Relation between a diet with a high glycemic load and plasma concentrations of high-sensitivity C-reactive protein in middle-aged women

BACKGROUND: Recent prospective data suggest that intake of rapidly digested and absorbed carbohydrates with a high dietary glycemic load is associated with an increased risk of ischemic heart disease. OBJECTIVE: We examined whether a high dietary glycemic load was associated with elevated hs-CRP concentrations and whether this association was modified by body mass index (BMI; in kg/m(2)). DESIGN: In 244 apparently healthy women, we measured plasma hs-CRP concentrations and determined average dietary glycemic loads with a validated semiquantitative food-frequency questionnaire. Using multiple regression models, we evaluated the association between dietary glycemic load and plasma hs-CRP after adjusting for age; treatment status; smoking status; BMI; physical activity level; parental history of myocardial infarction; history of hypertension, diabetes, and high cholesterol; postmenopausal hormone use; alcohol intake; and other dietary variables. RESULTS: We found a strong and statistically significant positive association between dietary glycemic load and plasma hs-CRP. The median hs-CRP concentration for the lowest quintile of dietary glycemic load was 1.9 mg/L and for the highest quintile was 3.7 mg/L; corresponding multivariate-adjusted geometric means were 1.4 and 3.8 mg/L, respectively (P for trend < 0.01). This association was significantly modified by BMI. Among women with a BMI greater-than-or-equal 25, the multivariate-adjusted geometric mean hs-CRP concentration in the lowest quintile was 1.6 mg/L and in the highest quintile was 5.0 mg/L; however, among women with a BMI < 25, the corresponding means were 1.1 and 3.1 mg/L, respectively (P = 0.01 for interaction). CONCLUSIONS: Dietary glycemic load is significantly and positively associated with plasma hs-CRP in healthy middle-aged women, independent of conventional risk factors for ischemic heart disease. Exacerbation of the proinflammatory process may be a mechanism whereby a high intake of rapidly digested and absorbed carbohydrates increases the risk of ischemic heart disease, especially in overweight women prone to insulin resistance.     

Maternal plasma phospholipid polyunsaturated fatty acids in pregnancy with and without gestational diabetes mellitus: relations with maternal factors.

BACKGROUND: The fatty acids arachidonic acid (AA; 20:4n-6) and docosahexaenoic acid (DHA; 22:6n-3) are essential for fetal growth and development, but their metabolism may be altered in insulin resistance. OBJECTIVES: The objectives were to determine maternal plasma phospholipid polyunsaturated fatty acid concentrations in pregnant women receiving dietary therapy for gestational diabetes mellitus (GDM) and to identify maternal factors associated with plasma phospholipid AA and DHA concentrations in the third trimester. DESIGN: Fasting plasma phospholipid fatty acids were determined in women with GDM (n = 15) receiving dietary therapy only and in healthy, pregnant women without GDM (control group, n = 15) at 27-30, 33-35, and 36-39 wk gestation. RESULTS: Maternal plasma phospholipid (as % by wt of total fatty acids and mg/L) linoleic acid (18:2n-6), AA, and 22:5n-6 concentrations did not differ significantly between women with GDM and control subjects. The other n-6 long-chain polyunsaturated fatty acids (% by wt) were lower in GDM subjects than in control subjects. Plasma phospholipid (expressed as % by wt and mg/L) linolenic acid (18:3n-3) and summed precursors of DHA were lower and DHA (% by wt and mg/L), adjusted for dietary DHA intake, was 13% higher in GDM subjects than in control subjects. Maternal blood hemoglobin A1C was inversely related to plasma phospholipid AA (% by wt) (r = -0.56, P = 0.03) in control subjects and positively associated with plasma phospholipid AA (% by wt) in women with GDM (r = 0.76, P = 0.001). Pregravid body mass index was negatively associated with plasma phospholipid DHA (% by wt) in control subjects (r = -0.55, P = 0.04) and in women with GDM with a body mass index (in kg/m2) <30 (r = -0.76, P = 0.007). CONCLUSIONS: This is the first report documenting alterations in maternal plasma phospholipid PUFAs in pregnant women receiving dietary therapy for GDM. In pregnant woman, both with and without GDM, maternal glycemic control and pregravid BMI appear to be significant predictors of plasma phospholipid AA and DHA, respectively, during the third trimester. Additionally, dietary DHA significantly affects phospholipid DHA concentrations.     

