The benefits of eating blueberries and strawberries may far outweigh any health risks. Dr. Eric Rimm of Harvard Medical School advises people of all ages to eat more berries for heart health. Some people may have allergic reactions to berries or experience digestive problems, however, if they consume too many. Choose the kinds of strawberries and blueberries you buy carefully, to avoid fruits contaminated with pesticides.
The Environmental Working Group, a nonprofit research organization, publishes an annual list of the “dirtiest” produce with the most pesticide residue, according to tests performed by the U.S. Department of Agriculture and the Food and Drug Administration. In 2014, strawberries ranked No. 2 for their pesticide content, while blueberries ranked No. 23, making them “cleaner” but still in the top 48. The Environmental Protection Agency reports that pesticides in food can pose serious health risks, possibly causing birth defects, nerve damage and cancer. They may be particularly harmful to children, whose organs and immune systems are still developing. Choose berries certified as organic, which indicates they were grown without the use of pesticides.
Fruit Allergy and Intolerance
A food allergy is an immune system response; in rare cases, it can be life-threatening. If you're allergic to birch pollen, you may experience itching around the mouth and inflammation when you eat raw strawberries and related fruits, such as apples, pears and cherries, but you'll be able to tolerate cooked or processed fruits. Strawberries also contain histamines, chemicals that can cause itching, wheezing and hives. Blueberries have a safer track record, with just a single known case of blueberry allergy on record, according to the American Academy of Allergy, Asthma and Immunology. If you eat raw berries and experience any symptoms of allergy, seek medical attention immediately. The histamines in strawberries might also trigger signs of a food intolerance, which results in uncomfortable digestive symptoms such as vomiting and diarrhea. If your symptoms don't resolve on their own, talk to your doctor.
Too Much Fiber
Raw berries are packed with fiber – more than most other fruits, according to registered dietitian Sharon Palmer on the Today’s Dietitian website. Fiber aids with digestion and elimination and can help lower your cholesterol. Strawberries contain 3 grams per 1-cup serving, while blueberries supply 4 grams of the 25 to 38 grams of fiber needed daily by women and men. But if you add too much fiber to your diet too quickly, you may experience gas, bloating and cramps. Also, too much fiber may interfere with the absorption of some minerals, such as iron and calcium. Talk to your doctor about your fiber needs and how to reach your daily goal.
The Plus Side
In spite of the few risks posed by these fruits, strawberries and blueberries may be among the healthiest foods to add to your diet. Both are rich in antioxidants called anthocyanins that give them their vibrant colors. Anthocyanins protect against inflammatory conditions such as arthritis and may slow memory loss as you age. They’re also good low-calorie, weight-loss foods because the fiber and water they contain help keep you feeling full. Frozen berries with no sugar added are just as nutritious as fresh, according to dietitian Joy Bauer.
- Harvard Health Publications: Eat Blueberries and Strawberries Three Times Per Week
- Environmental Working Group: All 48 Fruits and Vegetables with Pesticide Residue Data
- Environmental Protection Agency: Pesticides and Food
- University of Manchester: Allergy Information for Strawberry
- Allergy UK: Histamine Intolerance
- Today’s Dietitian: The Top Fiber-Rich Foods List
- Medline Plus: Fiber
- Joy Bauer: Health Benefits of Berries
- American Academy of Allergy, Asthma and Immunology: Possible Anaphylaxis to Blueberry
- Academy of Nutrition and Dietetics: Food Allergies and Intolerances