Reduced or modified dietary fat for preventing cardiovascular disease

ABSTRACT: BACKGROUND: Reduction and modification of dietary fats have differing effects on cardiovascular risk factors (such as serum cholesterol), but their effects on important health outcomes are less clear. OBJECTIVE: To assess the effect of reduction and/or modification of dietary fats on mortality, cardiovascular mortality, cardiovascular morbidity and individual outcomes including myocardial infarction, stroke and cancer diagnoses in randomised clinical trials of at least 6 months duration. METHODS: Search methods: For this review update, the Cochrane Central Register of Controlled Trials (CENTRAL), Medline and Embase, were searched through to June 2010. References of Included studies and reviews were also checked. Selection criteria: Trials fulfilled the following criteria: 1) randomized with appropriate control group, 2) intention to reduce or modify fat or cholesterol intake (excluding exclusively omega-3 fat interventions), 3) not multi factorial, 4) adult humans with or without cardiovascular disease, 5) intervention at least six months, 6) mortality or cardiovascular morbidity data available. Data collection and analysis: Participant numbers experiencing health outcomes in each arm were extracted independently in duplicate and random effects meta-analyses, meta-regression, sub-grouping, sensitivity analyses and funnel plots were performed. MAIN RESULTS: This updated review suggested that reducing saturated fat by reducing and/or modifying dietary fat reduced the risk of cardiovascular events by 14% (RR 0.86, 95% CI 0.77 to 0.96, 24 comparisons, 65,508 participants of whom 7% had a cardiovascular event, I2 50%). Subgrouping suggested that this reduction in cardiovascular events was seen in studies of fat modification (not reduction - which related directly to the degree of effect on serum total and LDL cholesterol and triglycerides), of at least two years duration and in studies of men (not of women). There were no clear effects of dietary fat changes on total mortality (RR 0.98, 95% CI 0.93 to 1.04, 71,790 participants) or cardiovascular mortality (RR 0.94, 95% CI 0.85 to 1.04, 65,978 participants). This did not alter with sub-grouping or sensitivity analysis. Few studies compared reduced with modified fat diets, so direct comparison was not possible. AUTHORS' CONCLUSIONS: The findings are suggestive of a small but potentially important reduction in cardiovascular risk on modification of dietary fat, but not reduction of total fat, in longer trials. Lifestyle advice to all those at risk of cardiovascular disease and to lower risk population groups, should continue to include permanent reduction of dietary saturated fat and partial replacement by unsaturates. The ideal type of unsaturated fat is unclear.

Relationship of Vitamin D Status with Muscle Mass and Muscle Strength in Young Indian Adults – Evidence from Andhra Pradesh Children and Parents Study Cohort.

Objectives: Positive relationship of vitamin D status with muscle mass and strength has been observed in studies from the developed countries but evidence from the developing countries is sparse. This study assessed the relationship of vitamin D status with muscle mass and muscle strength in rural young adults from Hyderabad, India. Methods: The study participants (n=956; age 18-20 years; 42% women) were a part of Andhra Pradesh Children and Parents Study cohort which was established to assess the long term impact of early nutrition supplementation provided through a government programme. Their serum 25- hydroxyvitamin D was assessed using HPLC, appendicular skeletal muscle mass (ASM) was assessed using dual energy X-ray absorptiometry and grip strength was assessed using grip dynamometer. Results: The participants were lean with average body mass index of 19.5 kg/m2. Prevalence of vitamin D deficiency (serum 25(OH) vitamin D3 < 20 ng/ml) was 33.6% in men and 51.4% in women. Vitamin D deficiency was associated with lower ASM (β (95% CI): - 0.38 (-0.72 to -0.05) kg; p = 0.02) with a trend of lower muscle strength in unadjusted analyses. After adjustment for relevant confounders, the relationship of vitamin D deficiency with lower ASM (β (95% CI): -0.21 (- 0.37 to - 0.05) kg; p =0.01) persisted but not with lower grip strength. Conclusions: Prevalence of vitamin D deficiency was high in these rural young adults. Vitamin D deficiency was associated with lower muscle mass but not with lower muscle strength in this cohort. Alleviation of vitamin D deficiency may improve muscle mass.

Obesidad y mortalidad en hombres según el estado de su enfermedad coronaria / Obesity and mortality in men according to coronary heart disease status

Las pocas comunicaciones sobre la asociación de obesidad o sobrepeso con mortalidad en personas con enfermedad coronaria (EC) muestran hallazgos contradictorios. En el estudio Whitehall –en el que participaron empleados gubernamentales de sexo masculino de Londres–, 18 403 hombres de mediana edad que habían participado en un examen médico entre 1967 y 1970 fueron controlados durante 38 años. En los hombres que presentaban EC al inicio hubo pruebas de un riesgo ligeramente mayor de mortalidad por todas las causas y por EC, pero no por accidente cerebrovascular en los grupos con sobrepeso y obesidad en relación con los hombres de peso normal. Aunque estas tendencias fueron mucho más notables en los hombres sin EC al inicio del estudio, la diferencia según el estado basal de EC no alcanzó significación estadística en los niveles convencionales. Evitar la obesidad y el sobrepeso en la vida adulta tanto en hombres con EC como sin ella puede reducir el riesgo posterior de mortalidad total y mortalidad por cardiopatía coronaria.

The few reports on the association of obesity oroverweight with mortality in persons with existing coronary heart disease (CHD) reveal inconsistent findings.In the Whitehall study of London-based male government employees, 18 403 middle-age men were followed upfor up for a maximum of 38 years having participated in a medical examination between 1967 and 1970. In menwith baseline CHD, there was evidence of a modestelevated risk for mortality from all-causes and coronaryheart disease but not stroke in overweight and obesegroups relative to normal weight men. While these slopeswere markedly steeper in men who were CHD-free atstudy induction, the difference in the gradients accordingto baseline CHD status did not attain statistical significance at conventional levels. Avoidance of obesity and overweight in adult life in both men with and without CHD may reduce their later risk of total and coronary heart disease mortality.