Blueberries: Benefits and Side Effects

Blueberries are naturally high in fiber, potassium and vitamins A, C, and K. People refer to them as superfoods which are very low on calories. Statistics show that a large number of people consider them as their favorite fruit. There are plenty of health benefits you can get from eating blueberries, but they have side effects too. The benefits are very wide ranging from the prevention of cancer and heart disease to treatment of urinary tract infections. Side effects vary considerably from gastrointestinal distress to hypoglycemia to increased risk of bleeding. Let’s look at these benefits and side effects of blueberries in depth.

The Benefits

Reduce DNA Damage

Reduced DNA damage can protect you against aging and cancer. We all go through oxidative damage in our daily life since it’s unavoidable. DNA damage is what makes us grow older and causes multiple diseases like cancer. Blueberries are extremely rich in antioxidants which neutralizes some of the free radicals that damage our DNA. A group of people who drank 34 ounces (one liter) of mixed blueberry and apple juice daily, had a reduce DNA damage after four weeks by 20 percent.

Lower Blood Pressure

Blood pressure is a major risk factor for heart disease and blueberries seems to help with this condition. An eight-week study saw a reduction in blood pressure by four to six percent among obese people who were at a high risk of heart disease. This was through consumption of two ounces (50 grams) of blueberries daily. Different studies have obtained similar results especially for postmenopausal women.

Maintain Brain Function and Improve Memory

An accelerated brain aging can result from oxidative stress which affects brain function. An animal study indicated that the antioxidants in blueberries positively affect areas of the brain that are essential for intelligence. Generally, blueberries help aging neurons leading to improved cell signaling. A human study that involved nine older adults with mild cognitive impairment who consumed blueberry juice each day, found that they experienced improvement in several markers of brain function after 12 weeks. Another study found out that blueberries and strawberries delay mental aging by up to two and a half years.

Reduce Muscle Damage

Strenuous exercises can cause muscle damage and therefore, blueberries may help ease the effect. The exercises may cause soreness and fatigue due to inflammation and oxidative stress in the muscle tissue. Blueberries minimize this effect by lessening the damage that occurs at the molecular level. In a small study of 10 female athletes, blueberries were able to accelerate muscle recovery after strenuous leg exercises.

The Side Effects

Bleeding Risk

A cup of blueberries contains 29 micrograms of vitamin K, making them a medium vitamin K food. Vitamin K is useful to the body since it helps with blood clotting and maintains bone density. However, for people taking blood thinner prescription, eating blueberries isn’t a smart choice. In fact, they are encouraged to keep the same levels of vitamin K in their bloodstream every day. A sudden decrease or increase in the consumption of vitamin K rich foods before talking to the doctor to make changes to prescription blood thinner dosage can cause increased bleeding.

Stains on The Teeth

Blueberries can potentially cause stains on your teeth due to their intense pigmentation. It doesn’t matter if you eat them fresh, frozen, or juiced, their deep blue color can discolor your tooth enamel or white fillings. But you can try to reduce the staining effect by drinking water after eating them. Then take some milk to neutralize the acid and maintain your teeth strong. Additionally, eating hard cheese after consuming blueberries may help you to maintain that pearly white smile.

Salicylate Sensitivity

Blueberries have Salicylate, an active ingredient in aspirin that is found naturally in many plants, in large amounts. Salicylate can be a nightmare for people who are sensitive to it. For those with Salicylate intolerance, eating blueberries causes headaches, rash and gastrointestinal symptoms like nausea, vomiting, reflux, bloating, gas, diarrhea, and constipation. Blueberries juice contain even more Salicylate. Eating blueberries in small amounts can ease some of the pain or discomfort associated with ingestion of Salicylate.


Blueberries are naturally healthy but you should consume them in moderation too. Adults should eat a maximum of two cups a day to maintain a healthy balance. You should consider adding blueberries to your morning cereals or mix them with other fruits to make a smoothie. All in all, the health benefits of blueberries exceed the side effect although you should watch out for the most common negative effects like bleeding risk. Nevertheless, this nutritious fruit is what you need to avoid any chronic related disease. Plus, they can be added to salads, pancake or to dessert.

All images by Pixabay


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