Intermittent Fasting for High Blood Pressure and Cholesterol
Intermittent fasting produces real, measurable improvements in blood pressure and cholesterol.
- Intermittent fasting improves cardiovascular health by lowering blood pressure, reducing LDL and triglycerides, and modestly increasing HDL.
- It is particularly effective in people who are at higher risk (e.g., overweight, obese, high blood pressure and cholesterol).
- Intermittent fasting will not cure cardiovascular disease by itself. But it can be used alongside other treatments.
Cardiovascular disease remains the leading cause of death worldwide, and high blood pressure and cholesterol are two of the most prominent risk factors that can be reduced by lifestyle changes. In this article, we’ll look at the effects of intermittent fasting on blood pressure, cholesterol and cardiovascular health.
Cardiovascular disease does not usually arrive without a warning. It builds, slowly and quietly, over decades. The increases in blood pressure, worsening lipid and cholesterol profiles, an expanding waist and inflammation are all early signs.
All these changes are connected, and rarely occur by themselves. But the good news is that they can be controlled by what and when you eat. Intermittent fasting appears to address several of these cardiovascular health 'risk factors' at the same time.
Understanding cardiovascular health
You’ve probably had your blood pressure measured before. When it's too high (called “hypertension”), it damages your blood vessels, strains your heart, and dramatically increases the risk of heart attacks and stroke. Globally, hypertension is the single biggest cause of early death. It is often called a "silent disease" because it produces no symptoms for years.[1]
Cholesterol, your "lipoproteins", and your blood lipids are slightly more complex. Cholesterol itself is essential — your body uses it to build cell membranes, produce hormones, and synthesise vitamin D. The problem isn’t cholesterol itself; it’s how it's transported. Cholesterol is carried inside lipoproteins, and there are a few types.
- Low-density lipoproteins (“LDL” or “bad cholesterol”) carry cholesterol away from your liver.
- High-density lipoproteins (“HDL” or “good cholesterol”) carry cholesterol toward the liver, where it gets processed.
- Triglycerides (or "TGs") are a type of fat that your blood carries — too much of it is bad for your cardiovascular health.
The different amounts of these different types of cholesterol and fats are referred to as your blood lipid profile or panel. Low HDL, high LDL and triglycerides often occur together, which creates an environment that damages your blood vessels over time. Small dense LDL particles, VLDLs (“very low-density lipoprotein”), tend to block your blood vessels and cut off blood and oxygen to your tissues, which keeps them alive.
How does intermittent fasting affect blood pressure?
The evidence is pretty consistent: intermittent fasting can measurably reduce blood pressure, most obviously in those who are overweight and are hypertensive. You can expect, on average, a 2-7 mmHg decrease in your systolic pressure (the “top number”) and a 2-4 mmHg decrease in the bottom number (your 'diastolic' pressure).[2]
Decreased blood pressure occurs even without any weight loss, meaning that intermittent fasting's blood pressure-lowering effects are not just a result of the weight loss. However, it seems that the positive effects of intermittent fasting on blood pressure are not any better than a standard calorie-restricted diet.[3]
They are both effective at lowering blood pressure, but neither is better than the other. So it seems that just reducing the amount of calories (and possibly other things in your diet) is most important.[4]
In the short-term, fasting reduces the amount of sodium your body retains. Sodium loves water, so if the amount of sodium in your blood decreases, the volume of fluid in your blood will also decrease; this, in turn, goes on to decrease your blood pressure. This can occur within days of starting an intermittent fasting protocol.[5]
Over a few months of fasting, fat loss can occur. Some types of fat (“visceral fat”) produce substances that affect how your blood vessels regulate your blood pressure. Inflammation can also impair how your blood vessels keep your blood pressure under control, which intermittent fasting also decreases as well.[6][7]
Does intermittent fasting lower cholesterol and blood lipids?
Intermittent fasting appears to meaningfully reduce the “bad” LDL cholesterol levels, the total amount of cholesterol in your blood and increase HDL “good” cholesterol in people who are overweight or obese.[4]
The rare shift from small LDL to the larger HDL is particularly beneficial at reducing cardiovascular disease, and may not always be picked up on standard blood tests. Alongside the overall decrease in cholesterol and the lipoprotein profile shifts, intermittent fasting also decreases your blood triglycerides.
Elevated triglycerides are usually a result of eating too much food, too much fat and sugar. So it is not surprising that both intermittent fasting and calorie-restriction diets lower your triglycerides.
In addition to limiting the quantity (and possibly the type) of foods that you eat, fasting also supports fat loss (including loss of visceral fat and liver fat). Improving the function of your liver is generally good for your cholesterol levels, as it's your liver that helps control how much and what type of cholesterol and fat you have in your system.
Intermittent fasting also improves your insulin sensitivity. Insulin is a really important hormone which regulates a lot of things in your body. One of them is controlling the amount of triglycerides that are released and cleared from your blood. Better insulin sensitivity generally means you clear triglycerides more effectively from your blood, keeping their levels low.
Does intermittent fasting reduce cardiovascular disease?
So intermittent fasting reduces nearly all cardiovascular disease risk factors: body weight, body fat, visceral and liver fat, blood pressure, cholesterol, LDL and HDL, triglycerides, insulin resistance and inflammation.
Improving all of these, all at the same time, in the right way certainly suggests that intermittent fasting reduces the chances of cardiovascular disease. However, there is not as strong evidence showing that it actually reduces cardiovascular disease outcomes (like heart attacks, strokes, or cardiovascular disease deaths).
This is not unusual, though. These types of studies are difficult, expensive and take a long time to do properly. It is inferred that if you can improve cardiovascular disease risk factors, you'll also reduce your chances of having or dying from cardiovascular disease.
