(This is the fourteenth in a series of heal
th articles that are designed to help you gain a deeper appreciation for God’s amazing handiwork of the human body and a better understanding of how it works and how it can be better maintained by simple methods. George McDaniel is my father-in-law, and has been a registered nurse for many years, which, along with much research, has taught him many useful health principles. I pray that you are being blessed by these articles. Editor)
Sunlight – 2
Before one can address the many benefits to be derived from sunlight, it seems necessary to address the greatest fear of many people: Sunlight and its effect on aging of the skin and skin cancer.
Many people today think that even a moderate amount of sunlight is dangerous to the skin; that it will cause premature aging of the skin and skin cancer. There is evidence to support this belief. However, as will be seen, the safety of sunlight is closely related to nutrition. If one does not have a proper diet, sunlight will have a harmful effect on the skin. Exposure to sunlight is dangerous for those on a refined, high-fat, diet. Those on this type of diet should stay out of the sun and protect themselves from it. At the same time, they will suffer the consequences of both the high-fat, refined food diet and the deficiency of sunlight.
The culprit involved in the damage to the skin is called a free radical. Briefly defined, this is an atom or molecule that has lost an electron. Polyunsaturated fat, in the presence of oxygen, will form free radicals. This is what happens when fats or oils exposed to air turn rancid. This process is accelerated by sunlight. There are three classifications of fat: unsaturated, which are mainly of animal origin and are solid at room temperature, monounsaturated, such as olive and canola oil, and polyunsaturated, such as oil from corn, soybean and safflower. These latter have been regarded as healthful and have been promoted heavily.
Polyunsaturated fats seem to be the main contributor to free radical formation. Free radicals react abnormally with almost anything close by and can damage every system in the body. This damage to nerves, glands, antibody and enzyme producing tissues help produce the degenerating effects of old age.
Sunlight, oxygen and polyunsaturated fats all seem to play a part in the aging process. Then should we stay out of the sun, avoid deep breathing and polyunsaturated fats to delay the aging process? Fortunately, there is a better way.
The polyunsaturated oils most used today are in the form of refined oils and not in the natural foods that contain these fats. Certain vitamins and minerals that prevent free radical formation are present in abundance in the natural foods. These are removed when the food is refined. For example, when oil is removed from the soybean, wheat, corn or peanut, it is totally lacking in the vitamins and minerals that would accompany it if the whole food were eaten.
The vitamins and minerals that protect the oil from free radical formation are called antioxidants. Some antioxidants are Vitamins C and E, carotene, and selenium. There are many others less commonly known such as proanthocyanidins and alpha lipoic acid. People whose tissues are saturated with vitamin C are in a good position to avoid free radical formation and accelerated tissue aging. This takes a minimum of 800-1000 mg. of vitamin C per day to accomplish. In order to get this from the diet, one must eat abundantly of fresh raw fruits and vegetables. Good sources are citrus fruits, strawberries, kiwi fruit, mangoes, tomatoes, bell peppers and dark green leafy vegetables.
If you want to prevent premature aging, not only of the skin but of the whole body, eat a good natural diet rich in antioxidants. Limit, or, better yet, totally avoid, refined foods, including refined polyunsaturated oils. Enjoy sunlight. If the tissues are full of the necessary elements from the diet, sunlight can bring a healthy glow and at the same time keep the skin soft and flexible. Be sure, however, to avoid burning the skin.
Many experiments have been done with animals that show that ultraviolet light is a factor in producing skin cancer. Also, races of people with darker skin get less skin cancer than lighter-skinned races. Among the lighter-skinned races those who are exposed to the sun more get more skin cancer. Skin cancer occurs more often on the areas of the body more exposed to sunlight, such as the head, neck, hands and arms. When all this information is considered, it can’t be doubted that excessive sunlight is a factor in causing skin cancer.
Just how the sun causes skin cancer is not known. It probably has some relationship to the formation of free radicals, just as with skin aging. Burning of the skin causes free radicals to form. It is the free radicals that cause the damage. If free radical formation can be prevented, sunburning will be significantly reduced.
