Does Eating Sugar Increase the Risk of Breast Cancer?

“Sugar in Western diets increases risk for breast cancer tumors and metastasis,” announced a news release from the University of Texas MD Anderson Cancer Center about a new study its researchers published on the first day of this year.

It didn’t take long before the news media picked up this scary story.

“Sugar Intake May Increase Risk For Breast Cancer,” warned the CBS television station in Philadelphia.

Even the financial website Motley Fool couldn’t resist: “This Common Dietary Ingredient May Increase Breast Cancer and Lung Metastasis Risk,” it advised its readers.

“Sugar gave my family cancer,” claimed the ex-wife of a Rolling Stone guitarist when the story hit the British tabloids.SugarandCancer

The findings “support studies that suggest people who consume more sugar have a higher risk of cancer—especially breast cancer,” explained NBC News. “Tests in mice show a possible mechanism for how it happens.”

Only one problem: Sugar or sugary drinks do boost the risk of obesity, heart disease, and type 2 diabetes, but breast cancer?  Not so far.

“There isn’t much evidence in people that sugar increases the risk of breast cancer,” says Walter Willett, chair of the nutrition department at the Harvard T.H. Chan School of Public Health and one of the nation’s foremost authorities on the role of diet in disease.

But the new study’s authors also claim that sugar increases the spread of cancer, not just the risk of getting breast cancer in the first place.

“These findings help explain what other re­searchers have seen looking at cancer patients in general: Those who eat more sugary foods are more likely to have advanced cancer,” according to NBC.


“We have very little data on whether some foods or diets may make cancer more likely to spread,” says Willett.

But the lead researcher behind the new study is undaunted.

“A lot of patients are told it doesn’t matter what you eat after you are diagnosed with cancer,” MD Anderson’s  Lorenzo Co­hen told NBC News. “This preliminary animal research suggests that it does matter.”

Oh, OK. This was only a “preliminary” animal study and it merely suggested a problem?  Did viewers of NBC and CBS, readers of dozens of newspapers and websites around the world, and the Rolling Stone ex-wife catch that important qualification? Probably not.

Note: The mouse study was funded in part by Leighton Steward, co-author of the Sugar Busters books that were published 14 years ago. Steward, a former oil industry executive, is chairman of two non-profit organizations that advocate increasing, not decreasing, carbon dioxide levels in the atmosphere.


Study: A Sucrose-Enriched Diet Promotes Tumorigenesis in Mammary Gland in Part through the 12-Lipoxygenase Pathway.  Cancer Res. 2016 Jan 1;76(1):24-9. doi: 10.1158/0008-5472.CAN-14-3432.

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5 Replies to “Does Eating Sugar Increase the Risk of Breast Cancer?”

  1. I know that my sister who is now a survivor of bilateral breast cancer had a diet of 80% sugar, chocolate, dairy–and since cutting out ALL sugar and chocolate and dairy and eating a healthy diet of plants–fruit, nuts, vegetables, beans, and whole grains–and also exercising–walking an hour a day–she now is healthy and has lost 50 lbs. and feels full of life as opposed to her former life. Overweight is a known risk factor for cancer. Look at the foods that have sugar in them–mostly things that make you fat. Go to a plant-based diet with good fiber in your food and you don’t crave sugar any more.

  2. Preliminary, but since sugar, in most of its forms outside fruit, is nutrient-poor (that is , it has calories…and that’s about it), why bother with it? And no surprise if those starving themselves of nutrients while generously feeding cancer cells get noticeable cancers…
    On a side note, the DASH diets, DASH II with less sodium, led to current urgings for lower-sodium intake (at least in some populations), and both limited added sugars to 2, count’em, 2 teaspoons a day. Finally, haven’t read Sugar Busters, so can’t comment, but a Whole Foods Plant-Based diet remains by far the best for humans. Stay tuned.

  3. Amazing how quick this info has spread. I was recently operated for pancreatic cancer and the first thing people in my immediate circle advised was to reduce my sugar intake. However, my wife and I took upon ourselves to research the premise and could not find any facts that supported such a theory. Great to see this article that affirms our findings.

  4. Diabetes doubles the risk of pancreatic, liver and endometrial cancer. Also 20-50% increase in colon, breast and bladder cancer. Obesity and increase sugar intake are known to be correlated.

  5. Excellent article by Bonnie Liebman. Dr. Walter Willet has _always_ very sound comments regarding links between diet and disease. Some people, even in the medical field, jump too quickly to conclusions based on “preliminary” animal studies!

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