SOY: the prohealth bean

soy plantation

A newly released soybean offers farmers and consumers a major win. It has very high cancer-protectant isoflavone content, a wide planting window and the ability to produce higher yields than most existing soybean cultivars.

Developed by CSIRO Tropical Agriculture with support from growers through the GRDC, Melrose has the highest level of isoflavones of current favoured varieties.

Many health benefits

In addition to protein, fibre, polyunsaturated fat and omega-3 fats, soybeans contain a range of other possible health-promoting compounds. Research indicates that these substances may play a role in preventing or fighting some types of cancer, heart disease, osteoporosis and menopausal symptoms," said Cindy Hamill, a well-known Brisbane-based nutritionist.

"Most research has focused on the isoflavones, especially genistein. Soybeans are one of the best sources of two isoflavones, genistein and daidzein," she said.

So what are isoflavones exactly?

Both genistein and daidzein belong to the isoflavone group that in turn belongs to the family of phytoestrogens. Phytoestrogens are the plant substances that are a weaker version of the body's own oestrogen hormone.

"In pre-menopausal women phytoestrogens bind to some of the oestrogen receptors, taking the place of the body's own oestrogen. Less exposure to the body's oestrogen can protect against breast cancer. At menopause when the body drops its own oestrogen production, phytoestrogens can bind to the receptors and replace the body's oestrogen. This reduces the uncomfortable symptoms of menopause," Ms Hamill said.

Isoflavones also work in a number of non-hormonal ways. They act as antioxidants that help protect against cancer and heart disease, for example by making artery walls less stiff and more elastic. As anticancer agents they can also inhibit the several enzymes cancer cells need for growth, help cut off the blood supply to tumours so they can't grow, and encourage cancer cells to change back into normal cells.

Isoflavone levels in locally grown soybean varieties

"Melrose has all the health attributes of any soybean but three times the isoflavones. It has great potential for use in functional foods designed specifically for people who want to eat more isoflavones," said Ms Hamill.

Agronomic advantages

Melrose is also adaptable to wide or narrow row spacings. "Melrose has a higher yield potential than existing cultivars especially when grown in narrow rows, making it a more competitive alternate crop," said Andrew fames, CSIRO researcher and Melrose developer.

Peter Brodie from Philp Brodie Grains, the Darling Downs-based grain merchants and seed specialists exclusively marketing Melrose, sees the variety as "something completely new, given its wide planting window, and we have great expectations that it will do extremely well".

Melrose was released in southern Queensland and northern NSW. Its broad planting window is expected to permit a crop to be sown following rains which may occur in September to November, increasing the opportunity for planting. Early sowing may also mean more efficient water use, whilst Melrose's early maturity allows for enhanced continuity of supply of grain and perhaps reduced storage

Program 2.5.1

Contact: Mr Andrew James 07 3214 2278, email Andrew.James@tag.csiro.au or Mr Peter Brodie (Philp Brodie Grains) 07 4630 1944

Region North