A few weeks ago, we talked about onions. With their anti-cancer properties, this is one food you want to have in your kitchen! This week we consider more information on the best way to eat onions, compliments of Harriet Sugar-Miller.
Anti-Cancer Recipes: Should you Cook Onions?
Now that your anti-cancer kitchen is brimming with small red and yellow onions, the obvious question is: Should you cook them or eat them raw?
The short answer:
Both, but cook them lightly.
Like garlic and crucifers, onions contain enzymes that get activated when you cut the vegetables. In a cascade of actions, the enzymes produce sulfur-based compounds that fight cancer and protect your DNA. This chemical reaction is the plant’s protection from predators, explains Dr. Irwin Goldman, an onion expert and professor at the University of Wisconsin. When insects bite into the plant’s leaves, the enzymes get to work and generate pungent chemical warriors.
But the enzymes are very sensitive to heat.
As you know from previous posts, you have to first cut Alliums (the onion and garlic family) and crucifers to release the enzymes—and avoid cutting them into really tiny pieces or else the enzymes will quickly evaporate. Then you have to let the vegetables sit for a while so that the sulfur compounds have time to develop.
How long? Nobody really knows for sure, but Goldman suggests leaving onions for 30 minutes. (A garlic researcher I spoke with suggested about 15 minutes for garlic, and another sulfur expert, who wrote the book on garlic, thought both times were too long. Until science has a full answer, I’m hedging my bets and cutting well in advance.)
Then, you can eat the veggies raw—probably the best choice in the case of garlic and crucifers. Second best choice: a quick sauté or steam (with very little water, which you should also try to consume.) If you want to cook garlic longer for flavor, however, an easy way to compensate is to throw in some crushed raw garlic or its juice at the end.
Eating onion raw will maximize the sulfur compounds, but onions have another trait going for them that its garlic cousin appears to lack: The outer layers of onions are rich in quercetin, which acts as an antioxidant among many other benefits and has also been shown to inhibit estrogen. (That’s why you must peel onions ever so gently–and save the peels for your compost or soup stock.)
Quercetin, it turns out, may get concentrated with a little cooking, depending on how you cook it, although again scientists aren’t yet sure. In one study, baking onions at 350F for 15 minutes increased the quercetin. So did sauteeing it at 200F for 5 minutes (and stirring so the onions didn’t brown.) But let’s say you want to make a miso soup and boil the onions for a few minutes instead? Good idea or not? Boiling onions for 5 minutes decreased the quercetin, but the good news is that it leeched into the cooking water–meaning you could just lap it up.
That’s the quercetin quotient. So now let’s get back to the sulfur in onions. How long does it take before heat destroys their ability to make sulfur compounds? Goldman says that if you cook onions, you should saute them quickly–4 to 5 minutes at most–to preserve the enzymes. He also says that cooking in oil and cooking in water will lead to different types of health-promoting sulfurs.
Putting this together with all the other anti-cancer cooking tips in this blog, what’s the bottom line?
Eat onions raw AND lightly cooked. Choose the small red and yellow onions grown in northern soils, peel them lightly, cut them not too finely and let them sit, then eat them raw or saute them in olive oil on low to moderate heat for 4- 5 minutes max. And don’t let the oil smoke. For another meal, make that onion-filled miso soup. And if you cook onions longer than suggested (or even if you don’t), throw in some raw garlic or raw onion at the end of the cooking process to up the sulfur power. Some studies suggest that combining onions and raw garlic with olive oil and tomatoes may also increase the anti-cancer activity.
In other words, if you want to create a truly anti-cancer kitchen, embrace those stinky onions as often as possible! And p.s.: If you can’t handle the raw factor, which may cause the valve between your stomach and esophagus to open and close erratically and thus induce heartburn, I’ve heard the chlorophyll in green plants is a good antidote. Does it work for you?
Writer-researcher-broadcaster-producer Harriet Sugar Miller has been a freelance health journalist and cancer survivor for two decades. Before that she practiced law with a large NYC firm. She’s passionate about helping others find holistic paths tohealth and wellness and blogs accordingly—-at www.eatandbeatcancer.com, glowingolder.com and weedsofwisdom.com. Look for her digital guide and cookbook, coming soon, on what to eat — and what to avoid — to prevent and survive cancer.–From the Huffington Post