Does A Keto Diet Cause High Cholesterol – Even if you are at risk for cardiovascular disease, you may still be a candidate for the popular diet.
For every person who talks about the ketogenic diet, there is another warning about bad effects on your heart. The worry is that if you follow a very high-fat, moderate-protein, very low-carb diet, your cholesterol levels will rise as a result, which in turn could increase your risk of heart disease.
Does A Keto Diet Cause High Cholesterol
The concerns are certainly valid. On a keto diet, each day you eat up to 80 percent of your calories from fat and stick to 20 to 50 grams of net carbs, a term used in popular diets including keto and Atkins but one that is not officially recognized to the medical community. (To calculate net carbs, subtract fiber and sugar alcohols from total carbs, per Atkins.) All of this means you’ll be eating a lot of fat per day, and in the name of meeting that quota, that might include unhealthy choices like butter, coconut oil, and animal fat. These are all sources of saturated fat, which has been linked to poor heart health, according to the American Heart Association (AHA). (The purpose of keto is to shift your body from carb-burning to fat-burning, called ketosis.)
Foods To Eat On A Ketogenic Diet
But the effects of keto on heart health are not as simple as it sounds. In fact, the keto diet may not be as detrimental to your cholesterol as previously thought.
“When you look at the data, a few things are clear. “When you look at population studies and clinical trials, the effects of the keto diet on lipids are small,” says Daniel Soffer, MD, an internist and lipidologist at Penn Medicine in Philadelphia. Dr. Soffer is a member of the National Lipid Association, an organization dedicated to the management of lipid disorders. In October 2019, the National Lipid Association published a position statement on low- and very-low-carbohydrate diets, the ketogenic diet, and their relationship to lipids and published it in the Journal of Clinical Lipidology (PDF). Most commonly, he says, studies show that keto produces modest reductions in triglycerides, modest changes in heart-protective high-density lipoprotein (HDL, or “good”) and minimal changes in low-density lipoprotein (LDL, or “bad”) levels. Some studies, the review says, show an increase in LDL on low- or very-low-carbohydrate diets. (However, long-term studies are lacking.)
Whether these numbers – especially HDL – go up or down depends largely on the quality of the keto diet. “One problem is that there is no single ketogenic diet. There are different ways to follow it, and some are careful about what fat it eats, while others don’t,” says Soffer.
To his point, one previous paper noted that in human studies of normal-weight and obese people, the keto diet is generally associated with a decrease in total cholesterol, an increase in HDL, a decrease in triglycerides, and a decrease in LDL. Meanwhile, other studies, the review notes, show something different: an increase in LDL or no fluctuation either way. In studies that lowered LDL, people ate a low-carb diet that was high in healthy unsaturated fat and limited in unhealthy saturated fat, the authors note.
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One earlier study found in the article above compared a low-calorie and very low-carb, high-fat diet (what would be considered a keto diet) in more than 360 overweight and obese participants. Some of the participants had diabetes, some did not. After about a year, those in the keto group saw total cholesterol, triglycerides, and LDL decrease while HDL increased.
To get an idea of whether a keto diet might have a negative effect on your cholesterol, consider your starting triglyceride count. According to the Mayo Clinic, triglycerides are another type of lipid in your blood that your body uses for energy; high triglyceride and LDL levels can lead to fatty deposits that chew up arteries, says the AHA. A normal level is less than 150 milligrams per deciliter (mg/dL). “About a quarter of the population has a triglyceride level above 150 mg/dL, which is the threshold for considering elevated triglycerides.” That’s a large percentage of the population, so it’s not uncommon,” says Soffer.
If you have normal levels, it’s probably safe to try keto. “For people with normal or perfect triglyceride levels, keto has little or no effect,” says Soffer. If, on the other hand, you have insulin resistance, type 2 diabetes and/or abdominal obesity and your triglycerides are elevated—it may seem like you should avoid keto, but the opposite may be true, Soffer explains. that the low-carb nature of ketosis tends to reduce insulin resistance and improve triglycerides.
