Daphne Miller, M.D. is the author of The Jungle Effect: A Doctor Discovers the Healthiest Diets from Around the World – Why They Work, and How to Bring Them Home. She is an associate professor of nutrition and integrative medicine at the University of California, and works in a private family practice in San Francisco.
Paula: What first got you interested in studying how indigenous diet effects health?
Daphne: So many of my patients have health concerns that are directly related to diet and lifestyle. And yet when I first began to practice as a Family Physician I was confused about how to counsel them. About five years ago I had an appointment with a lovely woman named Angela. Angela was overweight and really frustrated by the fact that she continued to add on a couple pounds with every passing year. She had borderline high blood pressure, knee pain and depression, all problems that I typically see in my family practice. However, the story she gave me was far from typical.
Angela told me that she had recently spent several months in her ancestral village in the jungle in Brazil. To her surprise, during her visit she had lost weight and all of her ailments had improved. All this despite the fact that she was eating more and exercising less than she did in her regular life. Sadly, when she came back to San Francisco, all her health problems came roaring back. She wanted to know what had been causing this “jungle effect.” I told her that being on vacation can make anyone feel better. I gave her a list of low calorie foods and recommended more exercise. Stupid me.
About six months later, by sheer coincidence, I ended up in the jungle a couple hundred miles upstream from Angela’s village. I went there with my husband and two kids to volunteer in a little remote village that was off a tributary of the Amazon. While I was there I treated snakebites, malaria and even machete wounds. But did I see one case of the common health problems (diabetes, depression, heart disease, cancer etc) that I see in my San Francisco practice? No. Not even the very elderly in the jungle seemed to suffer from these ailments.
I started to look more closely at what was going on in the village. Sure people seemed to move around more, smoke less and they were certainly less stressed than most of us. But what was most striking was the food. This was an incredibly remote place and most of what we ate was local. Veggies, fruits and nuts from the jungle, fish from the river, free range chickens and no processed or packaged foods. But it was not just that—I noticed that the combinations of the ingredients and the way the foods came together in the day also had their own healing qualities. Like Angela, other US volunteers who were down there reported that they too were eating more but weighing less and feeling more vital.
Paula: What makes indigenous diets so healthy?
Daphne: [In] the diets from various cold spots, places that had especially low rates of a specific chronic disease that plagues us here in the US, I discovered dozens of preparation techniques, food combinations and even eating rituals that enriched the nutritional value of traditional meals. It made me wonder how people living so many years ago could invent diets that were full of culinary wisdom and could pass the muster of even the most critical modern-day nutrition experts. There is no way it could all just be dumb luck and yet there is nothing to suggest that these traditional communities had a formal understanding of modern nutrition. Take the Tarahumara of Northern Mexico for example. They are a tribe that treated their corn with a lime solution for thousands of years—a process which enriches it with B vitamins and calcium. Surely their predecessors could not have known about a vitamin called niacin or a vitamin deficiency disease called Pellagra. From an evolutionary standpoint it all makes sense. We often talk about “survival of the fittest” in terms of species but the same seems to hold true for diets. By definition, indigenous diets evolve in a specific place using largely local food resources. As long as there is no access to highly processed, taste bud-duping convenience foods, we humans tend to make excellent choices—we go for foods that are healthy and make us feel good.
Paula: How do indigenous diets differ from the modern diet?
Daphne: I think that the answer to this question lies as much in what these indigenous diets omit as what they include. Take refined grains, such as white flour bread products, and processed sweeteners, most notably the high fructose corn syrup, for example. Both of these low-nutrient, high calorie, blood-sugar-raising types of food are a rare find in indigenous diets. The same goes for processed oils. Perhaps the most important omission is the slabs of hormone-filled, corn-fed, cage-confined meat that we can buy on clearance for as low as $1.50 a pound. This abundance of cheap meat is a uniquely American phenomenon. Locals from Crete to Cameroon still enjoy wild or pasture raised meat. For anyone who has tried their hand at hunting or raising livestock, you know that this kind of meat is expensive to produce, and challenging to catch, making it way too precious a commodity for every day consumption. When meat or dairy products are eaten in traditional diets, they’re treated more like a spice than as the centerpiece of the meal.
Paula: How are indigenous diets created? You talk about imitative, sensory and post-ingestive instincts. What role do they play?
