Satisfying Your Ancestral Appetite

My daughter inherited the luminous blue eyes and ash-blonde hair of her Slavic father. Like her northern Italian-Scottish mother, spicy foods make her tummy hurt. Our genes shape not only how we look but also how we respond to foods.

Researchers are taking an active interest in how genes and diet influence our susceptibility to obesity and diseases like diabetes and cancer. Eating a diet that is right for an individual's genetic heritage can be healthier, they are finding. For example, about one-fifth of people of European descent have a genetic modification that puts them at increased risk of cardiovascular disease if they don't consume enough dietary folate. A return to a traditional diet rich in plant foods and low in added sodium, sugars and saturated fats may also help us maintain a healthy weight and stave off heart disease, diabetes and other chronic conditions. And a genetically appropriate diet possesses advantages beyond maintaining your health: It can help ensure the survival of indigenous food plants and preserve traditional farming practices.

For millennia, people ate only plants or animals from their surroundings. As a result, we carry differences in our genes that permit us to digest and obtain nutrients from foods. For a simple example, look no further than milk. With the exception of people of European and African descent, most people cannot digest milk beyond infancy because the body stops producing lactase, an enzyme that breaks down the milk sugar, lactose. Europeans, however, acquired the ability to produce this enzyme into adulthood after they began keeping cattle about 7,500 years ago. Those that could digest milk survived lean times. African cattle herders separately developed and passed this trait to subsequent generations.

"We have dozens of diet experts offering us a quick fix as if all of us have the same nutritional and health needs," says Gary Paul Nabhan, Ph.D., ethnobotanist and author of Why Some Like It Hot: Food, Genes and Cultural Diversity (Island Press, 2004, $24) and a co-founder of the indigenous-seed conservation organization Native Seeds/SEARCH. In reality, says Nabhan, "We all have different nutritional needs, and our ancestries are one of the factors that shapes that."