Bilberry
OTHER NAME(S): bilberry, European bilberry, Vaccinium myrtillus, whortleberry
Overview
Bilberry is the fruit of a plant called Vaccinium myrtillus and is available as a food, juice, and dietary supplement. It is used for many different reasons, although its benefits are not well defined. Bilberry is usually well tolerated. Before taking bilberry, make sure to tell your health care provider about any health conditions you have or medicines you are taking.
Uses
What is bilberry used for?
Bilberry (Vaccinium myrtillus) is used for many different reasons. However, the benefits of bilberry are not well defined. Some common reasons that people use bilberry include the following.
- Mild diarrhea
- Poor blood flow to the veins in the legs (chronic venous insufficiency or CVI)
- Varicose veins
- Vision problems, including poor night vision
Note: The FDA has not reviewed bilberry for safety and effectiveness. Learn more about dietary supplements here.
How does bilberry work (mechanism of action)?
Bilberry is the berry of a plant called Vaccinium myrtillus. This fresh or dried berry is commonly available as a food and is often made into jam or juice. It is also available in dietary supplements. Bilberry is sometimes called whortleberry or blueberry, but it is not the same as the blueberry fruit commonly grown in the United States.
Bilberries contain chemicals called anthocyanins. These chemicals act as antioxidants in the body. They may also make the platelets in your blood less sticky, help relax your blood vessels, and strengthen blood vessel walls. Together, these actions may help reduce swelling (edema) and other symptoms in people with poor blood flow to the legs or varicose veins. But the benefits of bilberry are not well defined for these uses. These effects are also thought to be helpful for vision problems, including poor night vision, but the effects of bilberry for this use are unclear.
Bilberry fruits may also help reduce inflammation (swelling) in the gut. Dried bilberry fruits are sometimes eaten to help manage diarrhea. But it is not clear if bilberry helps with diarrhea.
Herbal products, like bilberry, naturally contain many different chemicals. The amounts of each chemical in a specific bilberry product may vary. Some, none, or all of these chemicals may have effects on the body. These effects may change depending on how much of each chemical is found in the product you are using.
How should I store bilberry?
You should store bilberry according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.
Side Effects
What are the most common side effects of bilberry?
Bilberry seems to be well tolerated. Tell your health care provider if you have any side effects that bother you.
There may be side effects of bilberry that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of bilberry?
While less common, the most serious side effects of bilberry are described below, along with what to do if they happen.
Severe Allergic Reactions. Bilberry may cause allergic reactions, which can be serious. Stop taking bilberry and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching or skin rash
- Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Precautions
Who should not use bilberry?
Allergies to Ingredients. People who are allergic to any of the following should not take bilberry.
- Bilberry
- European bilberry
- Vaccinium myrtillus
- Whortleberry
- Any of the ingredients in the specific product
Your pharmacist can tell you all of the ingredients in the specific bilberry products they stock.
What should I know about bilberry before using it?
Bilberry is available as a food, a juice, and a dietary supplement. It cannot be marketed to treat or cure a disease.
Read and follow the directions on the specific product you are taking, or take it as recommended by your health care provider.
Keep bilberry out of the reach of children.
Herbal products, such as bilberry, naturally contain many different chemicals. The amount of each chemical in a specific bilberry product can vary for many reasons, including the area where the fruit was grown, the weather during growth, and the way that the fruit was processed after it was harvested. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability. Talk to your health care provider if you have questions or concerns.
Most dietary supplements that contain bilberry are made from the fruit (berry) of the plant. These are also the products that have been studied in clinical research. But some dietary supplements may contain the leaf of the plant, which has not been well studied. It is important to read the label to confirm which part of the plant was used to make that product.
The FDA has not tested bilberry products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.
What should I tell my health care provider before using bilberry?
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know whether bilberry is right for you.
In particular, make sure that you discuss any of the following.
Diabetes.Bilberry products, such as juices, may contain added sugar. Read the product label closely and speak with a health care provider before using bilberry if you have diabetes.
Other Medicines and Supplements.Bilberry may interact with other medicines and supplements. Before taking bilberry, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.
Pregnancy. It is not known if or how bilberry could affect pregnancy or harm an unborn baby. Tell your health care provider if you are pregnant or plan to become pregnant.
Breastfeeding. It is not known if bilberry passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Does bilberry interact with foods or drinks?
There are no known interactions between bilberry and foods or drinks.
It is unknown if drinking alcohol will affect bilberry.
Does bilberry interact with medicines (drug interactions)?
Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
In particular, make sure that you discuss if you are using any of the following before taking bilberry.
- A blood thinner, which is a medicine used to treat or prevent blood clots
- An antiplatelet medicine, such as clopidogrel (Plavix), ticagrelor (Brilinta), aspirin/dipyridamole, or cilostazol, which is a medicine used to prevent blood clots
The interactions between bilberry and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with bilberry is incomplete. Always check with your health care provider before taking bilberry with any medicines.
Dosing
What should I do if I accidentally use too much bilberry?
If you or someone else has used too much bilberry, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
Read the product label closely and speak with a health care provider about how to use bilberry safely. Do not take double or extra doses.
References
- Blumenthal, M. The ABC Clinical Guide to Herbs, American Botanical Council, 2003.
- Drugs and Lactation Database (LactMed) [Internet]: Bilberry.
- European Medicines Agency. Fresh bilberry fruit; Vaccinium myrtillus L., fructus recens.
- European Medicines Agency. Myrtilli fructus siccus - herbal medicinal product.
- Herbal Medicine: Biomolecular and Clinical Aspects. 2nd edition. Chapter 4: Bilberry (Vaccinium myrtillus L.).
- National Center for Complementary and Integrative Health: Bilberry.