Sunday, August 16, 2009
My training is in chemistry. Because of that, I tend to see the world as an array of chemicals, from the the cotton in my clothes to the gasoline in my car. But a comment on last week's post reminded me that in recent decades we have been trained to see chemicals in two different classifications--natural and man-made. We have been taught that natural things are by definition good and man-made things may very well be bad and could hurt us in the long run. For those of us who are interested in healthy eating, the distinctions have particular significance. In the world of low-carbing, are natural foods the safest foods? Not necessarily.
One of the natural foods we have been discussing lately is fructose. It's found in high-fructose corn syrup, of course, but it is also found in fruits and honey. Regardless of where it's found, fructose is fructose. The molecule stays the same. And the molecule fructose, when eaten in large quantities, is able to produce a fatty liver, protein glycation, and even gout.
Another natural food is potatoes. Potatoes are not recommended on low-carb diets, but some of us can't keep away from the french fries and chips. Potatoes are in the nightshade family of vegetables and contain the glycoalkaloids solanine and chaconine. These chemicals are acetyl cholinesterase inhibitors and are used to protect the potato from attack by fungus and insects. Unfortunately, they also have a negative effect on some people. They can produce joint pain and symptoms of digestive inflammation, and even mental confusion in a few cases. Cooking destroys some but not all of the glycoalkaloids in potatoes.
Whole wheat is beloved of those who promote a natural lifestyle. Wheat contains proteins called lectins, which act as a primitive immune system for a plant. When wheat is eaten by bacteria, insects, rodents or humans, the ingested lectins are able to bind to cell walls and membranes and cause the clumping of cells, as well as inappropriate cell division and hormone reactions. These effects can cause inflammation and damage to the lining of the small intestine, as well as possible autoimmune reactions if the lectins are absorbed into the circulation. Cooking or baking is able to break down some lectins but not all of them. It is interesting to note that early agriculturalists knew how to decrease lectin content by sprouting and fermenting the wheat they harvested.
Corn oil is another all-natural product that is used both in cooking and in the manufacture of margarine. Corn oil is high in total polyunsaturated fatty acids as well as omega-6 polyunsaturated fatty acids. A recent study in Sweden has shown an association between omega-6 fatty acid intake and breast cancer. A 2006 study showed that the addition of omega-6 fatty acids to prostate tumor cells doubled their growth rate in culture. Another study showed a similar result in a strain of mice that was bred to be susceptible to prostate cancer.
What does all of this mean? Is anything safe to eat? Probably not, but there are obvious risks to fasting indefinitely.
What these examples imply is that a description of "natural" is not a guarantee of safety. Not only that, it wouldn't matter if the foods described above were grown in an organic way on local farms or in the conventional way on huge industrial farms. The natural chemicals (fructose, glycoalkaloids, lectins, omega-6 fatty acids) would be there whether or not organic farming methods were followed.
Fortunately for us, experience has shown that humans are well able to tolerate small amounts of toxic substances. However, for those who are interested in following a maximally healthy lifestyle, each food needs to be considered on its own. Animals defend themselves with horns and hooves. Plants defend themselves with chemicals. Some of these chemicals are beneficial, but some are not, and it pays to be aware of the differences.