Green tea for weight loss

Green tea shows potential as an aid to weight loss. It has powerful antioxidants called polyphenols, and caffeine, the brain stimulant. A flavonoid called epigallocatechin gallate (EGCG) is believed to be mainly responsible for green tea's weight-reducing potential.

Green tea (Camellia senensis or Matsu-cha) is not to be confused with the black tea that many of us drink, although the two are from the same plant. Black tea is produced by allowing the leaves to ferment and oxidise, while green tea is cut fresh and steamed. Black tea has up to 10 per cent polyphenols, while green tea has up to 60 per cent. Because of this high percentage, green tea is purported to have many health benefits, including maintaining normal blood pressure.

The dried leaves of the shrub are used to make green tea available in the form of capsules, tea and extract. The suggested adult daily dose is 250 to 400mg or two to five cups of tea. One teaspoonful of the leaves in 8oz hot water makes one cup. Adding dairy products to green tea might decrease its therapeutic effects.

Speeds up metabolism

It is believed that EGCG speeds up the metabolism (that is, the breakdown, digestion and processing of food) which then increases the body's heat production and calorie-burning potential. It might also regulate insulin and blood-sugar levels. However, simply taking green tea on its own is not enough to make us lose weight and maintain weight loss - food-portion control and regular exercise must be included in any weight-loss plan.

Since green tea in its fresh form contains caffeine, which in large doses causes side effects such as nervousness, palpitations, restlessness, increased blood pressure, headache and depression, it is better to consume multiple daily doses of green tea in the form of extracts or capsules, which are usually decaffeinated.

It is important to purchase a high-quality product. Check that the manufacturer and supplier of the product (tea bag, extract or capsule), are reputable. A good extract is one which is standardised to 90 per cent polyphenols.

Remember that 'natural' and 'herbal' do not necessarily mean 'safe' and 'mild', so check with your doctor before using green tea or any herbal product, especially if you know that you have a condition, are pregnant or breastfeeding.

Dahlia McDaniel is a pharmacist and final year doctoral candidate in public health at the University of London; email: yourhealth@gleanerjm.com.