Table of ContentsView AllTable of ContentsHigh Blood Pressure ConcernsFasting and Blood PressureOther BenefitsRisksPlanning for a Fast
Table of ContentsView All
View All
Table of Contents
High Blood Pressure Concerns
Fasting and Blood Pressure
Other Benefits
Risks
Planning for a Fast
Intermittent fasting has become a popular dietary trend that benefits blood pressure, weight loss, inflammation, cholesterol, and blood sugar.Usually, a fasting window of between eight and 10 hours is cited in studies around these benefits.
But fasting to lower blood pressure also comes with some risks, according to more recent research. Some studies correlate the practice with a higher risk of gallstones and cardiovascular health issues.
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Concerns About High Blood Pressure
High blood pressure, orhypertension, 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:
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, which focused on men, showing a dramatic decrease of 11 systolic points and 10 diastolic 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, thenervous systemis 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 thegutmicrobiome, 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.
In addition to lowering blood pressure, intermittent fasting has been shown to have the following beneficial effects:
While benefits to lowering blood pressure from fasting have been found, some new research has also correlated the practice with health risks.
One 2024 study of more than 20,000 people suggested a correlation between an eight-hour restricted eating window and a higher risk of cardiovascular issues. The research found a 91% higher risk of cardiovascular death.
Other studies suggest that regularly fasting for more than 16 or 18 hours per day may be tied to a heightened risk of gallstones.
Since fasting can significantly lower blood pressure, individuals withlow blood pressureneed to carefully monitor that it doesn’t drop too low. Also called hypotension, this condition can cause symptoms of lightheadedness, dizziness, fatigue, and fainting.
Who Should Not Fast?
Some people may have an exaggerated response to fasting. The following people may be at higher risk of complications from fasting:
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.
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.
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 for weight, diabetes, and cholesterol.
There are also some potential risks of fasting, including cardiovascular and gallbladder health. 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.
19 Sources
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Dong TA, Sandesara PB, Dhindsa DS, et al.Intermittent fasting: a heart healthy dietary pattern?Am J Med. 2020;133(8):901-907. doi:10.1016/j.amjmed.2020.03.030
Johns Hopkins. Intermittent Fasting:What is it, and how does it work?
Wilkinson MJ, Manoogian ENC, Zadourian A, Lo H, Fakhouri S, Shoghi A, Wang X, Fleischer JG, Navlakha S, Panda S, Taub PR.Ten-Hour Time-Restricted Eating Reduces Weight, Blood Pressure, and Atherogenic Lipids in Patients with Metabolic Syndrome. Cell Metab. 2020 Jan 7;31(1):92-104.e5. doi: 10.1016/j.cmet.2019.11.004. Epub 2019 Dec 5. PMID: 31813824; PMCID: PMC6953486.
Centers for Disease Control and Prevention.High blood pressure facts.
American Heart Association.Health threats from high blood pressure.
Sutton EF, Beyl R, Early KS, et al.Early time-restricted feeding improves insulin sensitivity, blood pressure, and oxidative stress even without weight loss in men with prediabetes.Cell Metab. 2018;27(6):1212-1221.e3. doi:10.1016/j.cmet.2018.04.010
Gonzalez JE, Cooke WH.Influence of an acute fast on ambulatory blood pressure and autonomic cardiovascular control.Am J Physiol Regul Integr Comp Physiol. 2022;322(6):R542-R550. doi:10.1152/ajpregu.00283.2021
National Genome Research Institute.Microbiome.
Al-Jafar R, Zografou Themeli M, Zaman S, et al.Effect of religious fasting in ramadan on blood pressure: results from lorans (london ramadan study) and a meta-analysis.J Am Heart Assoc. 2021;10(20):e021560. doi:10.1161/JAHA.120.021560
Horne B, Bartholomew C, Anderson J, et al.Abstract 11123: intermittent fasting lifestyle and human longevity in cardiac catheterization populations.Circulation. 2019;140:A11123. doi:10.1161/circ.140.suppl_1.11123
Bartholomew C, Muhlestein J, Anderson J, et al.Abstract 10045: Intermittent fasting lifestyle and incidence of heart failure and myocardial infarction in cardiac catheterization patients.Circulation.2019;140:A10043. doi:10.1161/circ.140.suppl_1.10043
American Heart Association.8-hour time-restricted eating linked to a 91% higher risk of cardiovascular death.
National Institutes of Health.To Fast or Not to Fast
National Heart, Lung and Blood Institute.Low blood pressure.
Vasim I, Majeed CN, DeBoer MD.Intermittent fasting and metabolic health.Nutrients. 2022;14(3):631. 2022. doi:10.3390/nu14030631
Li Z, Heber D.Intermittent fasting.JAMA.2021;326(13):1338. doi:10.1001/jama.2020.15140
Grundler F, Mesnage R, Michalsen A, et al.Blood pressure changes in 1610 subjects with and without antihypertensive medication during long-term fasting.J Am Heart Assoc. 2020;9(23):e018649. doi:10.1161/JAHA.120.018649
Centers for Disease Control and Prevention.Water and healthier drinks.
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