Arguments in favor of the paleolithic diet
Proponents of the paleolithic diet frame their arguments as follows:
1. We have been eating meat, fish, vegetables, and fruits for 40,000+ years compared to 1,000-10,000 for agricultural products like milk, grains, beans, and potatoes. Some refined products like bleached white flour have been part of our diets for only 100 years, not nearly enough time for our digestive systems to adapt. Paleo proponent Dr. Loren Cordain calls this "."
2. Grains, legumes, and potatoes are toxic if eaten raw and have harmful properties that are not destroyed by cooking. These harmful properties rob the body of nutrients and even stimulate .
3. Grains, beans, and potatoes are high in carbohydrates, and a high carbohydrate diet leads to obesity and obesity-related diseases like diabetes.
Let's examine each one of these claims:
1. It is true that grains, legumes, potatoes, and dairy are relatively recent components of the human diet. It is not true that we haven't been able to adapt to them. Paleos often point to peanuts, soybeans, wheat, and dairy as being top food allergens. That is true, but fish, shellfish, eggs, and treenuts, allowed on the paleo diet, are also . Even paleos acknowledge that 1,000 years was long enough for milk-consuming peoples like northern Europeans and the Masai to evolve separate genetic mutations for lactose tolerance. Moreover, , affecting only 2% of the population. There is no reason for everyone to avoid foods just because a few people are allergic to them.
2. Legumes and true grains are both seeds, endowed with properties intended to discourage them from being consumed or digested. These protective properties are phytic acid and protease inhibitors. Phytic acid binds with minerals and carries them out of the body. Thus, people who consume a diet high in grains and beans are prone to mineral deficiencies. Protease inhibitors reduce the amount of protein that is digested by the body. These properties do make legumes and grains toxic in their raw state, but soaking, fermenting, sprouting, and cooking all reduce the phytic acid content and make more of the seed's nutrient available to the body. Moreover, protease inhibitors, far from being harmful, are actually .
Potatoes are members of the along with tomatoes, eggplants, peppers, and some other vegetables and fruits. Nightshades contain alkaloids that are toxic in high amounts. Green potatoes and raw potatoes are very high in alkaloids and should not be eaten. Unripe green tomatoes also contain a fair amount of alkaloids. The alkaloid content of non-green cooked potatoes, tomatoes, eggplants, and peppers is low, making these nutritious foods safe to eat.
3. Grains and potatoes do carry a high , but most legumes have a low GL. However, the real culprit behind diabetes is chronic overproduction of insulin, which wears out the beta cells in the pancreas. It is not only carbs but also protein and fat that require to enter most cells. Muscle cells do not need insulin and can take up glucose directly - one reason why exercise is so good for your body. Consumption of refined carbs low in fiber is correlated with , but a diet high in whole grains is . found that a modern diet of meat and refined grain products was strongly correlated with the onset of type 2 diabetes and that the foods most highly correlated were red meats and processed meats.
The results of that study are not surprising, for people who consume a modern diet of processed meats and refined grains tend to be overweight or obese, and obesity is a very strong risk factor for type 2 diabetes. More than , and the disease is virtually unknown in societies with low rates of obesity.
Type 2 diabetes is the culmination of a chain reaction of diet and lifestyle choices. As fat cells fill up, they become resistant to insulin. This causes the body to churn out more and more insulin, which in turn, causes the body's cells to become more resistant. Imagine your spouse calls you to come help with the dishes, and you don't want to, so you pretend not to hear. Your spouse then calls more loudly. You turn on some music. Your spouse begans shouting. In the same way, your cells' insulin receptors get annoyed by too much insulin and try to ignore it, so your pancreas kicks out even more. Being overweight increases your risk of diabetes because fat cells are resistant to insulin. Exercise lowers your risk because muscles don't need insulin to take in energy. The more muscle cells you have and the more you use them, the more energy your body can consume without raising insulin levels.
The example of the of the Southwest are the most compelling evidence that obesity, not a high-carbohydrate diet, is the primary cause of type 2 diabetes. Prior to the arrival of American settlers, the Pima Indians of southern Arizona, like their brethren in Mexico, consumed a diet high in starchy vegetables and low in animal protein and fat. Americans settling in the region during the last century diverted water that the Pimas used for irrigating their crops. Unable to feed themselves, the Pimas began eating government surplus milk, cheese, and white flour and became overweight. Pimas have "" that make them highly susceptible to type 2 diabetes, and most US Pimas will develop the disease by the time they're 40. Remarkably, type 2 diabetes is rare among Mexican Pimas, who stay lean by farming and eating a mostly vegetarian diet.
The estimated lifetime risk of type 2 diabetes for Americans is .
