The Paleo Diet - Loren Cordain [47]
Omega 3 Fats
I’ve already talked about the beneficial effects of omega 3 fats on insulin metabolism and how they lower blood triglycerides. Omega 3 fats are also exceptionally potent agents in preventing the irregular heartbeats that can make a heart attack fatal. They help prevent blood clotting and ease tension in clogged arteries as well.
In a landmark dietary intervention study, French physicians Serg Renaud and Michel de Lorgeril evaluated the effect of a diet rich in omega 3 fats in 600 patients who had previously survived a heart attack. In this investigation, known as the Lyon Diet Heart Study, half of the patients were assigned to the American Heart Association reduced-fat diet, in which 30 percent of calories come from fat. The rest followed a 35 percent fat traditional Mediterranean diet that was rich in omega 3 and monounsaturated fats and fruits and vegetables.
The results were striking: compared to the patients who followed the American Heart Association Diet, those who were on the Mediterranean diet had a 76 percent lower risk of dying from another heart attack, a stroke, or another cardiovascular disease. This remarkable protection from heart disease can be yours, too. Like the Mediterranean diet, humankind’s original diet is also high in cardioprotective omega 3 fats, fiber, monounsaturated fats, and the beneficial phytochemicals and antioxidant vitamins that are found in fruits and vegetables.
Diseases of Acid-Base Balance and Excessive Sodium
The average cereal-based, salt-laden, cheese-filled American diet—which is nearly devoid of fresh fruits and vegetables—tilts your body’s acid-base balance in favor of acid. As we discussed earlier, grains, cheeses, meats, and salty foods yield a net acid load to the kidneys, while fruits and vegetables always generate an alkaline load. An overload of acid foods—at the expense of alkaline foods—can cause numerous health problems, particularly as you age and your kidneys become less adept at handling dietary acid.
Of the four major acid-producing foods, three—grains, cheeses, and salt—were eaten rarely or never by our Paleolithic ancestors. Instead, they ate huge amounts (by modern standards) of alkaline fruits and vegetables, which buffered the acid from their meat-rich diets.
Many chronic diseases prevalent in Western countries develop because of a dietary acid-base imbalance. These include:
• Osteoporosis
• High blood pressure
• Stroke
• Kidney stones
• Asthma
• Exercise-induced asthma
• Ménière’s syndrome
• Stomach cancer
• Insomnia
• Air and motion sickness
The realization that such diverse problems could be linked to acid-base imbalance is fairly recent. Not so long ago, scientists connected many of these illnesses to too much sodium, or salt. But the chemical recipe for salt has two ingredients—sodium and chloride. And as I discussed earlier, it’s the chloride part of salt that makes it acidic—not the sodium. Chloride may also be more to blame than sodium as a dietary cause of high blood pressure.
Osteoporosis
Earlier, I talked about salt’s interplay with calcium in the body: people who eat a lot of salt excrete more calcium in their urine than do people who avoid salt. In turn, this calcium loss contributes to bone loss and osteoporosis, because the acidic chloride in salt must be buffered in the kidneys by alkaline base—and the body’s largest reservoir of alkaline base is the calcium in our bones. When we eat salty potato chips or a pepperoni pizza, we are leaching calcium from our bones. When we do it over the course of a lifetime, we may well develop osteoporosis.
Asthma and Exercise-Induced Asthma
But salt is not just bad for the bones. Although it has not been shown to cause asthma or exercise-induced asthma, it can aggravate both conditions. Studies in humans and animals have shown that salt can constrict the muscles surrounding the small airways