People who fasted during the month of Ramadan — the ninth month of the Islamic calendar, which last took place from April 12 to May 12, 2021 — saw improvements in blood pressure regardless of whether they also lost weight, according to a new study published in the Journal of the American Heart Association.
Intermittent fasting — usually defined as fasting (not eating) during some portion of the day, or on certain days of the week — has gotten attention in recent years for certain potential health benefits, including improved blood glucose control and reduced insulin resistance. But fasting also carries risks that may be significant in some people with diabetes — particularly if you take insulin or a drug that increases insulin production in your pancreas, like a sulfonylurea. It’s important to check with your doctor before attempting any kind of fasting, and to listen to your body — if you experience weakness or fatigue, fasting is probably not right for you.
To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletters!
For the latest study, known as the London Ramadan Study, the participants were 85 residents of London, England (45 men and 40 women), with an average age of 45.6. The study took place in 2019, and involved recruiting participants from five London mosques. All participants were at least 18 years old and indicated that they planned to fast for at least 20 days during Ramadan. Participants made two different visits as part of the study — one before Ramadan, and one during the second week after Ramadan. During Ramadan, people who fast generally do so from sunrise to sunset, which translated to an average of 15.5 hours per day for study participants.
Fasting during Ramadan linked to reduced blood pressure
After adjusting for differences among participants that could affect blood pressure, the researchers found that fasting during Ramadan was linked to an average drop in systolic blood pressure (the “top number” measured during heartbeats) of 7.29 mmHg, and an average drop in diastolic blood pressure (the “bottom number” measured between heartbeats) of 3.42 mmHg when comparing measurements before and after the period of fasting. For comparison, they also analyzed 33 past studies involving 3,213 participants that looked at blood pressure before and after fasting during Ramadan, and found that in these studies, fasting was linked to a drop in systolic blood pressure of 3.19 mmHg and a drop in diastolic blood pressure of 2.26 mmHg. When looking at subgroups of participants, they found that this with high blood pressure, diabetes, or no chronic health condition were more likely to experience a drop in blood pressure, while people with chronic kidney disease saw no overall drop in blood pressure.
“Our study suggests beneficial effects of Ramadan fasting on blood pressure independent of changes in weight, total body water, and fat mass,” the researchers concluded, adding that this finding “supports recommendations for some governmental guidelines that describe Ramadan fasting as a safe religious practice with respect to blood pressure.”
Want to learn more about high blood pressure? Read “Treating High Blood Pressure” and see our “Blood Pressure Chart.”