Alcohol intake and methylenetetrahydrofolate reductase polymorphism modify the relation of folate intake to plasma homocysteine

BACKGROUND: Folate intake increases plasma folate and reduces total homocysteine (tHcy) concentrations, which may lower coronary artery disease (CAD) and cancer risks. Folate metabolism may be altered by alcohol intake and 2 common polymorphisms in the methylenetetrahydrofolate reductase (MTHFR) gene, 677C-->T and 1298A-->C. OBJECTIVE: We examined whether the associations between folate intake and plasma folate and tHcy concentrations were modified by alcohol intake or variations in the MTHFR gene. DESIGN: We conducted a cross-sectional analysis among 988 women by using multivariate linear regression models to estimate mean plasma tHcy and folate concentrations. Folate intake was the sum of food and supplemental sources. RESULTS: We observed an inverse association between folate intake and tHcy, which was modified by alcohol intake (P for interaction = 0.04) and MTHFR677 genotype (P for interaction = 0.05) but not by MTHFR1298 genotype (P for interaction = 0.97). In the lowest quintile of folate intake, moderate drinkers (>/=15 g alcohol/d) had significantly higher tHcy concentrations (15.2 +/- 2.9 nmol/mL) than did light drinkers (11.3 +/- 0.7 nmol/mL) and nondrinkers (11.0 +/- 0.8 nmol/mL). However, the reduction in tHcy between the highest and lowest quintiles of folate intake was significantly greater in moderate drinkers (-6.6 nmol/mL) than in light drinkers (-2.3 nmol/mL) and nondrinkers (-2.1 nmol/mL). The elevated tHcy in women with low folate intake who also consumed moderate amounts of alcohol was even higher (22.4 +/- 4.8 nmol/mL) in the presence of the variant MTHFR677 allele. The positive association between folate intake and plasma folate was somewhat modified by alcohol intake (P for interaction = 0.08) but not by either MTHFR genotype. CONCLUSIONS: Moderate alcohol intake and low MTHFR activity have adverse effects on tHcy, but those effects may be overcome by sufficient folate intake.     

Interaction between dietary fat intake and the cholesterol ester transfer protein TaqIB polymorphism in relation to HDL-cholesterol concentrations among US diabetic men

BACKGROUND: A low plasma HDL-cholesterol concentration is a major characteristic of diabetic dyslipidemia. HDL concentrations are determined by both environmental factors and genetic factors. Cholesterol ester transfer protein (CETP) plays an important role in the regulation of HDL metabolism, and the TaqIB polymorphism of the CETP gene has been associated with elevated HDL concentrations. OBJECTIVE: We examined the association between the CETP TaqIB polymorphism and plasma HDL concentrations and evaluated whether this association was modified by dietary fat intake. DESIGN: We followed 780 diabetic men aged 40-75 y who participated in the Health Professionals Follow-Up Study since its initiation in 1986. The participants had confirmed type 2 diabetes and were free of cardiovascular disease at the time blood was drawn. RESULTS: After adjustment for age, smoking, alcohol consumption, fasting status, hemoglobin A(1c), physical activity, total energy intake, and body mass index, HDL concentrations were significantly higher in men with the B2B2 or B1B2 genotype than in those with the B1B1 genotype (adjusted x +/- SE: 37.9 +/- 0.02, 40.3 +/- 0.01, and 42.6 +/- 0.02 mg/dL for B1B1, B1B2, and B2B2, respectively; P for trend = 0.0004). This inverse association of the B1 allele with plasma HDL concentrations existed for those with a high consumption of animal fat (P for interaction = 0.02), saturated fat (P for interaction = 0.02), and monounsaturated fat (P for interaction = 0.04). CONCLUSION: These data confirmed a significant effect of the CETP Taq1 gene on HDL concentrations and suggested a potential interaction between the CETP TaqIB polymorphism and intake of dietary fat on plasma HDL concentration.     

The relation of diet, cigarette smoking, and alcohol consumption to plasma beta-carotene and alpha-tocopherol levels

