Supplement Nonusers Research Articles

Dietary Factors and Biomarkers Involved in the Methylenetetrahydrofolate Reductase Genotype–Colorectal Adenoma Pathway

Methylenetetrahydrofolate reductase (MTHFR) is involved in intracellular folate homeostasis and metabolism. We assessed 2 polymorphisms in the MTHFR gene (C677T and A1298C) in relation to colorectal adenoma recurrence and conducted analyses to investigate their joint effects with plasma and dietary markers of folate status. We prospectively analyzed data from 1598 individuals genotyped for the C677T polymorphism and 1583 with data on A1298C. Among nonusers of multivitamin supplements, compared with wild-type carriage, higher odds of recurrence were observed for those with the 677 TT variant (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.04-2.63) and a nonsignificant increase was observed among those with the 1298 CC variant (OR, 1.50; 95% CI, 0.93-2.40). Diplotype analyses among nonusers of multivitamins showed that individuals who carry the MTHFR 677TT_1298AA or 677CC_1298CC combination were significantly more likely to have a recurrence compared with those with the double wild-type (OR, 2.05 for TT_AA and 1.85 for CC_CC). Higher odds of recurrence were observed among participants with low folate intake or plasma folate and the 677 TT or 1298 CC variants compared with those with lower levels and the wild-type or heterozygous genotypes. Stronger associations were shown for the combination of high homocysteine and the 677 TT variant (OR, 2.29; 95% CI, 1.00-5.26) but not the 1298 CC variant (OR, 1.09; 95% CI, 0.39-3.01). We propose that the effect of the MTHFR genotypes on increasing risk of adenoma recurrence in the presence of a low folate status is through their increase in homocysteine concentrations, which in turn could result in DNA hypomethylation via pathways involving S-adenosylhomocysteine.

Nutritional supplement use in Mexico and its contribution to adequacy of nutrient intakes

The use of nutrient supplements is increasing and could contribute to the reduction of nutrient inadequacies. The contribution of supplements to nutrient intakes in Mexico has not previously been reported. The objectives of this analysis were to describe the supplement use practices among non-pregnant, non-lactating Mexican women (12–49 y) and estimate their contribution to adequacy and excess intake of select nutrients using data from a national probabilistic nutrition survey in Mexico (1999). Information was collected by questionnaire on the frequency and duration of supplement use in the last 6 months among 17,794 women. Dietary intakes by 24-hour recall were determined in a representative sub-sample of 2,599 women. Frequency of use and available information on the nutrient content of supplements was used to estimate daily equivalent intakes. Supplement use during the last 6 mos was reported by 17.6% of women. The majority of these took supplements once daily (71%) and for ≤2 months (74.9%). The prevalence of inadequate intakes of Vitamins A, B6, B12, and C, Folic acid, calcium, iron, and zinc were significantly greater among the supplement non-users than users when the nutrient contribution of supplements was considered; nutrient intakes from the diet alone did not differ between users and non-users. The proportion of women with intakes > Upper Limit was greater among supplement users than non-users for iron, folate and vitamin B6. Supplement use contributes to the adequacy of nutrient intakes and to the possible risk of toxic intakes of some nutrients among Mexican women.

大学生におけるサプリメントの利用と食行動・食態度との関連―運動部学生と薬学部学生との比較―

A questionnaire survey was performed on college athletes (n2=255) and students of the faculty of pharmaceutical sciences (n=346) to clarify the relationship between dietary supplements and eating behavior and attitudes. The athletes had better dietary behavior and attitudes than the students. The ratio of supplement users among the male athletes was significantly higher than that among the male students. The supply of nutrients and keeping fit and healthy were common frequent purposes of supplement use by both groups. Fatigue recovery and muscular development were also frequent purposes by the athletes. The most frequently used supplements were protein, iron and amino acids by the athletes, and multivitamins, vitamin B and vitamin C by the students.Among the male athletes, most supplement users did not have the habit of eating instant foods and snacks, and would eat even disliked foods for nutritional balance, in comparison with the non-users. Among the male students, although most supplement users understood about their poor nutritional intake, they preferred to take tablets instead of having more nutritious foods and thought of their diet only as a way of filling the stomach, in comparison with the supplement non-users.These results suggest a different relationship between dietary supplement use and eating behavior and attitudes between male athletes and male students.

