To get the most out of so-called anti-aging supplements, it's best to take them during middle age, rather than waiting until after age 65, a new study on rats suggests.
Middle aged rats showed improvements in their physical abilities after receiving anti-aging supplements, while older rats did not, 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 study scientist Jinze Xu, a postdoctoral researcher at the University of Florida's Institute on Aging.
However, results in rat studies do not necessarily apply to humans, and further research will be needed to confirm the findings.
Scientists don't fully understand all the processes that lead to loss of function as people age. But more and more research points to the cell's powerhouses, called mitochondria, as an important player in aging. Mitochondria are largely responsible for generating energy within a cell, but they also produce so-called free radicals, which are molecules with extra electrons that can cause damage — throughout the cell and within the mitochondria itself. Too much damage can cause the mitochondria to stop working properly.
To address that problem, many anti-aging studies and supplements are geared toward reducing the effects of free radicals.
The current study tested a commercially available supplement marketed for relieving chronic fatigue and protecting against muscle aging. The supplement contains the antioxidant coenzyme Q10, creatine — a compound that aids in muscle performance — and ginseng, which also has been shown to have antioxidant properties. (Antioxidants ameliorate damage caused by free radicals.)
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.
At the end of the six weeks, grip strength had improved 12 percent in the middle-aged rats compared with controls. 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 these anti-aging supplements might be of greater effect before major age-related functional and other declines have set in, the researchers said.
More power to the powerhouses
Interestingly, although the older rats had no improvement in physical performance or mitochondrial function, they had less free radical damage compared with the control rats.
The researchers speculate that while the supplement helped to reduce the free radical damage, the damage may have been too great in these old animals for the effect to actually restore the mitochondrial function.
Future research should focus on boosting the health of the mitochondria, the researchers say, since well-working mitochondria will produce fewer free radicals. Also, clinical trials need to be performed to test the effectiveness of the supplements in humans.
The results were published last week in the journal PLoS One. The manufacturers of the supplement donated the quantity used in the study and provided support for the postdoctoral researcher and analyses. The animals used in the study were paid for through grants from the National Institute on Aging.