The relation of diet and nutritional supplements, cigarette use, alcohol consumption, and blood lipids to plasma levels of beta-carotene and alpha-tocopherol was studied among 330 men and women aged 18-79 years. Dietary carotene, preformed vitamin A, and vitamin E intake were estimated by a self-administered semiquantitative food frequency questionnaire. The correlation of dietary carotene with plasma beta-carotene was reduced in smokers compared with nonsmokers (r = 0.02 vs. 0.44 among men; r = 0.19 vs. 0.45 among women). Smokers had much lower plasma levels of beta-carotene than did nonsmokers (geometric mean 8.5 vs. 15.3 micrograms/dl for men; 17.3 vs. 26.3 micrograms/dl for women) despite only slightly lower intakes of carotenoids. In multiple regression analyses, men who smoked one pack per day had 72% (95% confidence interval (CI) 58-89) of the plasma beta-carotene levels of nonsmokers after accounting for dietary carotene and other variables; for women, the corresponding percentage was 79% (CI 64-99). In similar models, men drinking 20 g of alcohol per day had 76% (CI 65-88) of the beta-carotene levels of nondrinkers; women had 89% (CI 73-108) of the levels of nondrinkers. An interaction term for carotene intake and smoking was statistically significant in a model combining both sexes. These results suggest that plasma levels of beta-carotene among smokers and, perhaps, heavy consumers of alcohol may be reduced substantially below levels due to differences in diet. The correlation of calorie-adjusted intake of vitamin E with lipid-adjusted plasma levels of vitamin alpha-tocopherol was 0.53 for men (n = 137) and 0.51 for women (n = 193) and did not differ by alcohol consumption and cigarette use; these correlations were largely accounted for by use of vitamin supplements. In linear regression models, vitamin E intake and plasma lipids were significant predictors of plasma alpha-tocopherol levels.     

Moderate alcohol consumption is more cardioprotective in men with the metabolic syndrome

The aim of the present study was to evaluate the relation among alcohol consumption, the metabolic syndrome, and the risk of ischemic heart disease (IHD). The study was conducted in a cohort of 1966 men from the Quebec Cardiovascular Study. All men were initially free of IHD and, during the follow-up period of 13 y, 219 first cases of IHD were diagnosed. Alcohol consumption was determined by calculating the g/d intake based on standard portions of beer, wine, and spirits. Metabolic syndrome was diagnosed according to a modification of the National Cholesterol Education Program Adult Treatment Panel III definition. Men who consumed >or=15.2 g of alcohol/d (4th quartile of the distribution) were younger (P < 0.001), had elevated plasma HDL-C concentrations (P < 0.001), and lower plasma concentrations of insulin (P = 0.01), CRP (P = 0.01), and fibrinogen (P < 0.001) than men in the 1st quartile (<1.3 g of alcohol/d). After adjustment for a series of coronary risk factors, alcohol consumption >or=15.2 g/d was associated with a 39% reduction in the 13-y risk of IHD [relative risk (RR) of IHD = 0.61, P = 0.02]. Finally, an alcohol consumption <15.2 g/d was associated with an increase of the risk of IHD in men with the metabolic syndrome (RR = 2.24, P < 0.001) but not in men without the metabolic syndrome (RR = 1.31, P = 0.22). These results confirm that moderate daily alcohol consumption has cardioprotective properties and suggest that the effects may be more important in subjects with a deteriorated risk profile, such as those with the metabolic syndrome.     

Plasma lycopene concentrations in humans are determined by lycopene intake, plasma cholesterol concentrations and selected demographic factors

Higher plasma lycopene concentrations have been associated with a reduced risk of several chronic diseases. Determinants of lycopene concentrations in humans have received limited attention. We had blood lycopene concentrations and lycopene consumption data available from 111 participants in a two-center cancer prevention trial involving beta-carotene and examined determinants of plasma lycopene levels cross-sectionally. The median plasma lycopene level was 0.59 micromol/L (range 0.07-1.79). Low plasma concentrations of lycopene were associated with the following variables in univariate analyses: study site (Florida lower than Connecticut, P = 0.001), being nonmarried (P = 0.02), having lower income (P = 0.003), being nonwhite race/ethnicity (P = 0.03), having lower dietary lycopene intake (r = 0.29, P = 0.002), having lower plasma cholesterol (r = 0. 43, P = 0.0001) and triglyceride levels (r = 0.26, P = 0.005), and consuming less vitamin C (r = 0.20, P = 0.03). Women had slightly higher plasma lycopene levels than men (0.65 vs. 0.58 micromol/L; P = 0.31), despite lower dietary intake of lycopene (1,040 vs. 1,320 microg/d; P = 0.50). Plasma lycopene levels did not differ in smokers and nonsmokers. In stepwise regression analyses, the determinants of plasma lycopene were plasma cholesterol, dietary lycopene, and marital status; these three variables explained 26% of the variance in plasma lycopene. Relatively few lifestyle and demographic factors were important determinants of plasma lycopene levels, with plasma cholesterol, marital status, and lycopene intake being of greatest importance.     

Association between B vitamin intake and plasma homocysteine concentration in the general Dutch population aged 20-65 y

BACKGROUND: An elevated plasma total homocysteine (tHcy) concentration is associated with an increased risk of cardiovascular diseases. Folate, riboflavin, vitamin B-6, and vitamin B-12 are essential in homocysteine metabolism. OBJECTIVE: The objective was to describe the association between dietary intakes of folate, riboflavin, vitamin B-6, and vitamin B-12 and the nonfasting plasma tHcy concentration. DESIGN: A random sample of 2435 men and women aged 20-65 y from a population-based Dutch cohort examined in 1993-1996 was analyzed cross-sectionally. RESULTS: Univariately, intakes of all B vitamins were inversely related to the plasma tHcy concentration. In multivariate models, only folate intake remained inversely associated with the plasma tHcy concentration. Mean plasma tHcy concentrations (adjusted for intakes of riboflavin, vitamin B-6, vitamin B-12, and methionine and for age, smoking, and alcohol consumption) in men with low (first quintile: 161 microg/d) and high (fifth quintile: 254 microg/d) folate intakes were 15.4 and 13.2 micromol/L, respectively; in women, plasma tHcy concentrations were 13.7 and 12.4 micromol/L at folate intakes of 160 and 262 microg/d, respectively. In men, the difference in the mean plasma tHcy concentration between men with low and high folate intakes was greater in smokers than in nonsmokers (2.8 compared with 1.6 micromol/L) and greater in nondrinkers than in drinkers of >2 alcoholic drinks/d (3.5 compared with 1.4 micromol/L). In women, the association between folate intake and plasma tHcy was not modified by smoking or alcohol consumption. CONCLUSIONS: In this Dutch population, folate was the only B vitamin independently inversely associated with the plasma tHcy concentration. Changing dietary habits may substantially influence the plasma tHcy concentration in the general population.     

The total antioxidant capacity of the diet is an independent predictor of plasma beta-carotene

OBJECTIVE: To investigate the contribution of the total antioxidant capacity (TAC) of the diet to plasma concentrations of beta-carotene. DESIGN: Cross-sectional study. SETTING: Department of Public Health and Department of Internal Medicine and Biomedical Sciences, University of Parma. SUBJECTS: A total of 247 apparently healthy adult men (n=140) and women (n=107). METHODS: A medical history, a physical exam including height, weight, waist circumference and blood pressure measurements, a fasting blood draw, an oral glucose tolerance test and a 3-day food record. RESULTS: We observe a negative trend across quartiles of plasma beta-carotene for most biological variables clustering in the insulin resistance syndrome, as well as for traditional and new risk factors for type II diabetes and cardiovascular disease (CVD), including C-reactive protein and gamma-glutamyltranspeptidase (P<0.05). Regarding dietary characteristics, energy-adjusted intake of fat, fiber, fruits, vegetables, beta-carotene, vitamin C, vitamin E and dietary TAC significantly increased with increasing plasma beta-carotene (P<0.05), whereas alcohol intake decreased (P=0.013). Adjusted geometric means (95% confidence interval) of plasma beta-carotene significantly increased across quartiles of dietary TAC, even when single dietary antioxidants were considered in the model (QI=0.087 mg/dl (0.073-0.102); QII=0.087 mg/dl (0.075-0.103); QIII=0.114 mg/dl (0.098-0.132) and QIV=0.110 mg/dl (0.093-0.130); P for linear trend=0.026). When the population was divided on the basis of alcohol consumption, this trend was also observed in subjects drinking <20 g alcohol/day (P=0.034), but not in those with higher alcohol intake (P=0.448). CONCLUSIONS: Dietary TAC is an independent predictor of plasma beta-carotene, especially in moderate alcohol drinkers. This may explain, at least in part, the inverse relationship observed between plasma beta-carotene and risk of chronic diseases associated to high levels of oxidative stress (i.e., diabetes and CVD), as well as the failure of beta-carotene supplements alone in reducing such risk.     

Homocysteine,cardiovascular disease risk factors,and habitual diet in the French Supplementation with Antioxidant Vitamins and Minerals Study

