There’s a memorable scene in the documentary In Defense of Food that could change the way some Americans look at food. In it, a group of hunters from the Hadza tribe in Tanzania are tracking a kudu, a member of the antelope family, through the bush. The animal stops, giving one tribesman a clear shot. He places an arrow—its tip coated in a potent poison—onto his bow, silently draws the string back to his ear, and lets go. From the trail of fresh blood in the dirt, the tribe knows the kudu has been hit, and their hunt comes to an end when they finally spot the animal, lying dead with the arrow in its side.
The men waste no time skinning and butchering the kudu, starting a small fire, and cooking up a portion of the animal’s ribs then and there. After all, as some of the last true nomadic hunter-gatherers on the planet, this may be some the Hadza’s only meat for a while. The hunters share a meal before bringing the rest of the animal back to camp to savor with the rest of the tribe.
Meat, precisely because it is so difficult to procure, comprises a relatively small part of the Hadza diet. The tribe mainly dines on more than 200 foraged plants, berries, and tubers found in the surrounding bush. If food grows scarce, the nomads will pick up and move.
“These are the foods we seek, because they are the foods that are in our environment,” tribal elder Nyanzobe Mpanda says in the film. “They all have their times when we can eat them–the seasons.”
In Defense of Food is based Michael Pollan’s best-selling 2008 book of the same name, and premieres on PBS on December 30. In the film, director Michael Schwarz set out to build upon the book by answering the question: “What should we eat?” Narrated by Pollan and featuring interviews with more than 40 food and nutrition experts, In Defense of Food brings fresh research and stories to support the now-popular thesis set forth in the book: “Eat food. Not too much. Mostly plants.”
The film highlights a new body of research that brings into focus the Hadza diet, which has remained virtually unchanged for thousands of years. Dr. Alyssa Crittenden is a professor of anthropology and co-director of the Metabolism, Anthropometry, and Nutrition Laboratory at the University of Nevada, Las Vegas, where she has been studying the foodways of the Hadza for the past 11 years. She says the group’s diet can teach Westerners a lot about our ancestral diet.
Crittenden has found that the Hadza eat a vastly diverse and well-balanced array of foods—almost exclusively hunted and foraged within their environment, and none of which is processed or farmed. Meat, for instance, comprises around 35 percent of the Hadza diet, the majority of which is comprised of fruits, nuts, beans, roots, and a fairly large percentage of honey and honeycomb.
Although they’re a nomadic people with little access to hospitals or healthcare, many Hadza live long lives and suffer from diet-related diseases and cancers at a lower rate than other, more modernized Tanzanians.
Researchers suggest the tribe’s health may be a result of superior gut bacteria from the diverse array of foods that the Hadza forage and hunt. Crittenden and others have found that these tribespeople stress very little about the nutritional content of what they will eat; they simply eat the foods (mostly plants) that are available to them.
Crittenden co-authored a 2013 study that found the Hadza’s microbiome—the ecosystem of protective bacteria in all humans—was more rich and biodiverse than a control group of urban Italian participants.
Another ongoing study should shed even more light on why the Hadza diet has worked for the nomadic tribe for so long. The crowdfunded Human Food Project, launched by Jeff Leach, who is featured prominently in the documentary, seeks to expand on Crittenden’s study of the Hadza microbiome through analysis of fecal samples and the plants, berries, and trees in the tribe’s surrounding environment. According to its website, the project is “an effort to understand modern disease against the back drop of our ancestral/microbial past.”
“Westernization is associated with a reduction in the diversity of microbial life in the gut,” says Dr. Jeffrey Gordon in the film. Gordon directs the Center for Genome Sciences and Systems Biology at Washington University School of Medicine. He says that a lack of biodiversity in our diets, including a reliance on animal products to the detriment of plants, is likely to blame for this shift.
Dr. Joel Fuhrman has found that 55 percent of the modern diet is comprised of processed foods, with almost half of us reporting drinking at least one sugar-sweetened beverage daily. This “Western diet”—which has been exported to many places, with negative consequences—is a relatively new occurrence in human evolution, but is already wreaking havoc.
If the Western diet is killing us, what, then, should we eat? This is the question at the center of both Pollan’s book and Schwarz’s film. Crittenden says the Hadza demonstrate the importance of eating what nature gives us.
Although Pollan included the latest information about the human microbiome in his book, Cooked, most of it had not been published by the time In Defense of Food came out. But once Schwarz found out Leach was in Tanzania collecting bacteria samples from the Hadza and their environment, he decided to make the long, expensive trip to Tanzania to document the effort. Schwarz says the week he spent embedded with the Hadza was one of the most memorable of his life, but he was also struck by the difficulty of the lives the nomads lead.
“I certainly wouldn’t want viewers of the film to think we advocate going back to a hunter-gatherer diet or a Paleo diet,” Schwarz told Civil Eats. “There are a wide variety of healthy diets around the world, some of which are sometimes surprising. The common element is that they’re all based on the environments of the people who eat them; over time, those people have adapted to the foods from their environments.”