RESUMEN

The Dietary Approaches to Stop Hypertension (DASH) eating pattern has been shown to reduce blood pressure (BP) in previous clinical trials. In the PREMIER study, an established behavioural intervention, with or without DASH, promoted greater weight loss than an advice-only control group, but effects of the DASH intervention on BP were weaker. In these analyses, PREMIER data were used to evaluate whether change in dairy product or fruit and vegetable (FV) intake during the first six intervention months impacted changes in weight and/or BP. Study participants were classified as having low or high intakes of dairy products (<1·5 v. ≥1·5 servings/d) and FV (<5 v. ≥5 servings/d) at baseline and 6 months. For dairy products, in particular, participants with higher baseline intakes tended to decrease their intakes during the intervention. In these analyses, subjects consuming <1·5 dairy servings/d at baseline whose intake increased during the intervention lost more weight than those whose intake decreased or remained low throughout (10·6 v. 7·0 pounds (4·8 v. 3·2 kg) lost, respectively, P = 0·002). The same was true for FV intake (11·0 v. 5·9 pounds (5·0 v. 2·7 kg) lost, P < 0·001). We also found synergistic effects of dairy products and FV on weight loss and BP reduction. Specifically, subjects who increased their intakes of dairy products and also consumed ≥5 servings of FV/d lost more weight and had greater reductions in BP than other groups; in addition, higher FV intakes had the greatest benefit to BP among those consuming more dairy products. These results provide evidence that the DASH pattern was most beneficial to individuals whose baseline diet was less consistent with DASH.

Asunto(s)

RESUMEN

OBJECTIVES: Nutrition impacts the development of sarcopenia and protein intake is an important modulator of skeletal muscle mass loss in older people. The Optimizing Protein Intake in Older Men with Mobility Limitation (OPTIMEN) Trial was designed to assess the independent and combined effects of higher protein intake and a promyogenic agent, testosterone, on lean body mass, muscle strength and physical function in older men with mobility disability. The purpose of this paper is to describe the experimental design and nutrition intervention, including techniques used by research dietitians to develop and deliver energy and protein-specific meals to the homes of community-dwelling participants. Strategies to enhance long-term dietary compliance are detailed. DESIGN: Randomized, double-blind, placebo-controlled six-month intervention trial. SETTING: Participants were recruited from Boston MA USA and surrounding communities. PARTICIPANTS: Older men who were mobility-limited (Short Physical Performance Battery (SPPB) 3-10) and consuming less protein (<0.83 g/kg/day) were recruited for this study. INTERVENTION: Here we report the successful implementation of a double-blind, placebo-controlled, parallel group, randomized controlled trial with a 6-month intervention period among community-living men, age 65 years and older with a mobility limitation. A controlled feeding plan was used to deliver required energy intakes and prescribed protein quantities of 0.8 or 1.3 grams/kilogram/day (g/kg/d) in three meals plus snacks and supplements. A 2x2 factorial design was used to assess the effects of protein level alone and in combination with testosterone (vs. placebo) on changes in lean body mass (primary outcome), muscle strength, and physical function. RESULTS: A total of 154 men met the eligibility criteria; 112 completed a 2-week run-in period designed to evaluate compliance with the nutrition intervention. Of these, 92 subjects met compliance eligibility criteria and agreed to be randomized; 85% completed the full trial. The study successfully delivered three meals per day to subjects, with a high degree of compliance and subject satisfaction. Overall self-reported compliance rates were 80% and 93% for the meals and supplements, respectively. Details of compliance strategies are discussed. CONCLUSION: This community-based study design may serve as a model for longer-term nutritional interventions requiring monitoring of dietary compliance in a home-based feeding and supplementation trial.

Asunto(s)

RESUMEN

BACKGROUND: Epidemiological studies of red meat consumption often fail to distinguish between leaner and fattier or processed cuts of meat. Red meat has also been frequently linked with less healthy diet patterns. Data exploring the health effects of lean red meat in younger individuals are scarce, particularly in the context of a healthy diet. The present study examined the effects of lean red meat in combination with higher intakes of fruit/nonstarchy vegetables on lipid profiles in older adolescent girls. METHODS: Data from 1461 girls who were followed for 10 years, starting at 9-10 years of age, in the National Heart Lung and Blood Institute Growth and Health Study were used. Diet was assessed using multiple sets of 3-day records collected over eight examination cycles. Outcome measures included fasting levels of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), non-HDL-C and triglycerides at age 18-20 years. RESULTS: After adjusting for age, race, socioeconomic status, height, activity level, hours of television per day, and intakes of whole grains and dairy foods using multivariable modelling, girls consuming ≥6 oz lean red meat per week combined with two or more servings of fruit/nonstarchy vegetables per day had LDL-C levels approximately 6-7 mg dL(-1) lower (P < 0.05) than girls with lower intakes of lean red meat and fruit/nonstarchy vegetables. In addition, girls with higher intakes of both were 33% less likely (odds ratio = 0.67, 95% confidence interval = 0.48-0.94) to have an LDL-C ≥110 mg dL(-1) and 41% less likely (odds ratio = 0.59, 95% confidence interval = 0.42-0.83) to have an elevated LDL : HDL ratio (≥2.2) at the end of adolescence. CONCLUSIONS: These analyses suggest that lean red meat may be included in a healthy adolescent diet without unfavourable effects on lipid values.

