(6-9-12) vitamins, serum homocysteine levels and their association with depressive symptoms: the Zutphen Elderly Study

OBJECTIVE: Low B-vitamin status and high levels of serum homocysteine are found in depressed inpatients, but results of population-based studies of this association are inconclusive. We investigated whether a low dietary intake of B(6-9-12) vitamins and high levels of serum homocysteine are associated with depressive symptoms in elderly men. METHODS: The study sample included a total of 332 men aged 70-90 years who were free from cardiovascular diseases and diabetes at baseline in 1990. Depressive symptoms were measured with the Zung Self-rating Depression Scale at baseline in 1990 and dietary factors with the crosscheck dietary history method in 1985 and 1990. Serum levels of homocysteine were obtained in 1985. Multiple linear and logistic regression analyses were performed. RESULTS: Dietary intake of folate (-1.19, 95% CI -2.03; -0.36) and vitamin B(6) (-2.09, 95% CI -2.92; -1.26) per standard deviation increase was associated with lower levels of serum homocysteine, while vitamin B(12) was not associated with serum homocysteine. Intake of folate, vitamin B(6), vitamin B(12) and levels of serum homocysteine were not related to depressive symptoms. CONCLUSIONS: Our results do not support the hypothesis that a low dietary intake of B(6-9-12) vitamins and high levels of serum homocysteine are related to depression in healthy elderly men.     

Intake of folate and related nutrients in relation to risk of epithelial ovarian cancer

Assessments of the relation between folate intake and ovarian cancer risk have been limited and inconsistent. Therefore, the authors prospectively examined the association of dietary and supplemental intakes of folate, methionine, and vitamin B(6) with ovarian cancer risk among 80,254 Nurses' Health Study participants. Beginning in 1976, women completed biennial questionnaires assessing ovarian cancer risk factors; starting in 1980, food frequency questionnaires were administered every 2-4 years. During 22 years of follow-up (1980-2002), the authors confirmed 481 incident epithelial ovarian cancers. There were no associations between total folate (top quintile vs. bottom: relative risk (RR) = 1.21, 95% confidence interval (CI): 0.92, 1.60), methionine (RR = 1.00, 95% CI: 0.76, 1.33), dietary vitamin B(6) (RR = 1.09, 95% CI: 0.81, 1.47), or total vitamin B(6) (RR = 1.13, 95% CI: 0.85, 1.51) intake and ovarian cancer risk. Higher dietary folate was associated with a modestly decreased risk after exclusion of cases diagnosed during the 4 follow-up years after dietary assessment (RR = 0.66, 95% CI: 0.43, 1.03) and for the serous subtype (RR = 0.51, 95% CI: 0.31, 0.84). Results did not vary by alcohol intake, multivitamin use, menopausal status, or oral contraceptive use. There was little evidence that folate, methionine, and vitamin B(6) are important in ovarian cancer risk, although dietary folate was inversely associated with risk in some analyses.     

Association between dietary folate intake and blood status of folate and homocysteine in Malaysian adults

Folate is of prime interest among investigators in nutrition due to its multiple roles in maintaining health, especially in preventing neural tube defects and reducing the risk of cardiovascular diseases. We investigated the effect of dietary folate intake on blood folate, vitamin B(12), vitamin B(6), and homocysteine status. One hundred subjects consisting of Chinese and Malay subjects volunteered to participate in this cross-sectional study. Dietary folate intake was assessed by 24-h dietary recall and a food-frequency questionnaire (FFQ). Serum and red blood cell folate were analyzed using a microbiological assay, while serum vitamin B(12) was determined by electrochemiluminescence immunoassay (ECLIA), and high-performance liquid chromatography (HPLC) was used for the determination of serum vitamin B(6) and homocysteine. The mean folate intake, serum folate, RBC folate, serum vitamin B(12), and B(6), were higher in female subjects, with the exception of serum homocysteine. The Chinese tended to have higher folate intake, serum folate, RBC folate, and vitamin B(12). A positive association was found between folate intake and serum folate while a negative association was found between folate intake and serum homocysteine. Stepwise linear regression of serum folate showed a significant positive coefficient for folate intake whilst a significant negative coefficient was found for serum homocysteine when controlling for age, gender, and ethnicity. In conclusion, high dietary folate intake helps to increase serum folate and to lower the homocysteine levels.     

