Can fasting help lower blood pressure

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Fasting, the voluntary abstinence from eating and sometimes drinking for a specific period, has been practiced for centuries across various cultures and religions.

More recently, it has gained attention for its potential health benefits, including its impact on blood pressure.

This review explores the effects of fasting on blood pressure, summarizing recent research findings in simple terms to help non-scientists understand its potential benefits and risks.

Understanding Blood Pressure and Fasting

Blood pressure is the force that blood exerts on the walls of blood vessels. It is typically measured in millimeters of mercury (mmHg) and recorded as two numbers: systolic (pressure during a heartbeat) and diastolic (pressure between heartbeats).

High blood pressure, or hypertension, is a condition where blood pressure is consistently too high, which can lead to serious health problems like heart disease, stroke, and kidney disease.

Fasting affects the body’s metabolism, the process by which your body converts what you eat and drink into energy.

During periods of fasting, the body first uses up stored glucose and then turns to fat for energy, which can lead to changes in body weight, cholesterol levels, and insulin sensitivity, all of which can influence blood pressure.

Research on Fasting and Blood Pressure

Several studies have examined how different types of fasting affect blood pressure. One common form of fasting is intermittent fasting, which typically involves abstaining from food for 16–24 hours at a time on a regular schedule.

Another is periodic fasting, which might consist of fasting for two or more days in a week.

Intermittent Fasting: Research has shown that intermittent fasting can reduce blood pressure. A study published in the journal ‘Circulation’ found that intermittent fasting could reduce systolic blood pressure by 6 to 10 mmHg and diastolic blood pressure by 4 to 6 mmHg.

The mechanism behind this reduction is not fully understood but may relate to weight loss and improved insulin sensitivity.

Extended and Periodic Fasting: Longer fasting periods, such as those lasting 48 hours or more, have also been studied for their effects on blood pressure.

These studies have generally found that extended fasting can significantly lower blood pressure, possibly more than intermittent fasting. A study in ‘Hypertension’ noted a marked decrease in both systolic and diastolic blood pressure following periodic fasting.

Mechanisms: The blood pressure-lowering effect of fasting may be due to several factors, including hormone regulation, such as increased production of natriuretic peptides, which can enhance salt excretion and thus reduce blood pressure.

Fasting also reduces insulin resistance and decreases leptin resistance, both associated with lower blood pressure.

Considerations and Cautions

While fasting can offer health benefits, it’s not suitable for everyone. People with certain health conditions, such as diabetes, should approach fasting cautiously, as it can increase the risk of hypoglycemia (low blood sugar).

Additionally, fasting is not recommended for pregnant women, individuals with a history of eating disorders, or those who are underweight.

How to Approach Fasting Safely

For those interested in trying fasting as a way to lower blood pressure, it’s crucial to start slowly and choose a method that fits your lifestyle.

Intermittent fasting, such as the 16/8 method (fasting for 16 hours and eating within an 8-hour window), is often a manageable starting point. It’s also important to maintain a balanced diet during non-fasting periods and stay hydrated.

Consulting with a healthcare provider before starting any fasting regimen is essential, especially for those with existing health conditions or who are taking medications.


Fasting can be a powerful tool for reducing blood pressure, particularly when combined with other lifestyle changes like diet and exercise.

By understanding the types of fasting and their effects on the body, individuals can make informed decisions about incorporating fasting into their health regimen, potentially improving their blood pressure and overall health.

If you care about high blood pressure, please read studies about unhealthy habits that may increase high blood pressure risk, and drinking green tea could help lower blood pressure.

For more information about high blood pressure, please see recent studies about what to eat or to avoid for high blood pressure,  and 12 foods that lower blood pressure.

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