Declining physical activity with aging is seen in almost all species – just think of how much more active kids are than elderly people. This decline contributes to things like metabolic syndrome and frailty in old age. More importantly, life is less enjoyable in general when you're physically unable to do the things you could when you were younger.
To some degree, this process can be slowed down by physical activity itself. People who exercise tend to be more physically fit than people who don't. Nevertheless, no matter how active you are, the decline can only be postponed, not completely prevented. To retain our youthful vigor indefinitely, scientific breakthroughs in regenerative medicine are needed.
And yet, anything that is postponing the inevitable at this point might just prove to have been postponing what is evitable in the future. Stay healthy and stick around long enough and you might just see those breakthroughs happen in your lifetime. That's why anything that gives us even a few extra years of healthspan should be warmly welcomed.
Many people who are proponents of exercise are skeptical of using dietary supplements to increase healthspan, and rightly so: there is little if any evidence to show that popping a generic multivitamin will do any good. But what about a supplement that has a more scientific basis to it? A new study shows that a dietary supplement containing readily available ingredients ameliorates locomotor, neurotransmitter and mitochondrial aging in mice (link). It also modestly extends their lifespan.
Study design
The dietary supplement was developed with five factors related to aging in mind: oxidative stress, inflammation, mitochondrial function, insulin resistance and membrane integrity. A slurry of the supplement was soaked onto pieces of bagel and then given to normal mice and transgenic growth hormone mice (which show accelerated aging compared to normal mice). Here's the ingredient list:
| Ingredient | Mg |
| Bioflavonoids | 7.93 |
| Vitamin A (beta-carotene) | 0.22 |
| Vitamin B1 | 0.31 |
| Vitamin B3 | 0.31 |
| Vitamin B6 | 0.61 |
| Vitamin B9 | 0.006 |
| Vitamin B12 | 0.02 |
| Vitamin C | 3.51 |
| Vitamin D | .0002 |
| Vitamin E | 3.27 |
| Rutin | 3.05 |
| Chromium picolinate | 0.003 |
| Magnesium | 0.46 |
| Manganese | 0.19 |
| Potassium | 0.18 |
| Selenium | 0.0005 |
| Acetyl L-carnitine | 1.47 |
| Alpha-lipoic acid | 1.83 |
| Aspirin | 1.32 |
| Coenzyme Q10 | 0.61 |
| Cod liver oil | 12.20 |
| Flax seed oil | 12.20 |
| Garlic | 0.04 |
| Ginger root extract | 6.00 |
| Ginkgo biloba | 0.18 |
| Ginseng | 6.31 |
| Green tea extract | 4.88 |
| L-Glutathione | 0.31 |
| Melatonin | 0.007 |
| N-acetyl cysteine | 3.05 |
The amounts of ingredients in the original data are given in "mg/day/100 mice"; presumably all the treated mice were allowed to eat from the same food lot, which would mean that the amount of ingredients eaten varied between mice. I've divided the numbers by a 100 here to show the average amount for each mouse. You can get the original data from the link to the study if you need it.
Effect on activity levels
According to the authors, when the untreated normal mice reached 24 months of age, their physical activity levels had dropped by more than half. The untreated normal mice are represented by the second line from the top (and I may be missing something here, but it doesn't seem like the decrease is over 50% in the graph – still, a significant drop). Normal mice given the supplement, on the other hand, were almost as active in old age as in young ages.
As you can see, the transgenic mice (represented by the two bottom lines) showed much lower activity in general than the normal mice, which is to be expected. In the untreated transgenic mouse group (the first line from the bottom), activity was pretty uniformly low with not much further decline from aging. In younger transgenic mice (the second line from the bottom), the supplement clearly increased activity, but by the time they reached 13 months, they were as inactive as the untreated group.
According to the authors, exercise duration generally declined with age, but remained higher in supplemented normal mice across all ages. Bouts of intense activity decreased with age even in these mice, but this was offset by increases in moderate activity.
Effect on protein carbonyls
Protein carbonyls, a marker of oxidative damage, correlate negatively with cognitive skills and activity levels. Protein carbonyl levels were lower in the brains of supplemented mice than in untreated mice. Although this kind of damage tends to correlate well with aging (link), the number of protein carbonyls in the brain did not increase with age in either group of normal mice. In transgenic mice, supplementation resulted in a non-significant trend for reduced carbonylation.
Mitochondrial protein carbonyls increased with aging in normal mice. Young normal mice had only 34% of the mitochondrial carbonyls seen in old normal mice, and supplemented normal mice had only 64% of the carbonyls seen in untreated normal mice. In untreated transgenic mice, protein carbonyl levels were the highest, while in supplemented transgenic mice they were the lowest of all four groups. For some reason there appears to be U-curve in the level of protein carbonyls in transgenic mice, with young and old mice showing higher levels than middle-aged mice.
The fact that the dietary supplement reduced protein carbonyls in the brain and mitochondria means that it was able to cross the blood-brain barrier and mitochondria. These are considered key goals of aging interventions. Indeed, supplemented normal mice had an 11% increase in lifespan. The authors think of this as a modest increase and suggest that the increases in physical and mitochondrial activity are the reason the mice didn't live even longer. I'm not sure the "higher metabolic rate = pro-aging" theory they hint at is correct, but nevermind: the fact that normal, healthy mice showed increased maximum lifespan is what's important.
Conclusion
A dietary supplement containing non-prescription ingredients ameliorated the age-related decline in physical activity in both normal and senescence-accelerated mice. The supplemented mice retained their physical activity more than non-supplemented mice and had lower levels of protein carbonyls, an age-related marker of oxidative damage. Importantly, an lifespan increase of 11% was seen in normal mice, showing that an "anti-aging cocktail" based on dietary supplements is feasible at least in mice.
For more information on aging and lifespan extension, see these posts:
Aubrey de Grey in Helsinki, Finland
Giving Heat Shocks to Roundworms Extends Lifespan by Almost 40%
How to Live Forever: My 5 Steps to Immortality
Drinking 10 Cups of Green Tea Daily and Not Smoking Could Add 12 Years to Your Life