Feeding Infants and Toddlers Study: Do Vitamin and Mineral Supplements Contribute to Nutrient Adequacy or Excess among US Infants and Toddlers?

Objective To report the prevalence of dietary supplement use in a random sample of US infants 4 to 24 months of age, and to compare demographic characteristics, usual nutrient intakes, and food patterns of supplement users and nonusers. Design Data from 24-hour recalls collected for the 2002 Feeding Infants and Toddlers Study were analyzed. Recalls included nutrient contributions from dietary supplements as well as all foods and beverages. We estimated usual energy and nutrient intakes of supplement users and nonusers, as well as the prevalence of nutrient adequacy and excess in the two groups. We also compared demographic characteristics and food patterns of supplement users and nonusers and, for supplement users, estimated the proportion of total intake provided by foods and the proportion provided by supplements. Subjects A national random sample of 3,022 infants and toddlers age 4 to 24 months, including 430 vitamin and/or mineral supplement users and 2,592 nonusers. Statistical Analysis We compared means, percentile distributions, and proportions by age and supplement subgroup, and applied the Dietary Reference Intakes to assess usual nutrient intakes. We conducted regression analysis to determine which population characteristics predict the use of dietary supplements in this population. Results Overall, 8% of infants age 4 to 5 months received some type of dietary supplement. The prevalence of supplement use increased with age, to 19% among infants 6 to 11 months and 31% among toddlers 12 to 24 months. The vast majority of supplement users (97%) received only one type of supplement, most commonly a multivitamin and/or mineral supplement. Vitamin/mineral supplement use among infants and toddlers was associated with being a first-born child and being reported by the primary caretaker as being a picky eater. Characteristics that were independent predictors of supplement use were living in the Northeast, being male, and living in a household with fewer children. We found no significant differences between supplement users and nonusers in mean daily intakes of nutrients or nutrient density from foods alone, and few differences in food consumption. Overall, the prevalence of inadequate intakes was low (<1% to 2%). However, 65% of supplement nonusers and 9% of supplement users had vitamin E intakes less than the Estimated Average Requirement. Excessive intakes (ie, intakes above the Tolerable Upper Intake Level) were noted for both supplement users and nonusers for vitamin A (97% and 15% of toddlers) and zinc (60% and 59% of older infants and 68% and 38% of toddlers) as well as for folate among supplement users (18% of toddlers). Conclusions Generally, healthy infants and toddlers can achieve recommended levels of intake from food alone. Dietetics professionals should encourage caregivers to use foods rather than supplements as the primary source of nutrients in children’s diets. Vitamin and mineral supplements can help infants and toddlers with special nutrient needs or marginal intakes achieve adequate intakes, but care must be taken to ensure that supplements do not lead to excessive intakes. This is especially important for nutrients that are widely used as food fortificants, including vitamin A, zinc, and folate.

