Women who said they ate two or more servings of fruit each day were less likely to be diagnosed with uterine fibroids. - Photo by AFP

Women who said they ate two or more servings of fruit each day were less likely to be diagnosed with uterine fibroids than women who barely touched fruit, a US study of more than 20,000 black women said.

Fibroids are non-cancerous growths that don't always have symptoms, but they can be painful or cause menstrual periods to be long and heavy.

They may also grow very large, in some cases causing complications with pregnancy and fertility.

The study, published in the American Journal of Clinical Nutrition, tracked women in their 30s for more than a decade to see if their fruit and vegetable consumption was tied to the chance they developed fibroids.

Black women are up to three times more likely to get fibroids, and researchers have wondered if part of that could be explained by diet.

“These data suggest a reduced risk of uterine (fibroids) among women with a greater dietary intake of fruit and preformed vitamin A,” wrote lead researcher Lauren Wise at Boston University.

The data came from the Black Women's Health Study, which starting in 1995 had participants report how often they ate a range of foods, from multiple times a day to less than once a month.

Questionnaires sent every other year also asked women about any new medical diagnoses they had been given.

Based on these reports, 29 per cent of the 23,000 participants had a new case of uterine fibroids between 1997 and 2009.

Women who said they ate at least four servings of fruits and vegetables each day were 10 per cent less likely to get fibroids than those who ate less than one daily serving.

When fruits and vegetables were analysed separately, researchers found that eating more fruit was linked to the lower risk – but the same was untrue for vegetables.

Participants who ate two or more servings of fruit daily were 11 per cent less likely to say they had developed fibroids than those who had less than two servings a week.

There was no link between how much vitamin C or E, folate or fibre women ate and their risk of fibroids, but the study suggested that getting more vitamin A from dairy products might also be associated with a lower fibroid risk. “Many women have assumed that developing fibroids and developing fibroid symptoms is something that they can't do anything about,” said Elizabeth Stewart, who studies fibroids at the Mayo Clinic but wasn't involved in the study.

“Although this doesn't prove that if you change your diet you may be able to change your risk of fibroids, it does appear that there is some association between diet and fibroids.”

Researchers at this point cannot prove that the fruit itself protected women against fibroids, but Wise said that antioxidants in fruit may reduce the risk, possibly by affecting the action of compounds such as estrogen in the body.

“Our study suggests that uterine fibroids can now be added to the list of potential health outcomes for which increased fruit and vegetable intake might be beneficial.”