Intermittent fasting has become a popular diet and lifestyle trend, recently gaining momentum in the weight loss industry. While it may not be the right fit for everyone, intermittent fasting may offer various health benefits, such as a positive impact on your blood pressure. Can fasting lower blood pressure?
This article will explain the science behind intermittent fasting and its purported impact on our blood pressure. We’ll review what it means to have high blood pressure and its potential causes, so you can decide if low blood pressure fasting is right for you. So let’s talk about the effects of fasting on the heart!
What is Healthy Blood Pressure?
Blood pressure is best defined as the pressure of blood— imagine that— against the walls of our arteries. Our arteries carry blood from our hearts to other parts of our bodies, but if our blood pressure is too high or too low, our arteries may be unable to do the job well.
Our blood pressure typically rises and falls throughout the day, but it can have lasting health effects if it stays outside the recommended levels for too long. So what are the recommended blood pressure levels?
Blood pressure is measured in millimeters of mercury and broken down into systolic and diastolic numbers.
- Systolic blood pressure is defined as the maximum pressure during one heartbeat.
- Diastolic blood pressure is defined as the minimum pressure between two heartbeats.
According to the American Heart Association, blood pressure numbers less than 120/80 mm hg are considered within the normal range.1 If someone’s blood pressure levels are high or low, that may indicate hypertension or hypotension.
Hypotension is a blood pressure less than 90/60 mm Hg and can cause dizziness and fainting, among other symptoms. It’s usually caused by dehydration or severe medical conditions.
On the other hand, hypertension is characterized by blood pressure readings of 130/80 mm Hg or higher. It usually stems from lifestyle choices like a lack of physical activity or a high-sodium diet. However, it can also result from health conditions like type 2 diabetes and obesity.
Why is High Blood Pressure a Problem?
More than half of the adult American population has been diagnosed with hypertension.2 Hypertension can be dangerous to our overall health, putting us at increased risk for cardiovascular disease.
High blood pressure has been linked to heart disease in the form of high cholesterol, heart attacks, and heart failure. It can also cause kidney disease, stroke, and even eye disease.
What Causes Hypertension?
High blood pressure typically develops over time and, as mentioned before, is often related to lifestyle habits. Risk factors for hypertension include:
- Age: as we age, the risk of high blood pressure increases.
- Family history: you’re more likely to develop hypertension if an immediate family member has the condition.
- Obesity or overweight: excess body weight can change your blood vessels, kidneys, and other body parts that play a role in blood pressure.
- High-sodium diets: consuming too much salt can cause the body to retain water, increasing blood pressure.
- Low potassium levels: potassium is essential for maintaining the proper balance of sodium in the body’s cells. Potassium is a crucial component of heart health.
- Tobacco use or vaping: smoking, vaping, and chewing tobacco can raise blood pressure. Additionally, smoking tobacco can harden your artery walls.
- Lack of regular exercise: inactivity can cause elevated heart rates and weight gain, leading to hypertension.
- Excessive alcohol intake: alcohol intake has been linked to elevated blood pressure.
- Stress: high levels of stress can temporarily elevate our blood pressure and lead to stress-induced habits like the overconsumption of salt and other negative lifestyle habits.
Additionally, while the body needs insulin to regulate glucose, insulin resistance and hypertension often coexist as components of metabolic syndrome.3 Researchers have found that insulin resistance can develop in cardiovascular tissues, where insulin can play a role in developing high blood pressure. Unfortunately, insulin inhibits the body’s ability to produce nitric oxide, which our blood vessels use to expand their size and lower blood pressure.
How Fasting Affects Blood Pressure
So, how does fasting lower blood pressure? While there’s still a need for continued research regarding blood pressure and the effects of fasting diets, several studies point to a positive connection between the two. In addition, intermittent fasting may offer various health benefits, specifically antihypertensive benefits.
For example, fasting is often related to reduced caloric intake, and calorie restriction has been shown to support weight loss and, thus, lower blood pressure. Still, one recent study examined the effects of fasting during Ramadan and found that participants experienced lower blood pressure independent of weight loss.4
Additionally, some research has shown fasting can affect blood pressure by altering some of the mechanics of the gut microbiome.5 Other studies show that the nervous system is more relaxed during fasting periods, a contrast to heightened alertness and stress often associated with high blood pressure.6
Other Health Benefits of Fasting
Fasting and high blood pressure may not be the only factors with an inverse relationship. In addition to its anti-hypertensive properties, intermittent fasting may offer other potential health benefits:
May Aid in Weight Loss
Fasting or abstaining from food can result in a calorie deficit, ultimately leading to weight loss. Additionally, research indicates fasting schedules may support your metabolic health and your body’s metabolism.
May Improve Blood Sugar Control
Research points to a connection between time-restricted eating and improved insulin sensitivity, regardless of weight loss.7 In addition, studies indicate that even short-term intermittent fasting can support people with type 2 diabetes by improving their fasting glucose and postprandial variability.8
May Reduce Oxidative Stress
Oxidative stress and inflammation contribute to aging and chronic disease. Research indicates intermittent fasting may enhance the body’s resistance to inflammation or oxidative stress.9
It Can Be Sustainable
Because intermittent fasting doesn’t require calorie counting or the restriction of entire food groups, it has the potential to be sustainable. But, of course, it’s still a diet and does require regulation in some form.
Is Fasting a Good Fit for Everyone?
Intermittent fasting is not an appropriate choice for everyone.10 It may even result in severe complications for some.
