Israeli Doctor Explains Health Benefits and Myths Surrounding Onions
Translated & summarized from Cursorinfo by baba
An Israeli doctor, Dr. Maya Rosman, highlighted the health benefits of onions, including their antioxidant and antimicrobial properties, and their potential to reduce cancer risk and aid diabetes management. She also addressed cooking methods, sugar content, and debunked myths about cut onions becoming toxic.
The story in 5 lines · by baba
- Onions contain beneficial compounds like allicin and quercetin.
- Onion consumption may lower colorectal cancer risk.
- Cooking methods affect nutrient levels in onions.
- Cut onions do not become toxic in the refrigerator.
- Chilling onions can reduce tearing when chopping.
Onions, a common culinary ingredient, possess significant health benefits due to their antioxidant and sulfur-containing compounds, according to Dr. Maya Rosman, a scientific consultant for Plant Board. In an article for JPost, she detailed how these compounds, including allicin and quercetin, contribute to health. Allicin exhibits antimicrobial properties, inhibiting bacterial and fungal growth, as shown in a Planta Medica study. Quercetin, a potent antioxidant with anti-inflammatory and antiviral effects, is found in particularly high concentrations in red onions, according to research published in the Journal of Agricultural and Food Chemistry.
Furthermore, regular consumption of onions and garlic has been linked to a reduced risk of colorectal cancer, as indicated by an epidemiological study in the Journal of Oncology. An abstract presented at The Endocrine Society's conference suggested that onion extract, when taken with metformin, can improve blood sugar and cholesterol levels and enhance the drug's effectiveness in diabetes management.
Regarding preparation, Dr. Rosman clarified that there is no single "fresher is always better" rule. While heat can degrade some sulfur compounds, the effect on quercetin and polyphenols is more complex. Cooking methods influence nutrient retention; for instance, boiling can lead to a loss of quercetin glycosides into the water, but this loss might be mitigated if the cooking liquid is consumed, as in soup. Conversely, baking, grilling, and especially frying can increase the measurable levels of certain phenolic compounds and quercetin derivatives by altering the onion's tissue structure.
Onions contain 4 to 7 grams of sugar per 100 grams, primarily fructose, with red and purple varieties having slightly more than white onions. The sweetness intensifies when cooked, particularly through caramelization at temperatures around 120°C, where starches and complex sugars break down into simple sugars. The pungent taste of raw onions can mask their natural sweetness, but this is reduced when the compounds causing the pungency are destroyed during cooking.
Dr. Rosman also debunked the myth that cut onions become toxic in the refrigerator. She stated there is no scientific basis for this claim, as onions do not chemically transform into toxins. Instead, they may dry out, oxidize, or absorb odors. Proper storage in a sealed container in the refrigerator prevents spoilage and contamination. To minimize tears while chopping, she recommended chilling the onion, using a sharp knife, or rinsing/soaking the onion in water before cutting.