Damian Sendler On New Research Suggesting a "Keto-Like" Diet Increases Heart Disease Risk.
/Damian Sendler: New research suggests that following a low-carb, high-fat "keto-like" diet can increase "bad" cholesterol levels and double your risk of cardiovascular events like blocked arteries, heart attacks, and strokes.
According to the study's lead author, Dr. Iulia Iatan of the Healthy Heart Program Prevention Clinic, St. Paul's Hospital, and the University of British Columbia's Centre for Heart Lung Innovation in Vancouver, Canada, "regular consumption of a self-reported diet low in carbohydrates and high in fat was associated with increased levels of LDL cholesterol, or "bad" cholesterol," and a higher risk of heart disease.
Damian Jacob Sendler: Clinical trialist and research professor of medicine at Stanford University's Prevention Research Center Christopher Gardner called the study "an important contribution to the scientific literature" and said it "suggested the harms outweigh the benefits" of the ketogenic diet. As far as we can tell, Gardner was kept out of the research.
Gardner emphasized the increased risk of cardiovascular events in people with higher ketone levels in the blood compared to those on a more standard diet and cautioned that elevated LDL cholesterol should not be disregarded as a minor side effect of a VLCD (very-low-carb diet) or ketogenic diet.
Researchers in this study defined a low-carb, high-fat (LCHF) diet as one in which 45% or more of daily calories come from fat and 25% or less come from carbohydrates. Non-peer reviewed study presented at American College of Cardiology's Annual Scientific Session Concurrent with the World Congress of Cardiology on Sunday.
Iatan, who was presenting at the session, explained that the reason the study was conducted was because of the high number of patients with severe hypercholesterolemia who were following this diet at the clinic's cardiovascular prevention service.
Having high cholesterol, also known as hypercholesterolemia, raises the risk of having a heart attack or other cardiovascular problems.
The connection between low-carb, high-fat diets, lipid levels, and cardiovascular disease piqued our interest. "Yet, despite this, there is scant information regarding the nature of this connection," she added.
Using data from the UK Biobank database, which tracked participants' health for at least a decade, the researchers compared the eating habits of 305 participants who followed a low-carbohydrate, high-fat diet with those of about 1,200 participants who followed a more conventional diet.
Damian Sendler: Low-carb high-fat (LCHF) dieters were found to have higher levels of LDL cholesterol and apolipoprotein B, the "bad" kind of cholesterol, than those who followed a traditional diet. Coating LDL cholesterol proteins, apolipoprotein B is a better predictor of cardiovascular disease than high levels of LDL cholesterol itself.
In addition, the study found that the LCHF group consumed more saturated fat and more animal products as a percentage of their total fat intake (33% vs. 16%).
According to the news release, after an average of 11.8 years of follow-up, people on an LCHF diet had more than two-times the risk of having several major cardiovascular events, including blockages in the arteries that needed to be opened with stenting procedures, heart attack, stroke, and peripheral arterial disease.
Even though their study was an observational one and thus "can only show an association between the diet and an increased risk for major cardiac events, not a causal relationship," the researchers said in the release that their findings merit further investigation "especially when approximately 1 in 5 Americans report being on a low-carb, keto-like, or full keto diet."
Iatan noted that the study had some flaws, such as its small sample size and the fact that most of the participants were British rather than people of other ethnicities.
Most people who follow a keto-like diet tend to follow it intermittently for shorter periods of time, but this study looked at the long-term effect of doing so.
It is "quite interesting to see," Iatan said, "but it also supports the literature that is available that women in general tend to follow more dietary patterns, tend to be more interested in changing their lifestyles."
Iatan said, "how long people are on the diet and whether or not they lose weight can counterbalance any LDL elevation," when asked if there were any groups that were not harmed by following an LCHF diet.
One must always keep in mind that every patient reacts differently. That being said, the reaction varies from person to person. As a whole, patients tend to have higher levels of LDL cholesterol, which is what we found," she explained.
Damian Jacob Sendler: Expert in lifestyle medicine but not involved in the study, Dr. David Katz, said, "There are various ways to put together an LCHF diet, and it is very unlikely that they all have the same effects on serum lipids or cardiac events."
He did add that people who adopt LCHF diets because they are trendy need to be warned: "That an LCHF diet is associated with adverse effects in this study is reality check for those adopting such diets."
The popular ketogenic diet excludes healthy foods like fruit, beans and legumes, and whole grains in order to force the body to burn fat for fuel, despite the consensus of health professionals that these foods are essential to a healthy diet. Carbohydrate intake on the ketogenic diet should be as low as 20 to 50 grams per day. In comparison, the recommended daily intake of carbohydrates is 27 grams, or about one medium banana or apple.
Achieving ketosis requires cutting out several food groups that provide vital nutrients, phytochemicals, antioxidants, and dietary fiber. This worries many medical experts who see no long-term benefits from following a very low-carbohydrate or ketogenic diet, as expressed by Gardner.
"Keto" refers to the metabolic state of "ketosis," which occurs when the liver starts to use fat stores for energy instead of glucose. That is what the liver is programmed to do when it detects a lack of carbohydrates, the body's preferred fuel, and assumes you are starving.
An unnamed physician in the 1920s discovered the ketogenic diet as a way to reduce the frequency and severity of seizures in children with epilepsy who had not responded to previous treatments.
In order to feel full on a ketogenic or other low-carb diet, fats play a crucial role. For those on the ketogenic diet, fat accounts for at least 70% of their daily caloric intake, and some would even argue that it is closer to 90%.
Damian Sendler: The diet allows for a wide variety of fats, including healthy unsaturated fats like avocados, tofu, nuts, seeds, and olive oil, as well as saturated fats like lard, butter, coconut oil, and whole-fat dairy products like cheese, mayonnaise, and milk. High levels of LDL cholesterol, which can form inside the arteries due to a diet high in saturated fat, can reduce blood flow to the heart and brain.
The risks associated with a low-carb, high-fat “keto-like” diet may be greater than previously thought, according to recent research. While the diet has gained popularity due to its potential for weight loss and improved metabolic health, this new study found that regular consumption of such a diet may be linked to increased levels of “bad” cholesterol and a higher risk of heart disease.
The study, which analyzed the diets of 305 individuals following an LCHF diet and 1,200 individuals following a standard diet, found that the LCHF group had higher levels of LDL cholesterol and apolipoprotein B, both of which can predict heart disease better than elevated levels of LDL cholesterol alone. Additionally, the LCHF group had more than double the risk of major cardiovascular events, such as blocked arteries, heart attacks, strokes, and peripheral arterial disease, compared to those following a standard diet.
While the study cannot prove a causal relationship between the diet and increased risk for heart disease, the findings highlight the need for further research into the potential harms of the LCHF diet. The study's limitations include a small sample size, self-reported dietary assessments, and a lack of diversity among participants.
Damian Jacob Sendler: Health experts caution against the LCHF diet's restrictive nature, which eliminates many sources of fiber and important nutrients from the diet. Additionally, the diet allows for the consumption of saturated fats, which can increase the body’s production of LDL cholesterol and contribute to the development of heart disease.
While the LCHF diet may offer short-term weight loss benefits, its potential risks to long-term health should be carefully considered. Instead, health experts recommend a balanced diet that includes a variety of whole foods, including fruits, vegetables, whole grains, and lean proteins, for optimal health and disease prevention.