The Paleolithic Diet
The Paleolithic diet is a way of eating based on the ancient diet that various human species consumed during the Paleolithic era—a period of about 2.5 million years duration that ended around 10,000 years ago with the development of agriculture.
Strong anthropological evidence indicates our ancestors consumed a diet that included meats, fish, seafood, eggs, non-starchy plants, nuts, and fruit. Humans evolved eating this way, and evidence from DNA studies indicates that the human genetic blueprint (or genome) has changed very little in even the past 40,000 years. Hence, proponents contend that our bodies have been genetically coded to maintain the best health on a paleolithic diet.
The main idea is that we are not genetically adapted to eat the processed foods invented in modern times, and when we eat these foods, they make us sick. Paleolithic proponents point to the fact that modern human tribes eating traditional diets similar to those of Paleolithic hunter-gatherers are largely free of modern diseases.
What You Can Eat on a Paleolithic Diet
The Paleolithic diet is simple and straightforward. Foods should be as close to their natural state as possible. For example, grass fed domestic animals would be the better choice because the fat ratios would be closer to the ratios found in wild game. You can eat any of the following foods, in any amounts that satisfy your hunger:
Foods to Avoid on a Paleo Diet
Paleolithic diets AVOID the following foods:
But Aren’t Whole Grains Good For You?
The agricultural revolution, (Neolithic period) during which grain based foods became part of the human diet, only occurred 10,000 years ago, which is a very short time compared to the fact that the true human species has been walking the earth for more than a million years. There is clear skeletal evidence which shows that once grains were introduced into the diet of modern human populations, bone and teeth structures were weakened, malnutrition became rampant, and infectious diseases developed.
In addition, a recent analysis updating the picture of relative brain size changes in humans during our evolutionary history has revealed that human brain size has decreased by 11% in the last 35,000 years, with most of the decline happening in the last 10,000 years. Reference: Ruff C.B., Trinkaus E., Holliday T.W. (1997) "Body mass and encephalization in Pleistocene Homo." Nature, vol. 387, pp. 173-176. (Figures for brain mass across human evolutionary time found in Table 1 on p. 174.)
What About Dairy Foods?
Dairy foods have only been in the human diet for about 7000 years. Some Paleolithic diet enthusiasts avoid milk because it contains a protein called casein which breaks down in the digestive system to a substance called casomorphin. Casomorphin acts as an opiate substance within the body, and it has been linked to autism in children and as a trigger for the development of diabetes.
Personally, I think that milk products are essential for good health. However, if your gut health has already been compromised by eating grains, and your stomach pH has been altered by chronic antacid use, diary products may aggravate the situation.
Normal stomach pH allows for the full function of the enzyme pepsin, which can easily break up milk proteins into smaller amino acids which have no bioactivity. If stomach pH is too high, pepsin cannot work correctly, and the bioactive dairy casomorphines are left intact.
Grain based foods cause gut inflammation, leakage and heart burn, which necessitates the use of antacids, interferes with pepsin, and this starts a cycle of gut problems which the intact milk proteins may aggravate (not cause).
Resources for Further Reading