Can Cutting Carbs Protect Your Heart? Exploring the Link Between Low-Carb Diets and Reduced Heart Attack Risk

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Low-carbohydrate diets, such as keto or Atkins, have surged in popularity for weight loss and metabolic health, but their impact on heart health remains a topic of debate. While some warn that low-carb diets, often high in fats, could increase cardiovascular risks, emerging research suggests that when done thoughtfully, these diets may actually lower the risk of heart attack for certain individuals. This article explores how low-carb foods might contribute to better heart health and what you need to consider to make them work for you.

The Science Behind Low-Carb Diets and Heart Health

Recent studies have challenged the long-held belief that low-carb, high-fat diets are inherently bad for your heart. A 2021 study published in The American Journal of Clinical Nutrition found that overweight individuals who followed a low-carb diet (20% carbohydrates, 21% saturated fat) for 20 weeks showed improvements in cardiovascular risk factors, such as lipoprotein insulin resistance (LPIR) scores, compared to those on moderate- or high-carb diets. The study suggested that a carefully constructed low-carb diet, rich in nutrient-dense foods like vegetables and healthy fats, could reduce certain heart disease risk markers despite higher saturated fat intake.

Another study, presented in 2025 by The Lundquist Institute, examined metabolically healthy individuals on a long-term ketogenic diet with elevated LDL cholesterol. Surprisingly, the researchers found no link between high LDL or ApoB levels and increased coronary plaque progression over one year, suggesting that traditional cholesterol markers may not fully predict heart attack risk in the context of low-carb diets. Instead, pre-existing plaque was a stronger predictor of future issues, hinting that low-carb diets may not exacerbate heart disease in otherwise healthy individuals.

A 2020 meta-analysis further supports these findings, showing that low-carb diets were associated with a significant reduction in triglyceride levels (-0.15 mmol/L), a known risk factor for heart disease, particularly in shorter-term interventions (less than 6 months). Weight loss, averaging 1.58 kg, was also noted, which can indirectly benefit heart health by reducing strain on the cardiovascular system.

Why Low-Carb Might Work

Low-carb diets often replace refined carbohydrates—like white bread, pasta, and sugary snacks—with foods that have a lower glycemic index, such as leafy greens, nuts, seeds, and lean proteins. This shift can stabilize blood sugar levels, reduce insulin resistance, and lower triglycerides, all of which are linked to a reduced risk of heart attack. By prioritizing whole, unprocessed foods, low-carb diets may also increase intake of fiber and healthy fats (like those from avocados, olive oil, and fish), which are known to support heart health.

For example, a prospective cohort study of 82,802 women found that low-carb diets emphasizing vegetable-based proteins and fats were associated with a 30% lower risk of coronary heart disease compared to diets high in animal-based proteins and fats. This suggests that the quality of foods in a low-carb diet matters as much as the macronutrient ratio.

The Caveats: It’s Not One-Size-Fits-All

While these findings are promising, low-carb diets aren’t a universal fix. A 2018 study from the US National Health and Nutrition Examination Survey (NHANES) reported a 32% higher risk of all-cause mortality and a 51% higher risk of coronary heart disease death among those with the lowest carbohydrate intake over 6.4 years. This study, however, didn’t distinguish between the types of foods consumed, meaning processed meats or unhealthy fats could have skewed results.

Similarly, a 2023 study presented at the American College of Cardiology found that a “keto-like” low-carb, high-fat diet doubled the risk of cardiovascular events, with significantly higher LDL cholesterol and ApoB levels. This highlights the potential risks of poorly planned low-carb diets, especially those heavy in saturated fats from red meat or processed foods.

The key seems to lie in food choices and individual health profiles. For instance, low-carb diets may be riskier for those with pre-existing heart conditions or those who don’t balance their diet with nutrient-rich foods. Additionally, long-term adherence to very restrictive low-carb diets (like keto, with less than 50 grams of carbs per day) can lead to nutrient deficiencies or reduced fiber intake, which may negate heart health benefits.

Practical Tips for a Heart-Healthy Low-Carb Diet

If you’re considering a low-carb diet to support heart health, focus on quality and balance:

• Prioritize Healthy Fats: Choose unsaturated fats from olive oil, avocados, nuts, and fatty fish over saturated fats from red meat or butter.

• Load Up on Fiber: Include low-carb, fiber-rich foods like broccoli, spinach, and chia seeds to support heart health and digestion.

• Limit Processed Foods: Avoid processed meats and low-carb packaged snacks, which can be high in sodium and unhealthy fats.

• Monitor Your Health: Regularly check cholesterol levels and consult a doctor, especially if you have a history of heart disease.

• Cycle the Diet: Some experts suggest cycling on and off low-carb diets to maintain nutrient diversity and avoid long-term risks.

The Bottom Line

Low-carb diets, when thoughtfully designed with nutrient-dense foods, may lower heart attack risk by improving triglyceride levels, supporting weight loss, and reducing insulin resistance. However, the evidence is mixed, and the benefits depend heavily on food quality and individual health. Always consult a healthcare professional before making significant dietary changes, especially if you have cardiovascular risk factors.

For now, the data suggests that cutting carbs doesn’t have to mean risking your heart—it’s about choosing the right foods to replace them. By focusing on whole, plant-based, and nutrient-rich options, a low-carb diet could be a step toward a healthier heart, but it’s not a magic bullet. Moderation, personalization, and ongoing research will continue to shape our understanding of this complex relationship.

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