Vitamin status and cognitive function in a long-term care population

BackgroundAgeing can be associated with poor dietary intake, reduced nutrient absorption, and less efficient utilization of nutrients. Loss of memory and related cognitive function are also common among older persons. This study aimed to measure the prevalence of inadequate vitamin status among long-term care patients and determine if an association exists between vitamin status and each of three variables; cognitive function, vitamin supplementation, and medications which alter gastric acid levels.MethodsSeventy-five patients in a long-term care hospital in Guelph, Ontario were recruited to a cross-sectional study. 47 were female and the mean age was 80.7 (+/-11.5) years, ranging from 48 to 100 years. Blood was used to measure levels of vitamins B12 (cobalamin), B6 (pyridoxal-5'-phosphate/PLP), erythrocyte folate, vitamin B3 (niacin) and homocysteine (Hcy). The Standardized Mini-Mental State Examination (SMMSE) was administered to measure cognitive function. A list of medications and vitamin supplementation for each patient was provided by the pharmacy.ResultsThe prevalence of low vitamin (B12, B6, erythrocyte folate, niacin) or high metabolite (homocysteine) levels among 75 patients were as follows: B12 <148 pmol/L in 5/75 (6.7%); B12 between 148 and 221 pmol/L in 26/75 (34.7%); B6 ≤30 nmol/L in 4/75 (5.3%); erythrocyte folate <370 nmol/L in 1/75 (1.3%); niacin ratio ≤1 in 20/75 (26.7%); homocysteine >13.3 μmol/L in 31/75 (41.3%). There was no significant difference among residents grouped into marked (n = 44), mild (n = 14), or normal (n = 9) cognitive function when evaluating the effect of vitamin status. There were no significant differences in mean B12 and homocysteine levels between users and non-users of drug therapy (Losec, Zantac, or Axid). Compared to vitamin supplement non-users, supplemented residents had significantly higher mean B12 (p < 0.0001) and erythrocyte folate (p < 0.05) concentrations and significantly lower mean homocysteine (p < 0.01) levels; 229.1 versus 423.6 pmol/L for B12, 882.9 versus 1043.6 nmol/L for erythrocyte folate and 14.4 versus 12.0 μmol/L for homocysteine.ConclusionGiven the prevalence data on vitamin status in this sample population, the possible benefits of vitamin supplementation should be considered in clinical intervention studies using these populations of elderly.

Association between serum concentrations of 25-hydroxyvitamin D and gingival inflammation

Vitamin D has been shown to have immunomodulatory effects in in vitro and in animal studies. However, data from clinical studies of inflammatory diseases are scarce. The purpose of this study was to evaluate the association between serum concentrations of 25-hydroxyvitamin D [25(OH)D] and gingival inflammation. We analyzed data from 77,503 gingival units (teeth) in 6700 never smokers aged 13 to >90 y from the third National Health and Nutrition Examination Survey. Multiple logistic regression models adjusted for subject- and site-specific covariates included age, sex, race-ethnicity, income, body mass index, diabetes, use of oral contraceptives and hormone replacement therapy among women, intake of vitamin C, missing teeth, full crown coverage, presence of calculus, frequency of dental visits, and dental examiner and survey phase. Generalized estimating equations were used to account for correlated observations within subjects. Compared with sites in subjects in the lowest 25(OH)D quintile, sites in subjects in the highest 25(OH)D quintile were 20% (95% CI: 8%, 31%) less likely to bleed on gingival probing (P for trend < 0.001). The association appeared to be linear over the entire 25(OH)D range, was consistent across racial or ethnic groups, and was similar among men and women as well as among users and nonusers of vitamin and mineral supplements. Vitamin D may reduce susceptibility to gingival inflammation through its antiinflammatory effects. Gingivitis may be a useful clinical model to evaluate the antiinflammatory effects of vitamin D.

The Effect of Folate Fortification of Cereal-Grain Products on Blood Folate Status, Dietary Folate Intake, and Dietary Folate Sources among Adult Non-Supplement Users in the United States

