Is Fasting Bad For Your Heart? Expert Explains Benefits And Risks

Fasting has become a popular dietary pattern for many individuals aiming to lose weight and improve overall health. By limiting caloric intake during fasting periods, the body begins to utilise fat reserves for energy, which can lead to weight loss. Moreover, fasting may decrease insulin levels, increase growth hormone levels, and enhance metabolic rate, all of which can aid in weight management. When it comes to heart health, the effects of fasting can be complex. Some studies suggest that intermittent fasting may improve various cardiovascular risk factors. However, for certain individuals, especially those with existing heart conditions, extreme fasting could pose significant health risks. This raises the question: Is fasting safe for your heart?

Is fasting good for your heart?

A study published in the journal Cureus found that fasting not only aids in weight loss but also improves how the body manages sugar and fat, relieving stress on the heart and blood vessels. Researchers concluded that fasting is an effective strategy for lowering the risk of heart disease, as it can improve blood pressure, cholesterol levels, weight, and blood sugar levels. Additionally, fasting helps reduce systemic inflammation, which is a hidden cause of many chronic heart conditions. The study highlighted that the benefits of fasting were most pronounced when combined with regular exercise.

However, a research report presented at an American Heart Association (AHA) conference in March 2024 caused a massive stir because its findings directly contradicted years of previous research that suggested fasting is good for the heart.

The researchers looked at the eating habits of 20,000 adults over several years and found that individuals who consumed all their meals within an 8-hour window, a common practice in intermittent fasting, were 91% more likely to die from heart disease than those who ate over a longer period of 12-16 hours. This risk was even higher for those with pre-existing heart disease or cancer.

The researchers noted that individuals who fast often have less lean muscle mass, and losing muscle as one ages is associated with a higher risk of heart-related deaths. However, the study had limitations; it did not take into account other factors such as stress levels, food quality, smoking habits, and body mass index (BMI). For instance, fasting may not benefit individuals who smoke or have a higher BMI.

Therefore, most experts and existing studies still advocate that fasting is good for your heart, but you should focus on food quality and regular exercise to maintain muscle mass.

"Whether or not fasting is beneficial or harmful to an individual's heart will depend largely on the individual and the type of fasting undertaken. Intermittent fasting is a structured type of fasting that can support an individual's ability to achieve weight loss, as well as control blood sugar and cholesterol levels, and thus improve heart health. However, fasting for prolonged periods of time or undertaking an extreme fast can be detrimental for older adults, those with diabetes and existing heart disease, and those who are on medications for any medical conditions," explains Dr. Ranjan Modi, Senior Consultant, Interventional Cardiology, at Medanta Hospital Noida.

Dr. Modi also warns that individuals with pre-existing heart conditions or other chronic diseases should proceed with caution when fasting. "Many studies indicate that certain dangers may arise when fasting due to factors such as dehydration, hypoglycemia or low blood glucose levels, or electrolyte disturbances, including low potassium or magnesium levels. The changes caused by fasting can impact the heart's rhythm and result in a higher likelihood of arrhythmias. Fasting can also trigger stress responses in the body, which may contribute to increased heart rate and blood pressure. For individuals with predisposing factors to heart problems, this can decrease the amount of blood flow to the heart and create the opportunity for serious cardiac events to occur," he adds.

Fasting may help lower blood pressure, reduce cholesterol levels, and improve inflammatory markers. However, the effects of fasting can differ widely among individuals, and it's essential to weigh both the potential benefits and risks.

To ensure safe fasting for cardiovascular health, consider the following tips:

• Before starting any fasting regimen, it's crucial to consult with a doctor or a registered dietitian, especially if you have heart disease or other chronic health conditions.
• Avoid prolonged periods of fasting that are greater than 12 hours in duration without consulting a doctor.
• When you do eat, focus on consuming nutrient-dense foods, including fruits, vegetables, whole grains, lean proteins, and healthy fats to support cardiovascular health.
• Pay attention to how your body responds. If you experience dizziness, fatigue, or other concerning symptoms, reconsider your fasting approach.
• Regular physical activity is essential for heart health, so consider incorporating exercise into your routine during non-fasting periods.

While fasting can potentially offer benefits for weight loss and heart health, it should be approached cautiously and in consideration of individual health conditions. Balancing fasting with a nutritious diet and a healthy lifestyle is key to maximising the positive impacts while minimising risks.

Disclaimer: This content including advice provides generic information only. It is in no way a substitute for a qualified medical opinion. Always consult a specialist or your own doctor for more information. NDTV does not claim responsibility for this information.