Why Protein and Resistance Training Protect Muscle Across Life

Shane Parrish: Let's come back to sort of the framework for approaching this. And so we've talked about micronutrients a little bit. Let's talk about macro.

Dr. Rhonda Patrick: So, I mean, so I'm sitting here talking about all these micronutrients and it was like vegetables was a big thing we were talking about, right? But we also hit on omega-3s and that was fish. Protein, right? So fish is a source of protein. Protein is, you know, amino acids are something that we need to get from our diet every day. Much like we store glucose as glycogen in our liver and our muscles, we store fat like triglycerides, right, adipose tissue. We don't really store amino acids, although our muscle, skeletal muscle, is kind of a reservoir for them. And during periods of fasting or low protein intake, we pull from our muscle to get amino acids because they're essential to survive. And what does that mean? That means you're pulling important protein from your muscle, and that does cause muscle atrophy. So you want to avoid that, right? And so in order to help avoid that, all these, you know, regulatory committees had come up with, let's figure out how much protein people need to take in every single day to avoid those losses, right? You don't want to be pulling it from your muscle. You want to replenish everything that you're losing every day. And so studies were done many, many years ago, and that number came up to be 0.8 grams of protein per kilogram of body weight is what was the recommended daily allowance for protein intake. Fast forward decades, you know, you've got all this new science and new technology that's come out and new ways of measuring things. You know, any scientist will tell you that your data is only as sensitive as, you know, the tools that you're using. Okay, and so data from experts like Dr. Stuart Phillips and others, they started to, you know, look into how you measure protein losses and amino acid losses. And it turns out that those studies that were done decades ago were using tools that were basically underestimating the losses of amino acids. So it turns out using new techniques that are more sensitive that in order to just prevent your body from like pulling from, you know, your skeletal muscle to get amino acids, the minimum amount of protein you need to take in is actually 1.2 grams per kilogram of body weight, which is higher than the 0.8 grams per kilogram body weight, right? So, and that's just, you know, the bare minimum, like the minimum amount you need to prevent, like, again, to prevent your body from pulling from muscle. And they also did some studies looking at, well, what if you're physically active, right? You're causing damage to your muscle, you're using a lot of energy. I mean, lots of things going on. That number goes up to 1.6 grams of protein per kilogram body weight. And this was a big eye-opener for me a couple of years ago when I talked to Dr. Phillips and started looking and reading his research because I always thought people were getting enough protein. I thought, oh, well, people are getting enough. And turns out, a lot of people are not getting enough protein because they are not getting at least that 1.2 grams per kilogram, you know, body weight, bare minimum. And so that, I think, is— you have to think about, okay, well, where do I get my protein? Meat is— animal meat is probably one of the best sources because essential amino acids are very highly concentrated in poultry and meat and fish. If you're a vegetarian or a vegan, you just have to really work really hard and supplement with protein powders and stuff to kind of get that amino acid composition up.

Shane Parrish: Is all sort of, like, animal protein the same? Like, I would imagine you need the complete set of sort of amino acids for it to be the most bioavailable in your body. I don't know what I'm talking about here, obviously. But is there, like, a big difference between steak and chicken and sort of other sources of protein that we typically think of?

Dr. Rhonda Patrick: There are differences with respect to their micronutrient profiles in general, like, you know, like steak has a lot more iron, for example. You know, there's a lot of zinc in, like, shellfish, like oysters. So, you know, but with respect to just the essential amino acids, you know, like getting them from those, any of those sources, like fleshy sources, you know, meat, poultry, fish is pretty good with respect to, like, protein. You will find that they'll, like, per ounce of, you know, food that you're eating, maybe there's, like, a little bit more in, like, denser in meat than fish or something like that. But, yeah, there are subtle differences between them, but also just in the whole micronutrient profile itself, right? So, like, some of them have more zinc, some of them have more, you know, iron, some of them have more B12. So things like that also. And then fish have the omega-3 much more than steak.

Dr. Rhonda Patrick: So there's, generally speaking, there's a big difference in their, like, micronutrient composition, generally speaking. But with respect to the essential amino acids, like, if you're really trying to hit that 1.2 to 1.6 grams a day per— I mean, 1.6 grams per kilogram body weight, that's very important.

Shane Parrish: That's—that's a lot.

Dr. Rhonda Patrick: It's a lot of protein. It is. It actually is really a lot of protein, especially for people that are physically active. And you might be going, well, why? Why is that so important? Well, like you know, so if you are, if you are constantly pulling amino acids from your muscle, it's like pulling from your retirement fund early, right?

Dr. Rhonda Patrick: Our muscle mass peak is probably, I would say, anywhere between 20 and 30 years old. That's when we're at peak muscle mass. After 30, as you get into your 40s, you start going down. And then, you know, you get to 50, even more so. It starts to get harder. That's why exercise is so important as you age.

Shane Parrish: So important to maintain your—

Dr. Rhonda Patrick: Yeah, I mean, there's lots of reasons we can talk about aerobic exercise versus, you know, resistance training. But resistance training is the other way to stimulate, like, skeletal muscle protein synthesis and increase muscle mass, but also muscle strength. Both of those decline with age. And you want to try to build up that muscle mass reservoir earlier in life, kind of like you do with your retirement fund, right?

Dr. Rhonda Patrick: Like you want to build it up, because you're going to be pulling from it no matter what, even if you're working out later in life, you're still going to be pulling from it, because you just lose more muscle mass and strength as you age. It's just part of the aging process. And so the more, the more you can kind of counter that with resistance training, with making sure you're getting enough protein, then the better off you're going to be. But, you know, again, it's like, if you didn't do it earlier in life, it's never too late. Like, that's something also to, like, keep in mind. Like, don't give up. Like, oh, I'm already 50, it's too late for me. No, because, like, you can get gains in muscle mass and really actually great gains in strength, particularly with resistance training. Protein intake is one easy thing. Like, a lot of people, like, elder, like our parents, like, you know, not everyone's exercising, right? They're not doing resistance training. And so, that protein intake becomes even more important at that point. And something also that you might find interesting, Shane, is that we're talking about omega-3s. So, there's some work from Chris McGlory. He's up at— he was at McMaster. He's in Canada. Gosh, what university is he at now? I forgot. It slipped my mind. But he did training at McMaster with Stu Phillips. And he had basically done some research that have found omega— high-dose omega-3s could prevent disuse atrophy. So like when people are older, they're not using their muscles a lot. And when you're not using your muscles a lot, and you're certainly not getting enough protein, you start to atrophy even more, right? But if there was like— if you gave them a high-dose omega-3, so this was like 4 grams a day, 4 to 5 grams a day. It totally prevented disuse atrophy, and this was in younger—they did the study in younger adults, younger females—but it was, like, 50% less. And Dr. McGlory has looked into a lot of other—you know, he's done some other studies on the mechanism, and he thinks that what's happening is omega-3s are sensitizing your skeletal muscle to amino acids. In other words, you're getting more amino acids into the— you're getting more bang for your buck. So more amino acids are getting in when you have the omega-3s there because, yeah, omega-3s are really important for the skeletal muscle, like, membrane and stuff. And so it might be easier just to get the nutrients in.