BACKGROUND: An elevated plasma total homocysteine (tHcy) concentration seems to increase the risk of cardiovascular disease. OBJECTIVE: We evaluated the determinants of tHcy in healthy French adults. DESIGN: tHcy was measured by HPLC and fluorometric detection in 1139 women and 931 men aged 35-60 y. Subjects were participants of the Supplementation with Antioxidant Vitamins and Minerals Study, which investigates the effects of antioxidant supplementation on chronic diseases. Red blood cell folate (RBCF), plasma vitamins B-6 and B-12, and cardiovascular disease risk factors were also measured. The habitual diet was assessed in 616 subjects. Cross-sectional analyses were adjusted for age, smoking, energy intake, and concentration or intake of folate and vitamin B-6, where appropriate. RESULTS: The mean (+/-SD) tHcy concentration was 8.74 +/- 2.71 micro mol/L in women and 10.82 +/- 3.49 micro mol/L in men. In women, tHcy was positively related to age (P = 0.001), apolipoprotein B (P < 0.01), serum triacylglycerol (P < 0.01), fasting glucose (P = 0.02), and coffee and alcohol consumption (both P < 0.01) and inversely related to RBCF (P = 0.11) and plasma vitamin B-12 (P = 0.08) and vitamin B-6 (P = 0.01) intakes. In men, tHcy was positively associated with body mass index (P = 0.03), blood pressure (P < 0.02), serum triacylglycerol (P < 0.01), fasting glucose (P = 0.01), and energy intake (P < 0.01) and inversely associated with physical activity (P = 0.04), RCBF (P = 0.02), plasma vitamin B-12 (P = 0.09), and dietary fiber (P < 0.01), folate (P = 0.03), and vitamin B-6 (P = 0.09) intakes. CONCLUSION: To control tHcy, decreasing coffee and alcohol consumption may be important in women, whereas increasing physical activity, dietary fiber, and folate intake may be important in men.     

Dietary glycemic index and load, measures of glucose metabolism, and body fat distribution in older adults

BACKGROUND: Recent evidence suggests that the rate of carbohydrate digestion and absorption may influence the development of type 2 diabetes. OBJECTIVE: The aim of this study was to examine associations of dietary glycemic index and glycemic load with predictors of type 2 diabetes in older adults. DESIGN: This study evaluated cross-sectional relations of dietary glycemic index and glycemic load with measures of glucose metabolism and body fat distribution in participants of the Health, Aging and Body Composition Study, a prospective cohort study of adults aged 70-80 y (n = 2248). RESULTS: In men, dietary glycemic index was positively associated with 2-h glucose (P for trend = 0.04) and fasting insulin (P for trend = 0.004), inversely associated with thigh intramuscular fat (P for trend = 0.02), and not significantly associated with fasting glucose, glycated hemoglobin, or visceral abdominal fat. Dietary glycemic load was inversely associated in men with visceral abdominal fat (P for trend = 0.02) and not significantly associated with fasting glucose, 2-h glucose, glycated hemoglobin, fasting insulin, or thigh intramuscular fat. In women, although dietary glycemic index and load were not significantly related to any measures of glucose metabolism or body fat distribution, the association between dietary glycemic index and 2-h glucose was nearly significant (P for trend = 0.06). CONCLUSION: The findings of this cross-sectional study indicate an association between dietary glycemic index and selected predictors of type 2 diabetes in older adults, particularly in men.     

A prospective study of calcium intake from diet and supplements and risk of ischemic heart disease among men

BACKGROUND: Calcium intake is thought to have a protective effect on the risk of developing ischemic heart disease (IHD), but the existing data are inconsistent. OBJECTIVE: The objective was to assess the relation between calcium intake and risk of IHD among men. DESIGN: Men in the Health Professionals Follow-up Study who returned a dietary questionnaire in 1986 (n = 39 800) were followed up for 12 y. Intakes of calcium and other nutrients were assessed in 1986, 1990, and 1994. The endpoints of total IHD (nonfatal myocardial infarction and fatal IHD) incidence were ascertained by medical record review. Other IHD risk factors were recorded biennially. RESULTS: During 12 y of follow-up (415 965 person-years), we documented 1458 cases of IHD: 1030 of nonfatal myocardial infarction and 428 of fatal IHD. After control for standard IHD risk factors, the relative risk of developing IHD among men in the highest (median intake = 1377 mg/d) compared with the lowest (median intake = 523 mg/d) calcium intake quintile was 0.97 (95% CI: 0.81, 1.16; P for trend = 0.64), for vitamin D intake was 1.00 (95% CI: 0.80, 1.24; P for trend = 0.66), and for total dairy product intake was 1.01 (95% CI: 0.83, 1.23; P for trend = 0.57). For supplemental calcium intake, the relative risk of developing IHD in a comparison of the highest quintile with nonusers of supplements was 0.87 (95% CI: 0.64, 1.19; P for trend = 0.31). CONCLUSION: The results suggest that neither dietary nor supplemental intakes of calcium are appreciably associated with the risk of IHD among men.     

