Ovarian Cancer

In the United States, ovarian cancer is the third most common cancer of the female reproductive system and the sixth most common cause of cancer death in women, according to the American Society of Cancer’s 2024 annual report.¹ Most ovarian cancers occur in women aged 50 or older. Other risk factors include genetic mutations such as the BRCA mutations, a history of breast, uterine, or colorectal cancer, Eastern European or Ashkenazi Jewish background, and endometriosis.

Ditch Dairy Products

Research shows that dairy products, specifically whole milk, may increase the risk of ovarian cancer^.2  The relationship between dairy products and ovarian cancer may be due to the breakdown of the milk sugar (lactose) into galactose, a sugar that may be toxic to ovarian cells.³ Two studies, one conducted in Sweden and one conducted among African American women, showed that consuming lactose and dairy products was positively linked to ovarian cancer.^4,5 The Iowa Women’s Health Study found that women who consumed more than one glass of milk per day had a 73% greater chance of developing ovarian cancer than women who drank less than one glass per day.⁶

One study followed women with and without cancer from the African American Cancer Epidemiology Study and monitored consumption of dairy products, lactose, calcium, and vitamin D and cancer incidence rates.⁷ Those with the highest intake of whole milk and lactose increased their risk for ovarian cancer, compared with those who consumed the least, while those who consumed the most calcium decreased their risk for cancer by 49%.

A Harvard School of Public Health analysis of 12 studies found a 19% increase in ovarian cancer for women consuming greater than 30 grams of lactose per day, the equivalent of three or more servings of dairy milk. However, when this paper looked at those consuming more than three servings of milk per day, there was no significant association with ovarian cancer.⁸ Women who consume more dairy before a diagnosis of ovarian cancer have also been found to have a higher risk of dying from their cancer.⁹

Try these healthful, plant-based sources of calcium without the added risk from dairy.

Avoid Meat and Ultra-Processed Foods

According to the European Prospective Investigation into Cancer and Nutrition research, industrial trans fats, which are found in commercially baked foods and other ultra-processed foods, and fat used for deep frying foods, were linked to an increased risk of ovarian cancer.¹⁰ Trans fats can promote inflammation and oxidative stress in the body, which are in which conditions cancer cells flourish. Total dietary fat, saturated fat, and cholesterol are also associated with an increased risk of ovarian cancer.¹¹ Saturated fat and cholesterol are largely found in animal products. Processed meat is associated with an increased risk of ovarian cancer and other hormone-related cancers, such as breast and prostate cancer.¹²

Eat Fruits, Vegetables, and Soy

A meta-analysis published in 2020 found that women who ate the most fruit and vegetables before a diagnosis of ovarian cancer had an 18% and 22% lower risk of dying, respectively.¹³ Cruciferous vegetables, such as broccoli, cabbage, and cauliflower, in particular, have been found to reduce the risk of developing ovarian cancer and to improve survival in women diagnosed with ovarian cancer.^14,15 It has been suggested that the isothiocyanates found in cruciferous vegetables have anti-cancer properties.¹⁶ Green leafy vegetables, fiber, and flavonoids found in plants have also been linked to a lower risk of ovarian cancer.¹¹

Soy foods and isoflavones (a form of phytoestrogens) are associated with a lower risk of ovarian cancer, possibly working by binding to estrogen receptors in the ovaries and thereby blocking the cancer growth-promoting effect of human estrogen.¹⁷ Women who consume the most soy foods were found to have a 48% lower risk of ovarian cancer according to a meta-analysis in the British Journal of Obstetrics and Gynecology.¹⁸ Soy is also protective against other hormonal cancers, such as breast cancer, while red and processed meat may increase the risk of ovarian cancer.¹⁹

A vegan diet may help provide the most protection. Research from the Adventist Health Study-2 found that vegan women had a 29% decreased risk for female-specific cancers including breast, ovarian, and uterine cancers, compared with nonvegetarians.²⁰