Hypertension (high blood pressure) is a strong risk factor for cardiovascular disease. Many studies have shown that intermittent fasting can decrease blood pressure. The mechanisms are not fully understood, but intermittent fasting seems to influence blood pressure by balancing crucial signaling molecules within the cell and changing the gut microbiome.
Cardiovascular disease (CVD) is one of the leading causes of death worldwide. In fact, approximately 18.6 million deaths worldwide were due to CVD...and that number increases every year (1). CVD can present itself in a number of ways including stroke, heart attack, and more.
While there are many risk factors that can provide you some insight to the likelihood of you having a cardiovascular-related issue, high blood pressure (or hypertension) is one of them.
Research suggests that intermittent fasting can lower blood pressure and thereby decrease your CVD risk. But before getting into detail, let’s have a closer look at what hypertension is.
Let’s first start by explaining what blood pressure is.
When you have your blood pressure taken, you’ll usually get a reading in the form of two numbers, for example 120/80 (read as “120 over 80”).
The first number (120) is your systolic blood pressure. When your heart beats, it squeezes and will push blood through your arteries to the rest of your body. The amount of pressure that occurs when your heart is squeezing is your systolic blood pressure.
The second number (80) is your diastolic blood pressure. This indicates how much pressure your blood is exerting against your artery wall when the heart is resting between beats. This is when the heart fills up with blood right before it beats.
If you have normal blood pressure, your blood pressure is less than or equal to 120/80. Anything higher than that may be considered high. Below you’ll find a chart made by the American Heart Association on categorizing high blood pressure (2).
If you’ve been diagnosed with hypertension, if you have a family history of it, or if you’re just trying to make sure you never have it, making dietary changes could really help decrease your blood pressure and/or decrease your risk of ever having it to begin with.
You’ve probably already heard that consuming less salt, alcohol, and fat may help but intermittent fasting could help too!
There have been various human studies that have shown how intermittent fasting can help you manage your blood pressure.
For example, one group of scientists used a 6-hour feeding window intermittent fasting dietary pattern and found a significant decrease in blood pressure in eight pre-diabetic men after 5 weeks (3).
Another study consisting of 1422 people found similar results. The participants fasted from 4-21 days but were allowed one small meal (200-250kcal) a day on fasting days. One year after completing the fasting, the authors reported that participants still had a significant decrease in blood pressure (4).
Another study used a 16/8 intermittent fasting model (fasting 16 hours of the day and eating for the remaining 8 hours) in 23 obese adults and found a significant decrease in systolic blood pressure. No significant difference was found in diastolic blood pressure (5).
We must also bring up the fact that there are some studies that don’t report any significant change in blood pressure (6, 7). Seeing conflicting results is very common with diet-related studies and can usually be explained by study length, the type of participants enrolled, (and in terms of intermittent fasting) the type of intermittent fasting used in the study.
It seems that most of the participants who did see a significant improvement in blood pressure were obese and/or had some type of metabolic disease. This means that individuals who have the most room for improvement will likely see it with intermittent fasting.
But keep in mind, intermittent fasting has many benefits so you can still help improve your overall health even if you don’t see a decrease in your blood pressure. Just something to keep in mind!
Now you may be wondering how intermittent fasting can help decrease your blood pressure – and that’s a good question!
Unfortunately, there aren’t many studies that have investigated the metabolic changes that occur during intermittent fasting that result in a decrease in blood pressure. However, there are a couple of proposed mechanisms and we’ll talk about those in this article.
To begin, fasting increases brain derived neurotrophic factor (BDNF), a protein found in the body, may play a role. BDNF has been shown to dilate blood vessels, which causes a reduction in blood pressure. BDNF also activates cholinergic neurons, which are a type of nerve cell. These nerve cells help regulate blood pressure and when activated, can help decrease blood pressure (8, 9).
Another possibility is that AMP-activated protein kinase (AMPK) can play a role in decreasing blood pressure. When people participate in intermittent fasting, AMPK has been shown to increase. AMPK helps to release more nitric oxide, a compound that expands the blood vessels. AMPK also helps to “reprogram” the kidneys by changing some of their metabolic processes. After this change, the kidneys will stop retaining so much water, and you can expect to see a decrease in blood pressure (10, 11).