Daphne: Dr. Paul Rozin, a food psychologist at the University of Pennsylvania, explained to me that all humans past and present value convenience when it comes to obtaining food and therefore tend to select foods that are readily at-hand. When our ancestors selected their specific diet out of an array of available plants and animals they would call upon three basic human instincts which he roughly categorizes as imitative, sensory and post-ingestive. These instincts help us negotiate a very dangerous situation: the sampling of new foods. By “imitative” Rozin means that we would copy a local population or try and imitate the eating behaviors that we brought with us from our previous life. “Sensory” relates to our basic human preference for sweet, salty, meaty and fatty foods. These are the taste sensations that we tend to go for first and foremost. And “post-ingestive” describes how we experience the after effects of a food. Does it make us feel good or give us a horrible belly ache? These instincts, when applied over generations, are what collectively form a local indigenous cuisine.
Paula: Why do these three instincts no longer work in the same way in an industrial world?
Daphne: When your food choices do not include modern processed convenience foods, these are excellent food seeking instincts. A preference for sweet will help you find your way to whole grains and fruits and the occasional nectar or honey. Enjoyment of salty nets you nutritious foods like seaweed, fish and naturally fermented foods. A preference for fatty and meaty helps you find your way to nuts and fatty fruits like olives and avocados, legumes as well a the occasional precious free range animal product. Now if you take any of us out of a traditional food setting and plop us in the middle of a modern market, which is essentially what happened to us collectively some time circa 1950, then these food-seeking instincts suddenly become a deficit rather than an asset. All of a sudden, we are surrounded by high fructose corn syrup, processed flour and oil and cheap meat—and nothing is in balance. It is no wonder that we are all getting sick with our modern food system. Our hardwiring has practically guaranteed it.
Paula: Was it more difficult than you thought it would be to find people still subsisting on indigenous diets?
Daphne: Oh yes. Global “McDonaldization” is near complete. Even the poorest and most remote communities have access to packaged foods these days. I personally have hiked to the deepest corner of the Cameroonian rainforest and, at journey’s end, been offered a warm Coca Cola by a Babinga pygmie tribesman. I recently read that the average Mexican now drinks 487 cans of Coca Cola per year, twice the amount they drank 10 years ago. In the same space of time, India has gone from being one of the lowest to one of the highest consumers world wide of refined vegetable cooking oil. As a result, it is no longer possible to find an indigenous or native diet in its purest form. Even in the rainforest in Peru, the medical assistant at the clinic was starting to extract rotten teeth on a weekly basis. When Weston Price [the dentist who studied indigenous teeth] was traveling through that area he never saw cavities. Despite all this, I did find some isolated communities around the globe who remain relatively free of modern diseases. I believe that these communities have a lot to teach us.
Paula: How do modern fats differ from indigenous uses of fats?
Daphne: Modern fats are fats that need heavy machinery and chemical treatments in order to get them into a usable form. These include processed cooking oils like corn oil, canola oil, and soybean oil. These fats are hardly ever found in traditional diets for one simple reason: they are too hard to make with basic equipment like a grindstone or a hand press. It turns out that these same processed vegetables oils are probably not as good for you since they are rich in a fat with an Omega-6 structure which tends to be very inflammatory and may even be partly to blame for our soaring rates of diabetes and other modern chronic diseases. On the other hand, indigenous oils such as olive oil, palm fruit oil, or even lard—actually have a pretty healthy fat composition. Lard is a great example. All of my nutrition training had taught me that lard was a four-letter word and yet I saw a number of cold spots where lard was the preferred cooking oil. Of course I realized that it had everything to do with the quality of the lard. What your meat eats matters. Lard from a free range pig is actually pretty full of healthy omega 3 and monounsaturated fats. Plus you can use it in relatively small quantities and have it give a lot of flavor.
Paula: You say that simmering was the preferred method of cooking for indigenous foods, is simmering healthier?
Daphne: The scarcity of processed oils in indigenous diets has another nutritional benefit. Because traditional cooks do not have the oil to deep-fry or cook at high heats, they leave their pots and pans at a simmer. In addition they have limited amounts of fuel and often do not have modern stoves that can generate a steady strong flame. The result is that their ingredients have a chance to leisurely meld together, producing a final product with rich, complex flavors. In addition this slow-cooking method preserves the nutrient content of vegetables and grains and prevents fats, which include oils, from becoming transformed into unhealthy compounds.
Paula: During the course of writing this book were there particular foods or ideas that surprised you?
Daphne: Perhaps one of the biggest surprises was how different all these diets are from one another. How can such dramatically different ways of eating all do such a darn good job of helping folks live a long, disease-free life?
Paula: Do you think eating indigenously relates to Slow Food’s ideas on what to eat (that which is good, clean and fair)?
Daphne: Absolutely. I believe that what the Slow Food movement is trying to do is take these traditional systems of eating to the next level. Many of us have lost our ancestral recipes and/or we live in places in the world where the ingredients needed to make our traditional foods are no longer our local food resources. What I feel we need to do is take the principles, food combinations and eating rituals that have been developed over generations and use them to develop a new set of indigenous diets. These are really exciting times!