Asunto(s)

RESUMEN

BACKGROUND AND AIMS: Few studies have evaluated the effects of food-based eating patterns on adolescent lipid levels. This study examines whether usual adolescent eating patterns (ages 9-17 years) predict lipid levels at 18-20 years of age. METHODS AND RESULTS: This study uses previously collected data from the longitudinal NHLBI Growth and Health Study in which 2379 girls were enrolled at ages 9-10 years and followed for ten years. Food-based eating patterns were derived from multiple 3-day diet records. After adjusting for age, race, socioeconomic status, height, physical activity, and television viewing, girls with higher intakes of dairy, fruit and non-starchy vegetables had about a 40-50% reduced risk an LDL-C ≥ 170 mg/dL and non-HDL-C ≥ 145 mg/dL. Diets characterized by higher intakes of dairy and whole grains had similar benefits on TC and LDL-C. Girls consuming more fruits and non-starchy vegetables as well as more whole grains were much less likely to have high-risk lipid levels. Lean meat, poultry and fish when consumed in the context of other healthy eating patterns had no adverse effects on lipid levels in late adolescence. In fact when consumed with higher amounts of fruit and non-starchy vegetables, lean meat, poultry and fish had beneficial effects on HDL. Finally, dietary patterns that included more whole grains tended to be associated with lower TG levels. CONCLUSION: Healthy childhood eating patterns characterized by higher intakes of a variety of fruits, vegetables, whole grains, dairy, lean meat, poultry and fish are important modifiable predictors of lipid levels in late adolescence.

Asunto(s)

RESUMEN

BACKGROUND: It is unclear whether the increased risk of colon cancer associated with obesity differs for men and women, by distribution of body fat, or by location of the tumor. The primary goal of this study was to address these questions. METHODS: Eligible subjects from the Framingham Study cohort were classified according to body mass index (BMI) and waist size during two age periods: 30-54 y (n=3764) and 55-79 y (n=3802). All eligible men and women were cancer-free at baseline and had complete information on the following potential confounders: age, sex, education, height, activity, smoking, and alcohol. There were 157 incident lifetime cases of colon cancer among those followed beginning at 30-54 y of age and 149 lifetime cases among those whose follow up began at 55-79 y. Subjects were stratified further by gender, activity, and tumor location. The Cox Proportional Hazards Models were used to adjust for possible confounding by the above-described factors. RESULTS: A BMI >/=30 led to a 50% increased risk (95% CI: 0.92-2.5) of colon cancer among middle-aged (30-54 y) and a 2.4-fold increased risk (95% CI: 1.5-3.9) among older (55-79 y) adults. The BMI effect was stronger for men than for women and for cases occurring in the proximal colon. These adverse effects generally diminished when waist was added to the multivariable models. A larger waist size (>/=99.1 cm (39 in) and 101.6 cm (40 in) for women and men, respectively) was associated with a two-fold increased risk of colon cancer; this risk increased linearly with increasing waist size and was evident for both proximal and distal colon cancer. There was no attenuation of these effects when BMI was added to the multivariable models. A larger waist had a particularly adverse effect among sedentary subjects (relative risk (RR)=4.4 for middle-aged adults; RR=3.0 for older adults). CONCLUSION: These findings suggest that waist circumference is a stronger predictor of colon cancer risk than is BMI, and that central obesity is responsible for an increased risk of cancer of both the proximal and distal colon.

Asunto(s)

RESUMEN

This study was designed to evaluate the effects of maternal obesity and diabetes mellitus on the risk of nonchromosomal congenital defects. We used data from 22,951 pregnant women enrolled in a prospective cohort study of early prenatal exposures and pregnancy outcome. The relative risks [prevalence ratios (PRs)] of major nonchromosomal congenital defects associated with obesity and diabetes, alone or in combination, were calculated using multiple logistic regression analysis. In this study, in the absence of diabetes, obese women (body mass index > or =28) had no higher risk, overall, of having an offspring with a major defect [PR = 0.95; 95% confidence interval (CI) = 0.62-1.5]. Their offspring, however, did have a higher prevalence of certain types of defects, including orofacial clefts; club foot; cardiac septal defects; and, to a lesser extent, hydrocephaly and abdominal wall defects. Women with pre-existing or gestational diabetes who were not obese also had no excess risk overall of having offspring affected by a major defect (PR = 0.98; 95% CI = 0.43-2.2), although they did have a higher prevalence of musculoskeletal defects. The pregnancies of women who were both obese and diabetic were 3.1 times as likely (95% CI = 1.2-7.6) to result in an offspring with a defect than were those of nonobese, nondiabetic women, which suggests that obesity and diabetes mellitus may act synergistically in the pathogenesis of congenital anomalies. The defects were largely craniofacial or musculoskeletal.

