Effect of increased fruit and vegetable consumption on physical function and muscle strength in older adults

Fruit and vegetable (FV) intake, which is often low in older people, may be associated with improved muscle strength and physical function. However, there is a shortage of intervention trial evidence to support this. The current study examined the effect of increased FV consumption on measures of muscle strength and physical function among healthy, free-living older adults. A randomized controlled intervention study was undertaken. Eighty-three participants aged 65-85 years, habitually consuming ≤ 2 portions of FV/day, were randomised to continue their normal diet (≤ 2 portions/day), or to consume ≥ 5 portions of FV/day for 16 weeks. FV were delivered to all participants each week, free of charge. Compliance was monitored at baseline, 6, 12 and 16 weeks by diet history and by measuring biomarkers of micronutrient status. Grip strength was measured by a hand-held dynamometer, while lower-extremity physical function was assessed by performance-based measures. Eighty-two participants completed the intervention. The 5 portions/day group showed greater change in daily FV consumption compared to the 2 portions/day group (P < 0.001). This was reflected in significant increases in biomarkers of micronutrient status. No significant differences were evident in change in physical function between the two groups. However, there was a trend towards a greater change in grip strength in the 5 portions/day compared to the 2 portions/day group (mean change at 16 weeks ± SD, 2.04 ± 5.16 and 0.11 ± 3.26 kg, respectively, P = 0.06). Increased FV consumption may modestly increase grip strength but has no effect on physical function in healthy older adults.