Let’s look at some numbers. Just one cup of blueberries a day can provide loads of nutrients: 24 percent of your daily intake of vitamin C, 36 percent of vitamin K, 25 percent of manganese, which helps with blood clotting and promotes bone and muscle strength, and 14 percent of dietary fiber, according to the Cleveland Clinic. “These little nuggets are phenomenally full of vitamins and minerals,” says Evelina Grayver, MD, a cardiologist at North Shore University Hospital at Northwell Health in New York City. “It is very important to understand how they help manage cholesterol, potentially help manage blood sugar, how they reduce blood pressure, and how overall they decrease inflammatory response in the vessels and thus decrease the risk of heart disease.” How exactly can eating blueberries improve your heart health?
Manage Cholesterol
Blueberries are high in soluble fiber, which helps your gut remove bile and manage cholesterol, a known risk factor of cardiovascular health. Soluble fiber does this by binding to the cholesterol, salts, minerals, and other bile components and removing it through the body’s waste. “Soluble fiber is a natural cleansing system, helping keep your cholesterol levels down,” says Julia Zumpano, RD, a registered dietitian at the Cleveland Clinic in Ohio. A review published in May 2019 in Nutrients found that blueberries had more grams per cup of fiber than apples, strawberries, peaches, and plums. The same study found that most Americans do not consume the necessary amount of fiber per day — 38 grams per day for men under 50 and 25 grams for women under 50 — so adding blueberries to your diet would be an easy way to up your fiber and keep your cholesterol in check. “Right now, we’re in the midst of a hot summer, and we all love to have a nice cool watermelon or melons, which are great. However, there’s so much sugar,” says Dr. Grayver. “Blueberries are actually low in sugar, no matter how sweet they may taste.” This means they are less likely to cause blood sugar levels to spike, a key benefit for those with diabetes who also have a heart condition. A controlled study published in Current Developments in Nutrition in March 2020 found that eating 22 grams (g) of freeze-dried blueberries every day (equivalent to about one cup of fresh blueberries) benefited cardiometabolic health in men with type 2 diabetes. But more research must be done to account for all people. Zumpano says that while diabetes is often not the first thing to come to mind when dealing with heart problems, it doesn’t mean the two are not connected. “Elevated blood sugars can lead to an unhealthy heart, inflammation, and elevated risk of insulin resistance or diabetes, which doubles your risk of heart disease,” she says.
Reduce Stress
An unhealthy diet and stress cause wear and tear on the body, typically through oxidative stress, which is an imbalance of unstable molecules and antioxidants in the body that can lead to cell and tissue damage. “The more we ingest antioxidant-rich foods, we’re creating barriers around some of the stressors that we may not be able to control, like environmental toxins, to help protect the cells from being damaged,” says Zumpano. Some studies show that antioxidants like anthocyanin, which blueberries are loaded with, play a role in reducing oxidative stress and cell damage, although much of this research has been done on rodents, not humans. Wild blueberries have elevated levels of anthocyanin, and Zumpano recommends them if they are available in your area and are affordable.
Lower Blood Pressure
Blueberries are high in nitric oxide, a molecule that relaxes the inner muscles of blood vessels. This characteristic helps lower blood pressure. A randomized controlled trial published in June 2019 in the American Journal of Clinical Nutrition looked at 115 people with metabolic syndrome and tested how eating blueberries affected symptoms. Participants were split between a placebo group, those who ate half a cup of blueberries, and those who ate a full cup per day for six months. While insulin resistance remained unchanged, sustained improvements in vascular function, cholesterol concentrations, and underlying nitric oxide activity (which helps increase blood flow by relaxing blood vessels) following 1 cup of blueberries per day were observed, predicting a 12 to 15 percent reduction in cardiovascular diseases. “That was just one particular study, but we have seen blood pressure and inflammation being reduced with just general healthy eating and high antioxidant foods,” says Zumpano.
Add Blueberries to Your Diet
The good news is there are tons of ways you can eat blueberries. Zumpano suggests adding them to oatmeal, Greek yogurt, or a smoothie for something quick. Blueberries can also be added to salads or cottage cheese for something more savory. Grayver and Zumpano agree that cooking blueberries will cause them to lose some of their nutritional value, and eating them raw is best, but that still leaves plenty of options. And when they are out of season, you can always choose frozen, which are just as good and contain most of the nutrients of fresh berries. Grayver says she adds blueberries to at least one meal a day, typically breakfast, because of their great nutritional value. “I actually like to put them on pretty much everything,” says Grayver. “If you have one cup a day, you can actually get enough of the benefits.”
