New research suggests ‘keto-like’ diet may be linked to heart disease

CNN
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A low-carb, high-fat ‘keto’ diet may be linked to higher levels of ‘bad’ cholesterol and double the risk of cardiovascular events such as blocked arteries, heart attacks and accidents, according to new research. cerebrovascular.

“Our study found that regular consumption of a self-reported low-carb, high-fat diet was associated with increased levels of LDL cholesterol – or ‘bad’ cholesterol – and a higher risk of heart disease,” said the study’s lead author, Dr Iulia. Iatan from the Healthy Heart Program Prevention Clinic, St. Paul’s Hospital and the Center for Heart Lung Innovation at the University of British Columbia in Vancouver, Canada, said in a press release.

“This study makes an important contribution to the scientific literature and suggests that 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 viewed as just a negligible side effect of a VLCD (very low calorie diet) or a ketogenic diet,” Gardner said, noting the higher risk of cardiovascular events in women. people with higher blood ketone levels. , compared to those following a more standard diet.

In the study, researchers defined a low-carb, high-fat (LCHF) diet as 45% of total daily calories from fat and 25% from carbohydrates. The study, which has not been peer-reviewed, was presented to the American College of Cardiology Annual Scientific Session with the World Congress of Cardiology.

“The rationale for our study 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.

Hypercholesterolemia, or high cholesterol, increases the risk of heart attack or other adverse cardiovascular events.

“It got us wondering about the relationship between these low-carb, high-fat diets, lipid levels, and cardiovascular disease. And so, despite that, data on that relationship is limited,” he said. she stated.

Researchers compared the diets of 305 people on an LCHF diet with around 1,200 people on a standard diet, using health information from Britain’s UK Biobank database, which followed people for at least a decade .

Researchers found that people following the LCHF diet had higher levels of low-density lipoprotein, also known as LDL, cholesterol, and apolipoprotein B. Apolipoprotein B is a protein that coats LDL cholesterol proteins and may better predict heart disease. heart disease than high LDL cholesterol levels. can.

The researchers also noticed that the total fat intake of the LCHF diet participants was higher in saturated fat and had double the consumption from animal sources (33%) compared to those in the control group (16%).

“After an average of 11.8 years of follow-up — and after adjusting for other heart disease risk factors, such as diabetes, high blood pressure, obesity, and smoking — people on the LCHF diet had more than twice the risk of having several major cardiovascular events, such as blockages in arteries that needed to be opened with stenting procedures, heart attack, stroke, and peripheral arterial disease,” found the researchers, according to the press release.

The researchers said in the statement that their study “can only show an association between diet and an increased risk of major cardiac events, not a causal relationship” because it was an observational study, but their results warrant further study, “especially when about 1 in 5 Americans report following a low-carb, keto-like, or whole-keto diet.

Iatan said the limitations of the study included measurement errors that occur when dietary ratings are self-reported, the study’s small sample size and the fact that most participants were British and did not include no other ethnic groups.

The study also looked at the longitudinal effect of following the diet, as most people who follow a keto-type diet tend to follow it intermittently for shorter periods of time.

Most of the participants – 73% – were women, which Iatan says is “pretty interesting to see, but it also confirms the available literature that women in general tend to follow more diets, tend to be more interested in changing their way of life. ”

When asked if there were any groups that weren’t harmed by following an LCHF diet, Iatan replied how long people were on the diet and whether or not losing weight “can offset any LDL elevation”.

“The bottom line is that each patient reacts differently. And so, there really is an inter-individual variability between the responses. What we found is that, you know, on average, patients tend to increase their LDL cholesterol,” she said.

Dr. David Katz, a lifestyle medicine specialist who was not involved in the study, said that “there are different ways to implement an LCHF diet, and it is highly unlikely that they all have the same effects on serum lipids or cardiac events”.

However, he added, “The fact that an LCHF diet was associated with adverse effects in this study is a reality check for those who adopt such diets simply because they are fad.”

Most health experts say that trendy keto diet, which bans carbs so your body burns fat for fuel, cuts out healthy foods like fruits, beans, and legumes, as well as whole grains. On the keto diet, you limit your carb intake to just 20-50 per day – the lower, the better. To put that into perspective, a medium banana or apple contains about 27 carbs, or a full day’s supply.

“These food groups that must be eliminated to achieve ketosis are the main 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 diet VLCD or ketogenic is harmful to long-term health,” Gardner said.

Keto is short for ketosis, a metabolic state that occurs when your liver begins to use stored fat to produce ketone energy. The liver is programmed to do this when your body loses access to its preferred fuel – carbohydrates – and thinks it is starving.

The keto diet has been around since the 1920s, when a doctor stumbled upon it to control epileptic seizures. epileptic children who have not responded to other methods of treatment.

Low-carb diets like keto rely heavily on fat to fill you up. At least 70% of the keto diet will consist of fat; some say it’s more like 90%.

While you can get all that fat from healthy unsaturated fats like avocados, tofu, nuts, seeds, and olive oil, the diet also allows saturated fats like lard, butter, and olive oil. coconut oil, as well as whole milk, cheese and mayonnaise. Eating lots of foods high in saturated fat increases the production of LDL cholesterol, which can build up in the arteries and restrict blood flow to the heart and brain.