Anti-aging supplements made up of mixtures might be better than single compounds at preventing decline in physical function, according to researchers at the University of Florida's Institute on Aging. In addition, it appears that such so-called neutraceuticals should be taken before very old age for benefits such as improvement in physical function.
The findings from rat studies, published last week in the journal PLoS One, have implications for how dietary supplementation can be used effectively in humans.
"I think it is important for people to focus on good nutrition, but for those of advanced age who are running out of energy and not moving much, we're trying to find a supplement mixture that can help improve their quality of life," said Christiaan Leeuwenburgh, Ph.D., senior author of the paper and chief of the biology of aging division in the UF College of Medicine.
Scientists do not fully understand all the processes that lead to loss of function as people age. But more and more research points to the mitochondrial free radical theory of aging, that as people age, oxidative damage piles up in individual cells such that the energy-generation system inside some cells stops working properly.
To address that problem, many anti-aging studies and supplements are geared toward reducing the effects of free radicals.
The UF researchers investigated the potential anti-aging benefits of a commercially available mixture marketed for relieving chronic fatigue and protecting against muscle aging. The supplement contains the antioxidant coenzyme Q10, creatine - a compound that aids muscle performance - and ginseng, which also has been shown to have antioxidant properties.
The study gauged the effects of the mixture on physical performance as well as on two mechanisms that underlie the aging process and many age-related disorders: dysfunction of the cells' energy producing powerhouses, known as mitochondria, and oxidative stress.
The researchers fed the supplement to middle-aged 21-month-old and late-middle-aged 29-month-old rats - corresponding to 50- to 65-year-old and 65- to 80-year-old humans, respectively - for six weeks, and measured how strongly their paws could grip. Grip strength in rats is analogous to physical performance in humans, and deterioration in grip strength can provide useful information about muscle weakness or loss seen in older adults.
Grip strength improved 12 percent in the middle-aged rats compared with controls, but no improvement was found in the older group.
Measurements of the function of mitochondria corresponded with the grip strength findings. Stress tests showed that mitochondrial function improved 66 percent compared with controls in middle-aged rats but not in the older ones. That suggests that supplementation might be of greater effect before major age-related functional and other declines have set in, the researchers said.
"It is possible that there is a window during which these compounds will work, and if the intervention is given after that time it won't work," said Jinze Xu, Ph.D., first author of the paper and a postdoctoral researcher at UF.