Functional foods do more that nourish both genders, but these five are particularly beneficial to women's health needs.

According to the U.S. Census Bureau 2000 report, women account for approximately one-half of the population in the United States.1 Since female physiology differs significantly from male physiology, maintaining optimal health varies between genders. For many years, the medical community viewed women’s health with a bikini approach, focusing essentially on the breast and reproductive system.2 The assumption used to be that men and women reacted comparably to diseases and drugs; however, with the emergence of sex-specific medicine over the last decade, that thought process is changing. North American women are at unique risk for certain major nutrition-related diseases and conditions, including diabetes mellitus, cardiovascular disease, several cancers, and osteoporosis.2-5 Medical nutrition science is evolving to target sex-specific recommendations to help fight each gender’s natural propensity toward certain diseases.

Epidemiological research is delving deeper into the “why” behind the health benefits of functional foods, or “super” foods. Isolated components inherent in certain foods—such as antioxidants, polyphenols, flavonoids, and phytonutrients—have become newsworthy buzz words in public health circles. These descriptors conjure up positive relationships to health and longevity, but what is at the heart of their healthful etiology? Consider the following five functional foods for women, their health benefits, and the science behind them.

1. Papaya: Savor the Vitamin C
Chock full of vitamin C—188 milligrams per 10-ounce serving (double that of an orange)—and a powerful digestive enzyme called papain, the sweet, buttery-tasting papaya holds specific promise for female health and longevity. This ascorbic acid powerhouse is believed to help keep the gall bladder in good working order.

According to a study in the Archives of Internal Medicine, women are twice as likely than men to develop gall bladder problems. Scientists from the University of California, San Francisco discovered—after analyzing serum levels of vitamin C in more than 13,000 people—that women who had lower levels of vitamin C were more likely to develop gall bladder illnesses.6

How much vitamin C is enough? According to the Institute of Medicine (IOM) Dietary Reference Intakes, 75 milligrams to the upper limit of 1,000 milligrams per day of vitamin C is recommended for women aged 19 to 70. The functionality of this vitamin, according to the IOM, is its capabilities as a powerful protective antioxidant and a cofactor for reactions requiring reduced copper or iron metalloenzymes.7 According to Ann Louise Gittleman, PhD, CNS, in her book Super Nutrition for Women, vitamin C is a micronutrient that helps keep copper and iron levels balanced. It lowers serum copper levels by binding with it to pull it out of storage or carry it out of the body, and it enhances iron absorption in the body.8 This is precisely why the recommendation for consuming a good vitamin C food source, such as papaya, with an iron-rich meal is the rule of thumb for optimal absorption of nutrients. It helps stave off iron-deficiency anemia and appears to benefit gall bladder health in women, too.

2. Fish: The “Good” Fat Food
It seems counterintuitive to recommend a greater fat intake for cardiovascular health, but research has shown that the type of fat matters in keeping the heart healthy. Alarming statistics from the American Heart Association (AHA) reveal that cardiovascular deaths in men have declined, whereas the number of cardiovascular deaths in women remains unchanged or is increasing.9 Coronary heart disease (CHD) accounts for nearly 250,000 female deaths annually. Nearly every minute, a U.S. woman dies from a cardiovascular event.10 With CHD being the leading cause of death for women both in the United States and in most of the industrialized world, it is more important than ever that nutrition practices be used in CHD prevention.9

According to the current USDA Dietary Guidelines for Americans 2005, evidence suggests that two servings of fish per week (8 ounces) may reduce the risk of mortality from CHD. Specifically, the omega-3 fatty acids, eicosapentaenoic acid and docosahexaenoic acid, found in fatty fish—such as salmon, mackerel, and halibut—play a role in reducing risk of mortality in people who have already had a cardiac event.11 “Fish has a positive impact on women’s health because of the strong correlation between omega 3s and decreased heart disease risk,” explains Lona Sandon, MEd, RD, LD, a national spokesperson for the American Dietetic Association (ADA) and assistant professor at the University of Texas Southwestern Medical Center.

