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Dear Dietitian – Does sugar increase cancer risks?

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PICT Leanne McCrate Dear Dietitian
Leanne McCrate, RD, LD, CNSC

Dear Dietitian,

I enjoy a small glass of juice every morning at breakfast and was shocked to read that sugary drinks, even fruit juices, can increase the risk for cancer! Is this true?


Dear Jane,

You are wise to question just about anything referring to nutrition in the media. Many headlines are attention-getting and even shocking, so let’s take a look at the science.

The NutriNet-Santé study, was a prospective, cohort study, which included over 100,000 participants, and the results were published in theBritish Medical Journal. It found that sugary drinks, like soda pop, sports drinks, and energy drinks were associated with a greater risk of breast cancer and overall cancer. No link was found in prostate and colorectal cancer. While most studies have not found a link in natural sugar, like that found in fruit juice, and cancer risk, this one did. There was no link found between artificially sweetened beverages and cancer. (1)

It’s important to note the study was observational, and does not prove cause and effect.

What does this mean? As Angela Dowden points out, it is an important study in the context of studies pertaining to sugar and cancer risk. Most studies show little, if any, increased risk of breast cancer associated with overall sugar intake, and it is unlikely that sugar in one product would be a cancer risk but overall sugar intake is not. (2)

One aspect we have to explore is the process of weight gain and subsequent obesity in a diet that is high in sugar. Many cancers, such as endometrial, kidney, and pancreatic, are linked to obesity. Although this study adjusted for obesity, it begs the question: Is there something in the process of weight gain that initiates tumor development? More studies are needed to shed light on this area.

The US Dietary Guidelines recommend limiting added sugar to 10% of total calories. On a 

2,000- calorie diet, this translates to 12 teaspoons of sugar each day, which comes to 48 grams and 192 calories. This will be a big change for many Americans, who consume an average of 20 teaspoons of added sugar each day. Keep in mind this is added sugar and not natural sugar in food.

What does this look like on your plate? Try the following suggestions to decrease the amount of added sugar in your diet:

  • Choose one sugar-added item per day: one regular soda, one candy bar, one serving of ice cream
  • Choose fruit on somedays instead of fruit juice.
  • If eating canned fruit, select fruit in its natural juice.
  • Avoid candy and junk food as much as possible. 
  • Choose non-sugar sweetened soda pop, sports drinks, energy drinks
  • Save dessert for a once weekly treat.


  1. Chazelas, E, Srour, B,  Desmetz, E, et al. Sugary drink consumption and risk of cancer: results from NutriNet-Santé prospective cohort. BMJ 2019;366:l2408
  2. Dowden, A (2019, July 14) Do Sugary Drinks Cause Cancer? Retrieved from

Good health to you!

Dear Dietitian

Leanne McCrate, RD, LD, CNSC, aka Dear Dietitian, is an award-winning dietitian based in Missouri. Do you have a nutrition question? Email her today at