If you’re a bodybuilder, then you may not enjoy this post. It even makes me a little concerned. I’ve lived a bodybuilding lifestyle for over two decades, not that I can do anything about the past, of course!
I recently received an impressive review paper from Professor John Speakman, Director of the Institute of Biological and Environmental Sciences at the University of Aberdeen in Scotland. He and his colleague, Sharon Mitchell, wrote about the topic of caloric restriction in their paper, which was recently published in the journal Molecular Aspects of Medicine (1).
As I told Dr. Speakman by email, I’m no PhD; nevertheless, I can appreciate the immense amount of work that must have gone into preparing his review paper. I found it very impressive. It was also quite ironic.
What made the paper ironic is the following. Referring to extensive research, Drs. Speakman and Mitchell discuss a number of factors, the restriction or down-regulation of which may delay aging. Yet these are some of the very same factors that bodybuilders -often encouraged by bodybuilding supplement marketers- hope to increase or up-regulate. Therein lies the irony. Let’s hope they aren’t making themselves age faster.
I’ll briefly cover a few examples below. If you want more details, definitely read the full paper.
(1) Caloric restriction: Animal studies suggest that by eating fewer calories, aging may be delayed.
(2) Protein restriction: Restriction of protein may also delay aging. In fact, some of the anti-aging effects of caloric restriction may be due to the restriction of protein per se.
(3) mTOR: If you read enough bodybuilding supplement ads, you’re bound to come across one talking about how the advertised product stimulates mTOR, which in turn increases muscle protein synthesis, the essential element of building muscle. This is common with amino acid formulas, especially those containing leucine. Ironically, mTOR has also been suggested to play a role in aging. That’s why some scientists are studying compounds (e.g. resveratrol) that may lower mTOR activity.
(4) Insulin and insulin-like growth factor 1 (IGF-1): These two anabolic hormones are often talked about within bodybuilding circles. Bodybuilders generally try to increase their levels, not reduce them. More irony: Reducing insulin and IGF-1 levels may delay aging. Dairy protein (think whey and casein) has been shown to increase insulin and IGF-1. In large (~5-gram) doses resveratrol may lower IGF-1.
(5) Metabolic rate: This is an oldie but still a goodie. Animals with higher metabolic rates tend to age faster. Yet what are all those stimulant-containing “fat-burners” (a.k.a. “thermogenics”) designed to do? Stimulate your metabolism.
A caveat: Yes, much of what I’ve written above remains to be proven. Still, after reading the review paper of Drs. Speakman and Mitchell, it’s hard not to wonder if a bodybuilding lifestyle may encourage you to age more quickly. Again, let’s hope this isn’t the case.
REFERENCE
1. http://www.ncbi.nlm.nih.gov/pubmed/21840335
Caloric restriction
John R. Speakman ⇑, Sharon E. Mitchell
