A growing trend for natural ingredients in cosmetics and body products is encouraging Japanese manufacturers to re-examine some components that had been discarded in the past.

With the people of Okinawa famous - even in Japan - for their longevity, researchers from Kanebo Cosmetics examined why the women of this sub-tropical chain of islands have the longest life expectancy in the world.

They learned that their health and longevity is largely attributed to their diet, which includes a number of plants unique to these islands, and can also be incorporated into cosmetics.

Kanebo Cosmetics has released a range of wrinkle-repair treatments, under the Sensai brand, that are based on what Okinawans call the Moon Peach.

Capable of growing to a height of four meters, the shell ginger plant ( Alpinia Zerumbet) has been a key part of the customs, cuisine and folk medicine of the islands, acting as a natural insect repellent while its antibacterial properties make it ideal for wrapping food.

Kanebo discovered that the leaves of the Moon Peach are extremely rich in polyphenol - 30 times more than red wine - and has extracted the component that stimulates collagen synthesis, thereby combating the formation of wrinkles.

The company has expanded its research into other medicinal plants that have been used since ancient time in the folk medicines of the Far East, incorporating more of them into its products.

The extract of the Kakyoku fruit, for example, has been used as a skin moisturizer by the peoples of northwest China and was reportedly prized by the legendary eighth century beauty Yang Guifei, the mistress of the Chinese emperor, for its beautifying effects.

Similarly, the extract of the Kinginka, or Japanese honeysuckle, has been used in Oriental herbal remedies for centuries for its astringent and antipyretic effects.

Kanebo has discovered that kinginka helps to reinforce the barrier function by enhancing the junctions between epidermal skin cells.

And Bukuryo, a fungus known in English as tuckahoe, is a potent diuretic that has been put to use in China for two millennia.

Shiseido Co. has similarly experimented with ingredients native to Japan, with the Tsubaki line of shampoos and conditioners hugely popular with Japanese women keen to protect the lustre of the hair.

The products include specially refined camellia oil, according to Megumi Kinukawa, a spokeswoman for the company.

"Many cosmetics makers have found that these kind of natural ingredients are more tolerant towards sensitive skin or hair and much better than chemical-based products," she said.