The Sugar and Breast Cancer Link: Does Sugar Really Feed Cancer?

The intersection shared by obesity, cardiovascular disease, and breast cancer is fascinating and noteworthy. Are these potentially pieces of the same puzzle?

Where we were previously inclined to view cardiovascular disease and cancer as separate entities, current interpretation is changing as connections are being revealed. What are the common threads between these conditions, and more importantly, how do we target them with helpful nutritional interventions?

Of particular interest is the precept that sugar feeds cancer. Let’s begin here.

Sugar, Obesity and Breast Cancer

Sugar doesn’t directly cause breast cancer, or any type of cancer for that matter.1 However, excess energy intake, particularly from processed sugars which contain no significant nutritional value, can cause weight gain and can lead to obesity. Obesity increases the risk of various cancers, including breast cancer.2

Therefore, it is on obesity whose back we need to place a target, not simply sugar. In fact, as part of a balanced and healthful diet, sugar is acceptable in natural forms (honey, agave, pure maple syrup, molasses, brown rice syrup, evaporated cane syrup, “Sugar in the Raw”, etc.) and when portioned appropriately. Portioning of foods and nutrients is the key here, leading us to focus on this concept not only in relation to sugar but for energy intake as well.

While we need to fill our cars with gas to run, it would be fruitless (not to mention damaging) to overfill them. The same concept applies to our bodies. This point at which we allow adequate fuel to turn into excessive intake is the exact point at which we deviate, drifting in past the gateway that leads to metabolic syndrome to become entangled in dietary patterns that do not serve us.

Metabolic Syndrome & Breast Cancer

Metabolic syndrome is “a syndrome marked by the presence of usually three or more of a group of factors (such as high blood pressure, abdominal obesity, high triglyceride levels, low HDL levels, and high fasting levels of blood sugar) that are linked to increased risk of cardiovascular disease and type 2 diabetes-also called insulin resistance syndrome”.3

If we are not engaging in vigorous physical activity, excess calories lead to excess body weight that is essentially comprised of excess fat tissue. It is this fat tissue that contributes to inflammation and sets the stage by creating a metabolic environment (the same one that is associated with metabolic syndrome) conducive for a host of conditions, including diabetes, cardiovascular disease, and cancer, to occur in.

Glucose (the form of sugar utilized by the human body) feeds every cell in the body and is especially essential for brain function. However, when carbohydrate intake (all of which turns into glucose) is in excess of what the body needs, it can lead to hyperinsulinemia (elevated insulin level in the body.) This can serve as an indirect link to skewed carbohydrate metabolism, metabolic syndrome, obesity, and an increased cancer risk.4

Sugar & The Western Diet

Additionally, the dietary pattern that most often goes hand-in-hand with increased refined sugar intake is associated with the Western so-called unhealthy diet and includes red or processed meats, refined grains, sweets, and high-fat dairy products, all of which have been associated with increased cancer risk.

Conversely, a prudent and healthy diet pattern which includes higher intake of vegetables, fruits, fish, poultry, whole grains, and low-fat dairy products has been shown to decrease cancer risk. In specific regard to breast cancer, the evidence has been less consistent, with some reports supporting the prudent dietary pattern as being inversely associated with risk of breast cancer while others found no association. However, dietary fat, alcohol, and processed and red meat intakes have more consistently been attributed to an increased risk of breast cancer.5

Furthermore (and in my opinion, most importantly), when consuming sugar and empty calories takes the place of more nutritious and cancer-fighting foods, we deprive ourselves of the opportunity to optimize our bodies and change the scenery that is developing or already in place.

Therefore, instead of focusing on what feeds cancer, let’s invert our lens to view what enhances an internal environment supportive to health.

What We Can Do

Knowing what our own risk factors are is essential, as, when we do, we can work toward choosing risk reducers that take on new meaning because they are personal.

And this is empowering.

So, what should we remove?

  • Processed meats (salami, bologna, hot dog, etc.)
  • Red meat (excessive portions from non-organic sources)
  • Refined grains (white flours)
  • Refined sugar (white sugars)
  • Refined oils (hydrogenated oils and trans-fats)
  • High-fat dairy products (frequent consumption of large portions)

What should we limit (or consider removing altogether, depending on our own lipid panels)?

  • Red meat (small to moderate portions, lean cuts, organic sources)
  • High-fat dairy products (moderate consumption of small to moderate portions, organic sources)
  • Saturated fats (refer to Nutrition Facts label on products)
  • Alcohol (defer to your healthcare team for specific instructions for you)

And, what should we include?

General Cancer Nutrition Guidelines

  • Moderate meals that include lean protein, whole grain carbohydrate, and healthy fat to achieve and maintain balanced blood glucose levels
  • MyPlate method for meal structure
  • Plant-based diet that includes a rainbow of phytochemicals (plant compounds) that optimize our bodies in fighting cancer—choose as many colors as possible daily6

Lastly, physical activity is recommended as appropriate per the ability of an individual. And don’t forget adequate hydration from water and other non-caffeinated sources as the power of hydration is often underestimated! Remember that our bodies are largely comprised of water and need adequate hydration to function properly and optimally.

In total, this inverted lens that moves the focus off of sugar as a culprit and onto a whole food-based diet in combination with physical activity is the key to personal empowerment and breast health.


  1. American Cancer Society
  2. National Cancer Institute
  3. Merriam Webster
  4. Oncology Nutrition
  5. American Heart Association
  6. American Institute for Cancer Research