Dr. A explains how carnitine shuttles fatty acids into mitochondria for energy, why intense exercise or ketogenic diets deplete it, and how to supplement. Load with 1,000 mg L-carnitine three times daily for a month, then maintain at 1,000-1,500 mg daily. Doses above 2,500-3,000 mg long-term can suppress thyroid function.
Carnitine, if you looked at the question and you see we might get it from food, is amine structure. It's an amino acid, usually in a supplement form. They call it L-carnitine, which is just the chemical form of the carnitine that's there. And carnitine, the reason it would come up when I'm talking about the mitochondrial function and activity is that carnitine is used specifically in a place called the carnitine shuttle to help put fatty acids into the mitochondria. To undergo something called beta oxidation, so they can be chopped up into energy-producing units. And without beta oxidation and fatty acids being broken down that way, a lot of our energy substrate—the place where energy comes from—would not be burned or used. Now, why would we have an amino acid amino structure involved in this carnitine shuttle? Well, the place outside the mitochondria is the cytosol—the big part of the cell where all the organelles live—and fatty acids. Go into the cell all of the time. There are these big long things that look like a kind of a zigzag. And the problem is we want to burn them in the mitochondria, for example. There's no natural diffusion or way that a fatty acid wants to go in the mitochondria. Now, our bodies evolving knew this, and so they set up a carnitine shuttle for fatty acids. So fatty acid comes by and it is grabbed through a 3-step process where carnitine is in the middle to hold the fatty acid and pull it into A place called CPT2, which puts the carnitine into the mitochondria to burn it up in beta oxidation. Now, amino acids are often used as what they call a conjugate, where the carnitine is there and it comes up along my fatty acid here and adds to it, conjugates to it. So it sort of makes it a cumbersome molecule. What it does in that step, so that's in the carnitine acyltransferase step, that then makes that molecule fall over to the CPT2. Transporter and the fat gets stuck. It can't go back outside and then gets shoved into the mitochondria to be burned up in beta oxidation to make energy. So why would I bring this up in mitochondrial talks? It's because mitochondria have a lot of carnitine. They use a lot of carnitine to feed fatty acids in. Now there's other mechanisms for carbohydrate residues to go in that don't use carnitine, but we're talking about carnitine today. What could be a sign that we've used up a lot of carnitine? It could be fatigue. Now, when is a real common time that we would see fatigue related to carnitine being used up? And I want to make it clear, it doesn't mean there's no carnitine in your body. It just means that maybe you've used up what was available and you have to replace it. Well, the big area that can do that would be either exercise where the demand goes up, so you're pulling more fatty acids in. Another area is you switch your diet around. Maybe you're doing like a ketogenic diet or a low carbohydrate diet that's not ketogenic, but you're— there's more fats available. And so you go from not burning as many fats to burning more fats. That's another reason, because you're shoving more fats in there, you're going to use up the carnitine. And then there's little combinations of all of the above. You go from being sedentary to working out more, and your, you know, muscle cells' preferred energy, you know, for a lot of purposes would be burning fat. Well, maybe you've burned more fat, used up more carnitine. So then you say, well, where would I get carnitine in my diet if I need more? Well, carnitine was named because it was originally found in meat. So carne, carnitine. And meat. Now meat's not the only place that you can find it. And with the magic of the internet, you can look up plant sources of carnitine and you can certainly find those there. But in higher dense protein sources, especially animal proteins, that's one easy place to get more carnitine. As I said, there are some plant sources and you can just look up carnitine food sources and it will tell you more than you ever wanted to know on the internet about that. But then there's a couple related things to think about if you're going to supplement carnitine. So a lot of people, if they're like otherwise, They're pretty healthy, but they're doing more working out or they've shifted their diet or something and they're feeling, you know, a little more fatigued, maybe recovery's a little slow, whatever. We will often therapeutically give them a carnitine supplement on top of their diet. And there are 2 forms. One is L-carnitine and one is acetyl-L-carnitine or acetyl-L-carnitine, same thing. And the difference is the absorption. So L-carnitine absorbs a little more poorly. Acetyl-L-carnitine's a A little bit easier trip in through the GI tract. And so if you are taking them and someone's recommending doses, for example, an L-carnitine dose at 1,000 or 1,500 milligrams might only need to be 500 to 700 milligrams for acetyl-L-carnitine, or maybe even less. Now, we use this a lot with people, usually give it to them in the morning, and that can help a lot with those things. Is there any cautions with carnitine? Well, generally carnitine in, in your diet, no. Carnitine in supplements at low dose, no. Interesting. If you take a lot of carnitine for a long period of time, meaning 2,500, 3,000 milligrams or higher, longer than a month or two, it can have a feedback mechanism towards your thyroid and it can slow your thyroid down. So where we might give somebody who's very fatigued or they switch their diet and they're working out more or whatever, we might give 'em a loading dose in the beginning of say an, you know, acetyl carnitine at 500 milligrams twice a day or 1,000 milligrams or something, or L-carnitine at, you know, 1,000 milligrams 3 times a day. Might do that for a month. That's fine. But after a month, the L-carnitine dose equivalent of about 3,000, we want to cut that down to 1,000, 1,500. Acetyl-L-carnitine, 500 to 1,000. And then you're not going to affect your thyroid. The thyroid effect really starts at those higher gram doses of either of the products. And that is basically the major medical concern with carnitine. Otherwise, it's just going to make you feel better. One thing that you can also notice with amino acids in general, taking them orally. If you have a lot of disrupted bacteria, you know, dysbiosis and stuff in the gut, sometimes you'll take amino acids and get more, say, gas, bloating, that sort of thing. That doesn't mean you're reacting to the amino acid. It means that the bugs in your GI tract are not the good ones and they're eating the amino acid, making you feel poorly. All right, so today we talked about your questions about carnitine. We looked at the fact that we get a lot of carnitine in dense protein sources. It was originally found in meat, but you can look up on the internet, some vegetable sources as well. Carnitine helps pull fats into the mitochondria to burn them and give us more energy. Carnitine gets depleted when we increase exercise or decrease carbohydrates in the diet, et cetera. And we can supplement it, which is generally very safe. But if you're looking at thousands of milligrams for long periods of time, the one medical issue that you want to watch for would be slowing your thyroid down, which obviously you don't want to do that. But short-term higher doses are fine. Then we usually go to Lower doses long-term. All right, I'm Dr. A. I hope that answered the question that came in about carnitine. Thank you so much everybody for liking, sharing, and all the new subscribers, all the current subscriber group that we have. We just went over 100,000 subscribers. We're so thankful for that. I'm going to post some other content up here you can take a look at. I'll see you all on the next video.
