Ask A Cardiothoracic Surgeon: The Truth About Keto and Heart Health

Added: 2026-05-12

[00:00:01]Hey everyone, Dr. Michael Richmond, double board certified cardiothoracic surgeon. So today, let's talk about the ketogenic diet. Obviously, it's everywhere. Social media, fitness blogs, and even some wellness influencers swear by it, which seems to be contradictory wellness, right? But we're going to go further. I want to give you the bottom line that you don't always hear online.

[00:00:26]Uh the fact is there's not one reputable board-certified cardiologist, cardiothoracic surgeon, or vascular surgeon that think it's beneficial long term. And as a cardiac surgeon, I can tell you with 100% certainty, the risks outweigh the benefits. So then you ask, why is it so popular? Because in the short term, it does cause weight loss.

[00:00:48]But remember, any diet causes weight loss if you do it right. But the question we have to ask is at what personal cost? And the only way we can do that is by looking at the science. So what does keto actually do to your cells. So first a quick refresher to those of you who know, and if you don't know, it's new, but a true ketogenic diet limits carbs to 50 grams a day, which is about one banana, one bag of potato chips. And the goal is to force your liver to produce what's called ketones or ketone bodies, which become an alternate fuel for your brain when glucose is scarce and your heart. I know this sounds clever, but here's the problem. Your cells don't function optimally in a prolonged ketoic state, regardless of what you hear, because evolution would have made it that way if it was good for long term. So to keep making ketones, you have to massively reduce fruit intake, vegetables, whole grains, and legumes. In fact, one review found that even a wellplanned 4:1 ketogenic diet is often deficient in multiple vitamins, including vitamin K and C and folic acid and fiber. And even though I'm not into multivitamins on this, you need a multivitamin because of nutritional shortfalls. Now, let's talk weight loss because that's why most of you are on it. Yes, keto can induce short-term weight loss. Again, just like any diet, a 2020 metaanalysis of 30 different studies show low carb diets led to slightly more weight loss than low-fat diets at 6 months. 6 months. But here's the catch. At two years, there's no significant difference between both the diets. But as a cardiac surgeon, I can tell you what keeps me up at night and worries me, and that's what it does to your lipid or your cholesterol profile. So, normally when you lose weight, your cholesterol drops about 2 milligrams per deciliter, which is negligible per kilogram lost. Keto is often the exception. And I'm going to give you some real numbers. Okay. So in 2002 a study by Westman showed that 29% of the participants had rise in their LDL cholesterol which is the bad cholesterol by an average of 18 milligs per deciliter. One participant LDL cholesterol went from 123 to 225 milligrams per deciliter. And another went from 184 to 283 milligrams per deciliter, which is insane because they should have been on lipid lowering medicine to begin with. And how they were led in this trial is beyond me. And this doesn't just occur in older or unhealthy people. In fact, a 2018 pilot study of young fit adults average age 31 found that after 12 weeks on keto, despite losing three kilograms, their LDL cholesterol increased by 35% from 114 to 154 milligrams per deciliter. So, what is ketogenic diet in summary? It can reduce body weight, but they're not more effective than any other diet at 2 years. They come with marked risks.

[00:03:54]Rising bad cholesterol which leads to atheroscllerotic cardiovascular disease.

[00:03:59]Nutrient deficiencies I didn't talk about a damaged gut microbiome in increase of red meat and saturated fat besides cardiovascular disease are increased are linked to increased rates of cancer, diabetes, and there's even some suggested of Alzheimer's. There's also data showing pregnant women on low carb diets have a higher risk of neural tube defects in their children even when given the normal pregnancy uh folic acid supplementation. So I'm not here to give you a fear of hydro carbohydrates. I'm here to tell you that balance wins. The current evidence suggests that for most people the risks of a ketogenic diet far outweigh the benefits. So with that, hope you learned something. Thank you for listening. Um, and I hope you have a great day.