Snapshot of watercress benefits…


No single food can maintain and promote good health. That comes from the overall benefits of a healthy diet and lifestyle, but some foods have been classed as 'superfoods' because they are especially rich in health-promoting nutrients, antioxidants or phytochemicals (bioactive plant compounds) British Nutrition Foundation (2006) Superfoods. Nutriton Bullitin 31 (3), 171-172) and therefore pack more of a nutritional punch than others. So is watercress one of the original superfoods? Evidence suggests it is.

This Website provides science-based information for health professionals and focuses on:

• the nutritional composition of watercress

• the potential health benefits of watercress

• a summary of research studies relating to watercress

Key research findings include:

• Watercress is a cruciferous vegetable and population studies associate an increased intake of cruciferous vegetables with reduced risk of cancers at several sites.

• Daily consumption of watercress resulted in a significant decrease in lymphocyte (white blood cell) DNA damage. DNA damage is an important event in cancer development.

• Watercress is a rich source of the glucosinolate-derivatives phenylethyl isothiocyanate (PEITC) and methylsulphinylakyl isothiocyanates (MEITCs), which show a range of anti-cancer activities.

• Beneficial effects on the three key stages of carcinogenesis (initiation, proliferation and metastasis) were observed in a study involving watercress extract and colon cancer cells.

• When smokers ate watercress with each meal for 3 days, the activation of a key carcinogen (cancer causing agent) in tobacco was inhibited.

• An in vitro study involving breast cancer cells found that the addition of a watercress extract inhibited their invasive potential.

• A study investigating the effects of a diet supplemented with PEITC in mice grafted with human prostate tumours resulted in a 50% reduction in tumour weight.

• Watercress is a good source of key nutrients and carotenoids, such as lutein and beta-carotene, associated with the maintenance of eye and skin health. Daily consumption of watercress increased plasma lutein levels by 100% and beta-carotene levels by 33%.

• Daily watercress consumption has been shown to decrease plasma triglyceride levels by about 10%.

• Watercress is rich in vitamin A (via beta-carotene) and vitamin C, and a source of folate, calcium, iron and vitamin E. It also contains a variety of phytochemicals including glucosinolates, lutein, flavonoids and hydroxycinammic acids.

• Watercress has significant antioxidant activity in vitro.

• 80g (one cereal bowl full) of watercress provides one of the 'at least five a day' portions of fruit and vegetables recommended by the Department of Health to help reduce the risk of many chronic diseases.

• As a low calorie vegetable, watercress may play a role in weight management.

• Nutrients and phytochemicals in fruit and vegetables appear to work synergistically.

• The mix of nutrients and phytochemicals in watercress make it a valuable food throughout life, as part of a healthy diet and lifestyle.