Acid - alkaline balance
Dr Loren Cordain has pioneered the evolutionary basis of the health benefits of a diet with a higher than average alkalinity.
Cordain explains that the chloride in salt, especially in combination with cereals, dairy products, legumes and meats, yield a net acid load to the kidneys after they are digested (The Paleo Diet, page 17).
What does a "net acid load" lead to? As our bones are our calcium store as well as providing our skeletal structure, our body draws on this store to reduce the acidity of material in the digestive process. As well as osteoporosis, Cordain lists nine other conditions (including high blood pressure, stroke and kidney stones - page 87) which develop because of dietary pH imbalance. He says that scientists had previously linked these conditions to excessive salt intake. The link was correct, but the reasoning was incomplete: it was the chloride component of salt and also the digestive acidity of a diet which strayed from the Pleistocene which was the real cause.
What can we do about it? Three things.
1. Don't add salt to your food
2. Eliminate processed foods to the extent that they contain salt
3. Buffer the acidity in meat and fish with fresh fruit and vegetables.