San Francisco Chronicle: Dr. Daphne Miller’s Jungle Diet.

When new patients first visit Dr. Daphne Miller's family practice, they are asked to bring in every vitamin and prescription medication they typically ingest, which has led to some comic moments.

"Patients walk in with a shopping bag full of supplements," Miller says with a laugh. "And we'll find that altogether they're taking 40,000 IUs of vitamin A daily - when no one should take more than 10,000."

But because the doctor believes that eating, say, an organically grown carrot is superior to popping any number of pills, she straightens out the dosages and gets down to what really matters: "We talk about what they eat."

It wasn't always so. In the early years of her medical practice, she was flummoxed by the number of patients "who were trying to change their diet to lose weight or deal with a chronic health problem." At the same time, the drugs she prescribed to lower blood pressure, blood sugar or cholesterol were causing every kind of unpleasant side effect.

"My standard approach was not getting at the root of so many of these health problems - the foods my patients ate on a daily basis," Miller says.

"Today, people are so crazy-busy, they say they don't have time to cook," she adds. "But when they get sick, they have time to go to the doctor."

Miller's 8-year-old family practice is in a bite-size former warehouse in Noe Valley, renovated in pared-down environmental chic by her architect husband, Ross Levy, whose offices are upstairs. One sign of their commitment to eco-aware living is invisible: The walls are stuffed with "blue jean insulation," recycled scraps made of cotton, a renewable resource with a rapid growth cycle.

A global worldview

On this recent morning, Miller, her dark curls still wet from a post-run shower, slides in through sleek glass doors, passes the latest show of paintings lining the walls - the lobby doubles as an art gallery - and settles into her office to talk about the genesis of her recently released book, "The Jungle Effect: A Doctor Discovers the Healthiest Diets From Around the World - Why They Work and How to Bring Them Home." (Collins).

A month before publication, Miller presented her research at Andrew Weil's 5th Annual Nutrition and Health Conference in Phoenix. (A Harvard Medical School graduate who did her residency at UCSF, Miller was a 2006 fellow in Weil's Program of Integrative Medicine at the University of Arizona.) In May, she gave a talk at Google - where the list of speakers rivals the best-seller list as a gauge of influence - and noticed several patients in the audience. "I know you're a healthy bunch," she told them.

Today, Miller says, "I've always been interested in other cultures, partly for what they can teach me about myself." Her belief in the benefit of "getting outside of our very self-referential world" comes from early experience. She was conceived on an Israeli kibbutz, where her American parents lived before serving in the Peace Corps. After time in Morocco, Afghanistan and Tunisia, the family returned to the States.

Citing a recent study by the World Health Organization, she says, "In the past year, chronic diseases, including heart disease and diabetes, for the first time have surpassed injury, famine and infectious disease as the most common cause of death."

The news seems to confirm her book's message: "The majority of serious health problems can be traced back to poor diet."

The breakthrough

The link between food and health was illuminated in a lightbulb moment during an intake interview several years back. The new patient, a native of Rio de Janeiro, had tried every diet under the sun without success. Her weight seesawed, her energy plummeted and she increasingly suffered knee and joint pain.

The doctor asked if she had always struggled with her weight. Well, yes ... except for a few years during her childhood, when she lived with her grandparents in the Amazon rain forest.

She recalled being physically active and feeling wonderfully fit. The food seemed strange at first - she missed dessert - but soon she grew to love the diet of fresh-caught fish, taro, beans, fruits and vegetables.

Miller realized that during this jungle idyll, her patient had burned not just more calories but also the right kind of calories. She had thrived on a locally grown, indigenous diet built on food wisdom gained over centuries.

But what was the secret of such indigenous diets? And how could people take advantage of them today?

Miller was still mulling over these questions when, six months later, she went with her husband and their two children to Peru on one of the philanthropic vacations they favor, in part to escape San Francisco's freezing summers. There, she worked at a health clinic in a small Amazonian village.

In short order, she and the other American volunteers - all of whom were regular exercisers - felt more energetic and fit than ever, despite the heat and humidity.

From her perch in the clinic, she observed that the village elders, who still lived as their ancestors had for centuries, not only appeared vital, fit and younger than their years but were also untouched by the chronic diseases that are the most common killers in developed nations.

Conversely, Miller saw that members of the younger generation who had returned to the village after time in the city tended to be overweight. Many showed early symptoms of "metabolic syndrome," a forerunner of diabetes or cardiovascular disease, as a result of eating processed foods and adopting a more sedentary lifestyle. These youngsters were victims of what she calls "the new global killers: refined flour, refined oils and high-fructose corn syrup."

Studying the 'cold spots'

There was something else. As she learned the food wisdom of the jungle elders, she heard echoes of stories told by her patients back home, who hailed from all corners of the world. It seemed that every one of them told of older relatives who lived active lives into their 90s without contracting diabetes or heart disease.

What did these people have in common?

They all ate a traditional diet of locally grown fresh foods, eaten in combination and in sequences that enhanced their nutritional and disease-fighting qualities.

This thesis was proved again and again in her research. Over three years and tens of thousands of frequent-flier miles, she cultivated the food wisdom of five global "cold spots" where certain chronic diseases are rare, if not nonexistent: colon cancer in Cameroon, heart disease in Crete, depression in Iceland, diabetes in Mexico, and breast and prostate cancer in Okinawa. With all this, the book reads like an exotic, ever-unfolding international mystery - with recipes.

Despite early victories, including her Brazilian patient's steady weight loss and regained vitality, Miller still worries.

"Food is a powerful medicine," she says, "and my intention with the book was to document this disappearing medicine." She fears that soon, perhaps in just five years' time, it will be impossible for such a book to be written.

"The older people will be gone."