The Paleo Diet - Loren Cordain [31]
5. Too Much Salt, Not Enough Potassium
Paleo diets were exceptionally rich in potassium and low in sodium. Just about everything Paleolithic people ate—meats, fish, fruits, vegetables, nuts, and seeds—contained about five to ten times more potassium than sodium. This means that when you eat only fresh, unprocessed food, it’s impossible to consume more sodium than potassium.
We don’t know exactly when farmers began to include salt in their diet, but we can guess why. Salt performed a great service, in the centuries before refrigeration, in preserving meats and other foods. It helped make foods like olives edible; it added flavor to bland cereals and other foods. At least 5,600 years ago, archaeological evidence shows us, salt was mined and traded in Europe. It remains a staple today; in fact, the average American consumes about twice as much sodium as potassium. And that’s not healthy.
6. An Acid-Base Imbalance
Very few people—including nutritionists and dietitians—are aware that the acid-base content of your food can affect your health. Basically, this is what happens: everything you digest eventually reports to the kidneys as either an acid or an alkaline base. Acid-producing foods are meats, fish, grains, legumes, dairy products, and salt. Alkaline-producing foods are fruits and vegetables. You need both kinds—acid and alkaline. Fats are generally neutral.
The average American diet is slightly acidic—which means that our kidneys must handle a net acid load. For example: Suppose you have a typical “light” lunch, probably available at a dozen places near your home or office, of pepperoni pizza and a small salad with Caesar dressing. This meal is a disaster for the body’s acid-base balance: the pizza’s white-flour crust, melted cheeses, and salty pepperoni are all highly acidic. Add salt, and you make it even more acidic. Any alkaline remnant available in the tiny salad is neutralized by the salt and cheese in the Caesar salad dressing.
In the long run, eating too many acid foods and not enough alkaline foods can contribute to bone and muscle loss with aging. There are more immediate dangers, too: excessive dietary acid can raise blood pressure and increase your risk of developing kidney stones. It can also aggravate asthma and exercise-induced asthma.
7. Not Enough Plant Phytochemicals, Vitamins, Minerals, and Antioxidants
The Paleo Diet is rich in vitamins and minerals. One of the best ways to prove how healthy our diet used to be is to show what happened when our ancestors fiddled with it.
Vitamin C deficiency, a disease unknown to Paleolithic people, causes scurvy. Paleolithic people didn’t have this problem; their diets were extremely high in vitamin C (around 500 milligrams per day) because they ate so many fresh fruits and vegetables. But even Eskimo groups—who for thousands of years have eaten virtually no plant foods for most of the year—didn’t get scurvy. How can this be? They got their vitamin C from other natural sources—raw fish, seal, and caribou meat.
But as our ancestors began eating more cereal grains and fewer lean meats, fresh fruits, and vegetables, they lost much of the vitamin C in their diets. Cereal grains have no vitamin C, which is one of the body’s most powerful antioxidants. Vitamin C helps lower cholesterol, reduces the risk of heart disease and cancer, boosts the immune system, and helps ward off infections and colds.
Vitamin A deficiency, like scurvy, could only have emerged after the coming of agriculture. Paleo diets were always rich in fruits and vegetables—excellent sources of beta-carotene, a nutrient that can be converted to vitamin A by the liver. (Our ancient ancestors also ate the entire carcasses of the animals they hunted and killed, including the vitamin A-rich liver.) Again, trouble happened when cereals took over and fresh fruits, vegetables, and organ meats were pushed aside. Vitamin