Ki-67 (or Ki67) is used as a measure of the proliferative activity of breast cancer cells. Ki-67 can often, but not always, be found on breast cancer pathology reports. High Ki-67 has been linked to unfavorable breast cancer outcomes in numerous breast cancer studies. Please see our article on Ki-67 and breast cancer for more information. Below we focus on foods that have been shown to reduce or increase proliferation of breast cancer cells in the laboratory.

Foods that have been shown to lower proliferation

The foods below have been shown to reduce breast cancer cell proliferation, as well as being on our recommended list. Among them are allium vegetables such as onions and garlic, cruciferous vegetables, fatty fish, and sources of quercetin, resveratrol or insoluble fiber.

Apples
Arctic char
Arugula
Bell peppers
Black pepper
Blackberries
Blueberries
Bok choy
Boysenberries
Broccoli & broccoli sprouts
Brussels sprouts
Buckwheat
Cabbage
Carrots
Cauliflower
Celery
Cherries

Chives
Collard greens
Cranberries
Flaxseed oil
Garlic
Grapes, red
Herring
Horseradish
Kale
Lake trout
Leeks
Mackerel
Mushrooms
Mustard
Mustard greens
Oats
Onions, all types

Parsley
Pomegranates & pomegranate juice
Rice, brown, black or purple
Raspberries
Saffron
Salmon, wild
Sardines
Scallions
Seaweed
Tomatoes
Turmeric
Turnips
Turnip greens
Walnuts & walnut oil
Watercress
Zucchini

The following foods have also been shown to reduce breast cancer cell proliferation, but there is not enough other positive evidence concerning their chemopreventive effects to put them on our recommended list:

Artichokes
Asparagus
Chocolate
Grapefruit
Holy basil

Lemons
Mangoes
Oranges
Plums
Potatoes

Rhubarb
Strawberries
Tea, black
Vinegar, red wine or brown rice
Wheat bran

Women with type 2 diabetes tend to have tumors with higher Ki-67 than non-diabetics. However, the anti-diabetes drug metformin has been shown to reduce proliferation.

Foods and supplements that have been shown to increase proliferation

The following foods and supplements have been found to increase breast cancer cell proliferation in the laboratory:

Alcohol
Genistein and daidzein
Lima beans
Molasses
Soy protein isolate
Well-done or fried meat or fish
The U.S. beef, veal and lamb industries use zeranol (Ralgro), a non-steroidal formulation with estrogenic activity, as a growth promoter. Zeranol has been found to stimulate human breast cancer cell growth and proliferation.

Please see our article on how to optimize your breast cancer diet for information on what to eat during all stages of treatment and recovery. Below are links to recent studies on inflammation. For a more complete list of studies, please click on the tag Ki-67.