Objective: Since January 1998, the Federal Drug Administration has required folic acid fortification of all enriched cereal-grain products in the U.S. This program intended to increase folic acid intake among women of childbearing age in order to decrease their risk of pregnancies affected by neural tube defects. The aim of this study was to explore the changes in serum and erythrocyte folate status of the adult U.S. population following folic acid fortification of enriched cereal-grain products and to explore accompanying changes in food sources and dietary total folate intake.Methods: We compared data from two National Health and Nutrition Examination Surveys (NHANES): NHANES III, conducted during 1988 to 1994, reflecting the time prior to folate fortification, and NHANES 1999–2000, reflecting the time period after fortification.Results: Mandatory folic acid fortification led to significant increases in both serum and erythrocyte folate concentrations in all sex and age groups. In the overall study population the mean serum folate concentration increased more than two-fold (136%), from 11.4 nmol/L to 26.9 nmol/L, and the mean erythrocyte folate concentration increased by 57 percent, from 375 nmol/L to 590 nmol/L. Less than 10% of women of childbearing age reached the recommended erythrocyte folate concentration of greater than 906 nmol/L that has been shown to be associated with a significant reduction in neural tube defect (NTD) risk. After fortification, the category “bread, rolls, and crackers” became the single largest contributor of total folate to the American diet, contributing 15.6% of total intake, surpassing vegetables, which were the number one folate food source prior to fortification. Dietary intake of total folate increased significantly in almost all sex and age groups, except in females over 60 years of age. The mean dietary total folate intake of the study population increased by 76 μg/d (28%), from 275 μg/d to 351 μg/d.Conclusions: The fortification of enriched cereal-grain products with folic acid lead to a significant improvement of blood folate status of the overall adult, non-supplement using, US population. However, women of childbearing age may take folic acid supplements to reach erythrocyte folate levels that have been associated with decreased risk of NTDs.

Self-reported quality of life in users and nonusers of dietary supplements in cancer

To describe the Quality of Life (QoL) characteristics of users of dietary supplements vs nonusers. A survey of 225 cancer patients presenting for treatment at Cancer Treatment Centers of America was completed between November 2001 and October 2003. A validated instrument assessed the use of 56 dietary supplements in the past month. Two validated questionnaires assessed QoL. Mean QoL scores were compared between the users and nonusers using univariate and multivariate linear regression. Of 225 patients, 91 (40%) were males and 134 (60%) females. Sixty seven (30%) had breast cancer, 40 (18%) colorectal cancer, and 32 (14%) lung cancer. One hundred sixty four (73%) had used dietary supplements in the past month, while 61 (27%) had not. Mean European Organization for Research Treatment of Cancer QoL scores were significantly better among the users for physical and emotional function scales and fatigue, nausea, appetite loss, and constipation symptom scales adjusting for tumor site. In the stratified analysis, lung cancer patients did not show any statistically significant differences in QoL scores between the users and nonusers. Colorectal cancer patients demonstrated statistically significant differences in constipation symptom, with dietary supplement users having better QoL. Breast cancer patients demonstrated statistically significant differences in several QoL scale scores between users and nonusers. Contrary to some of the previously published research, this study, conducted at a community hospital comprehensive cancer center that combines alternative treatment approaches with conventional cancer care, found better self-reported QoL among the users of dietary supplements, as compared to nonusers. The next step in this research is to prospectively evaluate the patterns of changing QoL in relation to dietary supplement use across the entire duration of cancer diagnosis and treatment.

Supplement Use Is Associated with Health Status and Health-Related Behaviors in the 1946 British Birth Cohort1-3

Use of dietary supplements may be one of a number of health-related behaviors that cluster together. The current study investigated the underlying diet, health-related characteristics, and behaviors of users and nonusers of dietary supplements in a longitudinal study of health. Participants (n = 1776) completed a 5-d food diary including information on dietary supplement use (vitamins, minerals, and nutraceuticals) at age 53 y. Sociodemographic information and data on smoking, alcohol, and physical activity were obtained along with anthropometric measurements, blood pressure, and a blood sample (nonfasting subjects). A significantly greater percentage of women reported supplement use compared with men (45.1 vs. 25.2%). Supplement use was associated with lower BMI, lower waist circumference, higher plasma folate and plasma vitamin B-12 concentrations, nonsmoking, participation in physical activity, and nonmanual social class in women and with plasma folate concentrations and participation in physical activity in men. Nonsupplement users tended to be nonconsumers of breakfast cereals, fruit, fruit juice, yogurt, oily fish, and olive oil and had lower dietary intakes of potassium, magnesium, phosphorus, iron, and vitamin C even after adjustment for sociodemographic and behavioral factors. Overall, supplement users tended to differ from nonsupplement users on a range of health-related behaviors and health status indicators, although there were fewer significant associations in men. Similarly, dietary supplements users tended to have underlying diets that, were healthier and those taking supplements may be the least likely to need them. These results support the notion of a clustering of healthy behaviors and cardiovascular risk factors, particularly for women.

