There’s little argument for sugar as a health food, but there’s a lot more to the story. Despite a common sugar and cancer myth, there’s relatively little evidence that sugar causes cancer. While not a recommended part of a healthy diet, there’s almost no evidence showing that cancer patients who eat sugar have worse outcomes during treatment.
Where did the supposed link between sugar and cancer get started?
Does Sugar Feed Cancer? It’s Complicated.
The myth of sugar feeding cancer, or accelerating cancer cell growth and proliferation, likely started in the lab. Physicians use a radioactive tracer during PET scans, or positron emission tomography. These tracers typically use a glucose base. All cells that absorb the solution, including cancer cells, swell up. This may have caused the misconception that glucose, the root form of sugar, exacerbates cancer cell growth.
Glucose has not been shown to increase normal or abnormal cell growth, but that doesn’t mean sugar is off the hook.
What is Sugar?
To understand the real risk of sugar, we need to look at it from a biological perspective. Sugar is a blanket term for multiple forms of a molecule. In its most elemental form, sugar is a single molecule of glucose or fructose. Table sugar is actually a form of sucrose, which is a combination of both glucose and fructose.
Sugar is also found naturally in many foods, including in more complex configurations calls polysaccharides. They may not taste as sweet, but the carbohydrates in bread, rice, pasta, vegetables and other foods are, in large part, based on these complex sugar-based molecules. Carbohydrates are the most readily-accessible forms of energy in the human diet and are a critical component of healthy cell function.
Diets low in carbohydrates still use glucose to function. When forced, cells can turn protein and fat into glucose, but it’s energy-intensive and inefficient.
A Crash Couse in Misconception
Cancer cells’ deadly and fascinating biological trick is to grow quickly. This requires an exceptional amount of energy. It would make sense that glucose, the most accessible form of energy, would accelerate cancer cell growth and proliferation. Unfortunately, that’s an oversimplification.
All cells need glucose. Even if we were able to completely eliminate sugar in our diets, our cells would still make glucose out of other nutrients.
Today, there is no evidence that eating a low or sugar-free diet lowers the risk of developing cancer. Nor is there evidence that sugar-free diets have any impact on the health outcomes of cancer patients.
The Indirect Link Between Cancer and Sugar
Instead, sugar’s impact on cancer and overall health is based on other factors. Diets high in sugar have been linked to an increased risk of diabetes, obesity, high blood pressure and other lifestyle diseases.
Instead of accelerating cell growth, sugar, like diets high in fat and cholesterol, accelerate the growth of our waistlines. Sedentary lifestyles, increased screen time and barriers to healthcare access exacerbate these risks.
Does Sugar Cause Cancer? Not Directly
Like many other health risks, diets high in sugar play a role in causing negative health outcomes and lowering quality of life. However, there is no direct link between sugar and cancer. Still, we know that eating balanced diets with sparing use of sugar can lower cancer risk.