It is common knowledge that salt contributes to high blood pressure. Doctors routinely recommend a low-sodium diet in response to hypertension, or high blood pressure. However, not many people know about the role of sugar, particularly fructose, in causing high blood pressure. Here are the reasons why you should reduce sugar intake to maintain healthy blood pressure.
Understanding High Blood Pressure
Blood pressure is a measure of the force of blood pushing against arteries. A normal blood pressure essentially ensures that the blood from your heart is reaching the rest of your body. Without it, all of your cells, tissues, and organs wouldn’t receive any oxygen or nutrients. Blood pressure is also responsible for delivering white blood cells, antibodies, and hormones throughout the body.1
Blood pressure is measured with two numbers. The systolic blood pressure measures the pressure of your heart pushing blood out as it contracts, while the diastolic blood pressure measures the pressure as your blood relaxes and refills with blood. The physics of this means that the systolic number should always be higher than the diastolic reading.
Blood pressure can fluctuate based on a variety of factors, but the condition of the heart and arteries has the most immediate effect on blood pressure and blood flow. Narrowing or clogged arteries can increase blood pressure and eventually become blocked entirely, which results in a heart attack or stroke. High blood pressure may also contribute to an increased risk of other health issues.1
Sugar’s Effects on Blood Pressure
Your diet has the most direct impact on your heart, arteries, and blood pressure. While salt tends to be the most common culprit for increased blood pressure, sugar can also modulate blood pressure.
1. Sugar can get absorbed into the bloodstream.
Table sugar comprises two molecules, glucose and fructose. Glucose is a simple sugar and often your body’s easiest, most accessible source of energy, while fructose is a basic sugar found mostly in fruits. Both glucose and fructose are soluble in water and get absorbed directly into the blood during digestion. This means that table sugar is osmotically active and can cause blood pressure to go up when it is consumed, absorbed, and dissolved in blood.
2. Fructose may increase the re-absorption of salt and water.
All forms of sugar can also contribute to physiological and metabolic effects that may cause a rise in blood pressure, but this is most apparent with fructose. The exact connection between high blood pressure (hypertension) and fructose still requires further study, but research shows that fructose may raise blood pressure through various mechanisms. Fructose increases the reabsorption of salt and water in the small intestine and kidney. This means that fructose causes the body to hold onto salt and water instead of urinating out, raising blood pressure. The kidneys are particularly sensitive to these effects as high amounts of fructose easily reach renal tissue.2
3. Fructose increase uric acid levels in the body.
Lowering uric acid levels has been found to reduce hypertension, but when fructose is broken down, it releases uric acid as a byproduct. Along with causing gout, increased uric acid can result in a higher blood pressure. In a randomized, controlled trial, 74 men were given 200 grams of fructose per day for two weeks. Researchers measured ambulatory blood pressure, lipids, glucose, insulin, body mass index, and general criteria for metabolic syndrome. Results of the study found that ingestion of fructose led to increases in ambulatory blood pressure (for both systolic and diastolic values). Lowering uric acid levels was found to prevent any increases in mean arterial blood pressure. Excessive fructose intake was also found to play a role in obesity and diabetes.3
4. Fructose can contribute to the formation of free radicals.
Fructose can also contribute to high blood pressure through more indirect means. Fructose can contribute to the formation of free radicals. Free radicals are a natural product of oxidation, but they can cause damage to cells and even your DNA, resulting in inflammation and an increased risk of certain diseases. This consistent cellular damage is known as oxidative stress.
5. Fructose may increase stress.
Fructose also contributes to increased stress.4 Stress is a natural response to any potential environmental threat, resulting in the instinctive “fight or flight” response. Although stress is necessary and sometimes beneficial in the short-term, chronic stress puts your body in a constant state of “fight or flight”. This is normally meant to be a survival state. Increased epinephrine results in a faster heart rate and higher blood pressure to temporarily increase the amount of blood that gets sent to your muscles.
