Can Onions Be a Powerful Tool in the Fight Against Cancer and Other Diseases?

Even though onions belong to the Allium plant family and are closely related to garlic, they do not receive as much recognition for their health benefits compared to their botanical relatives.

However, onions contain essential natural compounds that can enhance health and combat chronic diseases. For instance, onions can assist in preventing cancer, diabetes, obesity, stroke, Alzheimer’s disease, and Parkinson’s disease.

While onions may not be commonly associated with fighting cancer, they possess natural chemicals that can help reduce the risk of some prevalent and fatal cancers.

Consider colorectal cancers, which affect about 150,000 individuals annually in the U.S. Recent statistics indicate a one percent yearly increase in the incidence of colorectal cancer in individuals under 50 years old.¹

An Asian study compared the diets of over 800 individuals with colorectal cancer to those without the disease. The study revealed that individuals who consumed higher amounts of onions and other Allium vegetables (such as leeks, chives, and garlic) experienced a significant 80 percent reduction in colorectal cancer risk.²

This result is remarkable! Moreover, the anti-cancer properties of onions have been confirmed in other studies as well.

Superfood Tumor Fighter

Upon concluding their research on how onions can aid the body in resisting tumor formation, researchers at the University of Guelph in Canada began referring to onions as a cancer-fighting "superfood."

The Canadian researchers focused specifically on red onions. Red onions not only have a high level of quercetin, an antioxidant and anti-inflammatory flavonoid present in all onions, but they also contain anthocyanin – the pigment responsible for the red color of red onions.

The team discovered that anthocyanin enhances the antioxidant properties of quercetin.

According to researcher Abdulmonem Murayyan, "We found onions are excellent at killing cancer cells. They activate pathways that encourage cancer cells to undergo cell death (apoptosis). They promote an unfavorable environment for cancer cells, and they disrupt communication between cancer cells, which inhibits growth."

Additionally, a study in Japan revealed that a compound in onions called onionin A (ONA) can help inhibit ovarian and lung cancers.

ONA is the Secret Weapon Against Cancer

ONA was found to reduce the growth of ovarian tumors by impeding the tumor-promoting actions of myeloid cells – blood cells that malignant cells exploit to spread and metastasize.

Similar results were observed with lung cancer cells as well.

The Japanese researchers suggest that ONA could potentially enhance the efficacy of cancer drugs and serve as a beneficial supplement for cancer patients.^{4, 5}

Onions have also been proven to:

• Decrease the risk of osteoarthritis: Studies in England have shown that onions and other Allium vegetables can interfere with joint enzymes that cause arthritic damage to cartilage. They contain a compound called diallyl disulfide, which helps in maintaining joint function with reduced pain.⁶
• Protect against obesity, stroke, diabetes, Alzheimer’s disease, and Parkinson’s disease: Onions contain a moderate amount of EGCG, an antioxidant compound also found in green tea. An Italian review of natural foods containing EGCG highlighted its potential to prevent and counteract various human diseases with chronic metabolic and inflammatory components, such as diabetes, stroke, obesity, Parkinson's, and Alzheimer's diseases.⁷
• Lower the risk of blood clots and heart issues: A review study in England provided strong evidence that natural compounds in onions can prevent problematic blood clots.⁸ Similarly, studies in Japan demonstrated their support for improved arterial function.⁹

My Takeaway

If you opt to increase your onion consumption, incorporating them in various forms can provide you with natural compounds that may enhance your health. However, fried onions may not be advisable as they could contain damaged fats from the frying oil, potentially triggering diseases onions are known to prevent.

Raw onions, if enjoyed, contain beneficial compounds that are lost during cooking, as noted by experts at Tufts.¹⁰ Additionally, research from Guelph suggests that the pigments in red onions offer extra advantages. Consuming any type of onion, along with a variety of fruits and vegetables, is a wise choice for improving your overall health.

1. Colorectal Cancer Statistics
2. Diet and Colorectal Cancer Risk Study
3. Onion and Cancer Cell Death Research
4. ONA in Ovarian Cancer Progression Study
5. Osteoarthritis and Onions Research
6. EGCG in Onions and Human Diseases Review
7. Onions and Blood Clots Prevention
8. Onions and Improved Arterial Function
9. Nutritional Value of Raw Onions