Choose Wisely for Heart-Healthy Cooking
Some food-savvy environmentalists say that if you can afford to buy only one organic food item, it should be culinary oils. They base their assertions on several things, but at the top of the list is the fact that heavy metals (which can show up in sewage sludge used to treat some non-organic farms) and industrial chemicals such as pesticides tend to stick to fats.
The right amounts of the right kinds of high-quality oils are especially important for babies with developing nervous systems.
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Many common cooking oils—canola, soy and cottonseed chief among them—are genetically engineered to withstand more pesticide spraying than their common counterparts. Although the Food and Drug Administration (FDA) finds them safe for human consumption, environmentalists are increasingly concerned about the effects on the ecosystem and on their bodies. One way to make sure GE plants are not in your food is to buy organic.
Further, non-certified oils and those not labeled "cold" or "expeller" pressed may be extracted using the solvent n-hexane, a nervous system toxin. N-hexane, made from crude oil, primarily raises health concerns for workers exposed to it as it evaporates. The FDA does approve chemically extracted oils, but people who prefer to buy organic may find such assurances inadequate.
Critical Building Blocks
Despite the real concerns about too much fat in modern diets, the right amounts of the right kind of high-quality oils are critical for health. Fats make up the building blocks of hormones and are especially critical for babies as they develop their nervous systems, since the oils help coat growing nerve cells.
"Oil is very important," explains Dr. Chris Meletis, a naturopathic physician and dean of the National College of Naturopathic Medicine. "Without oil, there’s increased inflammation, altered immunity and increased menstrual cramps." Fats, he says, "are critical for the creation of every cell."
Fats have gotten a bad rap because two kinds—saturated and transfatty acids—feed heart disease. Saturated fats come from both animal and plant sources. Oils with high saturated content are generally solid at room temperature: Think of coconut and palm oils, or butter and lard. Transfatty acids occur when oils are modified to make them solid at room temperature, as in the case of margarine. That process, known as hydrogenation, also reduces or eliminates many of the healthy components of the oil.
Dietician Connie Diekman, director of university nutrition at Washington University, says transfatty acids and saturated fats cause the same kinds of heart-health problems. She recommends using oils in lieu of hardened fat whenever possible. That might make for a denser cake, she says, but the health benefits are worth it.
But other types of fats are critical for good health. Monounsaturated fats actually help undo the heart-blocking effects of saturated fats. Olive, canola, peanut, sesame, almond, avocado and high-oleic safflower and sunflower oils each have more than 50 percent monounsaturated fats, according to Spectrum Naturals, a leading oil distributor.
Polyunsaturated fats, composed of Omega-3 and Omega-6 fatty acids, also have some cholesterol-lowering properties. They are also the most important oils nutritionally, because the body can’t synthesize them. But getting the right balance isn’t always easy. Most dieticians say the body needs two or three times as much Omega-3 as Omega-6. (This is bad news for hemp advocates, since their oil has the reverse ratio.) Common culinary oils such as canola, corn, safflower, sunflower, walnut, sesame and soy are rich sources of Omega-6, but offer little if any Omega-3. Canola and hemp both have better ratios, but remain relatively heavy on plentiful Omega-6.
Flax seed oil is the best vegetable source for righting the Omega-6 to Omega-3 imbalance, with a ratio reverse that of hemp. Fish such as cod, salmon and mackerel are also excellent sources of Omega-3s. Their oil is available in supplements, but also survives cooking in the meat. Plant-based sources should not be heated.
Care And Handling
All oils need to be protected from heat and light, which oxidize them and make them rancid. Oils high in Omega-3 are particularly sensitive and should be refrigerated.
Aside from smelling and tasting bad, rancid oils are high in free radicals, explains Jim Gallagher, a professor of nutrition at Bastyr University. Free radicals bond to protein layers in the body and break them down, leading to a host of health problems.
Oils can go rancid over time simply by exposure to air, so Gallagher recommends buying oils in small quantities so they are used quickly. Bulk bins often leave oils exposed to oxygen, but if the oil sells quickly it will have little time to develop problems. Clean containers well so you’re not adding good oil to rancid remnants.
Heating oils speeds the oxidation process, which is one reason fried food is bad for you. Burned oils—those that start to smoke—can be downright dangerous: "A lot of oils when they get superheated turn into cancer-causing agents," Meletis says. That’s true of burned popcorn oil and the smoking oil that comes up from the coals during a barbecue.
To avoid such problems, choose the right oil for the job. For high-heat frying, searing and browning at temperatures up to 500 degrees Fahrenheit, Spectrum Naturals recommends their super canola oil, almond, apricot kernel, high-oleic safflower or sunflower, peanut or soybean oils. For stir frying and baking below 375 degrees, try canola, walnut, sunflower or sesame. Use olive, corn, or any of the higher-heat oils for sauces, baking or light sautéing under 320 degrees. Save flax, hemp, wheat germ, borage and black currant oils for salads or drizzling on foods after cooking. Spectrum products have a handy gauge on each bottle showing the range for that oil.
The Canola Controversy
Canola oil—made from the seed of a broccoli relative unfortunately named "rape"—has become controversial among health food advocates in recent years. The debate began with an article in Perceptions magazine that made several claims, including that canola is an industrial lubricant and a carcinogen.
According to the FDA, rape plants (also known as wild mustard) were grown for centuries in Central Europe. Oil extracted from the seed was used in Canada during World War II as a substitute for scarce petroleum lubricants. But animal studies of long-term consumption of rapeseed oil linked one of its constituents, erucic acid, to heart lesions. Canadians began cross-pollinating the rape plants, and by the 1970s developed a variety that contains less than two percent erucic acid. That oil, called Canadian oil or canola, is what appears on store shelves today.
No one contacted for this story could link canola to cancer beyond the concerns associated with overheating. Some of the concern may be a misunderstanding of the difference between hybridization (the kind of cross-pollination that developed corn larger than a finger or wheat that doesn’t shatter until harvest) a
nd genetic engineering, which uses laboratory procedures to add genes that were never naturally present in the plant. Canola has been the subject of both kinds of modification, first to lower erucic acid levels and then to increase pesticide resistance. And while pesticide-heavy, genetically engineered canola is a concern for many people, organic varieties are free of both.
Cindy Moore, director of nutrition therapy at the Cleveland Clinic Foundation, recommends canola because it has low saturated fat levels, a good balance of mono- and polyunsaturated fats, and contains up to 10 percent Omega-3.
Meletis won’t weigh in on the controversy himself, but says he opts for olive over canola. "I never suggested canola even before the controversy," he explains, "because the Mediterranean diet has been proven to be heart friendly and generally promotes overall good health."