Is there a link between sugar and cancer?

Is there a link between sugar and cancer?

Can eating too much sugar put you at risk for cancer growth and recurrence? While research has not definitively proven that high sugar intake increases the risk of cancer, several studies have suggested a connection. However, studies have linked high sugar intake to weight gain and metabolic syndrome, which includes obesity. Studies have also shown that obesity is a risk factor for cancer.

What does this mean for your diet? We talked to Shayna Komar, LD, RD, a licensed and registered dietitian at Thomas F. Chapman Family Cancer Wellness at Piedmont, to learn more.  

The case for cutting back on sugar

Although science has not proven that sugar directly leads to cancer, we do know eating too much sugar can lead to inflammation and obesity, two potential cancer-causing triggers.

Sugar and inflammation

"When you eat too much refined sugar, it causes chronic low-grade inflammation in your body and inflammation has been linked to cancer," says Komar.

Sugar and obesity 

While it adds flavor to the foods we eat, refined sugar has no nutritional value. Even worse, it can set you up for cravings and overeating later. When you eat more calories than you should, weight gain is inevitable.

"Too much sugar can overload the liver and trick your body into eating more because it turns off leptin, the satiety hormone that helps you feel full," explains Komar. "You keep wanting more food, which is why you can end up eating the whole sleeve of cookies."  

How much sugar is too much?

"Our bodies can metabolize about 6 teaspoons of added (also known as refined or processed) sugar per day without a problem," she says. "However, the average American eats three times this amount of extra sugar. The majority of excess sugar is then stored as fat."

Recent guidelines by the U.S. Department of Health and Human Services and the Department of Agriculture recommend limiting added sugar to 10 percent or less of your daily caloric intake. The American Heart Association recommends even less: fewer than 9 teaspoons per day for men and less than 6 teaspoons per day for women.

What is added sugar?

All sugar is not created equal.

"When we talk about limiting sugar, we are talking about processed and refined foods with sugar, not fruit or milk, which contain naturally occurring sugar," says Komar.


Common sources of added sugar include:

  • Baked goods (cake, cookies, pie, etc.)

  • Ice cream

  • Sweetened beverages (soda, juice, sports drinks, sweetened tea)

  • Frozen meals

  • Condiments like ketchup, barbecue sauce and salad dressing

  • Flavored yogurt

  • Tomato sauce

  • Granola or protein bars

  • Cereal

  • Canned fruits

While fresh and frozen fruit contains sugar naturally, Komar still recommends limiting how much you eat.

"I recommend a ratio of three servings of veggies to one serving of fruit per day," she says.

How to cut back on sugar

  • Limit your intake of processed foods, even those that do not taste sweet - they may contain more sugar than you realize

  • Stick to unsweetened beverages, such as water, unsweetened tea or unsweetened coffee

  • Read nutrition labels for sugar content

While it may take some practice, limiting your intake of added sugars may help reduce your risk of cancer as well as diabetes, weight gain and heart disease.


Obesity is a risk factor for cancer

U.S. Dietary Guidelines

BMI and Sugar Intake

Potential Role of Sugar in Epidemic of Obesity

Intake of Sugar-Sweetened Beverages and Weight Gain

Effects of Soft Drink Consumptions on Nutrition and Health


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