The myth of blueberry extract as eye-vision booster - CHOICE # 377

Can blueberry (or bilberry) in extract or other forms of concentrated dosage really boost up your eye health and vision?

Marketers of these dietary health supplements with the aid of heavy advertising would have us believe that it is the case.

But a Consumer Council study has revealed that scientific evidence is sadly lacking to support their product claims.

In the study, the Council has enlisted the help of medical experts consisting of academics, dietitians and pharmacists as well as the Department of Health, and the Centre for Food Safety.

In general, they were of the view that while blueberry and bilberry products may be potentially beneficial to eye health, there is no scientific evidence that they can actually improve eye vision or (in some bilberry claims) night vision.

According to the Chinese University of Hong Kong's Department of Ophthalmology and Visual Sciences, laboratory studies have demonstrated that anthocyanins, a group of water-soluble pigments found in berries (and various fruit and vegetables), have some potential beneficial effects on the health of the eyes.

But these effects have not been proven by "randomized controlled clinical trials", so it remains uncertain whether such effects could be translated into significant clinical benefits on vision.

The Hong Kong Dietitians Association (HKDA) noted that bilberry extract has been evaluated overseas for efficacy in various aspects, for example, its anti-oxidant effect, anti-inflammatory effect, and as a lipid-lowering agent. Though pre-clinical studies have been promising, human data are limited and largely of poor quality.

Further, there are research findings to suggest that contrary to some bilberry claims, bilberry in fact does not improve night vision.

Consumers are also alerted to the possible interaction of blueberries and bilberries with drugs. For example, the HKDA has pointed out that blueberries might have an effect of lowering blood pressure and blood sugar.

People on anti-hypertension drugs or diabetic drugs should, therefore, seek medical advice before taking these supplements. Blueberry supplement might also have a side effect of diarrhea.

The Drug Education Resources Centre of the Society of Hospital Pharmacists of Hong Kong conceded that it is possible that, according to the Natural Medicines Comprehensive Database, blueberry could improve retinal problems caused by hypertension or diabetes.

Both the Department of Health and the Centre for Food Centre are strong advocates of the importance of a balanced diet, with sufficient daily consumption of fruit and vegetables, and a healthy lifestyle to achieving good health.

There is no scientific evidence to confirm whether commercial preparations and extracts of berries are any better (or worse) than the natural fruit.

The anthocyanins that are present in blueberries and bilberries, can also be found in other fruit and vegetables such as strawberries, grapes, cherries and sweet potatoes. Therefore, choose a wide variety of fruit and vegetables in order to take in different nutrients.

Consumers are also advised to consult medical professionals before taking any health supplement. Read the product labels carefully and take note of such information as contra-indications, dosage, storage and expiry date.