It is no secret that “diseases of civilization” plague the modern, Westernized world. More than one third (37.9 percent) of American adults are obese, and 32.8 percent of American adults are overweight. This totals over seventy percent of the population. Some of the many obesity-related health conditions include high blood pressure, type 2 diabetes, certain types of cancer, and cardiovascular disease, which is the leading cause of all deaths in the US. What is interesting about these threats to public health is they are all at least partially attributable to diet.
There is an interesting and growing theory that the environmental changes brought about by the advent of agriculture and animal husbandry roughly 10,000 years ago, as well as the industrial revolution only a couple of centuries ago, have played a key role in bringing about these negative changes to our health. The theory concludes that these profound changes occurred too recently in our evolutionary history for our genetic makeup to adjust. Hence, we see the epidemic of modern chronic disease. While much more research needs to be done, the hunter-gatherer ancestral-type diet warrants a closer look as we keep searching for the ideal diet.
Were they actually healthier?
Several studies have shown that those in non-industrial populations, including hunter-gatherer populations, have better cholesterol levels, aerobic fitness, and lower rates of diabetes. One study on former hunter-gatherers living a modern lifestyle in Australia showed great improvements in their fat and carbohydrate metabolism when they were returned to their previous hunter-gatherer lifestyle. Archaeological studies have shown markers of nutritional stress during the transitional period between the hunter-gatherer lifestyle and the advent of agriculture. While the average life expectancy was short (only 30-35 years), deaths were mostly due to infections, and they rarely had chronic diseases that plague us today.
So what did they eat?
Reasonable approximations have been made based on published data from modern-day hunter-gatherers as well as anthropological data. There was most likely no single diet followed by all hominins back five to seven million years ago. This is similar to historically-studied hunter-gatherers, whose diets differed according to location, climate, and ecological niche. That said, there are core characteristics believed to be universal among ancestral diets. It is probably safe to assume that foods were limited to minimally processed wild animal and plant foods. These foods are very different from what humans in industrialized nations consume today.
There was very little cereal grain consumption until the advent of agriculture roughly 10-11,000 years ago. Wild grains would have been small and difficult to harvest, and especially difficult to digest without grinding or cooking capabilities. While some believe that our genes have adapted to grain consumption since this period of time, it is difficult to argue that genetic adaptations have caught up with the current large intake of refined grain consumption. Refined grains became possible during the Industrial Revolution 150-200 years ago with the advent of mechanized steamroller mills and automated sifting devices. These processes removed the bran and germ, leaving behind the mostly starchy interior of the grain. This part is mostly devoid of nutrients, but is carbohydrate-dense. 85% of cereal grains today are refined. Similarly, consuming sugars on a mass scale could not have been possible before industrialization. While our massive intake of refined sugars is topic for a another article, it is clear that there has been no precedent in human history for consumption of sugar on this scale.
The consumption of dairy would have also been nearly impossible before the domestication of livestock. (However, it is clear that some populations have adapted to this and are able to digest milk well.) Since our early hunter-gatherer ancestors had little grain and dairy, their carbohydrate sources came mostly from wild vegetables and fruits, with small and sporadic amounts of honey when it was found. This meant that their diets were naturally very high in fiber. Estimates of their fiber intake range from 70-150 grams per day. Current intake among American adults is roughly 15 grams per day.
While it is difficult to know exactly how much protein our ancestors ate, studies indicate it is more than what we consume today (19-35% of total calories versus 15%). Higher protein diets can help with weight loss, and there is increasing evidence that it can have a protective effect on heart health. Animal flesh from wild animals represented the bulk of their protein intake. This included both larger game as well as smaller animals like birds and lizards, as well as fish and seafood in coastal communities. Because wild animals forage on wild foods, the meat was usually very lean, with levels also cycling throughout the year depending on food availability. This is in sharp contrast to most animals of today, which are often kept in feedlots and fed grain instead of wild foods. The quality of this meat is greatly inferior to wild meat as explained below. Roughly 99% of all beef consumed in the US is feedlot beef, according to some estimates.
Game animals have more mono- and polyunsaturated fatty acids (MUFAs and PUFAs) than do commercial feedlot animals due to their natural diets. As mentioned above, the saturated fat content of wild game was likely higher during only a few months of the year when food was plenty; the rest of the year, during times of less food, their fat stores were more depleted, resulting in less saturated fat. The year-round grain-heavy diets of feedlot animals produce more omega-6 fats, which are more inflammatory, as well as more saturated fats. It also produces “marbling” of fat within the meat, something not seen in wild game. Omega-3 levels are especially higher in grass-fed animals, and therefore probably higher in wild animals as well. Currently, omega-3 levels in the modern industrialized diet are low, while levels of omega-6 are too high.
Another significant contributor to the high omega-6 content in modern diets is industrial seed oils such as canola, cottonseed, soybean, and corn oils, which are naturally high in this type of fat. These vegetable oils have not been around very long; the oil-seed processing industry began in the early 1900s. They are found in processed food products such as cookies, crackers, cakes, ready-to-go soups and cake mixes, among many other foods, which are all ubiquitous.
While an ancestral diet is clearly not for everyone, it is interesting to look back at our ancestors and think about what they ate. Could it be the ideal diet? There are many different opinions on this, and there is no clear answer. What we do know is there are many differences in terms of carbohydrate, protein, and fat content, as well as the types of foods that were consumed back then compared to now. While we continue to search for the “perfect health diet,” and wait for more research to be done, which is still needed, it may be wise to look to our ancestors for some guidance, and most importantly, to keep an open mind.
The information provided in this article is intended for general use only and is not to be used in place of medical advice from a licensed health professional.