Lower Dietary And Circulating Vitamin C In Middle- And Older-Aged Men And Women Are Associated With Lower Estimated Skeletal Muscle Mass, The Journal of Nutrition, 27 August 2020
To our knowledge, this is the first study assessing the relation of dietary and circulating vitamin C with the sarcopenic risk factor of loss of skeletal muscle mass in a large UK cohort [over 13,000 participants] of both men and women of middle and older age. Our results show significant positive associations between dietary vitamin C intake and measures of FFM [fat-free mass, a proxy for skeletal muscle mass] using multivariable regression models, adjusted for known lifestyle and biological covariates.
The mechanistic roles for vitamin C in skeletal muscle physiology include the synthesis of carnitine and collagen. These are important because collagen is a key structural component of skeletal muscle cells and tendons, and carnitine is essential for metabolism of long-chain fatty acids during physical activity.
Because vitamin C is an electron donor [that is, an anti-oxidant], this may reduce oxidative damage to muscle as well as reducing the concentrations of inflammatory cytokines in the circulation.
This study has shown significant positive associations between both dietary and circulating vitamin C and measures of skeletal muscle in a large cohort of free-living middle- and older-aged men and women. These results suggest that ensuring sufficient dietary vitamin C intake, by promoting a diet rich in fruits and vegetables, may help to reduce age-related loss of skeletal muscle and thus have wide-reaching public health benefit.
The study included this graph. I don’t think fruits and vegetables will surprise anyone. But, of the top four sources, why include a line item for potatoes? Because it ends up being where many people get their vitamin C, even if they don’t know it.
One medium baked potato has about 17 mg vitamin C. Here’s a slightly smaller potato that’s been microwaved that has about 24 mg. Compare that to a medium apple that has only about 8 mg. Or a medium tomato with 15 mg. (Still, it may be hard to beat an orange, which comes in at 63 mg.)