Why so many supplements?
For general health, I believe in a conservative approach: the body knows what it is doing, and I’m cautious about interfering. I eat “natural” foods and avoid most pharmaceuticals.
But in old age, the body is genetically programmed for self-destruction. “Natural” means deterioration and death. I’m willing to take risks to interfere with the body’s aging process, and to try supplements once I think there’s a better chance they’ll help me than that they’ll hurt me – a rather low bar.
I’ve taken a bold approach. You may prefer to be more conservative.
Summary for the impatient*
Recommended for everyone
Substances that have reduced mortality in epidemiological studies
This is the best evidence we could ask for that a substance actually contributes to longer life span. Unfortunately, there has been no systematic exploration of candidate substances, and these few for which we have evidence are lucky accidents, in that they happen to be widely consumed and mortality statistics were compiled for other reasons.
Substances that have extended life span in rodent studies
Supplements in this class are an elite club. Many chemicals that extend life span in worms and flies fail when they get to mammals. Many more deserve testing in mammals but have not been tested, because mice are expensive to keep.
Insulin sensitivity and Caloric restriction mimetics
We lose insulin sensitivity both with age and with weight. Loss of insulin sensitivity is both a symptom and a cause of aging. Supplements like Metformin, Alpha Lipoic Acid and Chromium can help preserve insulin sensitivity. Other substances trick the body into thinking it is thinner than it is, and so they work to increase life span via the same pathway as CR. These are some of the surest bets we have, but on the other hand we may “max out” on the benefits of CR. That is to say they are less effective if your weight is already low, and adding more CR mimetics is not likely to offer further benefits.
I don’t assume that because a supplement is an anti-oxidant, it therefore contributes to life extension, or that it does us any good at all. While it is true that there is oxidative damage that accompanies aging, particularly in the vicinity of our cells’ mitochondria, this damage seems to be under the body’s control, and it is an effect of aging rather than a cause. Free radicals (or ROS) are chemical bi-products of energy production in the mitochondria that attack sensitive biomolecules and lead to oxidative damage. The trouble is that these same ROS are also signals that stimulate the body to replace damaged cells and to repair tissues.
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