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Fast Fact
One of the great wonders of the human body is the ability of damaged cells to be repaired or replaced. Red blood cells, for instance, live for about 120 days. Each day, about 1% of your red blood cells retire to be replaced by a fresh generation. The lens of the eye is a notable exception. The cells of the lens of the eye are never replaced; the proteins of the lens are never replenished. The lens cannot repair itself; damage accumulates over a lifetime.
Cataracts are the result of gradually accumulating damage to the proteins of the lens. The most important source of this damage is exposure to ultraviolet (UV) radiation, especially while one is young.
Behind the lens lies the retina, the thin lining of the back of the eye. The retina is the eye's miracle. This patch of tissue, about the size and thickness of a postage stamp, is able to dissolve and create a new image every tenth of a second.
Today in the United States, retinal diseases are the leading cause of blindness. Macular degeneration, the accumulation of damage in the retina, is the leading cause of blindness from retinal disease. Slowly, over the years, the macula is irreversibly damaged by exposure to UV radiation. About one third of adults over age 65 experience this steady decline of central vision, not correctable by glasses.
Excessive exposure to sunlight during early childhood is harmful to the eyes. Sunlight contains harmful UV radiation.
The risk for retinal damage from the sun's rays is greatest in children less than 10 years old, although the consequences usually do not become apparent until well after they are adults.
All children should be taught to wear sunglasses, especially between 10 AM and 2 PM, when ultraviolet exposure is the most dangerous. This is true even for children with darker eye colors, even though their darker pigments afford partial protection. Of course, children with light-colored eyes need sunglasses all the more.
Ultraviolet exposure is at its peak when children are at high altitudes, snow-covered landscapes, bright sandy beaches, or near reflective bodies of water.
All sunglasses are not the same. Effective sunglasses should block both UVA and UVB radiation. The sunglasses must be measured to block 99% to 100% of UVA or UV400 (400 nm is the wavelength of UVA radiation). Thankfully, all sunglasses block UVB radiation.
Large lenses that fit close to the eyes are best. Those that block visible blue light are even safer.
Expensive brand names and polarizing lenses are no guarantee.
Ordinary sunglasses make the situation WORSE! The dark lenses cause the pupils to dilate, allowing more of the dangerous UVA radiation to damage the lens and the retina.
The effect of sugar intake on children's behavior is a hotly debated topic in pediatrics. Parents and educators often contend that sugar and other carbohydrate ingestion can dramatically impact children's behavior, particularly their activity levels. Physicians, on the other hand, have looked at controlled studies of sugar intake and have not found hypoglycemia or other blood sugar abnormalities in the children who are consuming large amounts of sugar.
An interesting article appears in the February 1995 edition of the Journal of Pediatrics. In contrast with other research teams, William Tamborlane, M.D., et al, of Yale University report a more pronounced response to a glucose load in children than in adults.
It is commonly acknowledged that as blood glucose levels fall, there is a compensatory release of adrenaline. When the blood glucose level falls below normal, the resulting situation is called hypoglycemia. Signs and symptoms that accompany this include shakiness, sweating, and altered thinking and behavior.
Tamborlane and his colleagues demonstrated that this adrenaline release occurs at higher glucose levels in children than it does in adults. In children it occurs at a blood sugar level that would not be considered hypoglycemic. The peak of this adrenaline surge comes about four hours after eating. The authors reason that the problem is not sugar, per se, but highly refined sugars and carbohydrates, which enter the bloodstream quickly and produce more rapid fluctuations in blood glucose levels.
A recent study supports the idea that a breakfast with a lower sugar load may improve short-term memory and attention span at school (Physiol Behav, 2007; 92: 717-24). Giving your child a breakfast which contains fiber (oatmeal, shredded wheat, berries, bananas, whole-grain pancakes, etc.) instead of loads of refined sugar should keep adrenaline levels more constant and make the school day a more wondrous and productive experience. Packing her/his lunch box with delicious fiber-containing treats (whole-grain breads, peaches, grapes, a myriad of other fresh fruits, etc.) may turn afternoons at home into a delight.
Some studies suggest that taking thiamine (vitamin B1) 25mg to 50 mg three times per day is effective in reducing mosquito bites. This safe vitamin apparently produces a skin odor that is not detectable by humans, but is disagreeable to pregnant mosquitoes. Click here for more of Dr. Greene’s Tips For Avoiding Mosquito Bites.
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