Pineapple

Benefit

• Useful source of vitamin C

Drawback

• Can trigger allergic reactions in rare instances

Traditional folk medicine credits the sweet, juicy flesh of the pineapple with various healing powers, with some apparent justification. The fruit does not, however, contain many useful nutrients. A standard 80g portion supplies a quarter of the daily requirement of Vitamin C, but other than that, it provides little in the way of vitamins and minerals.

Scientific interest has centred on the fact that the fresh fruit contains an enzyme called bromelain which breaks down proteins. Its action is so strong that people who work in pineapple plantations and canning factories have to wear protective clothing to prevent damage to their skin. Bromelain is sometimes used medicinally in concentrated tablet form for patients who have problems digesting protein.

Since bromelain's medical use was first investigated in 1957, some 400 papers have been written on its various applications. There are indications that it may help to break up blood clots and could therefore be useful in the treatment of heart disease. There is also some evidence that suggests it may help to combat sinus congestion and urinary tract infections. It might also augment the effect of antibiotics.

Bromelain has been used as an anti-inflammatory agent for the treatment of osteo and rheumatoid arthritis. And, because it is thought to accelerate tissue repair, it also has many applications for sports injuries, including bruises, blisters and sprains.

Pineapple power

Prior to such research, fresh pineapple was used in folk medicine to treat a variety of problems. Gargling with the juice is a traditional treatment for Sore throat, while eating pineapple has long been believed to help to relieve other disorders including catarrh, arthritis, bronchitis and indigestion.

The canning process affects the vitamin C content only minimally, but it destroys the bromelain. Weight for weight, pineapple canned in its own juice, rather than in syrup, contains only marginally more calories than the fresh fruit - 47 calories as opposed to 41 calories per 100g.

Pineapples do not become any sweeter after picking; good indicators of ripeness are a fruit that feels heavy for its size with fresh green leaves and, most important of all, a sweet, fairly strong fragrance.

In rare cases fresh pineapple can trigger an allergic reaction in sensitive individuals. A severe reaction needs immediate medical attention.