Feminine Fortification
September 1998 -- Nutrition Notes

By: Andrea Platzman, R.D.
Contributing Editor

  Besides looking and sounding different than their male counterparts, women have distinct nutritional requirements as well. Though they generally live longer than men, they aren't necessarily living better lives. Heart disease - the leading killer of American women - affects more than 245,000 of their ranks annually. Approximately 16 million American women suffer from osteoporosis and an estimated one-third are overweight. Improvements in diet might hold the key to better women's health.

Higher levels

  "The three vitamins/minerals many women are lacking or not consuming enough of are: calcium, folic acid and vitamin E," says Susan Finn, Ph.D., R.D., director of nutrition, Ross Laboratories, a division of Abbott Laboratories, Cleveland. Iron deficiency also might become a problem.

  Calcium is the most abundant mineral in the body, comprising about 2% of body weight. Approximately 99% of a person's calcium is found in his or her bones and teeth. The remaining calcium is carried in the blood, and performs a variety of life-maintaining functions, such as: controlling the heart's rhythm, clotting blood, healing wounds, contracting muscles for body movement, making hormones, and creating digestion-controlling enzymes.

  "When looking at women's diets," Finn says, "they just don't consume enough. Women need to get 1,200 to 1,500 mg of calcium, especially during the perimenopausal stage, where you may have a chance to delay or prevent osteoporosis. It is very difficult to get this amount of calcium without supplements.

  "It is recommended that if you don't drink milk or eat dairy products, that you take supplements in small doses and with meals for the best absorption," she says. "For example, with a 600 mg calcium supplement, about 40% of the calcium is actually absorbed."

  Bone tissue is constantly being broken down and rebuilt. With peak bone mass occurring between ages 35 and 40, a natural postmenopausal bone loss takes place. The decrease in circulating estrogens increases bone loss for women ages 42 to 58. In fact, bone loss during the immediate postmenopausal period may be as much as 2% annually. "You need to have adequate amounts of calcium for the prevention of osteoporosis," says Kristine Clark, Ph.D., R.D., director of sports nutrition, Pennsylvania State University, University Park, PA. "Dairy and fortified foods, such as orange juice with calcium, are the best dietary sources." A reduction of bone density of just 10% at the onset of menopause increases the risk of osteoporosis about 100%.

  Failure to get enough folic acid early in pregnancy increases the risk of giving birth to a child with neural-tube defects, a condition where the spinal column fails to close during fetal development. It is recommended that all women of child-bearing age consume 400 µg of folic acid daily. Recent research also has found that folic acid, along with vitamins B6 and B12, helps ward off heart disease by reducing blood levels of the amino acid homocysteine. High levels are a strong indicator for heart disease and stroke. Dietary sources include lentils, orange juice, spinach, asparagus and fortified whole grains. "The recent DASH (Dietary Approaches to Stop Hypertension) study recommends eight to 10 fruits and vegetables each day, which is not that hard to achieve when looking at portion sizes - an 8 oz. glass of orange juice is two fruits," Finn says. "It is important to remember that all of these fruits and vegetables work together synergistically."

  Vitamin E and other fat-soluble vitamins, such as vitamins A, D and K, may fall short in many women's diets. "Since many women are on low-caloric diets, and limit their consumption of oils, many fat-soluble vitamins are not absorbed fully, such as vitamin E, which has heart- and perhaps even breast-health benefits," Finn explains. Vitamin E has been recommended as a treatment for menopausal hot flashes, offering a 27% positive response.

  With the onset of menarche, the requirement for iron increases from 12.5 mg to 18 mg. "Iron-deficiency anemia plagues women and children," Clark explains. "It is important to get enough of this mineral - the best sources are red meats and fortified cereals." Symptoms of iron deficiency include dizziness and fatigue.

Turn it down

  Obesity is not just a matter of what we eat, but how much. "As we age, we need less calories," Clark says. "The metabolic rate decreases by 2% every decade, which translates into consuming about 100 calories less per day for every 10 years in order to maintain a healthy body weight."

  Of those calories, carbohydrates are key. It's important to obtain them from a variety of sources - such as lowfat dairy foods, fruits, vegetables and legumes - to maintain a balanced diet.

Hot flash

  About 60% of American women experience hot flashes. It's suspected that estrogen has something to do with this, but the relationship hasn't been confirmed. But it's interesting to note that in Eastern cultures, where women eat 3 to 4 oz. of soy foods daily (yielding 25 to 40 mg of isoflavones), hot flashes are unknown. These phytoestrogens appear to alleviate menopausal symptoms by inhibiting the binding of estradiol 17B (the most potent estrogen) to uterine cytosol receptors. Phytoestrogens are converted in the gut to hormonelike substances, equols, which the body might mistake for estrogen.

  Phytoestrogen concentrations reach 0.1% to 0.2% in most soy products, the major compounds being daidzein and genistein. "The greatest fear for all women is breast cancer, and many are looking for alternatives to estrogen-replacement therapy, including the consumption of soy foods," Finn says. "The benefits of soy include better health and possible breast-cancer prevention.

  "It is also important to pay attention to fiber (fresh fruits, vegetables and whole grains), since we're not getting enough," Clark says. "We need 25 to 35 grams per day, and are currently getting 7 to 10 grams per day. Fruits and vegetables are also rich in phytochemicals, which may prevent breast cancer and other forms of cancer."  Since women can be chemically different from one another, just as men are, it is important to get the correct balance among vitamins, minerals and nutrients for optimal nutrition.

  Andrea D. Platzman is a registered dietitian who is a consultant to the food industry, and regularly writes for nutrition publications. She earned a master's degree in nutrition from New York University, and has a culinary and business background.

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