Self -Reported Quality of Life in users and non-users of dietary supplements in cancer

8232 Background: Hospital-based surveys suggest that cancer patients routinely use dietary supplements, which include vitamins, minerals, and herbs. We described the QoL characteristics of users of dietary supplements versus non-users. Methods: A survey of 225 adult cancer patients presenting for treatment at Cancer Treatment Centers of America at Midwestern Regional Medical Center was completed between 11/01 and 10/03. A validated instrument (McCune Questionnaire) assessed the use of 56 dietary supplements in the past month. QoL was evaluated using the EORTC QLQ-C30 questionnaire. The mean QoL scores were compared between the dietary supplement users and non-users using linear regression models controlling for tumor site. Results: Of 225 patients, 91 (40%) were males and 134 (60%) females. 136 (57%) patients had failed prior treatment while 65 (29%) were newly diagnosed. 67 (30%) had breast cancer, 40 (18%) colorectal cancer, and 32 (14%) lung cancer. 164 (73%) had used dietary supplements in the past month while 61 (27%) had not. Patients with colorectal and breast cancer had statistically significantly better QoL as compared to those with lung cancer for most EORTC scales. Mean EORTC QoL scores were significantly better among the dietary supplement users for physical and emotional function scales and fatigue, nausea, appetite loss, and constipation symptom scales after adjusting for tumor site (Table 1). Conclusions: Contrary to some of the previously published research this study found better QoL among the users of dietary supplements, as compared to non-users. The next step in this research is to prospectively evaluate the patterns of changing QoL in relation to dietary supplement use across the entire duration of cancer diagnosis and treatment. Table 1. Relationship between dietary supplement use and QoL after adjusting for tumor site No significant financial relationships to disclose.

Prevalence of nonvitamin, nonmineral supplement usage among students in a Turkish university

BackgroundThere have been multiple studies carried out in many countries with regard to the use of nonvitamin, nonmineral (NVNM) supplements. These studies have shown that the use of NVNM supplements is on the increase throughout the world, particularly in western countries. The aim of this study was to assess the extent of NVNM supplement use among Turkish university students.MethodsThe survey was conducted between September and December 2004 at Osmangazi University, a public university located in the west of Turkey. Responses were analysed, using the chi-square (x2) test, t test and percent (%) ratios, according to gender and consumers. Differences were considered significant for p ≤ 0.05.ResultsOf 2253 students attending the university, 1871 participated in the survey (909 men and 962 women). Overall, the prevalence of NVNM supplement use was 16.5% (16.6% in men and 16.3% in women, p < 0.05).The three most commonly given reasons for use were 'improvement of energy and vitality (78.6%)', 'promotion of weight loss (71.1%)', followed by 'enhancement of athletic performance (64.3%)'. Twenty-six of the 308 reported NVNM users (26/308, 8.4%) reported having experienced an adverse reaction. Television (76.3%), magazines/newspapers (41.5%) and internet websites (37.3%) were the most frequently used sources for obtaining information about NVNM supplements. The three most frequently used NVNM supplements were echinacea, ginseng, and gingko biloba (38.6%, 36.4%, and 32.8%, respectively). Nutritional scores were higher in NVNM supplement users than in non-users (66.510.8 vs. 62.712.7) (p < 0.001). Users and nonusers of NVNM supplements differed significantly according to sex, age, Body Mass Index (BMI) values, types of school, mother and fathers' education levels, family income, most permanent place of residence up to the time of survey, smoking status, and participating in sports.ConclusionThe results indicate that the prevalence of NVNM supplement use is relatively modest among Turkish university students and more information is needed on why people use particular NVNM supplements.