Unfortunately, a consistent surge of epinephrine from chronic stress keeps blood pressure at a constantly high state while causing damage to the arteries and blood vessels, all of which can increase your risk of strokes and heart attacks. Cortisol, the main stress hormone, can also contribute to increased appetite and fat storage, leading to weight gain and a buildup of fat tissue.5 All of this can come from increased consumption of fructose.
6. Fructose may increase blood constriction.
Consuming fructose may also increase the production of organic compounds that constrict blood vessels. A rodent study found that rats fed fructose showed an increased production of vasoconstrictors, including prostanoids, endothelin-1, and endothelin-2. Constricted blood vessels contribute to an increase in blood pressure.6
Fructose is also known to contribute to metabolic syndrome. Metabolic syndrome refers to a combination of conditions that may occur together, increasing the risk of stroke, type 2 diabetes, heart attack, and cardiovascular disease. Metabolic syndrome can include increased insulin resistance, higher triglycerides, and increased fatty deposits in the liver.7
How to Lower High Blood Pressure
Sugar can be difficult to avoid, especially in Western diets that tend to be high in processed carbohydrates and packaged foods that contain high levels of added sugars. Here are some tips for reducing your sugar intake.
1. Avoid Sugary Beverages
Sugary beverages, which include soda, energy drinks, fruit juices, and sports drinks, comprise an estimated 44 percent of all the added sugar in the average American diet. This massive amount of sugar is exacerbated by the fact that these are beverages. Your body has trouble recognizing calories from drinks the same way as it does calories from food. As drinks do not make you physically full, you may consume a great deal of sugar from drinks while still eating the same amount (instead of eating less to compensate). That can all contribute to an increased sugar intake.8
Cutting back on sugary drinks can significantly reduce your overall sugar intake and contribute to better health overall. This can be difficult considering sugar’s naturally addictive nature, but try to swap out these sweet beverages in favor of:
- Sparkling water with a squeeze of lemon or lime
- Herbal or fruit teas
- Unsweetened tea
- Black coffee
2. Avoid Processed and Instant Meals
Over-processed, refined foods tend to be high in added sugar and salt, along with a variety of potentially unhealthy additives, like preservatives and artificial flavors. Ultra-processed foods also tend to have all of their vitamins and minerals processed right out of them, meaning that you get all of the calories without any of the nutritional value that food should give you. This is better known as “junk food”.8
Whole foods stand at the other end of the spectrum. These comprise foods that have been minimally processed and refined and contain next to no additives and artificial substances. This means less added sugar and fewer chemicals, while providing plenty of necessary nutrients. Focus on homecooked meals that use whole fruits and veggies, along with lean sources of protein.8
3. Read the Labels
Canned foods can be a convenient, affordable addition to your diet. Canned fruits and vegetables are usually as good as their fresh counterparts. However, make sure to read the label for any added sugars. Avoid canned foods that have been packed with syrup or any other added sugars. For canned fruits, look specifically for cans that say “no added sugar” or “in own juice.” If you do purchase canned vegetables or fruit with added sugar, try to rinse some of that excess sugar off with water.
Along with canned foods, be more aware of labels on all of your packaged foods. This can be difficult considering food labels do not differentiate between added sugar and natural sugars (like those in dairy and fruit). Food companies also have access to a list of over 50 names for different types and forms of sugar. Some of the most common include high fructose corn syrup, maltose, dextrose, and cane sugar.8
While this article may make it sound like you should avoid sugar at all costs, that is not the case. Sugar is naturally present in whole fruits and vegetables. The problem arises when these fruits and vegetables are processed and refined until there is no fiber or nutritional value left. This gets exacerbated by the amount of added sugar in other foods.
Consumption of whole fruits has many benefits as the fiber helps support feelings of satiety while contributing to a variety of other potential health benefits, but note that fruit juice has no fiber. While it can seem difficult, reducing your consumption of added sugars along with salt will go a long way in helping you to reduce your blood pressure naturally.