There it was, on news app after news app on my iPhone, the report about how "drinking muscle-building protein shakes" could threaten your health and reduce your life span.
That kind of news gets your attention, especially if you've spent a good part of your adult life tapping on the bottom of a protein shake, trying to give gravity an assist in draining the last few rivulets of protein into your mouth.
I looked up the study and sure enough, there it was. Scientists from the University of Fredonia recruited 12 bodybuilders. Six were designated as the control group and the other 6 were force-fed 12 gallons of protein shakes, causing all 6 to explode.
No, no, no. That wasn't the real study. I made that up. But the real study, or at least the way the real study was interpreted by the lay press, is just as ridiculous.
What The Silly Monkeys Did
I won't bother going into all the minute details of the study that was so widely mischaracterized. What you need to know, though, is that Australian scientists gave several groups of mice a diet of which 18% was protein from casein.
One group of mice, however, had about a third of their whole protein replaced with free-form branched-chain amino acids (BCAA). That group started to eat more than the other groups, got fatter, and then died earlier than the other groups.
What probably happened is that the large amount of BCAAs in their diet caused a decrease in serotonin production, thereby increasing their appetites and compelling them to overeat.
That's it. You're probably wondering how the hell anyone could make the deductive leap from mice that overdosed on BCAAs to humans dying from protein shakes. The answer is in the press release from the University of Sydney where the research took place. It made the observation that "BCAAs are included in all sorts of supplements for athletes," including protein drinks.
Got that? Since some protein drinks contain additional BCAAs, then protein drinks in general can supposedly damage an athlete's health. Never mind that the study itself never said anything at all about protein supplements. Never mind that no human is going to replace about a third of his daily whole-protein intake with BCAAs.
Besides, there's nothing inherently dangerous about BCAAs. The mice were just fed a stupid amount of them and it caused them to overeat.
What This Means To You
What does this mean to you? Absolutely nothing. Ignore it. Ignore all the articles about it that keep popping up in your health news apps.
The truth is, a good protein shake, made from a high-quality protein powder and not made in bargain-basement manufacturing companies in China from ingredients you don't want to know about, used as a supplement instead of a meal replacement, can do some great things for a body, like:
- Increase lean body mass (muscle!)
- Increase levels of growth hormone
- Increase serum levels of testosterone
- Reduce body fat percentages
- Greatly increase insulin sensitivity
- Improve cholesterol ratios (higher HDL levels).
As far as manufacturers adding BCAAs to their general-usage protein powders, it's often unnecessary except in peri-workout situations, but it certainly won't shorten your lifespan.
Likewise, BCAAs, taken by themselves, can be tremendously effective in building muscle, as long as you don't replace a good part of your whole protein intake with them!
Related: The Effects of Eating Truckloads of Protein
Related: More Protein Equals More Muscle
- Samantha M. Solon-Biet, et al. "Branched-chain amino acids impact health and lifespan indirectly via amino acid balance and appetite control." Nature Metabolism, 29 April 2019.