According to new research, a low-carb, high-fat “keto-like” diet may increase “bad” cholesterol levels and double the risk of cardiovascular events such as clogged arteries, heart attacks, and strokes. “Our study found that 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,” lead study author Dr. Iulia Iatan with the Healthy Heart Program Prevention Clinic, St. Paul’s Hospital, and University of British Columbia’s Centre for Heart Lung Innovation in Vancouver, Canada, said in a news release.
This study provides an important contribution to the scientific literature and suggests the harms outweigh the benefits
“This study provides an important contribution to the scientific literature, and suggests the harms outweigh the benefits,” said Christopher Gardner, a research professor of medicine at the Stanford Prevention Research Center who has conducted clinical trials on the keto diet. Gardner was not involved in the study. “Elevated LDL cholesterol should not be dismissed as simply a negligible side effect of a VLCD (very-low-calorie diet) or ketogenic diet,” Gardner said, pointing to the higher risk of cardiovascular events in individuals with higher ketone levels in the blood when compared to those on a more standard diet.
A low-carb, high-fat (LCHF) diet was described in the study as having 25% of daily calories from carbohydrates and 45% of calories from fat. The report, which has not undergone peer review, was presented on Sunday at the World Congress of Cardiology and the American College of Cardiology’s Annual Scientific Session. “Our study rationale came from the fact that we would see patients in our cardiovascular prevention clinic with severe hypercholesterolemia following this diet,” Iatan said during a presentation at the session.
A person’s risk of having a heart attack or other harmful cardiovascular events rises if they have hypercholesterolemia or high cholesterol. “This led us to wonder about the relationship between these low-carb, high-fat diets, lipid levels, and cardiovascular disease. And so, despite this, there are limited data on this relationship,” she said.
The researchers used health data from the UK Biobank database, which tracked people for at least ten years, to compare the diets of 305 people
The researchers used health data from the UK Biobank database, which tracked people for at least ten years, to compare the diets of 305 people following an LCHF diet with nearly 1,200 people following a conventional diet. Low-density lipoprotein, or LDL, cholesterol, and apolipoprotein B levels were found to be greater in those following an LCHF diet, according to the study’s findings. Higher levels of LDL cholesterol cannot predict heart disease as well as apolipoprotein B, a protein that coats LDL cholesterol proteins. The participants in the LCHF diet consumed twice as many animal sources (33%) as those in the control group (16%), and their total fat intake was higher in saturated fat.
“After an average of 11.8 years of follow-up – and after adjustment for other risk factors for heart disease, such as diabetes, high blood pressure, obesity, and smoking – people on an LCHF diet had more than two times higher risk of having several major cardiovascular events, such as blockages in the arteries that needed to be opened with stenting procedures, heart attack, stroke, and peripheral arterial disease,” researchers found, according to the news release.
The researchers said in the release that their study “can only show an association between the diet and an increased risk for major cardiac events, not a causal relationship,” because it was an observational study, but their findings are worth further study, “especially when approximately 1 in 5 Americans report being on a low-carb, keto-like or full keto diet.”
Iatan cited the limited sample size, measurement mistakes that can occur when dietary assessments are self-reported
Iatan cited the limited sample size, measurement mistakes that can occur when dietary assessments are self-reported, and the fact that the majority of the participants were British and did not represent other ethnic groups as study limitations. While most people who follow a keto-like diet tend to do so periodically for shorter periods of time, the study also looked at the long-term effects of the diet.
Most of the participants – 73% – were women, which Iatan said is “quite interesting to see, but it also supports the literature that’s available that women, in general, tend to follow more dietary patterns, tend to be more interested in changing their lifestyles.” When asked if there were any groups that were not harmed by following an LCHF diet, Iatan said how long people are on the diet and whether or not they lose weight “can counterbalance any LDL elevation.”
“What matters to remember is that each patient responds differently. And so, there’s really an inter-individual variability between the response. What we found is that, you know, on average, patients tend to increase their LDL cholesterol levels,” she said. Dr. David Katz, a lifestyle medicine specialist who was not involved in the study, said that “there are various ways to put together an LCHF diet, and it is very unlikely they all have the same effects on serum lipids or cardiac events.” However, he added, “That an LCHF diet is associated with adverse effects in this study is a reality check for those adopting such diets just because they are in vogue.”
The keto diet recommends keeping your daily carbohydrate intake between 20 and 50 grams
The majority of medical professionals claim that the popular keto diet, which forbids carbohydrates to force your body to burn fat for fuel, leaves out nutritious foods like fruit, beans and legumes, and whole grains. The keto diet recommends keeping your daily carbohydrate intake between 20 and 50 grams; the less, the better. To put it into perspective, the daily allowance of carbohydrates is about 27 grams in a medium banana or apple. “Those food groups that have to be eliminated to achieve ketosis are major sources of fiber in the diet, as well as many important nutrients, phytochemicals, and antioxidants. This is of concern to many health professionals who consider the VLCD or ketogenic diet to be harmful to long-term health,” Gardner said.
Keto is an abbreviation for ketosis, a metabolic condition in which your liver starts converting stored fat into the fuel ketones. When your body can no longer access its primary fuel, carbs, it is programmed to act as though it is starving. The keto diet has been around since the 1920s when a doctor discovered it as a way to treat epileptic youngsters who didn’t react to other forms of treatment for their seizures. Keto and other low-carb diets mainly rely on fats to make you feel full. The keto diet must contain at least 70% fat; other experts believe it should be closer to 90%. (www.genusinnovation.com)
The diet allows saturated fats like lard, butter, and coconut oil, as well as whole-fat milk, cheese, and mayonnaise, even though you can get all that fat from healthy unsaturated fats like those found in avocados, tofu, nuts, seeds, and olive oil. Saturated fat-rich diets enhance the body’s production of LDL cholesterol, which can accumulate in the arteries and obstruct blood flow to the heart and brain.