The cardiovascular benefits of fish first received notoriety when researchers looked at the high-fat diets of Eskimos. Despite their high-fat diets, this group had low incidences of cardiovascular diseases. A study in the American Journal of Clinical Nutrition, which looked at the Inuit Eskimos in Nunavik, Canada, showed a protective effect of omega-3 fatty acids on high-density lipoprotein cholesterol and triglyceride concentrations—which positively impact heart health. The researchers found that despite the high prevalence of obesity and smoking among the Inuit of Nunavik, the mortality rate of ischemic heart disease was low, most likely because of their traditional omega-3 rich diets.12

For other benefits of omega 3s associated with women’s health, Sandon points out, “The anti-inflammatory nature of this special fish fat can stave off other common female ailments, such as mild depression, arthritis, lupus, and even Alzheimer’s disease.”

3. Dark Chocolate: Sweet Flavonoids
Women have been eating chocolate as a premenstrual fix for decades without giving its health impact a second thought. According to the Journal of the American Dietetic Association, chocolate is the most craved food in North America, with the majority of chocolate cravers being women at 40% vs. 15% of men.13,14 Little did we know that our monthly cravings for melt-in-your-mouth treats could provide antioxidant protection and benefit cardiovascular health.

“Chocolate’s biggest claim to fame is its high antioxidant content,” says Sandon. However, not all chocolate is created equal. Not only is dark chocolate lower in sugar and saturated fat than milk chocolate, but the higher cocoa content of the dark varieties offers medicinal benefits. A recent AHA report sang the praises of the heart-healthy compounds—flavanols—found in cocoa. In food scientist language, flavanols are explained as one class of polyphenols, which in plants are expressed as nonconjugated molecules, including epicatechins and catechins, and as oligomers of these molecules—named procyanidins.15 The flavanol content in any chocolate varies—depending on the cacao plant’s flavanol content and the processing of the cocoa into chocolate. The AHA researchers found that the flavanols inherent in cocoa can actually aid in lowering blood pressure, improving blood sugar control, and reducing low-density lipoprotein (LDL) cholesterol by approximately 10%.16 For women, increased antioxidant consumption is particularly important for aiding the body in fighting off free radical damage that can result in atherosclerosis, cancer (particularly breast cancer), beta cell damage that can lead to diabetes, and impaired insulin action.

A report last year in the American Journal of Clinical Nutrition found that consumption of dark chocolate improved glucose metabolism and decreased blood pressure.17 The study compared the effects of dark chocolate vs. white chocolate on the health status of 15 healthy young adults. The subjects were divided into two groups—for 15 days, one group consumed dark chocolate and the other group was given white chocolate; both groups ingested no chocolate for seven days, and then the groups switched to the other chocolate for a subsequent 15 days. The authors found that the dark chocolate supplement was associated with improved insulin resistance and sensitivity and decreased systolic blood pressure, whereas white chocolate had no effect.17

However, this is not to say that chocolate should be eaten ad libitum. The February issue of Tufts University’s Health & Nutrition Letter cautioned people to eat chocolate as a treat, not a health food.18 According to Rachel Brandeis, MS, RD, LD, a national spokesperson for the ADA based in Atlanta, “The key is to get as much cocoa in the product as you can get. Look for at least 70% cocoa on the label.” On the cocoa scale, unsweetened baking chocolate contains 100% cocoa, whereas the FDA requires that milk chocolate contain only 16% cocoa—at the very least. From a calorie perspective, moderation is essential. “Be smart about caloric intake,” Brandeis advises her clients. “No more than one ounce of dark chocolate per day—not a whole candy bar.” In other words, women do not have to pack on excess pounds to get the vital antioxidants they need to help stabilize hormone levels, keep arteries unclogged, and fight inflammatory diseases.