Genetic polymorphisms of tumor necrosis factor-alpha modify the association between dietary polyunsaturated fatty acids and fasting HDL-cholesterol and apo A-I concentrations

BACKGROUND: Heterogeneity in circulating lipid concentrations in response to dietary polyunsaturated fatty acids (PUFAs) may be due, in part, to genetic variations. Tumor necrosis factor-alpha (TNF-alpha) is a proinflammatory cytokine that can induce hyperlipidemia and is known to be modulated by dietary PUFAs. OBJECTIVE: The objective was to determine whether TNF-alpha genotypes modify the association between dietary PUFA intake and serum lipid concentrations. DESIGN: The study involved 53 men and 56 women aged 42-75 y with type 2 diabetes. Dietary intakes were assessed with the use of a 3-d food record, and blood samples were collected to determine fasting serum lipids. DNA was isolated from blood for genotyping by polymerase chain reaction-restriction fragment length polymorphism for the TNF-alpha -238G-->A and -308G-->A polymorphisms. RESULTS: PUFA intake was positively associated with serum HDL cholesterol in carriers of the -238A allele (beta = 0.06 +/- 0.03 mmol/L per 1% of energy from PUFAs; P = 0.03), but negatively associated in those with the -238GG genotype (beta = -0.03 +/- 0.01, P = 0.03) (P = 0.004 for interaction). PUFA intake was inversely associated with HDL cholesterol in carriers of the -308A allele (beta = -0.07 +/- 0.02, P = 0.002), but not in those with the -308GG genotype (beta = 0.02 +/- 0.02, P = 0.13) (P = 0.001 for interaction). A stronger gene x diet interaction was observed when the polymorphisms at the 2 positions (-238/-308) were combined (P = 0.0003). Similar effects were observed for apolipoprotein A-I, but not with other dietary fatty acids and serum lipids. CONCLUSION: TNF-alpha genotypes modify the relation between dietary PUFA intake and HDL-cholesterol concentrations. These findings suggest that genetic variations affecting inflammation may explain some of the inconsistencies between previous studies relating PUFA intake and circulating HDL.     

Effect of dietary n-3 polyunsaturated fatty acids on plasma total and high-molecular-weight adiponectin concentrations in overweight to moderately obese men and women

BACKGROUND: Recent studies indicated that dietary n-3 polyunsaturated fatty acids (PUFAs) increase circulating adiponectin concentrations in rodents. OBJECTIVE: We aimed to investigate whether a diet rich in n-3 PUFAs increased plasma concentrations of total or high-molecular-weight (HMW) adiponectin in healthy overweight-to-moderately obese men and women. DESIGN: Sixteen women and 10 men with a body mass index (in kg/m(2)) between 28 and 33 were randomly assigned to consume a diet rich in n-3 PUFAs (3.5% of energy intake) from both plant and marine sources or a control diet (0.5% of energy intake from n-3 PUFAs). For the first 2 wk, these diets were consumed under isocaloric conditions; then followed a 12-wk period of ad libitum consumption that was associated with a moderate loss of approximately 3.5% of body weight in both groups. Total and HMW adiponectin plasma concentrations were measured before and after each diet phase. RESULTS: Plasma fasting adiponectin concentrations did not change during the isocaloric period, but they increased modestly ( approximately 10%) during the ad libitum period when subjects lost weight [P = 0.009 for time in repeated-measures analysis of variance] and to a similar extent in subjects consuming the control (x +/- SD: 0.42 +/- 0.69 microg/mL) and n-3 PUFA (0.45 +/- 0.85 microg/mL) diets (P = 0.920 for time x treatment interaction). Plasma concentrations of HMW adiponectin did not change significantly during the study. CONCLUSION: Dietary n-3 PUFAs consumed at levels of 3.5% of energy intake do not significantly increase plasma or HMW adiponectin concentrations in overweight-to-moderately obese healthy men and women over the course of 14 wk.     

Intake of soy products is associated with better plasma lipid profiles in the Hong Kong Chinese population

We describe the pattern of soy intake and its association with blood lipid concentrations in the Hong Kong Chinese population. Subjects were contacted by random telephone survey and invited to a hospital for a physical examination and blood tests. A total of 500 men and 510 women with an age range of 24-74 y completed the dietary intake study. The dietary assessment was based on a semiquantitative food frequency questionnaire that included 10 commonly consumed soy items. Many (88%) of the study population had consumed some soy products during the previous week. About 80% of the soy protein or isoflavones were obtained from different forms of tofu, and an additional 9% was obtained from soy milk. The mean weekly isoflavone intake was 102 +/- 107 mg in men and 77 +/- 90 mg in women. In men, soy intake and total plasma cholesterol were negatively correlated (r = -0.09, P: = 0.04), as were soy intake and LDL cholesterol (r = -0.11, P: = 0.02). The respective values in women <50 y old were r = -0.11, P: = 0.04 and r = -0.11, P: = 0.05. Soy protein remained significantly associated with these two lipid concentrations after adjustment for other social and dietary confounders. Higher soy intake seemed to be related to a better plasma lipid profile in men and in younger women, but more epidemiological studies and controlled clinical trials in this setting would help to confirm the optimal amount required for the prevention and treatment of hyperlipidemia.     

