Homocysteine and the methylenetetrahydrofolate reductase 677C-->T polymorphism in relation to muscle mass and strength, physical performance and postural sway.

BACKGROUND/OBJECTIVES: Elevated plasma homocysteine has been linked to reduced mobility and muscle functioning in the elderly. The relation of methylenetetrahydrofolate reductase (MTHFR) 677C-->T polymorphism with these associations has not yet been studied. This study aimed to investigate (1) the association of plasma homocysteine and the MTHFR 677C-->T polymorphism with muscle mass, handgrip strength, physical performance and postural sway; (2) the interaction between plasma homocysteine and the MTHFR 677C-->T polymorphism. SUBJECTS/METHODS: Baseline data from the B-PROOF study (n=2919, mean age=74.1±6.5) were used. Muscle mass was measured using dual X-ray absorptiometry, handgrip strength with a handheld dynamometer, and physical performance with walking-, chair stand- and balance tests. Postural sway was assessed on a force platform. The data were analyzed using regression analyses with plasma homocysteine levels in quartiles. RESULTS: There was a significant inverse association between plasma homocysteine and handgrip strength (quartile 4: regression coefficient B=-1.14, 95% confidence interval (CI)=-1.96; -0.32) and physical performance score (quartile 3: B=-0.53, 95% CI=-0.95; -0.10 and quartile 4: -0.94; 95% CI=-1.40; -0.48) in women only, independent of serum vitamin B12 and folic acid. No association was observed between the MTHFR 677C-->T polymorphism and the outcomes. High plasma homocysteine in the 677CC and 677CT genotypes, but not in the 677TT genotype, was associated with lower physical performance. CONCLUSIONS: Elevated plasma homocysteine concentrations are associated with reduced physical performance and muscle strength in older women. There is an urgent need for randomized controlled trials to examine whether lowering homocysteine levels might delay physical decline.

Consuming a diet complying with front-of-pack label criteria may reduce cholesterol levels: a modeling study.

BACKGROUND/OBJECTIVES: Front-of-pack nutrition labels can help consumers to make healthier choices and stimulate healthier product development. This is the first modeling study to investigate the potential impact on cholesterol levels of consuming a diet consisting of products that comply with the criteria for a 'healthier choice logo'. SUBJECTS/METHODS: National food consumption and food composition data were used to estimate the nutrient intake of the Dutch adult population (18-70 years) before and after replacing foods that did not comply with the choices front-of-pack label criteria. Different scenarios were established. The difference in cholesterol levels in the Dutch population was assessed before and after replacement by means of equations from meta-analyses that calculate how blood lipids change when diet composition changes. RESULTS: After replacing non-complying products with products, which comply with the label's criteria (maximum scenario), saturated fatty acids median intake reduced from 14.5 to 9.8 en%. Trans-fatty acids reduced from 0.95 to 0.57 en%. The average predicted changes in low-density lipoprotein and total cholesterol levels were -0.25 and -0.31 mmol/l, respectively. Because high-density lipoprotein (HDL) cholesterol levels reduced as well (-0.05 mmol/l), overall, the result was a slightly positive change in the total cholesterol/HDL ratio (-0.03). CONCLUSIONS: Our findings suggest that the consumption of foods complying with the criteria for a front-of-pack label could contribute moderately to cardiovascular risk reduction via influencing blood lipids. These findings were independent of other potential effects on related health outcomes.

Iodide excretion before and after revision of goiter prophylaxis (Dutch Nutrition Surveillance System).

To assess the iodine supply in The Netherlands after the revision of the goiter prophylaxis measures (Bread Act of 1982, with an increase of iodine content of bread salt) the data of a nationwide survey among Dutch elderly people conducted in 1984/1985 were analysed. Iodide excretion in 24 h urine samples was used as the main iodine status indicator. The data were compared with data on iodine nutriture obtained among an elderly population in The Netherlands before the revision of goiter prophylaxis. High prevalences (greater than or equal to 37%) of low iodine excretion (less than 0.78 mumol/24 h; 100 micrograms/24 h) were found for Dutch elderly people. Mean urinary iodide excretion was 0.95 mumol/24 h (121 micrograms/24 h) for men and 0.79 mumol/24 h (100 micrograms/24 h) for women which is low, especially among women, in comparison with the United States recommended dietary allowance (118 mumol/day = 150 micrograms/day). Consistent positive associations of iodide excretion were found with urinary potassium and sodium excretion, bread consumption and total iodine intake. Bread, as the iodine carrier chosen for goiter prophylaxis in The Netherlands, was found to be the main dietary iodine source. No improvement in iodine nutrition was found among the elderly studied in 1984/1985 in comparison with an elderly population seen in 1981. Therefore, it is concluded that the present measures regarding goiter prophylaxis in The Netherlands might be of limited effectiveness.