4. Flaxseeds: Estrogen Gatekeepers
Who would think that tiny, brown flaxseeds would pack such a healthy punch for women? Nutrition research is uncovering more and more benefits of flaxseed for female health, especially in the area of breast cancer. Steven G. Pratt, MD, and Kathy Matthews—authors of SuperFoods Rx: Fourteen Foods That Will Change Your Life—describe flaxseeds as an “all around treasure trove of nutrients.” Not only are flaxseeds full of alpha-linolenic acid, a type of plant-derived omega-3 fatty acid that has been found to aid in lowering total and LDL cholesterol and blood pressure, but they are a powerful source of fiber, protein, magnesium, iron, and potassium.19

“Flaxseeds are a powerhouse source of phytoestrogens or lignans. Nothing else compares to flax’s concentrated source of plant-based estrogen,” explains Brandeis. Flaxseed has lignan levels 100 to 800 times higher than those found in 66 other plant foods in the vegetarian diet.20 Lignans have been found to influence the balance of estrogens in the body and help protect against breast cancer. “Flaxseed is actually an estrogen modulator that helps decrease estrogen levels and transport excess out of the system,” explains Gittleman. Lignan metabolites bind to estrogen receptors, inhibiting the onset of estrogen-stimulated breast cancer.19

A joint randomized, placebo-controlled, double-blind, prospective study with the University of Toronto and Harvard Medical School conducted earlier this year tested the effects of flaxseed on breast cancer outcomes. In the subjects, postmenopausal women with breast cancer, a daily intake of 25 grams of flaxseed over 39 days significantly reduced cancer cell proliferation and expression of human breast cancer cells.21 The authors contend that if longer-term studies show similar outcomes, flaxseed shows promise as an inexpensive and readily available dietary alternative to currently used breast cancer drugs.

How much flaxseed is enough? Experts recommend 2 tablespoons per day of ground flaxseed or oil for positive health outcomes. However, Brandeis cautions, “the research is not conclusive enough about using flaxseed in place of hormone replacement therapy. My advice to [premenopausal] and perimenopausal women is to use flaxseed as an adjunctive therapy to natural or hormonal therapies.”

5. Whole Grains: Fertility Friendly Folic Acid
Alarming statistics reveal that less than 8% of adults in the United States consume more than three servings of whole grains per day.19 Whole grains, such as brown rice, barley, millet, buckwheat, and amaranth hold many health benefits for women from high fiber for blood sugar control and appetite regulation to iron for staving off anemia to vitamin E for producing adrenal and sex hormones. “Whole grains provide a total package for health,” states Brandeis.

For reproductive health, one of whole grains’ greatest contributions is dietary folate. The FDA mandated (as of January 1998) that enriched cereal grain products be fortified with folic acid at the level of 140 micrograms per 100 grams of product. The fortification resulted in lower incidence of birth defects, mainly neural tube defects.22 During pregnancy, low concentrations of dietary and circulating folate are associated with increased preterm delivery, low infant birth weight, and fetal growth retardation (ie, neural tube defects).23 In addition, folate deficiency leads to an elevation in maternal homocysteine, which has been correlated with habitual spontaneous abortion and pregnancy complications such as placental abruption and preeclampsia.23 Experts contend that whole grains are not a substitute for a prenatal vitamin. To ensure a healthy pregnancy, Brandeis says, “women should still get at least 400 micrograms of folic acid in a prenatal vitamin.”

Heart health is another reason for women to go whole grain. Two large, female-focused studies—the Iowa Women’s Health Study (IWHS) and the Nurses’ Health Study (NHS)—examined the effects of whole grains on health outcomes. The IWHS revealed that women who ate one serving or more of whole grain foods each day had a 14% to 19% lower overall mortality rate. Comparably, the NHS revealed that 2.7 servings of whole grains per day was associated with a 50% reduction of ischemic stroke risk.19 Since the heart disease issue is such a big one for women, it important to note that fasting insulin levels seem to be affected by whole grain consumption. “The evidence is showing an inverse association between whole grains and fasting insulin levels, too,” according to Brandeis. This is encouraging because decreased circulating insulin means lower fat deposition in the abdominal area and, therefore, less risk to the cardiovascular system.

