This article focuses on the relationship between fasting and blood pressure, reviews the problems that come with high blood pressure, and looks at how fasting may be one way to help lower it.
Concerns About High Blood Pressure
High blood pressure, or hypertension, affects nearly half of all Americans and increases the risk of several severe conditions. People with high blood pressure are more at risk for the following:
Heart attack Heart failure Stroke Kidney disease Eye disease
If you’ve been diagnosed with high blood pressure, there are many ways to lower it and decrease your risk. Lifestyle changes are a big part of controlling blood pressure, particularly dietary changes.
While choosing nutritious foods and lowering salt and processed food intake have shown to be beneficial, research also suggests that certain fasting patterns may lower blood pressure, too.
How Fasting Affects Blood Pressure
Various fasting methods have been shown to lower blood pressure, with one study showing a dramatic decrease of 11 points. Studies are ongoing to determine precisely how fasting lowers blood pressure. It appears that several mechanisms are involved in this relationship.
Firstly, caloric restriction has been shown to lower blood pressure. Fasting is often associated with an overall lower calorie intake, which can help explain some of its effects.
Studies also suggest that while fasting, the nervous system is in a more relaxed state, known as parasympathetic tone. This is in contrast to a state of heightened alertness, or sympathetic tone, associated with increased blood pressure.
Fasting may even affect blood pressure through the gut microbiome, the population of bacteria living in the gastrointestinal system that has effects ranging from digestion to the immune system.
Weight changes and water loss can also lower blood pressure, as seen in studies of people observing the Islamic practice of fasting during the holy month of Ramadan. During this time, observers of the religious fast do not eat or drink during daylight hours. One study found that people who fasted during Ramadan experienced lower blood pressure independent of changes in weight or body water content.
Hypotension Risk
Since fasting can significantly lower blood pressure, individuals with low blood pressure need to carefully monitor that it doesn’t drop too low. Also called hypotension, this condition can cause symptoms of lightheadedness, dizziness, fatigue, and fainting.
Other Benefits of Fasting
In addition to lowering blood pressure, intermittent fasting has been shown to have the following beneficial effects:
Children and seniors Pregnant or breastfeeding people People with underlying medical conditions, including frailty, orthostatic hypotension (low blood pressure after sitting/lying down), diabetes, and low blood sugar Underweight people People with or at risk of eating disorders Those with immunodeficiency, including those with organ transplantation on immunosuppressive medication
Prolonged fasting can also lead to hypotension due to dehydration, so ensuring adequate hydration is essential. Discuss fasting plans with your healthcare provider, especially if you’re taking blood pressure medications.
Improved cholesterol Weight loss Improved blood sugar and insulin sensitivity Decreased inflammation
Intermittent fasting may also help improve longevity by increasing lifespan. Rates of heart failure appear to also be lower, according to preliminary studies.
How to Plan for a Fast
If you are interested in fasting for its health benefits, it’s important to discuss your plans with a healthcare provider; they can provide guidance on the risks and benefits of your specific circumstances and recommend medication adjustments if needed.
First, choose a fasting plan. Plans vary by the length and timing of fasting. Depending on the specific intention for fasting, the plan may allow drinking fluids throughout the day. In either case, plan ahead to ensure you avoid dehydration and hypotension.
During periods of eating, choose foods that will provide substantial nutrition. Avoid simple sugars that can cause a sugar crash, and opt for a combination of complex carbohydrates, fat, and protein to prevent muscle wasting.
Summary
High blood pressure is a common and serious condition that increases the risk of heart disease and stroke. Studies have shown a beneficial effect of fasting on lowering blood pressure. Fasting also has benefits on weight, diabetes, and cholesterol. A safe fasting plan should include a discussion with your healthcare provider, plans for any medications you take, and a commitment to staying hydrated and getting enough nutrition.
A Word From Verywell
If you are among the nearly 50% of Americans with high blood pressure, you may be looking for ways to lower blood pressure. If you decide to try intermittent fasting, make sure to discuss your plans with a healthcare provider first.