Lead Exposure,B Vitamins,and Plasma Homocysteine in Men 55 Years of Age and Older: The VA Normative Aging Study

Background: Lead (Pb) exposure may influence the plasma concentration of homocysteine, a one-carbon metabolite associated with cardiovascular and neurodegenerative diseases. Little is known about the associations between Pb and homocysteine over time, or the potential influence of dietary factors.Objectives: We examined the longitudinal association of recent and cumulative Pb exposure with homocysteine concentrations and the potential modifying effect of dietary nutrients involved in one-carbon metabolism.Methods: In a subcohort of the Veterans Affairs (VA) Normative Aging Study (1,056 men with 2,301 total observations between 1993 and 2011), we used mixed-effects models to estimate differences in repeated measures of total plasma homocysteine across concentrations of Pb in blood and tibia bone, assessing recent and cumulative Pb exposure, respectively. We also assessed effect modification by dietary intake and plasma concentrations of folate, vitamin B₆, and vitamin B₁₂.Results: An interquartile range (IQR) increment in blood Pb (3 μg/dL) was associated with a 6.3% higher homocysteine concentration (95% CI: 4.8, 7.8%). An IQR increment in tibia bone Pb (14 μg/g) was associated with a 3.7% higher homocysteine (95% CI: 1.6, 5.6%), which was attenuated to 1.5% (95% CI: –0.5, 3.6%) after adjusting for blood Pb. For comparison, a 5-year increase in time from baseline was associated with a 5.7% increase in homocysteine (95% CI: 4.3, 7.1%). The association between blood Pb and homocysteine was significantly stronger among participants with estimated dietary intakes of vitamin B₆ and folate below (vs. above) the study population medians, which were similar to the U.S. recommended dietary allowance intakes.Conclusions: Pb exposure was positively associated with plasma homocysteine concentration. This association was stronger among men with below-median dietary intakes of vitamins B₆ and folate. These findings suggest that increasing intake of folate and B₆ might reduce Pb-associated increases in homocysteine, a risk factor for cardiovascular disease and neurodegeneration.Citation: Bakulski KM, Park SK, Weisskopf MG, Tucker KL, Sparrow D, Spiro A III, Vokonas PS, Nie LH, Hu H, Weuve J. 2014. Lead exposure, B vitamins, and plasma homocysteine in men 55 years of age and older: the VA Normative Aging Study. Environ Health Perspect 122:1066–1074; http://dx.doi.org/10.1289/ehp.1306931     

Magnesium intake and risk of coronary heart disease among men

OBJECTIVE: Our aim in this study was to assess the relationship between magnesium intake and risk of coronary heart disease (CHD) among men. METHODS: A total of 39,633 men in the Health Professionals Follow-up Study who returned a dietary questionnaire in 1986 were followed up for 12 years. Intakes of magnesium, zinc and potassium and other nutrients were assessed in 1986, 1990 and 1994. Total CHD incidence (nonfatal myocardial infarction (MI) and fatal CHD) was ascertained by biennial questionnaire and mortality surveillance confirmed by medical record review. Standard CHD risk factors were recorded biennially. RESULTS: During 12 years of follow-up (414,285 person-years), we documented 1,449 cases of total CHD (1,021 non-fatal MI cases, and 428 fatal CHD). The age-adjusted relative risk (RR) of developing CHD in the highest quintile (median intake = 457 mg/day) compared with the lowest quintile (median intake = 269 mg/day) was 0.73 (95% CI 0.62-0.87, p for trend <0.0001). After controlling for standard CHD risk factors and dietary factors, the RR for developing CHD among men in the highest total magnesium intake quintile compared with those in the lowest was 0.82 (95% CI 0.65-1.05, p for trend = 0.08). For supplemental magnesium intake, the RR comparing the highest quintile to non-supplement users was 0.77 (95% CI 0.56-1.06, p for trend = 0.14). CONCLUSIONS: These results suggest that intake of magnesium may have a modest inverse association with risk of CHD among men.     