Asunto(s)

RESUMEN

OBJECTIVES: In developing countries, there is evidence that the median age of the population and the life expectancy at birth are increasing as a result of decreasing fertility rates and infant mortality. The result is an aging population more prone to non-communicable diseases such as diabetes, cancer, or heart disease later in life. In addition, changing lifestyle factors such as tobacco use, physical inactivity, and high fat diets, may accelerate the emergence of such chronic diseases as major causes of death and disability in these countries, particularly in urban areas. To test the premise that urban living predisposes residents to reduced activity levels, less healthy diets, cigarette smoking, elevated blood pressure, and increased body fat early in life, we studied rural/urban differences in these risk factors among schoolchildren in the Republic of Cameroon. METHODS: One hundred and nineteen Class 7 schoolchildren (50 urban and 69 rural) were interviewed concerning diet, physical activity, smoking, and alcohol use; blood pressure and anthropometric measurements were also taken. RESULTS: Physical activity among rural children was more than twice that of urban children, and most of the activity for rural children was work-related. Rural children consumed fewer foods containing fat and more fruits and vegetables. Adjusting for age, systolic and diastolic blood pressures of urban boys were higher than those of rural boys, and among urban children there was a trend toward a larger age-adjusted mean body mass index (BMI). There were no differences in alcohol or tobacco use between urban and rural children. CONCLUSIONS: In this study, urbanization was associated with a less active lifestyle and a dietary pattern that was higher in fat and lower in fruit and vegetable intake. Since risk factors for non-communicable diseases tend to appear early in life and track into adulthood, it is important to identify those children, or groups of children, with unfavorable risk profiles and to structure health education and promotion programs to modify these trends.

Asunto(s)

RESUMEN

OBJECTIVES: This study compared the nutrient intake of children at 3 through 4 years of age with that in subsequent years to determine whether nutrient intake tracked over time. METHODS: Intakes of 10 nutrients were estimated by means of multiple days of food diaries collected over a span of up to 6 years of follow-up for 95 children in the Framingham Children's Study. All diaries collected during each of three age periods (age 3 through 4, age 5 through 6, and age 7 through 8) were averaged. Nutrient density intakes at each age period were compared. RESULTS: Nutrient-specific correlations ranged from .37 to .63 between nutrient density intakes at age 3-4 and age 5-6. Correlations between intakes at age 3-4 and age 7-8 ranged from .35 to .62. Consistency of classification was strong; 35.7% to 57.1% of children in the highest quintile of intake at age 3-4 remained in that quintile at age 5-6, and 57.1% to 85.7% remained in the top two quintiles. At age 7-8, 40.0% to 66.7% of those with the highest intake at baseline were still in the top quintile, and 60.0% to 93.3% remained in the top two quintiles. Results were similar in the lowest quintile of intake. Extreme misclassification was rare. CONCLUSIONS: This study suggests that tracking of nutrient intake begins as young as 3-4 years of age.

Asunto(s)

RESUMEN

BACKGROUND: Studies in animals indicate that natural forms of vitamin A are teratogenic. Synthetic retinoids chemically similar to vitamin A cause birth defects in humans; as in animals, the defects appear to affect tissues derived from the cranial neural crest. METHODS: Between October 1984 and June 1987, we identified 22,748 pregnant women when they underwent screening either by measurement of maternal serum alpha-fetoprotein or by amniocentesis. Nurse interviewers obtained information on the women's diet, medications, and illnesses during the first trimester of pregnancy, as well as information on their family and medical history and exposure to environmental agents. We obtained information on the outcomes of pregnancy from the obstetricians who delivered the babies or from the women themselves. Of the 22,748 women, 339 had babies with birth defects; 121 of these babies had defects occurring in sites that originated in the cranial neural crest. RESULTS: For defects associated with cranial-neural-crest tissue, the ratio of the prevalence among the babies born to women who consumed more than 15,000 IU of preformed vitamin A per day from food and supplements to the prevalence among the babies whose mothers consumed 5000 IU or less per day was 3.5 (95 percent confidence interval, 1.7 to 7.3). For vitamin A from supplements alone, the ratio of the prevalence among the babies born to women who consumed more than 10,000 IU per day to that among the babies whose mothers consumed 5000 IU or less per day was 4.8 (95 percent confidence interval, 2.2 to 10.5). Using a smoothed regression curve, we found an apparent threshold near 10,000 IU per day of supplemental vitamin A. The increased frequency of defects was concentrated among the babies born to women who had consumed high levels of vitamin A before the seventh week of gestation. CONCLUSIONS: High dietary intake of preformed vitamin A appears to be teratogenic. Among the babies born to women who took more than 10,000 IU of preformed vitamin A per day in the form of supplements, we estimate that about 1 infant in 57 had a malformation attributable to the supplement.

