CUMULATIVE EFFECTS OF NUTRITION
There is an increasing concern among health professionals regarding the cu-mulative effects of nutrition. Cumulative effects are the results of somethingthat is done repeatedly over many years. For example, eating excessive amounts of saturated fats for many years contributes to atherosclerosis, which leads to heart attacks. Years of over-eating can cause obesity and may also contribute to hypertension, type 2 (non-insulin-dependent) diabetes, gallbladder disease, foot problems, certain cancers, and even personality disorders.
When nutrients are seriously lacking in the diet for an extended period, defi-ciency diseases can occur. The most common form of deficiency disease inthe United States is iron deficiency, which is caused by a lack of the mineral iron and can cause iron deficiency anemia. Iron deficiency is particularly common among children and women. Iron is a necessary component of the blood and is lost during each menstrual period. In addition, the amount of iron needed during childhood and pregnancy is greater than normal because of the growth of the child or the fetus.
Rickets is another example of a deficiency disease. It causes poor boneformation in children and is due to insufficient calcium and vitamin D. These same deficiencies cause osteomalacia in young adults and osteoporosis in older adults. Osteomalacia is sometimes called “adult rickets.” It causes the bones to soften and may cause the spine to bend and the legs to become bowed. Osteoporosis is a condition that causes bones to become porous and excessively brittle. Too little iodine may cause goiter, and a severe shortage of vitamin A can lead to blindness.
Examples of other deficiency diseases (and their causes) are included in Table 1-3.