Women's Bodies, Women's Wisdom (158 page)

Osteoporosis.
Fracture rates in Asian populations that consume far more soy than is typical in the United States are significantly lower. There appears to be some bone-sparing effect of soy isoflavones.
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Though this effect is not nearly as robust as getting optimal vitamin D, calcium, magnesium, and weight-bearing exercise, it’s worth consuming some soy products as part of your overall bone health strategy.

Soy doesn’t disrupt thyroid function in those with normal thyroid function and adequate iodine.
The relationship between soy and thyroid function has been studied for more than seventy years. Since then, fourteen human clinical trials have studied the effects of soy foods and soy isoflavones on thyroid function. All involved presumably healthy subjects, and with few exceptions, the soy product used was isolated soy protein. Now here’s the important part. With only one exception, all of the studies showed either no effects or minor and clinically irrelevant effects of soy on thyroid function.
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The one trial that noted marked antithyroid effects (and the one that is often cited in anti-soy literature) involved Japanese adults who were fed roasted soybeans that had been pickled and stored in rice vinegar. It is not known what the soy protein or isoflavone content of this food was. And the study was not controlled. So no firm conclusion can be drawn.

Considering the number of women who are first diagnosed with thyroid problems at midlife, I was particularly reassured by a study of thirty-eight postmenopausal women between the ages of sixty-four and eighty-three who were given daily doses of 90 mg of soy isoflavones or a placebo.
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Thyroid hormone levels were tested at the beginning of the study and again at 90 and 180 days. After six months, the differences in thyroid hormones between the groups were statistically indistinguishable. Given all this, most experts agree that soy foods and isolated soy protein have little if any effect on thyroid function in normal, healthy adults who consume soy at moderate levels as part of a well-balanced diet.

However, soy isoflavones, especially in high doses, can disrupt thyroid function in those who are iodine deficient (estimated to be 13 percent of the population) and in those who have compromised thyroid function.

Moderation is key.
Oscar Wilde once said, “Nothing succeeds like excess.” And in our culture, if something has been found to be beneficial, Americans tend to overdo it. That is the case with soy, too. Some people think that if some is good, then more is better, leading them to subsist mainly on soy protein.

Soy foods (and other isoflavones) appear to have protective and healthful effects when consumed as part of a healthful, well-balanced diet beginning in childhood. Healthy dietary intakes of soy isoflavones, as reflected in Asian diets, appear to be in the range of 20–90 mg per day.

In summary, both the scientific evidence and my years of experience strongly support the role of a moderate amount of soy protein (as soy protein isolate; fermented soy or nonfermented soy) in the diets of the vast majority of people.
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In addition to being far more ecologically sound to produce—it takes 20 pounds of soybeans to make 1 pound of beef—soy protein also confers a number of well-documented health benefits.

As always, it’s the quality of the food that counts. So look for soy that is non-GMO and, if possible, organically grown. Don’t spend your time reacting to extreme views on anything. This, in and of itself, is a health risk. There are far more important matters in life—such as forgiveness, laughter, and joy—than being afraid of soy.

Eat the Right Kinds of Fats

Our bodies can produce most fatty acids from the carbohydrates that we eat. However, there are two fatty acids, known as essential fatty acids, that our bodies cannot produce and that we must therefore get in our diets. These two acids are linoleic acid (LA), an omega-6 fatty acid, and alpha-linolenic acid (LNA), an omega-3 fatty acid. LNA is the starting material for the biosynthesis of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two important polyunsaturated fatty acids. LNA, EPA, and DHA are the main members of the omega-3 family of fatty acids.

For the majority of human evolution, omega-6 fats (especially corn oil, peanut oil, soy oil, and safflower oil) and omega-3 fats have been consumed in a ratio of about 2:1. But because of all the omega-6 oils that have been used in cooking or prepared food over the past fifty years or so, that ratio has shifted so that it is now anywhere between 10:1 and 20:1. We have also decreased our intake of omega-3 fats considerably. To flourish we need both, but in the right amounts. The majority of us get more than enough omega-6 fats, so we need to concentrate on necessary intake of omega-3 fats.

The essential fatty acids are converted in our bodies into two important classes of eicosanoids—leukotrienes and prostaglandins. These later compounds are hormone-like substances that influence a huge num ber of metabolic processes. An overabundance of the wrong kinds of eicosanoids leads to—you guessed it—cellular inflammation. Eating enough omega-3 fats (1,000–5,000 mg per day) helps prevent cellular inflammation, which is what causes menstrual cramps, joint pain, breast pain, PMS, and a host of other problems.
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(Note: Many pharmaceutical drugs, such as Celebrex and Advil, work in part by suppressing cellular inflammation from free radical damage and imbalanced eicosanoids.)

Omega-3 fats (found in fish and fish oil, egg yolks, dark green leafy vegetables, flaxseed and its oil, macadamia nuts and their oil, hemp seed oil, and sea algae) are essential for the optimal functioning of every cell mem brane in the body. As a result, getting enough of this nutrient is highly beneficial to your immune system, cardiovascular system, brain, and eyes. A deficiency in omega-3 fats can lead to dry skin, cracked nails, brittle hair, fatigue, depression, memory problems, hormone imbalances, achy joints, arthritis, and a poor immune system. Hundreds of studies have shown the health benefits of increasing your intake of omega-3 fats while also decreasing refined carbohydrates, saturated fats, trans fats, and omega-6 fats.

A body of evidence suggests that our current epidemic of heart dis ease began in the last seventy years, when partially hydrogenated fats (trans fatty acids), the foods containing them, and refined foods devoid of antioxidant vitamins were introduced into the mainstream diet. Trans fats are not found in nature, so our bodies haven’t evolved to deal with them. Produced instead by a chemical process in which hydrogen is added to naturally occurring polyunsaturated fat at extremely high temperatures, these fats are solid at room temperature and have an extremely long shelf life (making them useful for margarine, as well as just about every processed food product you can think of, including cookies, crackers, baked goods, and even baby formula). Processed foods containing trans fats often replace foods in which naturally occurring essential fatty acids are found, such as almost all unprocessed nuts, whole grains, and many vegetables.

BENEFITS OF “GOOD” FATS

People with higher blood levels of omega-3 fats have lower BMIs, narrower waists, and smaller hip circumferences. In fact, cell membranes of overweight and obese people are nearly 14 percent lower in omega-3 fats than are those of people with healthy weights.
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Omega-3 fatty acids (in the form of fish oil supplements) lower cholesterol better than the statin drugs
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and also lower triglyceride levels.
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Several prospective cohort studies have found an inverse association between fish consumption and risk of cardiovascular disease.
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Essential fatty acids also decrease hardening of the arteries by reducing the “stickiness” of blood cells, so they cling less to artery walls.
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Other studies have shown that the essential fatty acids can mod erate the cancer-causing effects of radiation and certain chemicals because of their ability to balance inflammatory chemicals.
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The right dietary oils may also help inhibit the development of breast and other forms of cancer by regulating immune system function in the body.
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Omega-3 fats (particularly DHA) support brain function. Studies have shown that sufficient amounts of DHA for fetuses and infants have been linked to higher IQs, while deficiencies have been associated with learning disabilities such as attention deficit/hyperactivity disorder (ADD, ADHD) and dyslexia.

DHA can stabilize your moods. Deficiencies are a contributing factor to depression, postpartum depression, preeclampsia, and various postmenopausal conditions.