Mannose Sugar Shows Potential as Novel Cancer Treatment: Study

Malignant cancer treatable with a spoonful of sugar? This may not be too good to be true.
Mannose Sugar Shows Potential as Novel Cancer Treatment: Study
George Citroner

Could a spoonful of sugar help treat malignant cancer?

A recent study published in eLife is the latest to suggest that mannose, or D-mannose, a natural sugar lethal to honeybees and abundant in many fruits, starves human cancer cells by blocking their ability to build DNA and grow.

New (Sweet) Way to Combat Cancer

In recent years, mannose's anti-cancer properties have garnered much attention from researchers. Several studies have shown that mannose can inhibit the growth of various cancers, including lung, colorectal, and prostate cancer. The mechanism of action isn’t yet fully understood but is thought to involve the disruption of glycosylation processes in cancer cells, which impairs cell growth and DNA synthesis. The following are some of the cancers that mannose has been shown to fight:
  • Lung cancer: An animal study published in Cancer Management and Research in 2020 found that mannose slowed lung cancer tumor growth and helped make chemotherapy more effective at fighting the disease. "Mannose could probably solve the problem of drug resistance during chemotherapy," the study authors wrote.
  • Prostate cancer: Research from 2022 found that mannose can retard growth and stimulate cell death of prostate cancer in mice through its effect on the mitochondria of these cancer cells.
  • Colorectal cancer: A 2022 study found that mannose can halt tumor growth in mice with colorectal cancer.

Possible Role in Preventing Cancer

While the exact mechanisms are still being unraveled, some scientists hypothesize that mannose may also help prevent cancer by supporting healthy cells in the following ways:
  • Activating the immune system: Mannose has been suggested to enhance the activity of immune cells, particularly macrophages, which play a role in identifying and eliminating cancer cells.
  • Reducing inflammation: Chronic inflammation is associated with an increased risk of cancer. Mannose may have anti-inflammatory properties that could help reduce chronic inflammation.
  • Inhibiting tumor growth: One 2021 study suggested that mannose can hinder the growth of tumors by interfering with specific metabolic pathways that cancer cells rely on for energy.
  • Disrupting glycosylation: Mannose is involved in glycosylation, a process through which sugar molecules are added to proteins. Some cancer cells exhibit abnormal glycosylation patterns. The theory is that mannose supplementation may interfere with this abnormal glycosylation, inhibiting the growth and spread of cancer cells.

Latest Research

“It’s been known for more than a century that mannose is lethal to honeybees because they can’t process it like humans do—it’s known as ‘honeybee syndrome,’” Hudson Freeze, who holds a doctorate in biology and is the director of the Human Genetics Program at Sanford Burnham Prebys Medical Discovery Institute and co-author of the study recently published in the eLife journal, said in a statement.

His team investigated whether this syndrome is connected to mannose's anti-cancer effects.

Using genetically engineered human cancer cells from fibrosarcoma, a rare cancer in connective tissue, the researchers replicated honeybee syndrome in the lab. They found that the cancer cells struggled to build DNA and replicate without the enzyme to process mannose, making them more vulnerable to chemotherapy.

Although promising, more research is required to determine which cancer types respond best to this treatment.

“If we can find cancers that have a low activity of the enzyme that processes mannose, treating them with mannose could give just enough of a nudge to make chemotherapy more effective,” Mr. Freeze said, noting that this approach is an unexplored frontier and may represent an “untapped treasure trove” of potential treatments.

Already Used to Treat Some Diseases

Mannose is a naturally occurring simple sugar found in fruits, including blueberries, cranberries, oranges, apples, and peaches. Chemically similar to glucose, it's less sweet and affects blood sugar differently.
Mannose isn't readily absorbed, so it elicits a lower insulin response, potentially beneficial for diabetes, Emily Feivor, a registered dietitian at Northwell Long Island Jewish Forest Hills, told The Epoch Times.


Mannose nurtures the growth of good bacteria in the gut, Ms. Feivor said, noting that this is unlike regular table sugar.

“[Mannose] may have preventative properties for urinary tract infections due to it being metabolized through the kidneys and excreted as urine,” she said.

A healthy gut microbiome can have cascading effects on the body, including an improved immune system.

Mannose may prevent recurrent UTIs, a 2013 randomized controlled trial found. A systematic analysis of more than 32,000 studies found that mannose is an effective and safe treatment for cystitis and other UTIs, especially during pregnancy.

Genetic Disorders

Mannose sugar has also shown effectiveness in treating congenital disorders of glycosylation, a group of rare genetic conditions that affect the incorporation of sugar building blocks.
Glycosylation is a process that involves adding sugar molecules to proteins and lipids to stabilize their structure and function. Disorders in the process can cause severe symptoms, including seizures and stroke-like episodes. Mannose was found to normalize this process.
The only side effects associated with use have been minor. According to one study, the most common adverse reaction was diarrhea.
George Citroner reports on health and medicine, covering topics that include cancer, infectious diseases, and neurodegenerative conditions. He was awarded the Media Orthopaedic Reporting Excellence (MORE) award in 2020 for a story on osteoporosis risk in men.