Following the Keto diet may raise the risk of heart disease and other deadly cardiovascular conditions, a study suggests.
The ultra-low-carb diet has become incredibly popular in recent years as a powerful weight-loss tool, with up to 13 million Americans estimated to be following it.
But Canadian researchers who tracked 1,500 people for over a decade found the diet may drive up ‘bad’ cholesterol levels.
They found those following a high-fat, low-carb diet were twice as likely to suffer cardiovascular events such as blocked arteries, heart attacks and strokes than their peers.
The team believed this was because high levels of bad cholesterol cause fatty deposits to build up in artery walls that can narrow or block them.
Americans sticking to the Keto diet have higher levels of bad cholesterol and double the risk of heart disease, a study has found (stock image)
Dr Iulia Iatan, a physician at the University of British Columbia’s Center for Heart Lung Innovation who led the study, said: ‘Among the participants on an low-calorie high-fat [Keto-like] diet, we found that those with the highest levels of LDL cholesterol were at the highest risk for a cardiovascular event.
‘Our findings suggest that people who are considering going on an LCHF diet should be aware that doing so could lead to an increase in their levels of LDL cholesterol.
‘Before starting this dietary pattern, they should consult a health care provider.
‘While on the diet, it is recommended they have their cholesterol levels monitored and should try to address other risk factors for heart disease or stroke, such as diabetes, high blood pressure, physical inactivity and smoking.’
However, one major limitation of the 12-year study is that participants were only asked about their diets once. There was no way to verify if they stuck to the same diet for all those years.
Our bodies naturally produce ‘bad’ cholesterol, or low-density lipoprotein (LDL), but eating diets high in saturated and trans fats causes your body to produce even more LDL.
LDL contributes to the build-up of inflamed fatty deposits known as plaques in the arteries, which raises the risk of a heart attack or stroke.
It is one of two types of cholesterol in the body. The other – high-density lipoprotein (HDL) – absorbs cholesterol in the arteries and ferries it back to the liver, which then flushes it from the body. For this reason it has been dubbed ‘good’ cholesterol.
The Keto diet involves getting between 60 to 80 percent of daily calories from fats, including cheese, avocado and fatty fish, and 20 to 30 percent from proteins.
Followers try to consume as little carbohydrates as possible, which means cutting down on bread, rice and potatoes, among other sources.
Carbohydrates are the main source of energy the body uses when exercising or moving on a daily basis.
But the lack of carbs in the body pushes people into a state called ‘ketosis’ where it starts to break down fats for energy.
The idea is to hopefully tap into stubborn fat stores and speed up weight loss, and help with mental clarity – though there are mixed results on how effective this is,
Celebrities like actress Halle Berry swear by the Keto diet and has been following it for more than 30 years to help manage her type 1 diabetes.
Legendary basketball player LeBron James also reportedly followed a version of the diet, when he just ate meat, fish, vegetables and fruits for 67 days back in 2014. He even turned down desserts made for him by a resort in Greece.
In the study, led by scientists at the University of British Columbia in Vancouver, researchers scanned the UK Biobank for participants who followed the Keto diet.
After finding 70,684 people who had data on daily calorie intake and cholesterol levels in their blood taken once, they checked found 305 participants who followed a ‘Keto-like’ diet.
This was defined as getting more than 45 percent of their daily calories from fats and less than a quarter from carbohydrates.
They were matched with 1,220 individuals whose diets did not meet this definition — and were described as ‘standard eaters’.
Overall, about three-quarters of participants were female and had an average age of 54 years. They were all also considered to be overweight.
Data was analyzed, adjusting for factors including diabetes, high blood pressure, smoking and obesity.
During the 12-year study, about 9.8 percent of people in the Keto-like diet group suffered a serious cardiac event.
This included heart attacks, strokes, and a blockage in the artery that needed a stenting procedure — an operation where a coil of wire mesh is inserted into an artery to support it and keep it open.
For comparison, in the group that ate the standard diet, only 4.3 percent faced serious cardiac events over the same period.
The researchers also found higher levels of LDL cholesterol — or bad cholesterol — and apolipoprotiein B, a protein helping to carry fat and cholesterol through the body in the Keto group.
Limitations of the study include that participants were only quizzed on their diets once, meaning they may not have stuck to them throughout the 12-year study.
The study was presented at the American College of Cardiology’s Annual Scientific Session Together with the World Congress of Cargiology in New Orleans, Louisiana, on Sunday.
What is the Keto diet and is it safe?
- According to Healthline, the Keto diet is a ‘low carb, high fat diet’ which ‘involves drastically reducing carbohydrate intake and replacing it with fat’
- The reduction in carbs puts your body into a metabolic state called ketosis. When this happens, your body becomes ‘incredibly efficient at burning fat for energy’
- UChicagoMedicine reported that the Keto diet could cause low blood pressure, kidney stones, constipation, nutrient deficiencies, and an increased risk of heart disease
- MayoClinic also claimed, ‘There’s very little evidence to show that this type of eating is effective – or safe – over the long term for anything other than epilepsy. Plus, very low carbohydrate diets tend to have higher rates of side effects, including constipation, headaches, bad breath and more. Also, meeting the diet’s requirements means cutting out many healthy foods, making it difficult to meet your micronutrient needs’