Intermittent fasting has become a popular dietary trend with benefits for blood pressure, weight loss, inflammation, cholesterol, and blood sugar levels. Studies on these benefits typically cite fasting times of 8 to 10 hours.
But more recent research shows that fasting to lower blood pressure also comes with some risks. Some studies have linked this habit to an increased risk of gallstones and cardiovascular health problems.
Peter Daisley/Getty Images
Concerns about high blood pressure
High blood pressure affects nearly half of all Americans and increases the risk of several serious conditions. People with high blood pressure are at increased risk of:
If you have been diagnosed with high blood pressure, there are many ways to lower your blood pressure and reduce your risk. Lifestyle changes, especially dietary changes, are a big part of controlling blood pressure.
Choosing nutritious foods and reducing intake of salt and processed foods has been shown to be beneficial, but research suggests that certain fasting patterns may also lower blood pressure. Masu.
Effects of fasting on blood pressure
Various fasting methods have been shown to lower blood pressure, with one study in men showing an 11-point reduction in systolic points and a 10-point reduction in diastolic points. Research is underway to determine exactly how fasting lowers blood pressure. Several mechanisms appear to be involved in this relationship.
First, calorie restriction has been shown to lower blood pressure. Fasting is often associated with lower overall caloric intake, which helps explain some of its effects.
Research also suggests that during fasting, the nervous system enters a more relaxed state known as parasympathetic tone. This is in contrast to the alertness and sympathetic tone associated with increased blood pressure.
Fasting can even affect blood pressure through the gut microbiomea group of bacteria that live in the digestive system and affect everything from digestion to the immune system.
Changes in weight and fluid loss can also lower blood pressure, as seen in a study of people observing Islamic fasting practices during the holy month of Ramadan. During this period, observers of religious fasting do not eat or drink during the day. One study found that people who fasted during Ramadan had lower blood pressure, independent of changes in body weight or body water content.
Other benefits
In addition to lowering blood pressure, intermittent fasting has been shown to have the following beneficial effects:
Improved cholesterol Weight loss Improved blood sugar and insulin sensitivity Reduced inflammation
Intermittent fasting can extend your lifespan and may even help improve longevity. Preliminary studies suggest that the incidence of heart failure also appears to be low.
risk
While the blood pressure-lowering benefits of fasting have been discovered, some new studies have also shown a correlation between fasting and health risks.
A 2024 study of more than 20,000 people suggests a correlation between an eight-hour period of food restriction and an increased risk of cardiovascular disease. The study found a 91% increased risk of cardiovascular death.
Other research suggests that regular fasting for more than 16 or 18 hours per day may be associated with an increased risk of gallstones.
Fasting can significantly lower blood pressure, so people with hypotension should be carefully monitored to ensure it doesn’t drop too low. This condition, also called hypotension, can cause symptoms such as lightheadedness, dizziness, fatigue, and fainting.
Who should not fast?
Some people may overreact to fasting. The following people may be at increased risk of complications from fasting:
Children and the elderly People who are pregnant or breastfeeding People with underlying health conditions such as frailty, orthostatic hypotension (low blood pressure after sitting or lying down), diabetes, or hypoglycemia People who are underweight People with eating disorders People or people at risk of immunodeficiency: People who have undergone organ transplantation and are receiving immunosuppressive drugs, such as those listed below:
Prolonged fasting can cause hypotension due to dehydration, so it is important to ensure adequate hydration. Discuss your fasting plan with your health care provider, especially if you are taking blood pressure medication.
How to plan a fast
If you are interested in fasting for health benefits, it is important to discuss your plan with your health care provider. They will provide guidance about the risks and benefits in your particular situation and recommend adjustments to your medication if necessary.
First, choose a fasting plan. Your plan will vary depending on the length and timing of your fast. Depending on your specific fasting intentions, your plan may allow for fluid intake throughout the day. In either case, plan ahead to avoid dehydration and low blood pressure. Most fasts include eight to 10 hours of eating time each day.
During your meals, choose foods that provide you with sufficient nutrition. Avoid simple sugars, which can cause a sugar crash, and choose a combination of complex carbohydrates, fats, and proteins to prevent muscle wasting.
summary
High blood pressure is a common and serious condition that increases your risk of heart disease and stroke. Studies have shown that fasting has a beneficial effect on lowering blood pressure. Fasting also has benefits for weight, diabetes, and cholesterol.
Fasting also has some potential risks, including cardiovascular and gallbladder health. A safe fasting plan should include a discussion with your health care provider, a plan for the medications you will take, and a commitment to staying hydrated and getting adequate nutrition.