Diet is another factor in the formation, not only of skin cancer but other kinds such as breast and colon cancer. Increasing the calories in the diet of experimental animals causes an increase in the amount of cancer. Diets with equal calories but more fat also cause an increase in cancer. Polyunsaturated fat causes more cancer than saturated fat.
Cells obtain their energy from the metabolism of glucose, and in some cases, fat, into carbon dioxide and water. This process takes place in small structures inside the cells called mitochondria. Oxygen is necessary for the conversion of glucose completely to carbon dioxide and water. The first phase of this process changes glucose to lactic acid. No oxygen is required for this and a small amount of energy is produced. Cancer cells have lost their ability to use oxygen to completely metabolize glucose. They can only obtain the small amount of energy that is produced by changing glucose to lactic acid. Cells need more energy than this to maintain normal internal structures and functions. Cancer cells are thus unable to maintain the normal cell structure and function. Normal cells communicate with one another and are able to stop abnormal cell division and wild growth. Cancer cells have lost this ability and so grow unchecked.
The mitochondria of cells are filled with fine membranes that are rich in polyunsaturated fats. Anything that interferes with the use of oxygen in these structures can cause a cell to become cancerous. Free radicals can damage the mitochondria.
Another product that can damage the mitochondria is called trans fat. A molecule of polyunsaturated fatty acid, as it naturally occurs, is shaped like a U. This u-shape is incorporated into the membranes of cells and mitochondria as part of the structure. This natural fat is called a cis fat. Cis and trans are two Latin terms. Cis means “on the same side.” Trans means “on the other side.” Trans fats are formed by adding hydrogen to the unsaturated areas of the molecule. This changes the structure from u-shaped to straight. Trans fats are also called “partially hydrogenated fats.” Most margarine and solid vegetable shortening contain a large percent of trans fats. When we eat a diet high in trans fat, the body tries to use it. When the body uses trans fat in the cell membranes, while the blueprint calls for cis fat, the membrane is not going to be very good. There may be holes in the membrane that allow harmful substances into the cell. For instance, in a normal cell with an intact membrane, sodium is in very low concentration inside the cell and potassium is in high concentration. Outside the cell the reverse is true. The cell has to actively pump the sodium out of the cell and the potassium in. If there are holes in the cell membrane, the cell has to work extra hard to move out the excess sodium. The mitochondria become swollen and their function is inhibited. They become unable to use oxygen, so the cell can become cancerous.
Another factor involved in the development of cancer is how well the immune system functions. Normally, the immune system recognizes a defective cell and destroys it. The only way for cancer to become established is to have a depressed immune system. Polyunsaturated fat inhibits the immune system.
Also, when the skin receives enough ultraviolet light to become burned, a substance called prostaglandin E is produced from one of the fatty acids in the skin. This substance contributes to the inflammation. It also suppresses the immune system.
An interesting fact is that while sunlight appears to increase the amount of skin cancer, it seems to decrease the amount of internal cancers. Tests on rabbits and mice showed that the more ultraviolet light they received, the less internal cancer they developed. A study done involving the U.S. Navy showed a high incidence of skin cancer, but a less than average amount of other cancers. This should be expected, since sunlight stimulates the immune system and increases the use of oxygen in the tissues.
From the foregoing information, we can see that the bad reputation the sun has is undeserved. It is not a moderate amount of sunlight, of itself, that is so harmful, but the diet most people eat. In order to avoid problems with exposure to sunlight, eat a diet rich in antioxidants. This means fruits, vegetables and seeds in a whole, natural condition, as fresh as possible. Avoid refined foods, especially refined and partially hydrogenated oils and fats. Also avoid alcohol and cigarettes as these are high in free radicals. Use moderation in exposing yourself to the sun.
This article has brought out some of the negative aspects of sunlight. In the next article, I hope to provide more positive information about the benefits of sunlight.
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