Research also points to this effect. A small randomized controlled trial published in August 2020 in Nutrition & Metabolism looked at 34 older adults with obesity over eight weeks. Those on the very low-carb diet lost three times more visceral fat compared to the low-fat group; low-carb diets also had greater improvements in insulin sensitivity, triglyceride levels, and HDL cholesterol.
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Speaking of which, the relationship between triglycerides and HDL cholesterol adds another layer. When triglycerides are high, HDL is usually low, says the AHA. Flip that script, and “anything that lowers triglycerides will also [tend to] raise HDL,” says Soffer. Remember, HDL is a type of “good” cholesterol that carries some LDL out of the bloodstream and into the liver where it can be metabolized and disposed of, according to the AHA — so increasing HDL is ultimately good for your heart.
The study only included 34 people—so more research (especially larger, long-term studies) is needed before researchers can fully understand the true effects of ketosis on insulin resistance and triglycerides.
A larger research group of 567 diabetics, drawn from more than 13 studies in a November 2020 meta-analysis in Nutrition & Diabetes, found that following a ketogenic diet reduced fasting blood sugar and – in eight studies – also reduced HbA1c levels (a measure of average blood sugar over time). . On average, HbA1c decreased by 1.5 percent; The authors note that research suggests that a 1 percent reduction in HbA1c could reduce the risk of heart attack by 14 percent.
But overall, when it comes to using keto for fat or weight loss, the research is mixed. One big caveat: There isn’t enough data to show whether keto can produce long-term results. As one earlier review pointed out, weight loss on keto peaks at five months, followed by a gradual weight loss. And a meta-analysis of 38 studies in the December 2020 issue of Nutrition that compared low-carb and low-fat diets concluded that each has different effects on the body, but only in the short term. A low-carb diet was associated with greater weight loss (about 3 pounds) and better HDL and triglyceride numbers compared to a low-fat diet. On the other hand, a low-fat diet more effectively lowered LDL and total cholesterol. However, these results were only valid in the short term, and the few studies that looked at results after two years found that the results were no longer significant, possibly because people had trouble sticking with it long term.
Using The Ketogenic Diet To Manage Diabetes
The effect of a high-fat, very low-carb diet on your LDL is less clear. Again, as the AHA says, LDL is the type of cholesterol associated with atherosclerosis, which can increase the risk of heart disease and stroke. It can go up, down or stay relatively the same. Hypothetically, if you have normal triglyceride levels and are doing keto to lose weight, your LDL may be stable, Soffer says. Similarly, if you have high triglycerides to begin with and that number drops on keto, your LDL may still go up.
The bottom line is that keto alone cannot contribute to the high cholesterol that some people report when they start the diet. But if you start eating more saturated fat because you’re on keto, your LDL will probably go up. Increasing saturated fat intake “has been shown over and over again” to raise LDL, Soffer says.
Where things get potentially dangerous is if you’re one of those people who has an inherited genetic mutation that affects how LDL particles are regulated. “If these individuals follow a keto diet, their LDL levels can skyrocket,” says Soffer. This finding doesn’t happen often enough to skew the overall results in population studies, but what matters most is the effect your diet has on your health. “This is a long-recognized phenomenon that has not been well publicized,” he says, adding that the genetics driving this response are not fully understood. (The APOE gene might be one, but it’s probably not the only one, he says.)
You may not be aware that you have a pre-existing genetic mutation, also called familial hypercholesterolemia (FH). In fact, as the AHA points out, only 10 percent of people with FH know they have it. Being aware of your family history, including members who have had a heart attack at a young age, is important and can help point the provider in the right direction. In some cases, research shows that a low-carb diet may actually be beneficial for those with FH who also have insulin resistance, previous analyzes suggest. This is not something to tease out on your own. Instead, it’s just another reason
