Fibroids usually start after puberty. Most women are diagnosed with them between 18 and 50 years but some cases happen earlier than that. Older research showed that Black women were 10 percent more likely to have fibroids than white women by age 50 (80 percent versus 70 percent). But we don’t know why the numbers are different. There have been limited studies looking into the reasons for this difference.
One problem is that Black women aren’t adequately recruited into scientific research.
“Family history, environment, and age are known factors affecting fibroid growth, information on genetics is limited. And because so few Black women are included in clinical trials and those trials are sometimes performed in locations with very few women of African descent, the research,” says Dallas Dr. Yolanda Lawson, 124th President of the National Medical Association.
Over time, several factors have been linked with fibroids, but the links haven’t been strong enough to prove causation. “Many studies have tried to determine why Black people are more prone to developing fibroids, but there are no definitive answers yet. Certain genes have been correlated with fibroid growth, but studies of these genes have not included a representative sample of Black people,” according to Dr. Michelle Louie, a minimally invasive gynecologic surgeon in Phoenix, Arizona.
An older study linked fibroids in African American women to hair relaxers. In the study, published in the National Library of Medicine women who used hair relaxers were 17% more likely to have fibroids and the risk went up for every year of relaxer use. The study hasn’t been repeated in other Black populations but experts think chemicals in relaxers known as phthalates are responsible for the increased risk because they can disrupt hormone balance.
Research also found stress to influence the growth of fibroids. Women who had experienced sexual, physical, or emotional abuse as children were more likely to have fibroids. However, emotionally supportive, loving relationships could provide some protection.
Other factors linked to a higher risk are age, having a mother who had fibroids, obesity, never being pregnant, high blood pressure, vitamin D deficiency, taking hormone replacement therapy after menopause, and certain food preservatives (such as butylated hydroxytoluene commonly found in cake mixes, dehydrated potatoes, and potato chips.)
The results for smoking, drinking soybean milk, and oral contraceptives were unclear. But research showed that alcohol, particularly beer, raises fibroid risk possibly because it can increase estrogen-like compounds known as phytoestrogens in the body. Caffeine (as found in coffee) was also linked to a higher risk in younger women who drink a lot of it.
On the other hand, another older study found that eating fruits and vegetables may help reduce risk. In that study, women who ate four or more fruits per day were 10 percent less likely to have fibroids when compared to women who ate no fruits or vegetables a day. In another study, fish was also found to reduce risk compared to red meat or ham.
Exercise may help reduce risk, with studies showing that women who get more than two hours of exercise a week have lower fibroid risk, and those who exercise more than 7 hours a week have the lowest.
Pregnancy also protects against fibroids. Women who had three pregnancies were five times less likely to have fibroids than women who had never been pregnant.
Dr. Lawson also says we need more research into fibroids and their occurrence in Black women. Meanwhile, she encourages women to do what they can to lower risk by managing their weight, getting enough vitamin D, and exercising.
And for women who have fibroids, she advises them to seek medical care early. “Not all fibroids are equal. Management plans can vary based on the fibroid location, size and symptoms, age, and desire for future pregnancy. If you are diagnosed with uterine fibroids, it is very important to work with your gynecologist to determine a specific treatment plan,” Lawson said.
