Editor's note: This article is a reprint. The first edition was published on his June 26, 2017.
Have you ever sat in a restaurant and smelled the delicious smell of sautéed onions sizzling as it moved to another table? You may decide. onion Add other vegetables to your meal the next night.
But did you know something? Differences between onion varieties in their health effects?In addition to both red and white onions being low-glycemic foods,1 One study found that red onions are superior in many ways. One of the most important is that red onions had a dramatic effect on cancer risk in study participants.
It was also found that of the five onion varieties, red onions killed three to four times more cancer cells than yellow or white onions.
In a Canadian study,2 This is undoubtedly due, at least in part, to the fact that cancer is the country's leading cause of death. flavonoids, specifically quercetin, myricetin, and kaempferol, found in five types of onions, were shown to „exhibit potential anticancer activity.“ Further afield:
„All onion varieties showed antiproliferative activity similar to purified flavonoids. The cytotoxic effects of Stanley and Fortress onion varieties were the strongest among the selected varieties.“3
What other nutritional benefits do red onions have compared to white onions? In addition to being milder, one of their benefits is their antioxidant properties, which is why they have a higher ability to protect against cancer. This is one of the.
a studyFour Stomach cancer, colorectal cancer, oral cancer, laryngeal cancer, esophageal cancer, and ovarian cancer are among the types of cancer that red onion's properties can help alleviate. in fact, stomach cancer The risk has been cut in half. Both red and white onions have blood thinning effects, but red onions are better at blood thinning because they are rich in flavonoids.
Another piece of wisdom — the outer skin of an onion contains the most nutrients. If you have to remove the two outermost layers, you will also remove 75% of the anthocyanin content, which is undesirable. Scientists recommend eating at least one red onion per week for maximum nutritional benefits. There are many delicious ways. Cut into pieces and add to cold salads or stir into sautéed vegetables.
More from Canadian Onion Research
To test the capabilities of different onion varieties, researchers used a newly developed technique to extract quercetin and other compounds and brought them into direct contact with human colorectal cancer cells.
Co-author Dr. Suresh Neethirajan, associate professor at Dalhousie University, said all five onion species were deemed „excellent“ at killing the cells. However, the red onion variety Ruby Ring had the highest total content of phenols, which are natural compounds produced by plants.
Although the onions used in this study had the highest concentration of quercetin compared to other onion varieties around the world and happened to be grown in Ontario, the study authors believe that the same It states that there are likely to be consequences. Red onions were grown elsewhere. Funding for this research was provided by the Natural Sciences and Engineering Research Council of Canada and the Ontario Ministry of Agriculture, Food and Rural Affairs.
The scientists who used the quercetin extraction technique, which uses water heated in a pressurized vessel, said their work would soon inspire other scientists to use this or similar methods for quercetin extraction. He said he was looking forward to it. They stress that this technology does not use toxic solvents or chemicals like other methods used for this purpose, and say that quercetin from red onions „someday will be used in various fortified foods and even pharmaceuticals.“ I hope that it will be added.“
However, rather than waiting for that day, you can extract the same healing properties by eating it whole. Research like this helps you decide which types to put in your shopping cart when you're preparing to make a big green salad with all the delicious vegetables and other vegetables, or even better, which onion seeds. This will help you know which seeds to put in. Bulbs to plant in the garden.
Quercetin, anthocyanins and other disease-fighting compounds
Numerous studies have already confirmed that quercetin helps reduce the risk of heart disease, diabetes, atherosclerosis, and high blood pressure. It also helps slow down the growth rate of cancer cells, especially tumors in the ovaries, prostate, endometrium, breast, colon, and lungs. If you like onions, you'll be happy to know that red onions provide 25% of your daily flavonol needs, according to a table created by the United States Department of Agriculture (USDA).Five
research notes6 It seems that onions contain about 25 types of anthocyanins. This is a plant pigment that supports the free radical scavenging activity of onions. Free radicals are partial molecules that cause inflammation that causes other health-damaging symptoms because they steal electrons from many proteins in the body, damage DNA, and cause various aspects of other serious diseases. .
