Interview with Prof. Mark Tarnopolsky. McMaster University (Canada)
My friend Dr. Chong He, former researcher at the Buck Institute (USA) and I recently interviewed Prof. Mark Tarnopolsky (McMaster University, Canada), one of the leading global experts on preserving muscle mass as we age.
Here are some of the most interesting parts from this interview.
What is sarcopenia?
Sarcopenia predominantly reflects muscle loss both in terms of size and function. What we care about at the end of the day is functional impairment and that's a problem because if our muscles are weak it's hard to go up a flight of stairs or get off of a toilet. It can eventually affect how we live our lives.
In fact, 30% of people over the age of 80 have functionally limiting sarcopenia, so it affects their daily activities. I think for most of us the most important thing is it's never too late to start. We've even done studies and folks up to age 92 where we put them on exercise training programs and they improved strength. I think exercise is really the core of almost any good therapy that's going to improve healthspan and lifespan.
So what kind of exercise will benefit the most?
So the most effective exercise is the one that you're going to do. I think the most important thing is to find what you enjoy. So if someone tells you to swim or to run, and that's the only way to do it, don't listen to them.
Find the activity that you enjoy. So what we found over many studies really is that it's probably best to do three times a week of endurance training and 2 to 3 times a week of resistance exercise to get the benefits of both.
We did a program with three months of endurance training and three months of resistance training. And as you would expect, participants got increases in VO2max and fitness when they did endurance, increases in strength when they did resistance. But there wasn't much crossover.
So I really think people need to do both.
What are the best supplements for muscle growth?
If you're an older person, if you just want to keep your muscles healthy, protein quality is important.
If you think about us as mammals, we split from birds and reptiles about 220 million years ago. Protein is normally present in meat and fish. So if you have a high meat or fish intake, you're probably getting enough.
Also creatine has been shown in many studies as being a safe supplement and probably 20 million people around the world are doing that to help to improve muscle mass.
And then the next thing that I would suggest for most folks is to identify and treat deficiencies, especially as you get older. So in North America and in most northern latitudes or extreme southern latitudes, you don't get as much sun exposure. We find that 85 percent of people don't meet the requirements for vitamin D and 15 percent are severely deficient.
The other important supplement I will mention is Omega3. Oh, and sorry, one other point, B12 deficiency. Yes, 12% of our patients are B12 deficient.
What are the greatest misconceptions about weight loss?
I think the biggest misconception about weight loss is that any loss is good loss.
And so unfortunately, the FDA, Health Canada, and pretty much every regulatory body in the world only looks at weight. So when you look at the incredible data from all these GLP-1 receptor agonist medications, Ozempic, Wijovi, and others. It's the weight that they're looking at. It's pretty clear now that these companies have sort of hidden or attenuated the data to show that in fact you lose a lot of muscle.
So for an older adult, when they lose weight, if you're losing 20 to 40% of that loss is skeletal muscle, which is what we're seeing with many of these products, that's an issue. If you were to just take Ozempic and eat highly processed food, lots of sugar, drink too much alcohol and do not consume whole grains and fruits and vegetables, you're not going to be a healthy individual.
You may well lose weight, but you've got to look at body composition. You've got to look at other factors. So what you eat is very important. I think eating as close to nature as you possibly can still is important.
The other issue too is that a lot of folks that I've been involved with in the obesity field say exercise is useless. It does nothing and people say that there's certain hunter-gatherers and all sorts of different reasons why they say exercise is not good. But keep in mind that from a weight loss perspective we've even shown that sometimes when you exercise you don't lose weight but you get a lot of other benefits: you get increases in vo2max, you get increases in lung capacity etc.
What about rapamycin and mTOR signaling?
Taking something like rapamycin is inhibiting protein synthesis. I don't think it is a good idea.
Even if you're on for three months and off, I don't think it's a great idea.
What's your take on VO2max as a predictor of longevity?
I'm a big fan of VO2max. It is a reflection of the sum total of the oxygen consumption by all active muscles, which is really a reflection of oxygen delivery and oxygen transport and uptake by the mitochondria ultimately. So it is an indirect reflection of your total mitochondrial capacity.
Enjoy the full version of this interview:
