Women represent 51% of the total United States population, 59% of the over-65 population, and 71% of Americans older than age 85, according to statistics from the U.S. Dept. of Health and Human Services’ Office on Women’s Health.
This majority of the population stands as a target for the functional food industry. Products specifically targeting women, such as General Mill’s Harmony cereal and Quaker® Instant Oatmeal Nutrition for Women™, have already hit the market shelves over the past several years. But still there is room for more innovative gender-specific products.
This month’s column will focus on some of the health conditions that affect women and some of the nutritional ingredients, such as carotenoids, soy, folic acid, and calcium, that research has linked to them. Don’t worry, men. I’ll be hitting your health issues in next month’s column!
Heart disease is the number one killer of American women, says the Office of Women’s Health. Although it is typically viewed as a man’s disease, more women actually die of heart disease each year than do men. In addition, women, on average, develop heart disease later in life than do men.
A recent study suggested that carotenoids may reduce the risk of heart disease in women (Osganian et al., 2003). Using a modified food questionnaire for carotenoids in 1984, Harvard researchers studied the eating habits and health of more than 73,000 female nurses. During 12 years of follow up, nonfatal heart attacks or fatal heart disease occurred in 998 of the subjects. The researchers investigated relationships between specific dietary carotenoids and the risk of coronary artery disease (CAD).
They found that women with the highest dietary intakes of beta-carotene and alpha-carotene were least likely to have fatal or nonfatal heart attacks. Those with the highest intake of beta-carotene were 26% less likely to have CAD than those with the lowest intake and those with the highest intake of alpha-carotene were 20% less likely to experience CAD. The carotenoids are thought to quench free radicals and reduce the oxidation of low-density lipoprotein (LDL) cholesterol.
Another study showed that grape polyphenols could reduce cholesterol in menopausal women (Zern et al., 2003). Researchers from the University of Connecticut used female guinea pigs, which had their ovaries removed, as a model for menopausal women. They were fed either a control diet or a diet containing a lyophilized grape preparation for 12 weeks, including 0.58 g of polyphenols per 100 g of the preparation. The diet included flavans, anthocyanins, quercetin, myricetin, kaempferol, and resveratrol. The diet also included 0.33 g of cholesterol per 100 g to raise plasma cholesterol concentrations and ensure the development of atherosclerosis in the animals.
--- PAGE BREAK ---
Blood levels of LDL cholesterol concentrations did not differ between groups, but plasma triglycerides were 39% lower and very low density lipoprotein (VLDL) cholesterol was 50% lower in guinea pigs fed the grape diet compared with controls. Phospholipids were 30% lower and concentrations of cholesterol in the aorta were 33% lower in guinea pigs fed the grape diet.
“These results suggest that grape intake in ovariectomized guinea pigs alters hepatic cholesterol metabolism, which may affect VLDL secretion rates and result in less accumulation of cholesterol in the aorta,” the authors wrote.
Another study found that high intake of foods rich in lycopene may reduce the risk of cardiovascular disease (CVD) in women (Sesso et al., 2003). The data were derived from the ongoing Women’s Health Study, which has been following 40,000 women for the past 11 years, who were free from cancer or CVD at the start of the study. After seven years of followup, the researchers recorded 719 cases of CVD. The present study analyzed the subjects’ food frequency questionnaires for associations between intake of lycopene and tomato-based foods and the risk for CVD.
For those women who consumed seven servings or more of tomato-based foods such as tomato sauce and pizza each week, there was a nearly 30% reduction in total CVD compared to the group with intakes of less than 1½ servings per week. Women who ate more than 10 servings per week had an even more pronounced reduction in risk (65%) for specific CVD outcomes such as heart attack or stroke.
While not statistically significant, the strongest association of dietary lycopene with CVD protection was seen among those participants with a median dietary lycopene intake of 20.2 mg/day, who had a 33% reduction in risk of the disease when compared with women with the lowest dietary lycopene intake (3.3 mg/ day). The findings suggest that dietary lycopene or other phytochemicals consumed as oil-based tomato products confer cardiovascular benefits.
In addition to carotenoids and antioxidants, omega-3 fatty acids are also important for women. The American Heart Association (AHA) recommends, for people who have elevated triglycerides, 2-4 g of eicosapentaenoic and docosa-hexaenoic acids (EPA and DHA) per day provided as a supplement. In addition, AHA says that healthy people should eat omega-3 fatty acids from fish and plant sources to protect their hearts.
