Vitamin C strengthens muscles in the elderly

The more vitamin C there is in your blood as you age, the stronger your muscles will be, report Japanese epidemiologists in the Journal of Gerontology: Medical Sciences. The Japanese data suggest that not only foods that are rich in vitamin C, but also supplements containing vitamin C can help maintain strength in the muscles of the elderly.

The more vitamin C there is in your blood as you age, the stronger your muscles will be, report Japanese epidemiologists in the Journal of Gerontology: Medical Sciences. The Japanese data suggest that not only foods that are rich in vitamin C, but also supplements containing vitamin C can help maintain strength in the muscles of the elderly.

The researchers studied a group of 655 women whose average age was 75. They measured the concentration of vitamin C in the women’s blood and used this data to divide the women into four equal-sized groups: one group with relatively low vitamin C levels, a group with slightly higher concentrations, and so on.

The researchers then assessed the women’s physical functioning. One aspect they looked at was the women’s handgrip strength. They noticed that this strength was significantly greater the more vitamin C there was in the women’s blood.

The number of seconds that the women were able to stand on one leg was also greater in the group with high levels of vitamin C in their blood.

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The effect was also visible when the researchers had corrected for the effect of fruit consumption. Fruit is the most important source of vitamin C in the Japanese diet, but fruit also contains many other important nutrients. A high vitamin C level can be an indicator of a high intake of these other substances.

“However, the statistical adjustment for fruit intake did not attenuate the relationship between plasma vitamin C and physical performance, suggesting that vitamin C did have some beneficial effects independently of other nutrients”, the researchers write.

That would mean that vitamin C supplements might also play a role in muscle maintenance in the elderly. The Japanese then searched the literature for confirmation of this theory, but did not find any supporting evidence. For every study in which vitamin C supplementation stimulated muscle growth or strength, there was one in which vitamin C had no or even a negative effect.

Animal studies have shown that elderly lab rats build up more muscle strength through a training programme if they are also given extra vitamin C and E in their food. In 2009 Canadian researchers discovered a similar effect in a human study. They discovered that elderly people who do weight training build up more muscle mass if they also take vitamin C and E.

A significant relationship between plasma vitamin C concentration and physical performance among Japanese elderly women.

Saito K, Yokoyama T, Yoshida H, Kim H, Shimada H, Yoshida Y, Iwasa H, Shimizu Y, Kondo Y, Handa S, Maruyama N, Ishigami A, Suzuki T.

Source

Research Team for Promoting Independence of the Elderly, Tokyo Metropolitan Institute of Gerontology, 35-2, Sakaecho, Itabashi, Tokyo, 173-0015, Japan. kyon@tmig.or.jp

Abstract

BACKGROUND:

Maintenance of physical performance could improve the quality of life in old age. Recent studies suggested a beneficial relationship between antioxidant vitamin (eg, vitamin C) intake and physical performance in elderly people. The purpose of this study was to examine the relationship between plasma vitamin C concentration and physical performance among Japanese community-dwelling elderly women.

METHODS:

This is a cross-sectional study involving elderly females residing in an urban area in Tokyo, Japan, in October 2006. We examined anthropometric measurements, physical performance, lifestyles, and plasma vitamin C concentration of participants.

RESULTS:

A total of 655 subjects who did not take supplements were analyzed. The mean age (±standard deviation) of participants was 75.7 ± 4.1 years in this study. The geometric mean (geometric standard deviation) of plasma vitamin C concentration was 8.9 (1.5) ?g/mL. The plasma vitamin C concentration was positively correlated with handgrip strength, length of time standing on one leg with eyes open and walking speed, and inversely correlated with body mass index. After adjusting for the confounding factors, the quartile plasma vitamin C level was significantly correlated with the subject’s handgrip strength (p for trend = .0004) and ability to stand on one leg with eyes open (p for trend = .049).

CONCLUSIONS:

In community-dwelling elderly women, the concentration of plasma vitamin C related well to their muscle strength and physical performance.

PMID: 21934124 [PubMed – indexed for MEDLINE]

Source: http://www.ncbi.nlm.nih.gov/pubmed/21934124  
  

 

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