Prevalence of dietary supplement use in adults with chronic renal insufficiency

There are currently no studies that have investigated dietary supplement use in the chronic renal insufficiency (CRI) population. The objectives of this study were to determine the prevalence of dietary supplement use in a sample of adults with CRI and to examine whether the prevalence of dietary supplement use was higher in the earlier stages of CRI. Cross-sectional survey conducted at an outpatient nephrology clinic. Adults (n = 100) with varying degrees of CRI. Interview-administered questionnaire. The questionnaire contained questions related to the use of dietary supplements, attitudes, and beliefs about dietary supplements, as well as medical and demographic data including gender, age, body weight, smoking status, concurrent chronic conditions, prescribed medications, serum creatinine, estimated glomerular filtration rate (GFR), etiology of CRI, income, and education level. The prevalence of dietary supplement use was 45%, with the most frequent use occurring in subjects with a mild to moderate degree of renal insufficiency. There were no significant differences in gender, age, body mass index, smoking status, number of concurrent chronic conditions, number of prescribed medications, income, or education level between supplement users and supplement nonusers. Further analysis of dietary supplement use showed that the number of supplements used ranged from 1 to 5 or more supplements per day, with an overall total of 36 different supplements. Dietary supplement users were significantly more concerned with their health than were supplement nonusers. The most frequent sources of supplement information were physicians and printed material; however, 75% of the dietary supplement users desired further information about their dietary supplements. This is the first study to investigate the use of dietary supplements in adults with CRI, and it provides valuable information for health care professionals regarding the dietary supplement use of their patients with CRI.

One-Carbon Metabolism,MTHFRPolymorphisms, and Risk of Breast Cancer

Accumulating evidence from epidemiologic studies suggests that risk of breast cancer is reduced in relation to increased consumption of folate and related B vitamins. We investigated independent and joint effects of B vitamin intake as well as two polymorphisms of a key one-carbon metabolizing gene [i.e., methylenetetrahydrofolate reductase (MTHFR) 677C>T and 1298A>C] on breast cancer risk. The study uses the resources of a population-based case-control study, which includes 1,481 cases and 1,518 controls. Significant inverse associations between B vitamin intake and breast cancer risk were observed among non-supplement users. The greatest reduction in breast cancer risk was observed among non-supplement users in the highest quintile of dietary folate intake [odds ratio (OR), 0.61; 95% confidence interval (95% CI), 0.41-0.93] as compared with non-supplement users in the lowest quintile of dietary folate intake (high-risk individuals). The MTHFR 677T variant allele was associated with increased risk of breast cancer (P, trend = 0.03) with a multivariate-adjusted OR of 1.37 (95% CI, 1.06-1.78) for the 677TT genotype. The 1298C variant allele was inversely associated with breast cancer risk (P, trend = 0.03), and was likely due to the linkage of this allele to the low-risk allele of 677C. The MTHFR-breast cancer associations were more prominent among women who did not use multivitamin supplements. Compared with 677CC individuals with high folate intake, elevation of breast cancer risk was most pronounced among 677TT women who consumed the lowest levels of dietary folate (OR, 1.83; 95% CI, 1.13-2.96) or total folate intake (OR, 1.71; 95% CI, 1.08-2.71). From a public heath perspective, it is important to identify risk factors, such as low B vitamin consumption, that may guide an effective prevention strategy against the disease.