Omega-3 fatty acids make the blood less likely to form clots that cause heart attack, and they protect against irregular heartbeats that cause sudden cardiac death, said a report in the November 2002 issue of Circulation (Kris-Etherton et al., 2002). The mechanisms responsible for omega-3 fatty acids’ reduction of CVD risk are still being studied, and include decreases in triglyceride levels and blood clots, lower risk of sudden death, improved arterial health, and lower blood pressure.
--- PAGE BREAK ---
Cancer is the second leading killer of American women. Since 1987, lung cancer has been the leading cause of cancer death among women in the U.S. At present, breast cancer is the second leading type of cancer killer of American women, followed by colorectal cancer.
• Breast cancer. More than 212, 600 new cases of breast cancer will be diagnosed in the U.S. in 2003, according to the American Cancer Society. At the 94th Annual Meeting of the American Association for Cancer Research, information was presented on how increasing levels of the amino acid cysteine may be able to reduce the risk of breast cancer. Cysteine is a precursor to glutathione, an antioxidant.
Lead investigator, Shumin Zhang of Brigham and Women’s Hospital, Harvard Medical School, and Harvard School of Public Health said, “The findings suggest that higher levels of total cysteine may predict a reduced risk for breast cancer. Based on these results, we are hopeful that cysteine or its precursors may have potential chemopreventive benefits against breast cancer.”
The study was conducted among 32,826 women in the Nurses’ Health Study, started in 1976 at Brigham and Women’s Hospital. A total of 712 incidents of breast cancer were matched to 712 controls by year of birth, time of day that the blood was drawn, fasting status, month of blood sampling, recent use of postmenopausal hormones at the time of blood collection, and menopausal status. Scientists used conditional logistic regression with adjustment for other breast cancer risk factors to estimate the relative risks for breast cancer by levels of plasma total cysteine.
Women in the group with highest levels of plasma cysteine had a 56% reduction in risk of developing breast cancer as compared with those in the lowest level group. The association was not significantly altered by any other major risk factors related to breast cancer, except that a stronger association was observed among leaner women.
A separate study showed that women who eat soy-rich diets have less “high risk” dense breast tissue and a reduced risk for developing breast cancer. Soy has long been thought to play a role in preventing breast cancer.
Researchers from Cancer Research UK, the National University of Singapore, and the U.S. National Cancer Institute looked at the results from two studies carried out in Singapore. The first looked at the women’s diet; the second used mammograms to assess the density of their breast tissue. It has previously been shown that dense tissue is associated with an increased risk of breast cancer. Four hundred and six women took part in both studies.
--- PAGE BREAK ---
The women who ate the most soy were 60% less likely to have the “high risk” breast tissue than women who had the least soy in their diet. The benefit could come from soy isoflavones, which mimic the action of the female sex hormone estrogen. Being exposed to the plant estrogens appears to lengthen a woman’s menstrual cycle. Previous studies have indicated that the fewer menstrual cycles a woman has in her life, the lower her risk of breast cancer.
Stephen Duffy of the Cancer Research UK’s Mathematics, Statistics and Epidemiology Dept. in London said, “There has always been a question mark over a connection between soy and breast cancer—some studies have suggested a link but others haven’t. This research shows for the first time how the amount of soy a woman eats may have an effect on breast tissue and in turn may potentially reduce her risk of breast cancer.”
In addition to soy, flaxseed has also been linked to breast health. Ongoing research by Paul Goss, director of the Breast Cancer Research Program at Princess Margaret Hospital in Toronto and professor of medicine at University of Toronto, has found that flaxseed oil shows the ability to reduce tumor growth. “We have shown a direct effect on human tumor cells from a dietary component. All the evidence is that eating flaxseed in your diet is a healthy thing to do. It is likely to be preventive of breast cancer,” said Goss.
Several substances in flaxseed are thought to contribute to its health benefits. Lignans are phytoestrogens, which may play a role in preventing cancers of the breast, endometrium, and prostate. Insoluble and soluble fibers in flaxseed are believed to help lower cholesterol, regulate blood sugar levels, aid in digestion, and prevent constipation. Flaxseed also contains alpha-linolenic acid, which is an omega-3 fatty acid.
• Endometrial cancer. Isoflavones, along with lignans, have also been linked to a reduced risk of endometrial cancer, the fifth most common cancer among women worldwide. The development of endometrial cancer is related to prolonged exposure to estrogens without cyclic exposure to progesterone. Phytoestrogens can remedy this balance and appear to reduce the risk of the cancer, which causes between 4,000–5,000 deaths in the U.S. each year, researchers reported (Horn-Ross et al., 2003). Pamela L. Horn-Ross and colleagues from the Northern California Cancer Center in Union City, evaluated the associations between dietary intake of seven specific compounds representing three classes of phytoestrogens (isoflavones, coumestans, and lignans) and the risk of endometrial cancer in a study of women aged 35–79 in the San Francisco area.
