Abstract
CONTEXT: Physical inactivity and sedentary behaviours are independent risks factors for numerous diseases.OBJECTIVE: We examined the capacity of a nutrient cocktail composed of polyphenols, omega-3 fatty acids, vitamin E and selenium to prevent the expected metabolic alterations induced physical activity and sedentary behaviors. DESIGN/SETTING/PARTICIPANTS: Twenty healthy trained men (averaging∼14,000 steps/d and engaged in sports) were randomly divided into a control group (no supplementation) and a cocktail group for a 20-day free-living intervention during which they stopped exercise and decreased their daily steps to averaging∼3000. During the last 10 days metabolic changes were further triggered by fructose overfeeding. On days 0, 10 and 20 body composition (DXA), blood chemistry, glucose tolerance (OGTT) and substrate oxidation (indirect calorimetry) were measured. Glucose tolerance included 1% fructose labelled with (U-13C) fructose to assess liver de novo lipogenesis. Histological changes and related cellular markers were assessed from muscle biopsies collected on days 0 and 20. RESULTS: While the cocktail did not prevent the decrease in insulin sensitivity and its muscular correlates induced by the intervention, it fully prevented the hypertriglyceridemia, the drop in fasting HDL and total fat oxidation, and the increase in de novo lipogenesis. The cocktail further prevented the decrease in type-IIa muscle fiber cross-sectional area and was associated with lower protein ubiquitination content. The circulating anti-oxidant capacity was improved by the cocktail following the OGTT. CONCLUSION: A cocktail of nutrient compounds from dietary origin protects against the alterations in lipid metabolism induced by physical inactivity and fructose overfeeding.