— Victoria Shanta-Retelny, RD, LD, is a practicing dietitian at Northwestern Memorial Wellness Institute in Chicago, freelance food and nutrition writer, and culinary spokesperson.

References
1. US Census Bureau, Current Population Survey, March 2000. Available at: http://www.census.gov. Accessed October 6, 2005.

2. Center for Disease Control (2002). National Diabetes Fact Sheet (2004) Available at: http://www.cdc.gov/diabetes/pubs/factsheets.htm. Accessed March 15, 2005.

3. Murphy SL. Deaths: Final data for 1998. Natl Vital Stat Rep. 2000;48(11):1-105.

4. National Center for Health Statistics, US mortality public use data tapes, 1960–1997, US mortality volumes, 1930–1959. Hyattsville, Md: U.S. Department of Health and Human Services; 2000. In: American Cancer Society facts and figures 2001. Atlanta.

5. National Osteoporosis Foundation. Osteoporosis, Disease Statistics (2002). Available at: http://www.nof.org. Accessed May 1, 2004.

6. Simon JA, Hudes HS. Serum absorbic acid and gallbladder disease prevalence among US adults: The Third National Health and Nutrition Examination Survey (NHANES III). Arch Intern Med. 2000;160(7):931-936.

7. Institute of Medicine Dietary Reference Intakes. Available at : http://www.iom.edu/Object.File/Master/7/296/0.pdf. Accessed October 8, 2005.

8. Gittleman, AL. Super Nutrition for Women. New York: Bantam Dell; 2004.

9. American Heart Association. Heart Disease and Stroke Statistics—2003 Update. Dallas: American Heart Association; 2002. Available at: http://www.americanheart.org

10. Wenger NK. Coronary heart disease: The female heart is vulnerable. Prog Cardiovasc Dis. 2003;46(3):199-229.

11. United States Department of Agriculture Dietary Guidelines for Americans 2005. Available at: http://www.health.gov/dietaryguidelines/dga2005/document/html/chapter6.htm. Accessed October 8, 2005.

12. Dewailly E, Blanchet C, Lemieux S, et al. n-3 fatty acids and cardiovascular disease risk factors among the Inuit of Nunavik. Am J Clin Nutr. 2001;74(4):464-473.

13. Bruinsma K, Taren DL. Chocolate: Food or drug? J Am Diet Assoc. 1999;99(10):1249-1256.

14. Rozin P, Levine E, Stoess C. Chocolate craving and liking. Appetite. 1991;17(3):199-212.

15. Fraga CG. Cocoa, diabetes, and hypertension: Should we eat more chocolate? Am J Clin Nutr. 2005;81(3):541-542.

16. Grassi D, Necozione S, Lippi C, et al. Cocoa Reduces Blood Pressure and Insulin Resistance and Improves Endothelium-Dependent Vasodilation in Hypertensives. Hypertension. July 18, 2005.

17. Grassi D, Lippi C, Necozione S, et al. Short-term administration of dark chocolate is followed by a significant increase in insulin sensitivity and a decrease in blood pressure in healthy persons. Am J Clin Nutr. 2005;81:611-614.

18. Sweet dreams: Will chocolate be the next health food? Tufts University Health & Nutrition Letter. February 2005, p. 6.

19. Pratt SG, Matthews K. SuperFoods Rx: Fourteen Foods That Will Change Your Life. New York: Harper Collins; 2004.

20. Thompson LU, Robb P, Serraino M, et al. Mammalian lignan production from various foods. Nutr Cancer. 1991;16(1):43-52.

21. Thompson LU, Chen JM, Li T, et al. Dietary flaxseed alters tumor biological markers in postmenopausal breast cancer. Clin Canc Res. 2005;11(10):3828-3835.