Consumption of isoflavones and lignans, but not coumestans, was associated with a reduced risk of endometrial cancer, particularly among postmenopausal women. Obese postmenopausal women consuming relatively low amounts of phytoestrogens had the highest risk of endometrial cancer; however, the interaction between obesity and phytoestrogen intake was not statistically significant.
“Some phytoestrogenic compounds, at the levels consumed in the typical American-style diet, are associated with reduced risk of endometrial cancer,” said the authors.
--- PAGE BREAK ---
According to the North American Menopause Society, menopause in the Western world occurs at an average age of 51.4 years. Today, most women spend about one-third of their lives post-menopause. In the year 2000, there were an estimated 42.19 million U.S. women over age 50. By the year 2020, the number of U.S. women over 55 is expected to be 45.9 million.
Hot flashes and vaginal dryness are the two most common menopausal symptoms in the U.S. Women in Western countries have an approximately 80% incidence of hot flashes. Hormone replacement therapy (HRT) is the most common treatment for menopausal symptoms. However, alternative treatments are being sought due to health risks associated with HRT. Dietary supplements containing isoflavones, from either soy or red clover, are used as alternatives to HRT, but studies on their effectiveness have been conflicting. For example, a red clover supplement was found to be no more effective than a placebo for relieving hot flashes in a study published in the Journal of the American Medical Association (Tice et al., 2003).
In light of conflicting reports, a one-year study is currently taking place at the University of Illinois Chicago (UIC). Researchers will investigate the effectiveness of the herbals black cohosh and red clover for the relief of menopause symptoms.
Stacie Geller, assistant professor of obstetrics and gynecology and director of the UIC National Center of Excellence in Women’s Health, said, “This study is designed to see whether botanicals can take the place of HRT, which is still the gold standard for the short-term relief of hot flashes, or at least provide enough relief to improve women’s quality of life. We’ll also examine whether black cohosh and red clover help reduce a wide range of other symptoms associated with menopause, including sleep and mood disturbances and sexual dysfunction.”
More than 100 healthy menopausal women have been recruited to participate in the study. They will be randomly assigned to one of four groups taking black cohosh, red clover, Prempro (a combined estrogen and progestin hormone replacement drug) or a placebo. Health effects will be monitored over 14 clinic visits.
The researchers will look for a reduction in frequency and intensity of hot flashes or other menopausal symptoms, including insomnia, joint pain, and fatigue. They will also examine whether the botanicals help treat sexual problems associated with menopause. Lipid levels, bone turnover, and effects on the endometrial tissue in the uterus will be monitored, as well as any longer-term effects and possible risks associated with use of the botanicals. The study is funded by the National Center for Complementary and Alternative Medicine at the National Institutes of Health.
--- PAGE BREAK ---
Osteoporosis is characterized by the thinning and increasing brittleness of bones, a condition that can lead to bone fracture. It afflicts more than 25 million Americans, 80% of whom are women. More than half of all women over age 65 suffer from this condition.
Each year, osteoporosis causes 1.5 million fractures of the hip, wrist, vertebrae, and other bones. Twenty percent of the women who suffer a hip fracture die within one year of that event.
Low calcium intake can lead to bone fractures and osteoporosis. Calcium is necessary for healthy bones, teeth, muscle contractions and other body functions. Daily calcium needs for an adult woman are approximately 1,000 mg. After menopause the need increases to 1,500 mg.
Many women start taking calcium supplements during menopause, but calcium deficiency increasingly is being seen in younger women, according to information from Mayo Clinic. Women who aren’t getting enough calcium in their diets should take a supplement, regardless of their age. But at any age, calcium benefits a woman’s bones as well as muscles and nerves.
In addition to calcium, vitamin D plays an essential role in bone health. It promotes the absorption of calcium and phosphorus and helps deposit these minerals in bones and teeth, making them stronger. Low consumption of vitamin D may lead to softening of the bones. Vitamin D needs are approximately 10 micrograms per day.
More than 80% of all American women have had a child by the age of 45, and the average woman has 2.2 children. The National Academy of Sciences recommends that all women capable of becoming pregnant consume 400 micrograms of folic acid from fortified foods and/or supplements daily.