Dietary fat intake and risk of coronary heart disease in women: 20 years of follow-up of the nurses' health study

The authors examined the associations of dietary fat and specific types of fat with risk of coronary heart disease (CHD) among 78,778 US women initially free of cardiovascular disease and diabetes in 1980. They documented 1,766 incident CHD cases (including 1,241 nonfatal myocardial infarctions and 525 CHD deaths) during 20 years of follow-up. Polyunsaturated fat intake was inversely associated with CHD risk (multivariate relative risk (RR) for the highest vs. the lowest quintile = 0.75, 95% confidence interval (CI): 0.60, 0.92; p(trend) = 0.004), whereas trans-fat intake was associated with an elevated risk of CHD (RR = 1.33, 95% CI: 1.07, 1.66; p(trend) = 0.01). The associations between intakes of polyunsaturated fat and trans-fat with CHD risk were most evident among women younger than age 65 years (for polyunsaturated fat, RR = 0.66, 95% CI: 0.50, 0.85; p(trend) = 0.002 and for trans-fat, RR = 1.50, 95% CI: 1.13, 2.00; p(trend) = 0.01). The inverse association between polyunsaturated fat intake and CHD risk was strongest among women whose body mass index was >or=25 kg/m(2). Findings continue to support an inverse relation between polyunsaturated fat intake and CHD risk, particularly among younger or overweight women. In addition, trans-fat intake was associated with increased risk of CHD, particularly for younger women.     

Childhood socioeconomic status and risk of cardiovascular disease in middle aged US women: a prospective study.

OBJECTIVE--To examine prospectively the relationship of childhood socioeconomic status and risk of cardiovascular disease in middle aged women. DESIGN--A prospective cohort of women with 14 years follow up data (1976-90). SUBJECTS--A total of 117,006 registered female nurses aged 30 to 55 years in 1976 and free of diagnosed coronary heart disease, stroke, and cancer at baseline. MAIN OUTCOME MEASURES--Incident fatal coronary heart disease, non-fatal myocardial infarction, and stroke (fatal and non-fatal). RESULTS--Low socioeconomic status in childhood was associated with a modestly increased risk of incident non-fatal myocardial infarction and total cardiovascular disease in adulthood. Compared with middle aged women from white collar childhood backgrounds, the age adjusted risk of total cardiovascular disease for women from blue collar backgrounds was 1.13 (95% CI 1.02, 1.24) and that of non-fatal myocardial infarction was 1.23 (95% CI 1.06, 1.42). No significant increase in risk was observed for stroke or fatal coronary heart disease. Adjustment for differences in family and personal past medical history, medication use, exercise, alcohol intake, diet, birth weight, being breastfed in infancy, and adult socioeconomic circumstance somewhat attenuated the increased risks observed for women from blue collar childhood socioeconomic backgrounds. In multivariate analysis, women whose fathers had been manual labourers had the highest relative risk of total coronary heart disease (RR = 1.53; 95% CI 1.09, 2.16) and non-fatal myocardial infarction (RR = 1.67; 95% CI 1.11, 2.53) when compared with women whose fathers had been employed in the professions. CONCLUSION--In this group lower childhood socioeconomic status was associated with a small but significant increase in the risk of total coronary heart disease as well as non-fatal myocardial infarction. For women from the most socioeconomically disadvantaged childhood backgrounds, the association is not explained by differences in a large number of cardiovascular risk factors, by differences in adult socioeconomic status, or by differences in indices of nutrition during gestation or infancy.     

Dietary iron and risk of myocardial infarction in the Rotterdam Study

Free iron has been implicated in lipid peroxidation and ischemic myocardial damage, and it has been suggested that iron is an independent risk factor for myocardial infarction. The authors investigated whether dietary iron is associated with an increased risk of fatal and nonfatal myocardial infarction in the Rotterdam Study, a community-based prospective cohort study of 7,983 elderly subjects in Rotterdam, the Netherlands. The study sample consisted of 4,802 participants who at baseline had no known history of myocardial infarction and for whom dietary data were available. From 1990 to 1996, 124 subjects had a myocardial infarction. No association was observed between total iron intake and risk of myocardial infarction after adjustment for age and sex (relative risk for the highest vs. the lowest tertile of intake = 0.89, 95% confidence interval (CI) 0.55-1.45, p for trend = 0.640). Heme iron intake was positively associated with risk of myocardial infarction (relative risk for the highest vs. the lowest tertile of intake = 1.83, 95% CI 1.16-2.91, p for trend = 0.008) after adjustment for age and sex, and this association persisted after multivariate adjustment (relative risk = 1.86, 95% CI 1.14-3.09, p for trend = 0.010). A distinction between fatal and nonfatal cases of myocardial infarction indicated that the association of heme iron with myocardial infarction was more pronounced in fatal cases. The results suggest that a high dietary heme iron intake is related to an increased risk of myocardial infarction and that it may specifically affect the rate of fatality from myocardial infarction.