Intermittent fasting is not recommended for individuals in periods of rapid growth ( i.e., children). Children typically benefit from a more intentional approach to eating.
Very few, if any, of the available studies regarding intermittent fasting focus on the older adult population. Losing too much weight can be dangerous for older adults, and some medications must be taken with food. For example, fasting while on blood pressure medication may cause imbalances in potassium and sodium.
Pregnant and Nursing Women
Prolonged periods of fasting can lead to a dangerous drop in blood sugars, resulting in dizziness, fainting, and decreased fetal movement. Furthermore, time-restricted feeding can also make it challenging to meet the increased nutritional demands of pregnancy and lactation.
People with Underlying Conditions
Those with underlying medical conditions, such as hypotension or diabetes, should avoid intermittent fasting as the required interventions may exacerbate symptoms.
People With or at Risk of Eating Disorders
Those with a history of eating disorders should avoid intermittent fasting, as restrictive eating can trigger unhealthy habits.
3 Bonus Tips to Get Started with Fasting
If you’re considering intermittent fasting, be sure to discuss it with your doctor or registered dietitian before starting. If it’s a safe choice based on your medical history, consider these tips to get started:
1. Start slow
You might be eager to get started and see the purported results that intermittent fasting offers, but slow and steady is the way to go. Restricting too much too soon can put you at risk for nutrient deficiency and other serious medical concerns. So instead of jumping right into alternate-day fasting, start with a small fasting window and gradually work your way up with the help of your registered dietitian or doctor.
2. Make Sure You’re Eating Enough
One of the most common pitfalls of intermittent fasting is excessive calorie restriction, despite signs of hunger. Our bodies need a balance of micro and macronutrients to survive and function properly. Even when following a time-restricted feeding schedule, ensure you meet your carbohydrate, fat, and protein needs. Try to eat nutrient-dense foods that serve your body well.
3. Plan Meals Ahead of Time
Planning is critical when you are forced to go hours without eating. Don’t get caught without your next meal or snack, making your twelve-hour fast a thirteen-hour fast. Try to have your post-fast meal ready to eat or cook in the fridge. This also ensures you meet your nutrition needs while following the fasting diet.
Learn More About Healthy Nutrition with Signos’ Expert Advice.
Continuous glucose monitoring can be an extremely valuable tool when fasting intermittently. Knowledge is power, after all! CGM provides real-time data, helping us understand how our bodies respond to the foods we consume.
Want to learn more about nutrition and healthy eating habits? Curious about how Signos can improve your health? Head over to the Signos’ blog to learn more about nutrition and healthy habits, and find out if Signos is a good fit for you by taking a quick quiz!
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Topics discussed in this article:
- Understanding blood pressure readings. www.heart.org. (2023, February 2). Retrieved April 5, 2023, from https://www.heart.org/en/health-topics/high-blood-pressure/understanding-blood-pressure-readings
- Centers for Disease Control and Prevention. (2023, January 5). Facts about hypertension. Centers for Disease Control and Prevention. Retrieved April 5, 2023, from https://www.cdc.gov/bloodpressure/facts.htm
- Zhou, M. S., Wang, A., & Yu, H. (2014). Link between insulin resistance and hypertension: What is the evidence from evolutionary biology?. Diabetology & metabolic syndrome, 6(1), 12. https://doi.org/10.1186/1758-5996-6-12
- Al-Jafar, R., Themeli, M. Z., Zaman, S., Akbar, S., Lhoste, V., Khamliche, A., Elliot, P., Tsilidis, K. K., & Dehghan, A. (2021, October 8). Effect of religious fasting in Ramadan on blood pressure: Results from ... JAHA. Retrieved April 6, 2023, from https://www.ahajournals.org/doi/10.1161/JAHA.120.021560
- Shi, H., Zhang, B., Abo-Hamzy, T., Nelson, J. W., Ambati, C., Petrosino, J. F., Bryan, R. M., & Durgan, D. J. (2021, February 18). Restructuring the gut microbiota by intermittent fasting lowers blood ... AHA Journals. Retrieved April 6, 2023, from https://www.ahajournals.org/doi/10.1161/CIRCRESAHA.120.318155
- Gonzalez, J. E., & Cooke, W. H. (2022). Influence of an acute fast on ambulatory blood pressure and autonomic cardiovascular control. American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. https://doi.org/R-00283-2021
- Sutton, E. F., Beyl, R., Early, K. S., Cefalu, W. T., Ravussin, E., & Peterson, C. M. (2018). Early Time-Restricted Feeding Improves Insulin Sensitivity, Blood Pressure, and Oxidative Stress Even without Weight Loss in Men with Prediabetes. Cell metabolism, 27(6), 1212–1221.e3. https://doi.org/10.1016/j.cmet.2018.04.010
- Arnason, T. G., Bowen, M. W., & Mansell, K. D. (2017). Effects of intermittent fasting on health markers in those with type 2 diabetes: A pilot study. World journal of diabetes, 8(4), 154–164. https://doi.org/10.4239/wjd.v8.i4.154
- Cienfuegos, S., Gabel, K., Lin, S., Oliveira, M. L., & Varady, K. A. (2020, July 15). Effects of 4- and 6-h time-restricted feeding on ... - cell metabolism. Cell Metabolism. Retrieved April 6, 2023, from https://www.cell.com/cell-metabolism/fulltext/S1550-4131(20)30319-3
- Li Z, Heber D. Intermittent Fasting. JAMA. 2021;326(13):1338. doi:10.1001/jama.2020.15140