Keto Diet (or keto diet), in which people consume very few carbohydrates and higher fat intake, has become popular recently. Unfortunately, studies have demonstrated that following such a regimen could result in increased levels of bad cholesterol as well as doubled risk of cardiovascular events like blocked arteries requiring stenting, angina attacks, strokes and heart attacks.
A recent study discovered that regularly eating a low-carb, high-fat diet led to higher LDL cholesterol levels and an increased heart disease risk.
Carbs are our bodies’ primary source of fuel and provide energy for daily activities. Incorporating low-carbohydrate diets (such as keto diet) into everyday life limits the intake of carbohydrates such as baked goods, bread, rice and grains, pasta dishes with carb-rich pasta sauce, potato-related products such as chips and fries as well as high carb vegetable and fruits into one’s daily meal.
Ketogenic diet advocates typically suggest restricting carbohydrates to 10% of daily calories, protein to 20%-30% and fat from 60%-88% as fuel sources for maximum effectiveness.
Prior studies have indicated that diets high in fat and low in carbohydrates may result in increased LDL cholesterol levels in some individuals, increasing risk for coronary atherosclerosis. Unfortunately, however, its effects on stroke and heart disease risk have yet to be thoroughly explored.
Researchers defined a low-carbohydrate, high-fat diet in this study as comprising of more than 45% of total daily calories from fat and no more than 25% from carbohydrates per day – or keto-like due to relatively lower fat and higher carb content than a strictly ketogenic diet. A standard diet was defined as those who didn’t meet these conditions through more balanced eating habits.
Data were extracted from the UK Biobank, an information database with over half a million British-residing individuals who have been followed for at least 10 years. A 24-hour self-reported diet questionnaire was completed by 70,684 individuals when enrolling into the Biobank; additionally their blood was drawn for cholesterol level checks.
At least 305 individuals fulfilled the definition of low-carbohydrate, high-fat diet in this study according to their questionnaire responses during a 24-hour reporting period, as defined by this research study. They were then matched against 1,220 persons reporting standard diet consumption.
73% of individuals in each group were women and had an average age of 54 years. People following a low-carbohydrate, high-fat diet averaged a BMI of 27.7; individuals on standard diets averaged 26.7; this falls within the overweight range (BMI 25-30).
Comparative to individuals on a standard diet, those eating a low-carbohydrate, high-fat diet had significantly higher LDL cholesterol levels as well as protein components called apoB that coat LDL particles.
Prior studies have demonstrated that elevated apoB may be an accurate predictor of cardiovascular disease risk than increases in LDL cholesterol. After 11.8 years of follow up and after accounting for other risk factors like smoking, obesity, high blood pressure and diabetes; those on a low-carbohydrate, high-fat diet had over twice the risk of experiencing major cardiovascular events such as heart attack, peripheral arterial disease, stroke or artery blockages that required stenting treatments.
Overall, 9.8% of individuals on a low-carbohydrate, high-fat diet experienced a new cardiac event compared to 4.3% who consumed standard diets – double that risk among those following low-carbohydrate, high-fat diets.
Studies conducted have revealed that individuals on low-carbohydrate, high-fat diets who had higher LDL cholesterol levels had an increased cardiovascular event risk. As such, those considering adopting such diets must keep in mind that doing so may increase LDL cholesterol levels significantly.
Before initiating a diet of this nature, individuals should speak to a healthcare provider. While on this diet it’s recommended that individuals monitor cholesterol levels closely as well as consider other risk factors for heart disease or stroke such as smoking, physical inactivity, hypertension, and diabetes.
The results of the study demonstrate that not every individual responds similarly to a diet with low-carbohydrates and high-fat. Although cholesterol levels typically increase on this type of diet, in certain individuals they can remain static or even decrease depending on underlying factors.
One limitation of the study was that diet information was only provided once by each participant, which should be taken into account when interpreting its results. Self-reporting can sometimes be inaccurate; although our questionnaire was thoroughly verified.
As this study was observational, only a correlation can be drawn between diet and an elevated major cardiac event risk and an increase in major cardiac event risk; not necessarily an implied causal relationship.