Despite the fact that folic acid can prevent spina bifida and other birth defects in babies, many American women of childbearing age fail to take daily doses of it. Simple forgetfulness is one of the main reasons, said a March of Dimes annual survey released this past September. Even though folic acid’s role in a healthy pregnancy may seem common knowledge, the survey found that almost 70% of American women of childbearing age fail to take the B vitamin every day, even though many of them are aware it helps prevent birth defects. The national telephone survey of 2,006 women aged 18–45 found that 32% take a daily multivitamin containing folic acid, an increase of 4% since 1995. When the other women in the survey were asked why they didn’t take folic acid daily, 24% said they forgot, 22% had no particular reason, 16% said they felt they didn’t need to, 9% said they ate a balanced diet, 4% said they don’t like taking pills, and another 4% said vitamins cost too much.
--- PAGE BREAK ---
The survey also found that one-third of the women interviewed who have seen television public service ads about folic acid believed the ads are for women who are trying to get pregnant or are for women in a different age group than theirs.
“It appears that many women are still in denial about their need for folic acid. About 50% of pregnancies in the U.S. are unplanned, so it’s important for every woman capable of having a baby to take a multivitamin with folic acid daily, even if she’s not thinking about having a baby,” said Jennifer L. Howse, March of Dimes president. “While rates of spina bifida and other neural tube defects have been decreasing, the rate can drop lower still with daily folic acid intake,” she said.
In response to her mother’s quest for a natural way to manage menopausal symptoms, Tori Stuart, president of Zoe Foods, Westwood, Mass., created the company’s first products, cereal and bars that contained both soy and flaxseed at the top of their ingredient lists. Since its first sales in January 2000, Zoe Foods has expanded its distribution to more than 1,200 natural food stores, including Whole Foods Markets and supermarkets with natural food sections.
According to the company, flaxseed and soy contain phytoestrogens. It is believed that phytoestrogens balance a woman’s estrogen level by attaching themselves to the body’s estrogen receptor sites. When attached, phytoestrogens can decrease estrogen levels in perimenopausal women and increase estrogen levels in postmenopausal women.
In addition, the company’s Web site cites an article in the November 1999 Tufts University Health & Nutrition Letter, where it states, “Today’s studies focus on foods containing phytoestrogens. The notion is that phytoestrogens may relieve symptoms of perimenopause and reduce the risk of heart disease and osteoporosis with fewer adverse effects than hormone replacement therapy. In other words, we may be able to eat our way through menopause rather than medicating ourselves against it.”
Zoe Flax & Soy Bars come in four flavors: chocolate, peanut butter, apple crisp, and lemon. The chocolate bar contains 4.5 g soy protein, 5 g fiber, 1,500 mg omega-3 fatty acids, approximately 1 tablespoon ground flaxseed, and 14 mg soy isoflavones. Zoe Flax & Soy Granola Cereal comes in three varieties: cranberries currants, almonds oats, and apple cinnamon. The apple cinnamon cereal contains 5 g soy protein, 6 g fiber, 2,400 mg omega-3 fatty acids, 1 tablespoon ground flaxseed, and 15 mg soy isoflavones.
by LINDA MILO OHR
Horn-Ross, P.L, John, E.M., Canchola, A.J., Stewart, S.L., and Lee, M.M. 2003. Phytoestrogen intake and endometrial cancer risk. J. Natl. Cancer Inst. 95: 1158-1164.
Kris-Etherton, P.M., Harris, W.S., and Appel, L.J. 2002. Fish consumption, fish oil, omega-3 fatty acids, and cardiovascular disease. Circulation: Journal of the American Heart Association 106: 2747-2757.
Osganian, S.K., Stampfer, M.J., Rimm, E., Spiegelman, D., Manson, J.E., and Willett, W.C. 2003. Dietary carotenoids and risk of coronary artery disease in women. American Journal of Clinical Nutrition. 77:1390-1399.
Sesso, H.D., Liu, S., Gaziano, J.M., and Buring, J.E. 2003. Dietary lycopene, tomato-based food products and cardiovascular disease in women. J Nutr. Jul; 133(7): 2336-41.
Tice, J.A., Ettinger, B., Ensrud, K., Wallace, R., Blackwell, T., and Cummings, S.R. 2003. Phytoestrogen supplements for the treatment of hot flashes: the isoflavone clover extract (ICE) study: a randomized controlled trial. JAMA. 290(2): 207-14.
Zern, T.L., West, K.L., and Fernandez, M.L. 2003. Grape polyphenols decrease plasma triglycerides and cholesterol accumulation in the aorta of ovariectomized guinea pigs. J. Nutr. 133(7): 2268-72.