July 2013 Issue
Nutrition Lessons from Our Past
A diverse diet based on a variety of whole plants, seafood and lean, grass-fed meats may bring you closer to the optimal diet of our ancestors.
Exploring our evolutionary eating habits is “in.” Just look at the success of popular diets, such as the “caveman,” “Paleolithic (“Paleo”),” “Stone Age,” “warrior,” and “origin” diets, which tell us to eat more like our ancient ancestors for good health. Proponents of this eating style believe that consuming foods that existed during Paleolthic (hunter-gatherer) times (the era from 2.5 million to 20,000 years ago), such as meat, fish, shellfish, eggs, tree nuts, vegetables, roots and fruits—comprise a diet that is genetically and biologically ideal for humans and will help reduce the incidence of chronic diseases and obesity. EN explores the rationale surrounding this eating pattern.
Ancient diets meet modern times. Few studies have examined how effective a “caveman diet” can be for optimal health today. One review (American Journal of Clinical Nutrition, 2005) suggests that the new foods introduced in the Industrial Era (beginning in the late 1800s), including refined cereals and sugars, fatty meats, and products high in sodium, made many important changes in the nutritional quality of our eating patterns. These early cultivated, “processed” foods took the place of the minimally processed wild plant and animal foods in our original diet, resulting in a poorer quality diet. And as our food supply became more industrialized, the diversity of our crops and foods declined. Some experts believe the introduction of these processed foods during this period ultimately negatively impacted the overall health and well being of the western world and contributed to the obesity crisis.
Poorly designed for poor nutrition. “Evolutionarily, our bodies were designed to eat a variety of foods. Our hunter and gatherer ancestors ate a wide selection of whole foods often, to escape food boredom. Today, although it appears our food system offers a wide variety of ingredients, in reality, our diets are primarily composed of foods high in corn products and refined sugar,” says anthropologist and Emory University professor, George Armelagos, Ph.D. He believes that evolutionarily our bodies are not designed to process the poor quality foods—sugary foods and beverages, refined flours, processed snack foods—we currently consume in such high proportions, resulting in the nationwide dramatic rise in obesity and diabetes. Today, our food supply offers large amounts of calories that require very little energy to ”hunt and gather,” you can spot a food vendor just about everywhere—bookstores, gas stations, and workplaces—offering high-calorie, low-nutrient food for your convenience.
There are even signs that moving away from hunter-gatherer diets to eating patterns based on cultivated crops, such as grains caused nutritional problems among our ancestors, according to Armelagos’ article in the International Journal of Environmental Research and Public Health. For example, the first signs of anemia (caused by iron-deficiency) were seen in skeletons beginning in the Neolithic period (beginning about 10,000 BC), as diets began to transition towards agricultural foods. In addition, the skeletons during these periods begin to show a reduction in average height by several inches, which may be due to a reduced supply of nutrients in their diet.
Lessons for modern day eating. So, should we all start eating a hunter-gatherer diet? Although most health professionals agree that we should eat more closely to Mother Earth, there are many things to consider before you adapt a “Paleo” diet. “Many people who use these evolutionary-type diets as justification for carnivorous preferences simply eat more of the kind of meats that are commonly found in our environments: bacon, hot dogs and hamburgers. We must remember that thousands of years ago the flesh of animals our ancestors ate was generally quite lean and was far more unsaturated than the fat in most modern meats, and even provided some omega-3. Grain-fed cattle, pigs fed slop, and domesticated feed animals raised without demands on their muscles were not found,” says nutrition and health expert David Katz, M.D. M.P.H., the founding director of Yale-Griffin Prevention Research Center.
Modern science yields longer lifespan. While it’s easy to romanticize our distant past, it’s also important to remember that our ancestors did not have the knowledge about health that we have today. In fact, modern nutrition research and medical care have expanded the human lifespan and enhanced the quality of life. According to Katz, the average human life expectancy during the Stone Age was about 20 years, and the life span extended only to about 40, while today the average life expectancy is over 78 years of age. “While it makes sense that our native diet is apt to be good for us, considering our current average life expectancy, we cannot conclude that a diet best suited to a two- to four-decade life is just as good for an eight-decade life,” states Katz.
Take the best from historical diets. Let’s face it: in today’s world it would be impossible for us to take on a hunter-gatherer lifestyle for all our foods. And scientific evidence does not support a modern-day adaptation of a Paleo diet, dependent on large amounts of conventionally raised animal products, as the optimal way to eat. However, we know that eating more minimally processed foods can be achieved in a variety of ways. For example, a large amount of research supports the health benefits of various plant-based eating patterns which have existed for centuries, including the traditional Mediterranean and Asian diets. And studies also support the health advantages of following a vegetarian diet.
Another lesson we should take from our ancestors is to be more active. Our ancestors burned many calories in pursuit of a meal—far more than the calories spent surfing the Internet, driving to the store, and microwaving a frozen meal. Now that is food for thought.
—Kaley Todd, M.S., R.D.