2006

Studies in white populations indicate that dietary magnesium may reduce the risk of developing type 2 (adult onset) diabetes. We assessed this possibility in the BWHS. Based on 1,964 women who reported having been newly diagnosed with the illness during 1995-2003 and using dietary information reported by participants on the 1995 questionnaire, we found that higher levels of magnesium, low-fat dairy, and whole grains were all associated with a reduced risk of diabetes. These findings suggest that diets high in magnesium-rich foods, particularly whole grains, lower the risk of diabetes in U.S. Black women. This is important because it is possible to increase whole grain intake in the diet by simple measures, such as substituting whole grain bread for white bread or whole grain cereal for other cereals. link to online article

Physical activity may prevent some illnesses. To study whether this is so, we need accurate information on physical activity. BWHS participants in the Washington D.C. area took part in a physical activity validation study at Howard University organized by Dr. Adams-Campbell. For a week the women wore “actigraphs”, which look like watches and which measure movement. During that week the women also wrote down their activities in diaries. We compared the actigraph measures, the diary reports, and what the women reported about physical activity on the BWHS survey. Women who had the highest actigraph measures also tended to report the most activity in their diaries and the most physical activity on the BWHS survey. These results show that physical activity information given by BWHS participants on the health surveys will be useful in studies of exercise and disease. We are grateful to the women who took part in this study. link to online article

The occurrence of hypertension (high blood pressure) is 2-3 times greater in Black women than white women, and the condition increases the risk of heart disease and other serious illnesses.   Stressors, such as experiences of racial discrimination, may increase the risk of hypertension. To see if this was happening in the BWHS, we studied the experiences of racism reported by BWHS participants on the 1997 BWHS health survey in relation to the occurrence of hypertension in the following years. Overall, the occurrence of hypertension was similar in women who did and did not experience racial discrimination. However, in the foreign born women, those who reported more experiences of discrimination also developed more hypertension.  If confirmed, this finding may mean that foreign born women have a different response to experiences of racism than women born in the United States. link to online article

Some types of colorectal polyps are thought to lead to colon cancer. We investigated the effect of physical activity from walking or vigorous exercise on colon polyps in an analysis that included 1,390 cases of colon polyps reported by BWHS participants. We found that the incidence of colon polyps was reduced among women who exercised, and the reduction was greatest for women who exercised the most. These results contribute to the large body of evidence that exercise has many health benefits. link to online article

We looked at whether the economic level of the neighborhoods in which BWHS participants live affects whether they smoke. To do so, we obtained information from the U.S. Census Bureau on what percent of people in particular neighborhoods are living below the “poverty level”, as defined by the federal government. BWHS participants who lived in neighborhoods with high levels of poverty were more often smokers than women who lived in neighborhoods with lower levels of poverty. Taking into account personal factors like educational level did not change this finding. We conclude that the surroundings in which women live play a role in whether they smoke. There are many possible reasons for this. As an example, more cigarette advertising is aimed a people who live in neighborhoods with higher poverty levels. link to online article

Intake of foods with a high glycemic index or load (e.g., potatoes) was associated with a higher risk of diabetes, whereas intake of foods high in cereal fiber was associated with a lower risk.

Fibroids in the womb (uterine leiomyomata) occurred more often in BWHS participants who reported frequent experiences of racism than in women who reported fewer experiences.

Participation in vigorous physical activity was associated with a decreased occurrence of hypertension among BWHS participants. The effect of walking was much weaker.

The risk of diabetes increased with increasing consumption of sugar-sweetened soft drinks, suggesting that risk could be reduced by decreasing intake of sugared soft drinks.

BWHS participants who exercised were less likely to develop colorectal polyps than women who were inactive.  The exercise included walking and vigorous activity such as jogging.

BWHS participants who gained weight were more likely to develop colorectal polyps than women whose weight was stable. Also, carrying the overweight in the waist was associated with a higher risk of polyps than carrying it in the hips.

Researchers looked at two types of physical activity:  walking for exercise and vigorous exercise (e.g., aerobics, running swimming, and basketball).  Results showed that women who took part in vigorous exercise in high school or adulthood, but not both, had fewer symptoms of depression than women who were never active.  Women who exercised vigorously both in high school and adulthood had the fewest symptoms of depression of all.  Walking for exercise lowered the risk of depression among women who were very overweight (Body Mass Index of 30 or higher) but not among women who were less overweight or of normal weight.  The BWHS results suggest that increasing levels of physical activity may improve mental health. link to online article

Millions of women in the U.S. have used menopausal female hormone supplements.  Epidemiologic studies have found that women who use female hormone supplements have an increased risk of breast cancer.  Most of the women in those studies were white women.  We investigated the effect of female hormone use on breast cancer occurrence in the BWHS.  From 1995 to 2003, 615 participants were diagnosed with breast cancer.  The incidence of breast cancer was 58% greater in women who used female hormone supplements for 10 or more years and were still using them than among nonusers.  The increases in breast cancer risk appeared to be greater for women who had taken estrogen with progesterone than for women who took estrogen alone, and the increases were more apparent in thinner women than in heavier women.  These data strengthen the evidence that use of female hormones increases the risk of breast cancer.  Current recommendations are that women who use female hormone supplements for the relief of menopausal symptoms should do so for the shortest time possible. link to online article

Many studies of white women have found that women who are overweight at age 18 have a lower risk of breast cancer before menopause compared to thinner women. The studies also show that women who are overweight after the menopause have a higher risk of breast cancer compared to thinner postmenopausal women. Preliminary results in the BWHS show that women who were overweight at age 18 have a lower risk of breast cancer later in life, whether before or after the menopause. Overweight after the menopause was not related to an increased risk of breast cancer.

Pap smears are a screening tool for the early detection of cervical cancer. We studied whether neighborhood socioeconomic factors influence whether women in the BWHS go for Pap smear screening. We found that women who lived in neighborhoods with high levels of poverty were less likely to go for screening than women who lived in wealthier neighborhoods. There may be barriers to Pap screening in the poorer neighborhoods, such as difficulties with obtaining medical care or transportation, that need to be addressed in order that all women have access to Pap screening. link to online article