Calcium intake and colorectal adenoma in a US colorectal cancer early detection program

Calcium can reduce the risk of colorectal tumors by binding secondary bile and fatty acids, which leads to antiproliferative effects in the bowel, or by acting directly on the colonic epithelium, which affects differentiation and apoptosis. We investigated calcium intake and risk of colon adenoma to evaluate the association of calcium intake with early stages of colorectal tumor development. We compared the supplemental and dietary calcium intakes of 3696 participants with histologically verified adenoma of the distal colon (ie, descending colon, sigmoid colon, or rectum) with the calcium intakes of 34 817 sigmoidoscopy-negative control participants in the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Calcium intake was assessed at study entry with a 137-item food-frequency questionnaire and additional questions on the amount and duration of calcium supplement use. After adjustment for known risk factors, adenoma risk was lower by 12% for participants in the highest quintile of total calcium intake (>1767 mg/d) than for participants in the lowest quintile (<731 mg/d) (odds ratio: 0.88; 95% CI: 0.76, 1.02; P for trend = 0.04). The protective association between total calcium and colorectal adenoma was largely due to calcium supplement use, with a 27% decrease in adenoma risk for participants taking >1200 mg/d than for nonusers of supplements (odds ratio: 0.73; 95% CI: 0.56, 0.91; P for trend = 0.005). The protective associations of total and supplemental calcium were strongest for colon adenoma (descending and sigmoid colon). High calcium intake, particularly from supplements, is associated with a reduced risk of distal colorectal adenoma.

Physical activity, exercise, and inflammatory markers in older adults: findings from the Health, Aging and Body Composition Study.

To examine the association between physical activity and inflammatory markers, with consideration for body fatness and antioxidant use. Cross-sectional study, using baseline data from the Health, Aging and Body Composition Study. Metropolitan areas surrounding Pittsburgh, Pennsylvania, and Memphis, Tennessee. Black and white, well-functioning men and women (N=3,075), aged 70 to 79. Interviewer-administered questionnaires of previous-week household, walking, exercise, and occupational/volunteer physical activities. Analysis of covariance was used to examine the association between activity level and serum C-reactive protein (CRP), interleukin-6 (IL-6), and plasma tumor necrosis factor alpha (TNFalpha) with covariate adjustment. Antioxidant supplement use (multivitamin, vitamins E or C, beta carotene) was evaluated as an effect modifier of the association. Higher levels of exercise were associated with lower levels of CRP (P<.01), IL-6 (P<.001), and TNFalpha (P=.02) (e.g., CRP=1.95 mg/L for no exercise and 1.72 for >180 min/wk). Adjustment for body fatness attenuated the associations somewhat. Use of antioxidant supplements modified the CRP (P(interaction)=.01) and IL-6 (P(interaction)=.08) associations such that concentrations were low in those taking supplements (e.g., CRP=1.79-1.84 across exercise levels) and higher in nonsupplement users who did no exercise (2.03) than in those who did the most (1.72). Among nonexercisers, higher levels of other physical activity were related to lower levels of CRP (P<.01) and IL-6 (P=.02) but not TNFalpha (P=.36), even after accounting for body fat. Inflammatory markers are lower in older adults with higher levels of exercise and nonexercise activity and in antioxidant supplement users regardless of exercise level.

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.

Environmental Influences: Factors Influencing a Woman's Decision to Use Dietary Supplements

Use of dietary supplements by women, particularly those over 40 years of age may be widespread in the United Kingdom. However, from surveillance data, there appears to be a disparity between nutrition and health needs and the rationale for and actual use of dietary supplements by women. This apparent paradox forms the basis for an inverse supplement hypothesis (i.e., supplement use in women appears to be most prevalent among those with least need). Little research has been done to examine the factors underlying the decision to use dietary supplements. Reasons for consuming dietary supplements are often complex, combining social, psychological, knowledge and economic factors. The theory of planned behavior is a widely used model for assessing factors influencing behavioral motivation and action that may be useful for assessing specific diet- and nutrition-related practices. It provided the basis for the development of a questionnaire to explore overall dietary supplement use in a cohort of women in the United Kingdom. The analysis of factors related to beliefs underlying dietary supplement use revealed differences between supplement users and nonusers. Differences included a stronger belief by users than nonusers that taking dietary supplements ensures against possible ill health. Both users and nonusers of supplements also perceived the media (books and magazines) to be a powerful influence on a person's decision to use supplements. These findings highlight the potential of the theory of planned behavior in exploring supplement-taking behavior while throwing light on the factors influencing an individual's motivations to use dietary supplements.

