2009

Fruits and vegetables are sources of many nutrients that may help protect against cancer.  Results based on 1,268 new cases of breast cancer show that eating at least 2 vegetables per day was associated with significantly lower risk of hormone receptor-negative breast cancer compared with consumption of fewer than 4 vegetables per week.  We also found evidence suggesting that certain types of vegetables, particularly cruciferous vegetables and carrots, are associated with lower risk of all types of breast cancer.

We obtained information on the “urban form” (for example, amount of sidewalks, distance to public transportation) of neighborhoods of BWHS participants living in New York City, Chicago, and Los Angeles during 1995-2001 and studied whether urban form was related to the amount of walking (to work, shopping, and church) reported by these women. The neighborhood characteristic that was most associated with walking was the “density” of the neighborhood—dense neighborhoods tend to have networks of sidewalks and to have public transportation that people can walk to. This information is important for city planners so that neighborhoods can be designed to encourage healthy activities such as walking. link to online article

In 1995, and then again in 1999, BWHS participants reported information on the occurrence of various illnesses in their parents, sisters and brothers, and daughters and sons, including family history of breast cancer. Our analyses of BWHS data found that women who had a mother, sister, or daughter with breast cancer were almost two times as likely to develop breast cancer as women who had no relatives with breast cancer. The National Cancer Institute recommends a mammogram every year or two starting at age 40 and suggests that women with a family history of breast cancer consult with their doctors about earlier or more frequent screening. link to online article

It has been suggested that “relative” income (a person’s income compared to that of similar people living in the same area or neighborhood) may be a better predictor of health outcomes than the actual amount of income. We studied relative income in relation to preterm birth in the BWHS and found no clear overall associations of measures of relative income with the occurrence of preterm birth. link to online article

The LOX gene is involved in suppressing the growth of tumors. Using DNA from saliva samples provided by BWHS participants, we found that women with a particular genetic variant in the LOX gene had a higher risk of estrogen receptor-negative breast cancer than women who did not have that variant. These results suggest that reduced ability to inhibit tumor formation is involved in breast cancer development. link to online article

We studied dietary patterns in relation to breast cancer risk using information on food intake that BWHS participants reported in 1995 and 2001, and breast cancer occurrences between 1995 and 2007. The “prudent” dietary pattern, characterized by greater intake of fruits, vegetables, fish, and whole grains, was associated with a lower risk of breast cancer, including estrogen receptor-negative breast cancer. The next step will be to determine which constituents of the prudent dietary pattern are most responsible for the reduction in risk. link to online article

To study the health effects of depression requires a valid measure of depressive symptoms. In 1999 BWHS participants completed the CES-D scale, which is twenty questions about how often the person experienced certain feelings, such as feeling fearful. Our analysis of BWHS data indicated that the scale is an appropriate measure of depressive symptoms among Black women. link to online article

In an assessment of weight change between 1997 and 2005 among BWHS participants, we found that women who reported frequent experiences of racism gained more weight than women who reported that they rarely or never experienced racism. These results suggest that experiences of racism may contribute to the occurrence of overweight and obesity among African American women. link to online article

In the BWHS, approximately 50% of participants reported having been subjected to childhood abuse. We found that a higher proportion of women who reported sexual abuse during childhood started menstruating at an early age than women who reported no abuse. There was a weak association of age at start of menstruation with physical abuse during childhood. Because the age at which a girl’s periods start is a predictor of various health outcomes later in life, an effect of childhood abuse on the age of onset is important. link to online article

Studies of white women suggest that obesity is associated with increased occurrence of new-onset asthma. We found this to be so in the BWHS as well. There were 1,068 women who reported newly-occurring asthma together with medications for asthma. The occurrence of asthma increased with as body mass index increased: the risk was 2.85 times greater among women with a body mass index of 40 than in women with a body mass index of 20-24, which is the recommended body mass index for good health. link to online article

Based on 2,928 newly-diagnosed cases of diabetes in the BWHS, we found that the incidence of the disease was reduced among women who participated in vigorous physical activity compared with inactive women, in agreement with many studies of white women. In addition, brisk walking was also associated with reduce risk of diabetes in the BWHS-this is good news because it may be possible for many women to fit brisk walking into a busy schedule. On the other hand, risk of diabetes was increased among women who spent five or more hours a day watching television, regardless of their physical activity. Women who do not wish to cut down on their TV viewing should consider limiting the snacks that often go along with TV watching. link to online article