From the earliest recorded history, allium vegetables, including especially garlic and onions, have played a prominent role in food and culture. Recall for example the story of the Israelites grumbling about manna in the desert after Moses led them out of captivity in Egypt; what they were yearning for was “leeks, onions and garlic.” For thousands of years, these intensely flavorful vegetables have been treasured in traditional foods around the world. And at the same time, many cultures recognized quite early in history that they had value for health.
You’ve probably also noticed that the powerful smells of foods easily evoke memories of people and events linked to them in our past. The smell of onions for me often brings to mind the many times during my youth when I would walk into my Aunt Helen’s kitchen around dinner time. Onions were almost always on the menu. My aunt was healthy and sharp well into her 80s, seemingly younger than her years. I wonder if it was all those onions….
Today, I am highlighting the value of onions in cancer prevention. Specifically, in 2020, the American Cancer Society pointed out that allium vegetables (onion and garlic) have potential cancer prevention properties that are being researched.
Additionally, a very large population-based study from southern Europe, published in 2006 in the American Journal of Clinical Nutrition, showed that onions have a protective effect against cancers of the larynx, colon/rectum, and ovaries. These findings add weight to a fundamental principle of nutrition science, that increased intake of a wide variety of vegetables and fruits is a cornerstone of cancer and heart disease prevention.
Good evidence also gives special value to certain foods in the prevention of specific diseases. So if you are already a fan of onions several times weekly, feel good about your eating, and continue to expand your variety beyond that. If you do not regularly eat onions, experiment with different ways of cooking and preparing until you find enough ways to enjoy some onions at least twice weekly.
And speaking of colorectal cancer, the second most common cause of cancer death for men and women in the US, it’s a good time to make sure you know how to reduce your odds of this. For colon cancer prevention, your best bets are to maintain regular physical activity, restrict your intake of red and processed meats, eat more vegetables and fruits, keep body weight low to normal throughout life, and avoid excess alcohol (that is, no more than one drink per day for women, or two drinks per day for men).
In addition to its cancer preventing potential, we know that onions are high in fiber, they don’t raise your blood sugar, they decrease inflammation in your body and they are a good source of vitamin C. As you might guess, though, I am not recommending onion rings (breaded and fried) as the fried batter creates an inflammatory health risk. So, stay with raw, cooking in stews and soups, and sautéing in olive oil.
To your health,
Robert Pendergrast, MD, MPH