alpha-Tocopherol intake and plasma concentration of Hispanic and non-Hispanic white elders is associated with dietary intake pattern

alpha-Tocopherol from foods has been associated with protection against several chronic diseases and maintenance of immune function. However, most people do not meet current recommendations for intake. We examined alpha-tocopherol intake and plasma concentration in a representative sample of Puerto Rican and Dominican older adults (n = 447) and in neighborhood-matched non-Hispanic whites (n = 155). A validated food frequency questionnaire was used to assess dietary intake. Mean dietary intakes of alpha-tocopherol were 6 mg in both ethnicities. Only 4.7% of women and 7.9% of men met the estimated average requirement (12 mg/d) for vitamin E from food alone. Top sources of alpha-tocopherol for Hispanics included oils and milk, and for non-Hispanic whites they were ready-to-eat breakfast cereal and sweet baked products. Mean plasma alpha-tocopherol concentrations were 24.5 micromol/L for Hispanics and 25.8 micromol/L for non-Hispanic whites (P > 0.05). Plasma alpha-tocopherol was positively associated with alpha-tocopherol intake (P = 0.003), and significance remained after adjusting covariates and after exclusion of supplement users (P for trend = 0.008). We identified the following 5 dietary patterns by cluster analysis: 1) fruit and breakfast cereal, 2) starchy vegetables, 3) rice, 4) milk and milk products, and 5) sweets. Those following the sweets pattern had the lowest plasma alpha-tocopherol relative to those following the fruit and breakfast cereal or milk patterns (P < 0.05 for all), although they had similar intakes. A large proportion of these elders (>90%) have inadequate intake of alpha-tocopherol, and plasma concentrations were associated with intake patterns.     

Association of diet with serum insulin-like growth factor I in middle-aged and elderly men

BACKGROUND: Insulin-like growth factor I (IGF-I) has been implicated in several chronic diseases, including cancer, heart disease, and osteoporosis. OBJECTIVE: Our aim was to assess whether intakes of total energy, alcohol, vitamins, minerals, and foods rich in protein and minerals (including red meat, fish and seafood, poultry, and milk) are associated with serum IGF-I concentrations in middle-aged and elderly men. DESIGN: We measured serum IGF-I concentrations in 226 free-living healthy men aged 42-76 y. The average of fourteen 24-h dietary telephone interviews performed over 1 y was used to estimate long-term dietary intake. RESULTS: We observed statistically significant positive associations between intakes of protein (P for trend = 0.001) and zinc (P for trend = 0.002) and serum IGF-I concentrations after adjusting for age. The difference in mean IGF-I concentrations for the highest compared with the lowest quintile of intake was approximately 17% (162 microg/L compared with 139 microg/L) for protein and approximately 16% (166 microg/L compared with 143 microg/L) for zinc. Consumption of red meat (P for trend = 0.05) and fish and seafood (P for trend = 0.07) was modestly positively associated with IGF-I concentrations. Other dietary factors were not associated with IGF-I concentrations. CONCLUSION: In this population of healthy well-nourished men, greater dietary intakes of protein, zinc, red meat, and fish and seafood were associated with higher IGF-I concentrations.     

The association between betaine and choline intakes and the plasma concentrations of homocysteine in women

BACKGROUND: Elevated total homocysteine (tHcy), a risk factor for many chronic diseases, can be remethylated to methionine by folate. Alternatively, tHcy can be metabolized by other 1-carbon nutrients, ie, betaine and its precursor, choline. OBJECTIVE: We aimed to assess the association between the dietary intakes of betaine and choline and the concentration of tHcy. DESIGN: We conducted a cross-sectional analysis in 1477 women by using linear regression models to predict mean fasting tHcy by intakes of of betaine and choline. RESULTS: tHcy was 8% lower in the highest quintile of total betaine + choline intake than in the lowest quintile, even after control for folate intake (P for trend = 0.07). Neither choline nor betaine intake individually was significantly associated with tHcy. Choline from 2 choline-containing compounds, glycerophosphocholine and phosphocholine, was inversely associated with tHcy. These inverse associations were more pronounced in women with folate intake < 400 mug/d than in those with intakes >or=400 microg/d (P for interaction = 0.03 for phosphocholine) and in moderate alcohol drinkers (>or=15 g/d) than in nondrinkers or light drinkers (<15 g/d) (P for interaction = 0.02 for glycerophosphocholine and 0.04 for phosphocholine). The strongest dose response was seen in women with a low-methyl diet (high alcohol and low folate intake) (P for interaction = 0.002 for glycerophosphocholine and 0.001 for phosphocholine). CONCLUSIONS: Total choline + betaine intake was inversely associated with tHcy, as was choline from 2 water-soluble choline-containing compounds. Remethylation of tHcy may be more dependent on the betaine pathway when methyl sources are low as a result of either inadequate folate intake or heavier alcohol consumption.     

