Eating this vegetable twice a week may cut breast cancer risk nearly in half

A new viral TikTok from Sarah Ballantyne, PhD, is reigniting interest in an old—but striking—study: Eating just 11 servings of broccoli a month may reduce the risk of breast cancer by as much as 40%. ^[]

Dr. Ballantyne highlights findings from a 2004 study showing that premenopausal women who ate 11 or more servings of broccoli monthly had significantly lower breast cancer risk than those who ate 3 or fewer servings. That’s less than a serving every third day.

While it’s not exactly a new recommendation to “eat your vegetables,” this one comes with an eye-popping number—and a reminder about the power of cruciferous vegetables.

What’s in broccoli that may fight cancer?

Broccoli and other cruciferous vegetables (Brussels sprouts, kale, cauliflower, cabbage, arugula, etc.) are rich in glucosinolates. ^[]

It’s not just about broccoli, Dr. Ballantyne noted. "The cancer preventive compounds found in broccoli are actually found in all members of the cruciferous vegetable family. Think: Brussels sprouts, kale, cauliflower, cabbage, radishes, turnip, rutabaga, bok choy, and arugula," she said.

What doctors should consider

The study Dr. Ballantyne cites was observational and focused on postmenopausal women, so it doesn’t prove causality—but the data point is compelling.

Patients already motivated by family history or personal risk may appreciate simple, achievable goals—like adding a few servings of cruciferous vegetables per week.

This may also be an opportunity to reinforce broader dietary patterns associated with reduced cancer risk (plant-forward, high fiber, low processed food intake, etc.).

The bottom line for your patients

Eleven servings of broccoli a month won’t replace screening, risk assessments, or genetics—but for patients looking to take proactive dietary steps, it’s an easy message: Just one extra helping of broccoli (or its cruciferous cousins) every couple of days might help protect against breast cancer.