Can Keto Be Good and Bad for Your Heart at the Same Time?
Yes. A ketogenic diet can improve some cardiovascular risk factors while worsening others.
This may seem contradictory. People following keto often lose weight and see improvements in blood sugar and triglycerides. Yet some also develop higher LDL cholesterol.
The explanation lies partly in the different effects of carbohydrates and dietary fats.
Why Does Keto Often Lower Triglycerides?
Triglycerides are fats circulating in the blood. High levels are frequently associated with obesity, insulin resistance and metabolic disorders.
Reducing carbohydrate intake, particularly refined carbohydrates and added sugars, can lower triglyceride levels.
Weight loss may contribute to this improvement.
However, lower triglycerides do not automatically mean lower overall cardiovascular risk.
Why Can Keto Raise LDL Cholesterol?
LDL cholesterol is carried in particles that contribute to the development of atherosclerosis, the buildup of fatty deposits inside artery walls.
Ketogenic diets are high in fat, but the type of fat matters.
1. Keto Rich in Saturated Fats
A diet emphasizing butter, cream, fatty meat and cheese may substantially increase LDL cholesterol in some individuals.
2. Keto Rich in Unsaturated Fats
A diet emphasizing olive oil, nuts, avocado and fish generally provides a more favourable fat composition.
Replacing saturated fats with unsaturated fats can help reduce LDL cholesterol, although this does not guarantee that every ketogenic diet will improve cholesterol levels.
What Do Clinical Studies Show?
A 2024 analysis of 27 randomized clinical trials involving 1,278 participants found that ketogenic diets reduced triglycerides, body weight and several metabolic risk markers.
However, LDL cholesterol increased on average.
A larger 2026 review of 53 randomized trials reported a similar pattern: lower triglycerides but higher LDL cholesterol.
These findings demonstrate why improvements in one blood test should not be interpreted as proof that a diet protects the heart.
Is Keto Safe for People With Cardiovascular Risk?
People with elevated LDL cholesterol, familial hypercholesterolemia or established cardiovascular disease should be particularly cautious.
If someone chooses a ketogenic diet, monitoring LDL cholesterol is important. Measuring apolipoprotein B (apoB), which reflects the number of potentially artery-damaging lipoprotein particles, may provide additional information.
We still lack sufficiently strong long-term evidence showing that ketogenic diets reduce heart attacks, strokes or cardiovascular mortality.
Based on Research
Wang Z et al. Impact of the ketogenic diet as a dietary approach on cardiovascular disease risk factors: a meta-analysis of randomized clinical trials. The American Journal of Clinical Nutrition, August 2024.
https://pubmed.ncbi.nlm.nih.gov/39097343/
Ketogenic diet–induced changes in adult lipid metabolism: a comprehensive systematic review and meta-regression of randomized controlled trials. BMC Cardiovascular Disorders, 2026.
https://pmc.ncbi.nlm.nih.gov/articles/PMC13281555/
