Load up on your cups of tea and orange slices, ladies, because it just might prevent you from getting ovarian cancer. A massive new study spanning three decades finds the compounds in citrus fruits and tea lead to substantial reductions in lifetime risk.

A warm cup of tea or satisfying piece of fresh fruit no doubt makes us feel better, but what’s really protecting our bodies is invisible and tasteless. Both items contain hearty quantities of flavonoids, natural compounds that help protect blood vessels from leakage, prevent cells from suffering oxidative stress, and stave off inflammation in the body. Without them, the body succumbs to easy bruising and frequent colds or infection.

Their absence may also contribute to a greater risk for ovarian cancer. In the United States, the disease is the eighth most common cancer for women and fifth-deadliest, behind lung, breast, colorectal, and pancreatic cancers. Each year, about 20,000 women are diagnosed with the disease, according to data from the Centers for Disease Control and Prevention.

Hoping to understand how that number could drop, nutrition research experts from the University of East Anglia and Brigham and Women’s Hospital at Harvard Medical School looked at data that tracked just under 172,000 women over a 30-year period. The women whose diets consisted of two types of flavonoids in particular, called flavonols and flavanones, showed markedly lower rates of cancer. Two cups of black tea per day, for instance, lowered a woman’s risk by an average of 31 percent.

Flavonols are found in cruciferous vegetables like broccoli and kale, in beverages like tea and red wine, and in fruits like apples and grapes. Flavanones are most often found in citrus fruits, such as oranges, lemons, and grapefruits. Other common sources of flavonoids include berries, soybeans and legumes, and herbs like parsley and thyme, although the researchers did not set out to study these.

Both types of flavonoids are already part of many people’s diets, which makes it easy to increase their consumption, according to Professor Aedin Cassidy, from the Department of Nutrition at UEA’s Norwich Medical School. This suggests “that simple changes in food intake could have an impact on reducing ovarian cancer risk,” said Cassidy, the lead author of the study, in a statement.

The study was the first to comprehensively examine the effect of different flavonoids on ovarian cancer risk, Cassidy added. While the lifetime risks are decidedly low — ovarian cancer accounts for roughly three percent of all cancers in women — prior research has found the risks may also drop with daily aspirin use. However, evidence does exist suggesting this could come with dangerous side effects, such as increased sodium levels and risk of stroke.

In any case, your best bet is probably to maintain a balanced diet with plenty of fruits and vegetables. But you already knew that, didn’t you?

Source: Cassidy A Huang T, Rice M, Rimm E, Tworoger Shelley. Intake of dietary flavonoids and risk of epithelial ovarian cancer. The American Journal of Clinical Nutrition. 2014.