Asunto(s)

RESUMEN

OBJECTIVE: To evaluate the effect of calcium supplementation on blood pressure in children. DESIGN: Randomized, double-masked, placebo-controlled trial. SETTING AND PARTICIPANTS: One hundred one fifth-grade students in one inner-city school. INTERVENTION: Each child consumed 480 ml of juice beverages, containing either no calcium or 600 mg calcium (as calcium citrate malate) daily for 12 weeks. MEASUREMENTS: At baseline we obtained nutrient data from three sets of 2-day food records on each subject. We measured blood pressure four times on each of three weekly sittings at baseline and at follow-up. Using multiple linear regression analysis, we compared mean blood pressure change in the intervention group with that in the placebo group. RESULTS: There were 50 girls and 51 boys; 61 subjects were black. At baseline, mean age was 11.0 years, systolic and diastolic blood pressures were 101.7 and 57.7 mm Hg, daily total energy intake was 1966 kcal, and calcium intake was 827 mg. With control for age, height, hours of television watched, and baseline blood pressure, systolic blood pressure increased 1.0 mm Hg in the intervention group and 2.8 mm Hg in the placebo group (effect estimate = -1.8 mm Hg; 95% confidence interval -4.0, 0.3). In black subjects the intervention effect estimate was -2.0 mm Hg (95% confidence interval -4.4, 0.4). From lowest to highest quartile of baseline calcium intake (per 1000 kcal), the intervention effect estimates were -3.5, -2.8, -1.3, and 0.0 mm Hg (p for trend = 0.009). There was little effect on diastolic blood pressure. CONCLUSION: These data suggest a blood pressure-lowering effect of calcium supplementation in children, especially in subjects with low baseline calcium intake.

Asunto(s)

Asunto(s)

Asunto(s)

RESUMEN

Nutrient intake affects many of the identified risk factors for coronary heart disease (CHD). Although CHD risk factors have been shown to aggregate within families, less is known about the familial aggregation of nutrient intake. We analyzed diet records for an average of 9 d per subject on 87 mothers, 83 fathers, and 91 children aged 3-5 y. A statistically significant but modest correlation (r less than 0.50) was found between parents' and children's intakes for most nutrients. The intake of nutrients was more strongly related between mothers and children than between fathers and children, and there was a stronger association with children's values for parents consuming more meals at home. The results of this study confirm that parents' eating habits have an impact on the nutrient intake of their preschool children; the study furnishes indirect support for dietary-intervention programs targeting families for the primary prevention of CHD.

Asunto(s)

RESUMEN

We have previously presented evidence for the formation of 1-O-alkyl dihydroxyacetone-P from acyl dihydroxyacetone-P via the initial formation of an intermediate 1-O-acyl endiol of acyl dihydroxyacetone-P. This reaction involves a stereospecific exchange of the pro-R hydrogen of the acyl dihydroxyacetone-P moiety without change in configuration. The fatty acid is replaced by a long chain fatty alcohol which retains the oxygen of the primary carbinol. In the absence of fatty alcohol, water substitutes and the product is dihydroxyacetone-P which has also exchanged the pro-R hydrogen with a hydrogen from the medium. An absolute requirement of the proposed mechanism is that the loss of the fatty acid must proceed via an unusual cleavage of the dihydroxyacetone-P C-1 to oxygen bond instead of the usual cleavage at the fatty acid acyl to oxygen bond. In the present investigation, we have synthesized hexadecanoyl dihydroxyacetone-P containing oxygen-18 exclusively at the dihydroxyacetone-P C-1 oxygen. Using this substrate, we have shown that cleavage of hexadecanoyl dihydroxyacetone-P at the C-1 to oxygen bond is linked to O-alkyl dihydroxyacetone-P synthesis. Inhibition of O-alkyl lipid synthesis by means of magnesium or NADPH inhibited the unusual cleavage. At the same time, we have shown that there was hydrolysis of acyl dihydroxyacetone-P which proceeded by the usual mechanism and which was not related to synthesis of O-alkyl dihydroxyacetone-P.

Asunto(s)