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

Calcium intake is thought to have a protective effect on the risk of developing ischemic heart disease (IHD), but the existing data are inconsistent. The objective was to assess the relation between calcium intake and risk of IHD among men. 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. 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). The results suggest that neither dietary nor supplemental intakes of calcium are appreciably associated with the risk of IHD among men.

Demographic, health, lifestyle, and blood vitamin determinants of serum total homocysteine concentrations in the third National Health and Nutrition Examination Survey, 1988–1994

Elevated serum total homocysteine (tHcy) is an independent risk factor for vascular diseases. Associations between serum tHcy and demographics, health and lifestyle factors, and blood vitamin concentrations were investigated. Data from the third National Health and Nutrition Examination Survey, 1988-1994 were used to examine associations in men (n = 2965) and women (n = 3580) between tHcy and age, sex, race-ethnicity, body mass index, systolic and diastolic blood pressures, alcohol consumption, supplement use, red blood cell (RBC) folate, and serum creatinine, folate, vitamin B-12, and cotinine (a measure of cigarette smoking). The unadjusted mean tHcy was 21.5% ( approximately 1.9 micro mol/L) higher in men than in women, 11.8% ( approximately 1.1 micro mol/L) higher in non-Hispanic whites than in Mexican Americans, 42% ( approximately 3.7 micro mol/L) higher in persons aged > or = 70 y than in persons aged < 30 y, and 10.9% ( approximately 1.0 micro mol/L) higher in supplement nonusers than in supplement users. The tHcy concentration was negatively associated with serum folate (P < 0.0001 for trend), RBC folate (P < 0.0001 for trend), and serum vitamin B-12 (P < 0.0036 for trend) and was positively associated with alcohol consumption (P < 0.0001 for trend), serum cotinine (P < 0.0001 for trend), and systolic blood pressure (P < 0.0001 for trend). Consumption of hard liquor (but not of beer or wine) was positively associated with tHcy concentration (P < 0.0001 for trend). In this population-based study, the significant predictors of tHcy concentration were sex, age, race-ethnicity, serum creatinine, systolic blood pressure, body mass index, hard-liquor consumption, smoking, supplement use, serum folate, RBC folate, and serum vitamin B-12.

Lipid standardization of serum fat-soluble antioxidant concentrations: the YALTA study

Blood lipids can influence fat-soluble antioxidant concentrations and confound their interpretation as indicators of antioxidant intake status and disease risk. The objectives were to identify lipoproteins that can confound the interpretation of serum fat-soluble antioxidants, to evaluate the amount of the confounding, and to recommend a method for standardizing blood concentrations of fat-soluble antioxidants. Several methods of lipid standardization of fat-soluble antioxidants were evaluated in a large cohort of young adults with the use of both cross-sectional and longitudinal data analysis. Tocopherol and carotenoid concentrations were associated with plasma total cholesterol and its components, LDL, HDL, and VLDL cholesterol (estimated as plasma total triacylglycerols/5), some of which were independent predictors for all of the fat-soluble antioxidants. Among supplement nonusers, the most amphipathic (polar) of the antioxidants (alpha-tocopherol, gamma-tocopherol, and zeaxanthin plus lutein) and lycopene were associated strongly with these lipid fractions (R(2) = 0.09, 0.40). Consistent with a causal association in which blood antioxidant concentrations change as blood lipid concentrations change, similar relations were found for changes in blood antioxidant and lipid concentrations over a 7-y period. Concentrations of the remaining carotenoids (beta-cryptoxanthin, alpha-carotene, and beta-carotene) had a weaker association with plasma lipoproteins (R(2) < 0.06). Similar relations were found for supplement users. The simultaneous adjustment of the concentrations of tocopherols, zeaxanthin plus lutein, and lycopene for VLDL, HDL, and LDL cholesterol is recommended. This method is practical and can provide a basis for the standardization of carotenoid and tocopherol concentrations.