Dietary glycemic load assessed by food-frequency questionnaire in relation to plasma high-density-lipoprotein cholesterol and fasting plasma triacylglycerols in postmenopausal women

BACKGROUND: In metabolic studies, both greater carbohydrate intakes and higher glycemic indexes (GIs) raise fasting triacylglycerol concentrations. In epidemiologic studies, dietary glycemic load (GL) is positively associated with risk of coronary artery disease and type 2 diabetes. OBJECTIVE: We examined both the physiologic relevance of GI and GL and the ability of dietary questionnaires to measure these variables. DESIGN: In the Nurses' Health Study, we measured plasma triacylglycerol concentrations in fasting blood samples from 185 healthy postmenopausal women and HDL-cholesterol concentrations in an additional 95 nonfasting samples. Dietary carbohydrate, GI, and GL were assessed by use of semiquantitative food-frequency questionnaires. The cross-sectional associations between these 3 variables and plasma triacylglycerol and HDL were assessed, with adjustment for potential confounding factors. RESULTS: For the lowest and highest quintiles of GL, the multivariate-adjusted geometric mean triacylglycerol concentrations were 0.98 and 1.75 mmol/L (87 and 155 mg/dL; P for trend < 0.001). Both overall GI (P for trend = 0.03) and carbohydrate (P for trend < 0.01) contributed independently to the strong positive association between GL and fasting triacylglycerol concentrations. GL was also inversely associated with HDL-cholesterol concentrations. For the lowest and highest quintiles of GL, the mean HDL-cholesterol concentrations were 1.50 and 1.34 micromol/L (58 and 52 mg/dL; P for trend = 0.03). The relation between GL and fasting triacylglycerol concentrations differed significantly by body mass index (BMI; in kg/m(2)) categories (P < 0.001 for interaction). For the lowest to the highest quintiles of GL, the mean triacylglycerol concentrations were 0.92 and 2.24 mmol/L (81 and 198 mg/dL) in women with BMIs > 25 (P for trend < 0.001) and 1.02 and 1.42 mmol/L (90 and 126 mg/dL) in women with BMIs < or = 25 (P for trend < 0.001). CONCLUSION: These data support the physiologic relevance of the GL as a potential risk factor for coronary artery disease in free-living women, particularly those prone to insulin resistance. These findings also document the ability of a semiquantitative food-frequency questionnaire to assess dietary GIs and GLs.     

Adherence to the Mediterranean dietary pattern is positively associated with plasma adiponectin concentrations in diabetic women

BACKGROUND: Although the typical diet of the Mediterranean region has received much recognition over the past several years for its association with substantial health benefits, it remains unknown whether its favorable effects are mediated through changes in adiponectin concentrations. OBJECTIVE: The objective was to determine whether adherence to a Mediterranean-type diet is associated with higher plasma adiponectin concentrations. DESIGN: This study was a prospective and cross-sectional evaluation of plasma adiponectin concentrations and dietary data from 987 diabetic women from the Nurses' Health Study who had no history of cardiovascular disease at the time blood was drawn in 1990. RESULTS: Women who scored highest on a 9-point scale that measures adherence to a Mediterranean-type dietary pattern tended to be older, were less likely to be current smokers, had lower body mass indexes and waist circumferences, and had higher total energy intakes, physical activities, and plasma adiponectin concentrations than did women with the lowest scores. Median plasma adiponectin concentrations were 23% higher in women who most closely followed a Mediterranean-type diet than in low adherers after adjustment for age and energy intake (P < 0.01). Body composition, lifestyle, and medical history explained some, but not all, of the observed association between diet and adiponectin concentrations because high adherers tended to have greater adiponectin concentrations than did moderate or low adherers, even after adjustment for these variables. CONCLUSIONS: Our data suggest that, of the several components of the Mediterranean dietary pattern score, alcohol, nuts, and whole grains show the strongest association with adiponectin concentrations. Close adherence to a Mediterranean-type diet is associated with higher adiponectin concentrations.