Smile through the tears. The power of these pungent bulbs to bring tears to your eyes upon first-chop may also be what supports your body’s immune system, and also what combats inflammation in the body.

In addition to being one of the key ingredients in a mirepoix, onions contain allyl sulfur compounds. To the plant, sulfur protects it from being eaten by deploying when it is bitten, crushed, or cut into. Sulfur is a mineral that has important roles in our bodies, and we will highlight a few of them here.

• The protection sulfur provides for plants also provides our bodies with needed sulfur to protect ourselves from being invaded. Sulfur is a compound in our bodies that help prevent free radicals from causing damage to our cells. Ongoing free radical accumulation in our bodies can lead to chronic disease, cancer being one.
• Another role of sulfur plays is to support the formation of proteins in our bodies, which helps keep our muscles strong, and our immune systems healthy.
• Sulfur is found in many plants, especially dark leafy green plants as well as in onions and garlic. These allyl sulfur compounds have interested scientists and they are currently being studied for their potential to slow tumor growth and to promote programmed cell death of unhealthy cells, which also helps to prevent potential cancerous cells from growing and spreading.

In addition to their protective sulfur compounds, onions are also a rich source of phytonutrients; plant-based nutrients that provide added protection for our bodies to reduce the risk of developing chronic diseases. There are many phytonutrients found in onions but quercetin is the one that has received the most attention. Cell studies on quercetin suggest that the compound may play an important role in slowing cancer growth. However, quercetin is not easily accessed by the body, and we are only beginning to understand its potential. It is important to note, that the current body of research on the potential cancer-fighting properties of onions cannot be used to inform any treatments or interventions in humans at this time.

More than anything, it is exciting to recognize that current scientific research may be able to unlock future cancer-fighting potential present in our everyday foods, which supports our recommendation to include a wide variety of fruits and vegetables rich in phytonutrients in your diet to provide the best possible protection against cancer and other chronic illnesses.

Onions also provide important nutrients known to support normal body function, including vitamins A and C, copper, manganese, biotin, and dietary fiber. Vitamin C, manganese, and copper play vital roles in supporting our immune function. Biotin and vitamin A encourage proper cell differentiation, and fiber is essential to healthy gut function.

Chef Tips

Try to find onions that have very little damage below the outermost, paper-like peel. Many of the most potent phytochemicals and nutrients are stored in the outer layers, so it’s best to keep and use as many as possible. Look for hard, firm onions, which will keep longer than those that give.

Not sure how to chop up an onion? Get our best tips here.

Onions range in sweetness and spice, so it is important to know which type of onion to buy when following a recipe.

Sweet Vidalia onions are grown in sandy soil, so much of the sulfur washes out with rainwater, making Vidalias especially sweet.

Purple or red onions are sweeter than the classic white ones and are often enjoyed raw, chopped on top of salads. They are especially delicious pickled in red wine or apple cider vinegar.

Yellow onions are best grilled, used in soups, or caramelized in a sauté pan. They are a standard addition to chicken and vegetable broth and play the lead role in French onion soup.