Is Keto Bad for Your Heart? Cardiologists Weigh In

The ketogenic diet, while praised for its weight loss and metabolic benefits, often faces skepticism regarding heart health. Critics argue that the high fat intake could raise cholesterol and increase cardiovascular risk. However, emerging science tells a more nuanced and positive story.

Let’s explore the latest research and unravel the truth about keto and your heart.

The Old Fear: High Fat Equals Heart Risk?

For decades, conventional wisdom linked dietary fat to heart disease. The fear was straightforward: eating fat raises blood cholesterol, which clogs arteries and increases heart attack risk. However, this view is now considered overly simplistic.

Current science shows that not all fats (or cholesterol markers) behave the same way in the body. Importantly, ketogenic diets tend to shift cholesterol profiles in a more favorable direction[1].

Keto’s Impact on Cholesterol: A Deeper Look

When people adopt a ketogenic diet, several things happen:

• HDL (“good”) cholesterol rises. Higher HDL levels are associated with a lower risk of heart disease[2].
• Triglycerides typically fall. Elevated triglycerides are a known risk factor, and keto reliably lowers them[3].
• LDL cholesterol may rise in some individuals, but particle size shifts. Keto tends to increase the size of LDL particles, making them less likely to contribute to arterial plaque[4].

A 2016 meta-analysis concluded that low-carb, high-fat diets resulted in greater improvements in HDL and triglycerides compared to low-fat diets, with no significant harm to overall cholesterol balance[5].

Inflammation and Heart Health

Chronic inflammation is a hidden driver of cardiovascular disease. Fortunately, ketogenic diets have been shown to lower markers of inflammation, such as C-reactive protein (CRP)[6].

Lower inflammation not only benefits the heart but also supports overall vascular health, reducing the risk of plaque formation and arterial stiffness.

Blood Pressure Improvements

Hypertension is a major cardiovascular risk factor. Studies consistently show that ketogenic diets can significantly reduce blood pressure levels[7].

This effect is likely due to both weight loss and improved insulin sensitivity—two well-documented benefits of keto.

Insulin Resistance and Heart Health

Insulin resistance is closely linked with cardiovascular disease. The good news is that keto shines in improving insulin sensitivity.

A landmark study by Virta Health found that participants with Type 2 diabetes who followed a ketogenic diet for one year experienced not only dramatic blood sugar improvements but also reductions in cardiovascular risk markers[8].

Improved insulin function means less arterial damage over time, supporting long-term heart health.

What About Saturated Fat?

A common critique of keto is its allowance of saturated fats. However, recent research has clarified this concern.

A comprehensive review published in the Journal of the American College of Cardiology found no significant evidence that saturated fat increases heart disease risk[9]. In fact, the impact of saturated fat on heart health depends heavily on the overall dietary context—and a whole-food-based keto diet is a very different environment compared to a processed, high-carb Western diet.

When saturated fats are consumed alongside nutrient-dense vegetables, omega-3-rich foods, and healthy lifestyle habits, their impact is far less concerning.

The Importance of Whole Foods Keto

Not all keto diets are created equal. A “dirty keto” approach, filled with processed meats and low-quality fats, is vastly different from a whole-foods ketogenic diet rich in:

• Avocado, coconut and olives
• Pasture-raised meats and wild-caught fish
• Non-starchy vegetables, select fruits, seeds and more.

Whole-food keto emphasizes anti-inflammatory, heart-supportive foods while still harnessing the metabolic benefits of carbohydrate restriction.

Real-World Evidence: Keto and Cardiovascular Risk Reduction

Beyond biomarkers, real-world data supports keto’s cardiovascular safety. In a two-year study, participants following a ketogenic diet experienced significant weight loss, improved lipid profiles, and reductions in cardiovascular risk scores[10].

Moreover, many keto dieters report subjective benefits such as improved energy levels, reduced blood pressure readings, and enhanced exercise tolerance—all positive signs for heart health.

Conclusion: Keto and Heart Health Can Coexist

While early concerns about fat intake and heart disease once cast doubt on the ketogenic diet, modern research paints a far more favorable picture. Keto not only improves weight management and insulin sensitivity but also supports heart health through better cholesterol profiles, reduced inflammation, and lower blood pressure.

The key lies in the quality of the keto diet. Prioritizing whole foods, healthy fats, and a balanced approach ensures that keto remains a heart-friendly lifestyle choice.

For those pursuing long-term cardiovascular health, keto emerges not as a threat, but as an ally.

References

1. 1. Volek JS, Phinney SD. The Art and Science of Low Carbohydrate Living. Beyond Obesity LLC; 2011.
   2. Santos FL, Esteves SS, da Costa Pereira A, et al. “Systematic review and meta-analysis of clinical trials of the effects of low carbohydrate diets on cardiovascular risk factors.” Obes Rev. 2012;13(11):1048-1066.
   3. Bueno NB, de Melo ISV, de Oliveira SL, da Rocha Ataide T. “Very-low-carbohydrate ketogenic diet v. low-fat diet for long-term weight loss: a meta-analysis of randomised controlled trials.” Br J Nutr. 2013 Oct;110(7):1178-87.
   4. Ravnskov U, Diamond DM, Hama R, et al. “LDL-C does not cause cardiovascular disease: a comprehensive review of the current literature.” Expert Rev Clin Pharmacol. 2018;11(10):959-970.
   5. Mansoor N, Vinknes KJ, Veierød MB, Retterstøl K. “Effects of low-carbohydrate diets vs low-fat diets on metabolic risk factors: a meta-analysis of randomized controlled clinical trials.” Br J Nutr. 2016;115(3):466-479.
   6. Forsythe CE, Phinney SD, Fernandez ML, et al. “Comparison of low fat and low carbohydrate diets on circulating fatty acid composition and markers of inflammation.” Lipids. 2008;43(1):65-77.
   7. Yancy WS Jr, Foy M, Chalecki AM, et al. “A low-carbohydrate, ketogenic diet to treat type 2 diabetes.” Nutr Metab (Lond). 2005;2:34.
   8. Hallberg SJ, McKenzie AL, Williams PT, et al. “Effectiveness and safety of a novel care model for the management of type 2 diabetes at one year: an open-label, non-randomized, controlled study.” Diabetes Ther. 2018;9(2):583-612.
   9. Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. “Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease.” Am J Clin Nutr. 2010;91(3):535-546.
   10. McKenzie AL, Hallberg SJ, Creighton BC, et al. “A novel intervention including individualized nutritional recommendations reduces hemoglobin A1c level, medication use, and weight in type 2 diabetes.” JMIR Diabetes. 2017;2(1):e5.