Medicine Man

High in the Andes, a shaman rubs a fluffy white rabbit all over Chris Kilham's body, murmuring in Quechua, the language of these barren plains.

Then she slits the animal's throat and lets the blood run into a tiny grave. To Kilham, the offering – an appeal to the gods for a bountiful harvest of maca, a local tuber – is just another day at the office. Part Sir David Attenborough, part Indiana Jones, the ethnobotanist from Massachusetts has scoured remote jungles and highlands for three decades looking for plants, oils and extracts that can heal.

He has eaten bees and scorpions in China, shot blowguns with Amazonian natives and learned traditional war dances from Pacific Islanders.

But behind the colourful tales lies the prospect of money – lots of it – for western pharmaceutical companies, impoverished indigenous tribes, and for Kilham, the self-styled Medicine Hunter.

Products that once seemed exotic, such as ginseng, ginkgo biloba or aloe vera, now roll off the tongues of westerners. Natural plant substances generate more than £38 billion in sales each year for the pharmaceutical industry, another £10 billion in herbal supplement sales and around £1.5 billion in cosmetics sales, according to a European Commission study. And, although the efficacy of some of the products is hotly debated, their popularity is not in doubt.

Kilham believes multinational drug companies don't make the most of the medicinal properties in plants. They pack pills with manmade compounds and sell them at huge mark-ups, he says. He wants westerners to use the pure plant medicines indigenous peoples have trusted for thousands of years.

"I want people using safer medicine, and that means plant medicine," he says.

Easygoing and earnest, Kilham, 55, caught the plant bug after taking a herb walk at an organic farm in 1971. A self-confessed hippie, he was already into "yoga, natural foods and meditation" and the discovery that plants had medicinal properties had a profound effect on him. He created a course in holistic health at the University of Massachusetts, where he is now on the faculty, and made his first overseas trip – to India – to track down exotic flora.

Now he can identify unusual plants by their Latin names and proudly regales the uninitiated on their individual properties. Shortly after leaving Lima, taking French businessmen to the Peruvian Andes, he stopped the van and enthusiastically explained how the tropane alkaloids in a dusty plant he spotted by the side of the road are used by ophthalmologists to dilate pupils for eye examinations.

Such properties are often well known by indigenous peoples. So-called bioprospectors can make their fortunes by bringing those advantages to the attention of companies who identify the plant's active compound and use it as a base ingredient for new products they can then patent.

Some 62 per cent of all cancer drugs approved by America's Food and Drug Administration come from such discoveries, according to a study by the United Nations University.

"Latin American nations, especially Amazonian nations, have extremely rich and diverse flora, so the potential for commercial applications appears great," says Tony Gross, a Brazil-based researcher at the university. "They say that in 1 in 10,000 plants you get something interesting. So it is not a goldmine, but when you do hit on something that becomes a market leader, you can make enormous amounts of money."

In Peru, Kilham is betting on maca, a small root vegetable that grows here in the central highlands – "a turnip that packs a punch," he says, adding: "It imparts energy, sex drive and stamina like nothing else." That view is supported by studies carried out at the International Potato Centre, a Lima-based research complex that is internationally funded and staffed. Studies there show that maca improves stamina, reduces the risk of prostate cancer and increases the motility, volume and quality of sperm. Studies published in the journal Reproductive Biology and Endocrinology back up those findings.

For centuries, maca has been a revered crop in this austerely beautiful region situated 155 miles north-east of Lima. Inca warriors ate it before venturing into battle. Later, Peruvians used it as currency to pay taxes to the Spanish conquistadors.

Today, locals consume it boiled alongside dried vicuna meat in soups; or diced with carrots, peas and cauliflowers in salads. Maca flour is used to make sponge cake. Flavoured with chocolate, it is made into maca puffs. Villagers offer visitors maca juice; airports sell maca toffees.

Kilham first heard about the tuber in 1996. Two years later, he went to Peru to find out more. There he formed a partnership with Sergio Cam, a Peruvian entrepreneur who invested much of the money he made as a construction worker in California to start Chakarunas Trading. The company is named after the Quechua word for men who build bridges between different cultures. Today, Chakarunas organises local growers to sell their maca to the French firm Naturex, which extracts it into concentrate. Naturex then sells that concentrate to Enzymatic Therapy, which makes and markets the finished maca products.

Thanks to the health supplements boom, both companies have grown, with Naturex's revenues topping £63.5 million in 2007 and Enzymatic Therapy's £40 million. According to the company's chief executive, Randy Rose, Enzymatic Therapy sells £100,000 worth of maca-based products each month. Kilham earns a retainer from both companies, plus royalties, which he says amounts to around £100,000 a year. And sales are so buoyant that he expects to make "in the mid-six figures" in royalties (in dollars) this year.

Kilham insists he is not in the business simply for financial gain. His motivation comes from promoting herbal medicines and helping traditional communities, he says.

"I have financial security and don't need to make money from this," he says. "I believe trade is the best way to get good medicines to the public, to help the environment and to help indigenous people."

He and Cam pay growers in Ninacaca a premium of 6 soles (about £1) per kilo of maca, almost twice the going rate. They have set up a computer room at the Chakarunas warehouse and a free dental clinic, the town's first.

Kilham is clearly adored by the locals in these desolate, windswept villages. On a recent visit, shamans, maca growers and their families flocked to him. Since only maca and potatoes grow at this altitude, they are thankful he is helping them sell their produce. He makes a point of returning regularly to affirm his commitment to the project.

On this trip, his third last year, he brought executives from Phythea, a French company that sold £30 million worth of natural products last year. Its president, Laurent Mallet, had heard about maca and wanted to see both the agricultural and social aspect of Chakarunas Trading up close.

Mallet says he was so touched by the people and the rawness of their surroundings – it took him seven hours by van to get there, and several doses of oxygen to offset the headaches and nausea brought on by the altitude – that he vowed to increase his order of maca from five to 25 tonnes this year, if clinical trials in Bordeaux confirm that it reduces hot flushes and night sweats in menopausal women.

"I think it could be a very good product for us," Mallet says. "I especially like the human dimension. They want to build a school and a medical centre."

But not everyone is so positive. Kilham runs the constant risk of being branded a "biopirate", an outsider who steals traditional knowledge and fails to pass on the benefits to the local community. In 2001 the company he worked for at the time, Pure World Botanics, obtained US patents for isolating and extracting maca's key active compounds. The Peruvian government accused the company of profiting from what was rightfully Peru's.

Kilham said he fought to make his bosses open up the patents. The company denied it had acted improperly but Naturex, which bought Pure World Botanics in 2005, granted Peruvian companies free licences to the patents and vowed to increase the price paid per kilo to maca farmers by 15 per cent.

"At Naturex," the company's marketing manager, Antoine Dauby, said in a statement, "we believe in giving back to the communities where we do business. And we're doing that in Peru."