Bilberry Ext.
Bilberry extract is a dietary supplement that is promoted for its potential health benefits. Bilberry fruit has been used by adults in doses of 160-240 mg by mouth daily for up to 6 months. Bilberry extracts are usually standardized to 25% anthocyanoside content, and 100 g of fresh fruit contains anthocyanin content 300 to 700 mg.
Bilberry contains chemicals called tannins that can help improve diarrhea, as well as mouth and throat irritation, by reducing swelling (inflammation). There is some evidence that the chemicals found in bilberry leaves can help lower blood sugar and cholesterol levels. Bilberry is also promoted as a dietary supplement for night vision, cataracts, varicose veins, and other conditions such as atherosclerosis (in which plaque builds up in arteries). Bilberry has been shown to have antioxidant and anti-inflammatory activity that protected the livers and kidneys of mice and rats from the damage caused by toxins and drugs.
A small study from 2015 found that taking 480 mg of bilberry extract every day reduced the symptoms of eye fatigue. An extract standardized to 36% anthocyanins (600 mg/day) improved spider veins in a clinical trial on over 1k people. Bilberry fruits (300-400 g/day) and extracts lowered blood sugar in three clinical trials on over 150 people with or at risk of type 2 diabetes. Bilberry also increased insulin release and sensitivity, which is important for preventing insulin resistance. Plus, it reduced sugar and insulin spikes after meals. There are few high-quality clinical trials of bilberry supplements. A few recent studies have suggested possible beneficial effects of bilberry. However, these studies involved small numbers of people. More research would be needed to confirm these findings.
Eating dried, ripe bilberry fruit in typical food amounts is likely safe for most people. Bilberry fruit extracts are possibly safe when taken in doses up to 160 mg daily for up to 6 months. But bilberry leaf is possibly unsafe to take in high doses or for a long time. Nausea, gas, hard stools, dying of the tongue and stools, and mild heartburn are some mild side effects reported in people with IBS.
