Health Benefits of Blueberries
Blueberries are an excellent source of vitamins C, B6 and K, manganese and fiber. A 1-cup serving provides the following for your recommended dietary allowance:17
- Vitamin K: 36 percent
- Vitamin C: 24 percent
- Vitamin B6: 5 percent
- Manganese: 25 percent
- Fiber (3.6 grams): 14 percent
Blueberries also contain a decent amount of vitamins B1 (thiamin), B2 (riboflavin) and E, as well as calcium, magnesium, phosphorus and potassium. In addition to their vitamin and mineral content, the phytonutrients in blueberries provide important health benefits.
Blueberries pack tremendous antioxidant power, which helps your body keep free radicals in check and fight inflammation. (The Atlantic has published a fascinating article about how a blend of scientific research and marketing has led us to associate blueberries as being super healthy due to their high antioxidant content.18)
Along with other berries such as cranberries, raspberries and strawberries, blueberries are among the best dietary sources of bioactive compounds, such as anthocyanins, flavonols, ellagic acid and resveratrol. Studies indicate blueberries reduce your risk of:19,20,21
- Cancer: Blueberries have been shown to be effective in the fight against breast cancer, colon cancer, esophageal cancer and cancers of the small intestine, most likely due to their antioxidant and anti-inflammatory properties
- Eye problems: The antioxidants in blueberries are also known to help prevent or delay age-related eye problems and vision loss, including cataracts, dryness, infections, macular degeneration and myopia
- Excessive aging: Due to their high antioxidant content, blueberries can help reduce the signs of aging such as age spots, hair loss and wrinkles
- High blood sugar: Results from three prospective longitudinal cohort studies,22 involving more than 187,000 participants, concluded that greater consumption of specific whole fruits, such as blueberries, is significantly associated with a lower risk of Type 2 diabetes
- Urinary tract infections: Blueberries and cranberries contain an antioxidant called epicatechin that inhibits the growth of bacteria in the lining of your bladder that causes urinary tract infections
Blueberries Protect Your Heart
Blueberries are highly regarded for their role in helping protect your heart and lower your blood pressure. Past research revealed that women ages 25 to 42 who ate more than three servings per week of blueberries (and strawberries) had a 32 percent lower risk of having a heart attack.23 The primary agents responsible for protecting your heart are certain flavonoids found in the berries known as anthocyanins, antioxidants responsible for giving berries their colorful hues.
Anthocyanins are known to benefit the endothelial lining of your circulatory system, possibly preventing plaque buildup in your arteries, as well as promoting healthy blood pressure. Other research has shown these antioxidants to protect against heart disease by reducing oxidative stress and inflammation, while enhancing capillary strength and inhibiting platelet formation.24
Eating blueberries has also been shown to lower your blood pressure. A study published in the Journal of the Academy of Nutrition and Dietetics25 involving postmenopausal women suggests blueberry consumption positively affects blood pressure.
The women, who had either prehypertension or hypertension, received a placebo powder or freeze-dried blueberry powder — an amount equivalent to about 1 cup of fresh blueberries — daily for eight weeks. While the placebo group saw no significant changes, the women supplementing with blueberries realized a 5 to 6 percent drop in both their systolic (top number) and diastolic (bottom number) blood pressure readings.
Measurements of nitric oxide were also significantly increased in the blueberry group, with no such change in the control group. Nitric oxide helps your blood vessels maintain their elasticity and also dilates your blood vessels, thereby reducing your blood pressure. The study authors stated: "Daily blueberry consumption may reduce blood pressure and arterial stiffness, which may be due, in part, to increased nitric oxide production."
Blueberries Are Beneficial, But Don't Overdo It
While there's no doubt blueberries are a healthy food, you will still want to moderate your intake of them. One cup of blueberries contains approximately 15 grams of sugar. I continue to advise that you keep your total fructose consumption below 25 grams per day, including fructose from fruits such as blueberries. If you have a chronic disease such as diabetes, heart disease, high blood pressure or insulin resistance you'd be wise to restrict your fructose to 15 grams or less per day until your condition improves.
Please take note that blueberries are on the Environmental Working Group's list of 48 fruits and vegetables containing pesticide residue.26 Because both domestic and imported blueberries sold within the U.S. are sprayed with toxic pesticides, be sure to buy organic, or better yet, grow your own.