Study: Sugar promotes tumor growth and metastasis in mouse model breast cancer
|At a glance||Questions for your doctor|
This study is about:
How sugar may drive breast tumor growth and metastasis in a mouse model of breast cancer.
Why is this study important?
This is an early step in understanding how high sugar intake might affect breast cancer growth and development.
- Sucrose (table sugar) intake increased tumor growth and metastasis in a mouse model of breast cancer.
What does this mean for me?
This study was done in a mouse model of breast cancer. Researchers expected that about half of the mice would develop breast cancer in the course of the experiment. While these types of early laboratory studies in mice are important for scientists trying to understand how cancer develops and spreads, they are not directly applicable to humans. It is important to remember that while the researchers tried to match the sugar levels the mice received to those found in Westernized diets, the rest of the mouse diet was not comparable to an average person’s diet.
The dangers of consuming excessive amounts of sugar are well established—the American Heart Association recommends that men and women consume no more than 37.5g and 25g of sugar, respectively. While this study does not conclusively show that sugar should be avoided or that excess sugar causes breast cancer to occur or spread, the overall health benefits of limiting sugar intake remain undisputed.
Jiang Y, Pan Y, Rhea PR, et al. “A Sucrose-Enriched Diet Promotes Tumorigenesis in Mammary Gland in Part Through the 12-Lipoxygenase Pathway.” Cancer Research (2016); 76(1): p. 24-28.
Miller PE, McKinnon RA, Krebs-Smith SM, et al. “Sugar-sweetened beverage consumption in the U.S.: novel assessment methodology.” American Journal of Preventive Medicine (2013); 45: p. 416–21.
Nutrition for people diagnosed with cancer
The National Comprehensive Cancer Network (NCCN) recommends the following for cancer survivors:
- Think about your food choices and amount of fruits, vegetables and unrefined grains you eat compared with red and processed meats, alcohol, and foods or drinks with added fat or sugar.
- Think about your eating habits, including portion size, snacking, how often you eat out and use of added fats or sugars.
- All survivors should be encouraged to:
- Make informed choices about food to ensure variety and adequate nutrient intake.
- Limit refined sugars.
- Eat a diet that is at least 50% plant-based, consisting mostly of vegetables, fruit and whole grains.
- Track calorie intake; monitoring of calories is an effective way to manage weight.
- Minimize alcohol intake to no more than one drink per day for a woman and two drinks per day for a man.
- For patients desiring further dietary guidelines, the USDA approximate food plate volumes are:
- Vegetables and fruits should comprise half the volume of food on the plate
- Vegetables: 30% of plate; Fruits 20% of plate
- Whole grains: 30% of plate
- Protein: 20% of plate
- Recommended sources of nutrients:
- Fat: plant sources such as olive or canola oil, avocados, seeds and nuts, and fatty fish.
- Carbohydrates: fruits, vegetables, whole grains and legumes.
- Protein: poultry, fish, legumes, low-fat dairy foods, and nuts.
The Academy of Nutrition and Dietetics, the United States Office of Disease Prevention and Health Promotion and the American Institute for Cancer Research also publish expert guidelines on nutrition and health.
- I've have had breast cancer, what type of diet is best for me?
- I've had breast cancer, are there any foods I should avoid?
- How can I lower my breast cancer risk?
- How can I better control sugar in my diet?
- Can you refer me to a nutritionist?
The following are studies focused on nutrition for people diagnosed with breast cancer.
- NCT04000880: AMPLIFY: An Online Weight Loss Study Specifically for Cancer Survivors. AMPLIFY is a nation-wide, web-based diet and exercise study recruiting overweight survivors of early stage breast, prostate, ovarian, renal, colorectal, endometrial cancer and multiple myeloma age 50 and older who are interested in becoming more active, eating better and losing weight.
- NCT04298086: A Study of the Body's Response to Exercise and a Plant-Based Diet in Overweight Postmenopausal Women With Breast Cancer. This study is looking to find out what effects exercise and a plant-based diet have on aromatase levels in postmenopausal women who are overweight and being treated with an aromatase inhibitor for their HR+ breast cancer.
- NCT04365569 Evaluating the Effectiveness of an Individualized Nutrition and Physical Activity Counseling Program. This pilot study looks at whether a tailored in-person and telephone-based nutrition and exercise counseling program can help breast cancer patients improve weight and fitness and thus improve cancer outcomes.
You can find a registered dietician in your area using the search tool from the Academy of Nutrition and Dietetics.
Who covered this study?
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Sugar increases risk and spread of breast cancer This article rates 2.5 out of 5 stars
Sugar may increase breast, lung cancer risk, study finds This article rates 2.0 out of 5 stars
Sugar in fizzy drinks and junk food increases chances of breast cancer and its spread to other organs, scientists claim This article rates 2.0 out of 5 stars
IN DEPTH REVIEW OF RESEARCH
Previous studies in humans have found associations between high sugar intake and breast cancer risk, including a recent study that found that increased consumption of sugar-sweetened beverages is a contributor to worldwide obesity, heart disease, and cancer. However, no study has directly studied whether a high-sugar diet can cause breast cancer to grow and/or affect breast cancer metastasis.
In January 2016, Yan Jiang and colleagues at the University of Texas MD Anderson Cancer Center published a paper in the journal Cancer Research looked at breast cancer development, growth, and metastasis in mice with various amounts of table sugar in their diets. This is the first study to look at a direct effect of consuming sugar and breast cancer development using mouse models of breast cancer.
Researchers of this study wanted to know:
Whether sugar consumption led to breast tumor growth and metastasis in mouse models of breast cancer.
Population(s) looked at in the study:
This study used two well-established mouse models of breast cancer. The first is a model in which 50% of the mice are known to develop tumors after six months under normal conditions. The second is a model in which breast cancer metastasizes to the mouse lung.
Compared to mice than did not consume sugar, mice that did consume sugar:
- developed more tumors.
- had a higher number of lung metastases.
- had significant quantities of a protein known as 12-LOX—which provides a clue to cellular changes that might have caused tumors to grow in response to sugar.
While this is the first study to look directly at the effect of sugar on tumor growth, more work is needed to determine whether the same effect occurs in humans. It is important to note that close to half of the mice in the study would have developed tumors after six months regardless of the amount of sugar they ate. While they were fed an amount of sugar that is equivalent to a Westernized diet, other nutrients in their diet were not the same as in a Westernized human diet.
This study suggests that sugar may play a role in breast tumor growth and metastasis. It does not, however, implicate sugar or a particular amount of sugar as a cause of breast cancer. It is important to remember that this is early research in mice and more work needs to be done to understand this effect in humans. Although limiting sugar consumption is recommended for overall health, the data from this study does not provide enough evidence for people to stop consuming sugar entirely to reduce their risk of breast cancer development, growth, or metastasis.
Aside from the results of this study, everybody should limit sugar consumption, as recommended by the American Heart Association; your own personal or family health history may dictate that you follow more specific health guidelines. If you are concerned with how your diet affects your cancer or cancer risk, please discuss your options with your health care provider.