Anthocyanins are the compounds responsible for the deep red, purple, and blue colors of fruits and vegetables. In fact, they are so powerful that many scientists recommend eating dark vegetables such as purple cabbage and red cabbage. purple grapes, blackberries, kale, strawberries, blueberries, beets and more – for this very reason. They contain more of this compound. An article in Time magazine explains:
„Researchers recently discovered that onions are also effective in killing breast cancer cells. Onions interfere with communication between cancer cells and promote an unfavorable environment for cancer cell growth. The next step, they added, is to test these theories in human trials. ”7
Allicin is another compound found in plants in the allium family, such as onions, leeks, and shallots. green onion and herbs garlic And chives. Allicin, which is produced when cut or crushed, has been shown to protect the heart, lower blood pressure, and both prevent and treat cancer.
Organically grown onions: Are they nutritious?
In 2013, a huge research group, over 200 in fact, was scrutinized to see if organically grown foods have any additional advantages over conventionally produced foods. Many scientists ultimately concluded that this was not the case. Others begged different.
Further research has since revealed exactly the opposite. The longest-running study to date on this issue found that organic foods contain more healthy phytochemicals and that organic onions have higher flavonoid levels and antioxidant activity than conventional onions. did. According to Science Daily,8
„The authors suggest that the conflicting results obtained from previous studies on phytochemical content in organic and conventional crops may be a function of the short study period and the exclusion of variables such as weather. …Measurements over six years of research have confirmed that weather can have an impact on flavonoid content, regardless of whether it was grown under organic conditions.”
Experts determined that flavonols in Red Baron onions decreased in 2010, when temperatures were the coldest, and increased in both 2011 and 2014, when the weather was hot and humid. Researchers reported that antioxidant activity was higher in Red Baron and Highskin organic onion varieties, and flavonols were 20% higher in organic vegetables.
Naturally, it's good to know the other nutritional benefits you can get from red onions.heal with food9 Just half a red onion has antibacterial, antifungal, and anti-inflammatory properties that can help prevent several disorders and diseases, including:
- Prevention and control of intestinal polyp formation
- Suppression of rhinovirus that causes colds
- psoriasis treatment
- Slows down the replication of viruses such as the herpes simplex virus that causes cold sores
- Reduces risk of stomach cancer by 50%
In case you're looking for more
Chromium, a trace mineral, is yet another compound found in onions that can control blood sugar levels.Ten Say.
„This is good news for people who suffer from insulin resistance, as chromium is essential for the activity of insulin in the metabolism of carbohydrates, fats, and proteins. If chromium-rich foods, such as onions, are not included in the diet, It can lead to insulin resistance and blood disorders, which can make it harder to control sugar levels and increase your risk of cardiovascular disease and type 2 diabetes.
Additionally, there is some evidence to suggest that severe chromium deficiency may make weight loss more difficult or cause weight gain. ”
Fiber is a very important element in your diet, and onions don't disappoint. Both are necessary, but Soluble dietary fiber and insoluble dietary fiber, most foods contain both, and red (or purple) onions contain more soluble fiber than insoluble fiber. Week& has a good explanation of why it's so important.
„Soluble fiber attracts water in the intestines, creating a slow-moving gel. This slows down digestion and allows vitamins and minerals to be absorbed through the intestinal wall. Insoluble fiber from onion skins It cleans the intestines like a broom and helps maintain regular bowel movements.
According to Colorado State University Extension, you need 14 grams of dietary fiber for every 1,000 calories you eat. Based on a 2,000 calorie diet, you need 28 grams of fiber per day. Purple onions provide about 1.5 grams per 1/2 cup of raw. ”11
Minimal heating will preserve most of the healthy compounds in onions, but the more you heat them, the more nutrients you lose. George Mateljian Foundation,12 Dedicated to the healthiest ways to cook and eat, he says the most recommended method of sautéing or steaming onions is on record in food science research for retaining as many nutrients as possible.3 It follows three basic guidelines and says it's very simple and easy to understand. :
- minimal heat exposure
- minimal cooking time
- Minimize contact with cooking liquids
Vitamin C, another abundant nutrient found in raw red onions, has several important functions throughout the body. It aids in wound healing, increases elasticity, supports collagen production, and has antioxidant capabilities that amplify the free radical-fighting effects of flavonoids.
Women need 75 milligrams (mg) per day, while men need 90 mg per day. Luckily, no matter how you cook onions, you'll get about 12 mg per half-cup serving, so it's not a difficult task.