One last possibility is that intermittent fasting may change your gut microbiome. Intermittent fasting can change the composition of your gut bacterial species, causing an increase in certain gut bugs that help regulate blood pressure (12).
There may be more mechanisms but studying the health benefits of intermittent fasting is still a relatively new topic, so we have a lot more to learn!
High blood pressure puts you at risk for different CVDs such as stroke and heart attack.
intermittent fasting is a good dietary strategy to use if you would like to decrease your blood pressure or decrease your risk of developing it in the future.
If you want to learn more about the health benefits of intermittent fasting, we invite you to join our intermittent fasting community for women only.
1. Roth GA, Mensah GA, Johnson CO, Addolorato G, Ammirati E, Baddour LM, Barengo NC, Beaton AZ, Benjamin EJ, Benziger CP, et al. Global Burden of Cardiovascular Diseases and Risk Factors, 1990–2019: Update From the GBD 2019 Study. Journal of the American College of Cardiology. Elsevier Inc.; 2020. p. 2982–3021.
2. Understanding Blood Pressure Readings | American Heart Association [Internet]. [cited 2021 May 24]. Available from: https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings
3. Sutton EF, Beyl R, Early KS, Cefalu WT, Ravussin E, Peterson CM. Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell Metab. Cell Press; 2018;27:1212-1221.e3.
4. De Toledo FW, Grundler F, Bergouignan A, Drinda S, Michalsen A. Safety, health improvement and well-being during a 4 to 21-day fasting period in an observational study including 1422 subjects. PLoS One [Internet]. Public Library of Science; 2019 [cited 2021 May 25];14. Available from: /pmc/articles/PMC6314618/
5. Gabel K, Hoddy KK, Haggerty N, Song J, Kroeger CM, Trepanowski JF, Panda S, Varady KA. Effects of 8-hour time restricted feeding on body weight and metabolic disease risk factors in obese adults: A pilot study. Nutr Heal Aging [Internet]. IOS Press; 2018 [cited 2021 May 24];4:345–53. Available from: https://pubmed.ncbi.nlm.nih.gov/29951594/
6. Moro T, Tinsley G, Bianco A, Marcolin G, Pacelli QF, Battaglia G, Palma A, Gentil P, Neri M, Paoli A. Effects of eight weeks of time-restricted feeding (16/8) on basal metabolism, maximal strength, body composition, inflammation, and cardiovascular risk factors in resistance-trained males. J Transl Med [Internet]. BioMed Central; 2016 [cited 2018 Mar 6];14:290. Available from: http://translational-medicine.biomedcentral.com/articles/10.1186/s12967-016-1044-0
7. Anton SD, Lee SA, Donahoo WT, McLaren C, Manini T, Leeuwenburgh C, Pahor M. The effects of time restricted feeding on overweight, older adults: A pilot study. Nutrients. MDPI AG; 2019;11.
8. Malinowski B, Zalewska K, Węsierska A, Sokołowska MM, Socha M, Liczner G, Pawlak-Osińska K, Wiciński M. Intermittent fasting in cardiovascular disorders—an overview. Nutrients. MDPI AG; 2019.
9. Buccafusco JJ. The role of central cholinergic neurons in the regulation of blood pressure and in experimental hypertension. Pharmacol Rev. 1996;48.
10. Tain YL, Hsu CN. AMP-activated protein kinase as a reprogramming strategy for hypertension and kidney disease of developmental origin [Internet]. International Journal of Molecular Sciences. MDPI AG; 2018 [cited 2021 May 24]. Available from: /pmc/articles/PMC6032132/
11. Liu J, Li X, Lu Q, Ren D, Sun X, Rousselle T, Li J, Leng J. AMPK: A balancer of the renin–angiotensin system. Bioscience Reports. Portland Press Ltd; 2019.
12. Maifeld A, Bartolomaeus H, Löber U, Avery EG, Steckhan N, Markó L, Wilck N, Hamad I, Šušnjar U, Mähler A, et al. Fasting alters the gut microbiome reducing blood pressure and body weight in metabolic syndrome patients. Nat Commun [Internet]. Nature Research; 2021 [cited 2021 May 24];12:1–20. Available from: https://doi.org/10.1038/s41467-021-22097-0
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