The sugar supplement that slowed tumor growth

More than 90 years ago, the Nobel Prize-winning physiologist and biochemist Otto Warburg made several astounding discoveries about cancer, including this one:

Cancer cells are fueled by sugar.

Normal, healthy cells create energy from oxygen. But those big, bad cancer cells that put your life in danger create energy from sugar.

That’s why many natural cancer prevention and treatment plans include low (or no) sugar diets. It makes sense, right? Cut out sugar, cut out cancer’s energy supply, so tumors can’t grow.

But here’s the problem…

Normal cells need glucose (another name for sugar once it’s in your body) too. So, you can’t deprive your body of sugars completely… at least not natural ones.

Enter mannose sugar.

Mannose sugar is a nutritional supplement that could block glucose from fueling cancer cells while still providing enough to the rest of your body.

Mannose sugar: A promising new cancer treatment?

A new study funded by Cancer Research UK and Worldwide Cancer Research found that mannose sugar can slow tumor growth and improve the success of chemotherapy in mice.

The study included mice with pancreatic, lung and skin cancer. Researchers added mannose sugar to their drinking water and gave it to them orally. This simple dietary change significantly slowed the growth of tumors without any side effects.

Researchers also wanted to see how mannose sugar impacted chemotherapy treatment, so they treated mice with two common chemotherapy drugs. Mannose sugar made the chemotherapy more effective. It slowed tumor growth, reduced the size of tumors and even increased lifespan in some mice.

These are promising results. But how does mannose sugar work?

Researchers think mannose sugar blocks glucose from tumors, while still providing enough glucose to the rest of the body.

“This is early research, but it is hoped that finding this perfect balance means that, in the future, mannose could be given to cancer patients to enhance chemotherapy without damaging their overall health,” said Professor Kevin Ryan, lead author from the Cancer Research UK Beatson Institute.

Should you try mannose sugar?

You may be thinking… what the heck is mannose sugar, anyway?

Well, mannose is a natural sugar found in certain fruits, including cranberries. And, it’s already available as a supplement. In fact, a lot of people take it to treat bladder infections. It’s sold under the name “D-mannose.”

Now, D-mannose is well-tolerated by most people. But the fact is, it hasn’t been tested for treating cancer in humans yet. So, it’s hard to say if it’s effective or if there are side effects.

Some people who take the supplement for other conditions do experience mild side effects like loose stools and bloating. There’s also the risk of kidney damage if it’s taken in high doses.

All in all, it’s probably too early to suggest adding D-mannose to your anti-cancer arsenal. But if this study is any sign, it looks like D-mannose has a promising future in cancer prevention and treatment.

In the meantime, the best way to keep cancer away is to eat a cancer-fighting diet that includes a balanced amount of sugar. Here are some guidelines to follow:

  • Eat lots of plant-based foods. The American Institute for Cancer Research says you should fill 2/3 of your plate with veggies, fruits and whole grains at every meal.
  • Swap refined grains for whole grains. Whole grains are higher in fiber, which lowers cancer risk.
  • Steer clear of processed meats. They’ve been linked to a higher cancer risk in several studies.
  • Keep alcohol intake to a minimum. Drinking too much increases cancer risk. Limit yourself to one drink per day if you’re a woman and two drinks per day if you’re a man.
  • Slash sugar intake too. For obvious reasons, don’t go overboard on the sweet stuff. Limit yourself to six to nine teaspoons of added sugar every day.


Diet — MD Anderson Cancer Center

AICR’s Foods that Fight Cancer — American Institute for Cancer Research

Sugary supplement mannose could help fight cancer — BBC News

Sugar supplement slows tumor growth and can improve cancer treatment — MedicalXpress

Mannose impairs tumour growth and enhances chemotherapy — Nature

D-Mannose — WebMD

Jenny Smiechowski

By Jenny Smiechowski

Jenny Smiechowski is a Chicago-based freelance writer who specializes in health, nutrition and the environment. Her work has appeared in online and print publications like Chicagoland Gardening magazine, Organic Lifestyle Magazine, BetterLife Magazine,, and