What We Didn’t Know About Cooking Oils
Fat was once maligned as a healthy diet’s greatest foe, but more and more nutritionists, trainers, and even psychiatrists are increasingly acknowledging the role of healthy fats in a balanced diet—oil and fat are critical for effective brain function, and, counterintuitively, actually help the body burn the types of unhealthy fat that lead to weight gain. But not all fats are created equal: Even the cleanest oils (like our standby EVOO) can counteract their own healthful effects if cooked past their smoke point; what’s more, over-processed oils like canola, which has to be bleached and deodorized (pretty gross), can actually rob the body of vital antioxidants.
Leading psychiatrist Dr. Daniel Amen wrote his new book, The Brain Warrior’s Way, and the accompanying cookbook, The Brain Warrior’s Way Cookbook, with his wife Tana, a nurse and long-time nutritionist. Their focus on food that improves brain health (and, by extension, promotes weight loss and prevents disease) involves a heavy emphasis on healthy fats and how to best use them. Below, we talked to the Amens about fats and oils—how to pick the healthiest ones, how to cook with them, and the role they play in long-term wellness. (For more oil-related surprises, see this goop piece on the global olive oil fraud—and what to do about it.)
A Q&A with Tana Amen, B.S.N., R.N., & Daniel Amen, M.D.
What’s the difference between omega-3 vs. omega-6 fatty acids? What’s the ideal ratio of one to another?
The first thing to know is that they are both referred to as “essential fatty acids”—“essential” being the operative word. Not only are they essential to the health of your brain, heart, skin, and hormones, but they must be consumed through food (or supplements) because your body isn’t capable of producing them on its own. Although it sounds paradoxical, we need some dietary fat in order to burn body fat. Extreme low-fat diets are associated with increased risk of depression, suicide, and neurodegenerative diseases.
OMEGA-3: Omega-3 fatty acids and monounsaturated fats are necessary for optimal health. They help our heart, brain, and body function well; and protect us from disease. Most cooking oils don’t contain Omega-3s—salmon, chia seeds, flax seeds, and leafy green vegetables are the best sources.
OMEGA-6: These fats are also necessary but can be harmful when eaten in excess, so they are good and bad. They are found in most vegetable oils (soybean, sunflower, safflower, corn, and canola), as well as many fried foods, cereals, and whole-grain bread. Omega-6 fats contribute to muscle health and increase inflammation in the body. Inflammation is a good thing in small doses (you need it to heal from a cut or other acute injuries), but long-term, chronic inflammation can trigger chronic diseases like diabetes, heart disease, and cancer, in effect canceling out the benefits of omega-3 fatty acids. In the vast majority of American diets, Omega-6 fatty acids are grossly over-represented. (In our clinic, the average is 20:1, and many places report an average of 25:1.)
We believe that man evolved with a ratio of 1:1 of omega-6 to omega-3 fatty acids; most physicians I work with recommend an optimum ratio of 2:1 for a modern diet, and certainly not higher than 4:1.
What’s the takeaway on unsaturated vs. saturated fats?
UNSATURATED FATS are considered good fats—they contribute to heart and brain health, decrease the risk of heart disease, balance blood sugar, normalize blood clotting, decrease LDL cholesterol (considered bad cholesterol), and raise HDL (considered good cholesterol). Unsaturated fats are broken into polyunsaturated and monounsaturated—both of which belong in your diet in moderation. Nut oils, like macadamia, are high in monounsaturated fat. Because polyunsaturated fats (e.g. the vegetable oils) are missing four or more hydrogen atoms, they are inherently unstable at high temperatures. You wouldn’t typically cook with them at high heats because they can go rancid.
SATURATED FATS are more complicated: We used to say they were bad, but now we know that not all saturated fats are the same. You want to avoid saturated fats like palmitic acid, which you’ll find in industrialized meat (i.e. in the “marbling”). Other saturated fats, like stearic (long-chain fatty acid in meat and chocolate) and lauric/capric/caprylic (medium-chain fatty acids found in coconuts/coconut oil) haven’t been found to be problematic. Also, it’s been shown that short-chain fatty acids, like the ones in butter, are healing to the gut. Butter is the one dairy product that I don’t avoid because it has this special property to it. I’ll sometimes add butter (and coconut oil) to my coffee; ghee is also great for that.
Can you break down the issues with canola oil? Do the same concerns hold true for all “vegetable” oils—or are some beneficial?
“Canola” sounds deceivingly wholesome: It’s a made-up name, stemming from the words “Canada” (a big producer) and “oil.” Canola plants are actually engineered from rapeseed plants. We suppose “rapeseed oil” would have been a marketing nightmare, not to mention that rapeseed oil is generally used for industrial purposes and is toxic to humans. It has been shown to cause pulmonary lesions and emphysema, among other health issues.
More than 90 percent of the canola grown in the US is genetically modified (and it is all genetically engineered). This means the canola is sprayed with pesticides. If that wasn’t enough, a chemical solvent is required to extract the oil from the plant, after which point it is “washed” and deodorized with more chemicals to get rid of its horrible smell. During this process, the omega-3s in canola are converted to trans fat, and there is nothing positive about trans fat (it increases tri-glycercides and the risk of heart disease, diabetes, and inflammation). Like other polyunsaturated fats, canola is missing multiple hydrogen atoms, which explains why it becomes unstable and creates damaging free radicals in high heats.
Vegetable oils in general are not the best choices for health (olive oil is an exception). Most commercial vegetable oils are bleached and processed using chemicals. This processing can cause increased inflammation in the body and a myriad of health issues. These processed oils oxidize quickly, which means they end up robbing the body of much-needed antioxidants that help keep your brain young. Also, safflower, sunflower, soy, corn, and cottonseed oils (plus vegetable shortening) all contain high levels of omega-6 fatty acids. These are on the “no” list—I avoid cooking with them whenever possible.
There are many oils beneficial for consumption, so why choose one shrouded with questions and controversy? Coconut, avocado, macadamia nut, almond, and olive are just a few oils known to have health benefits. In general, the less processing, the better, when choosing oils. Bleaching and deodorizing oils removes health benefits.
We’ve heard not to use old oils that may have oxidized. How does the body respond to oxidized oils?
When oil reaches its smoke point and beyond, it oxidizes. Think of the rust on an old car—that is oxidation. That same process occurs in your body when you consume foods (including fats and oils) that have been oxidized: Highly reactive compounds called free radicals are created, which are harmful to the body’s cells. Some studies have shown that consuming oxidized oils increases inflammation, which may damage your DNA and can make you more vulnerable to Alzheimer’s disease, diabetes, heart disease, and cancer.
What tips do you have for selecting cooking oils at the grocery store? Can you explain the significance (or not) of the common label terms (i.e. cold-pressed, unrefined vs. refined, unprocessed, virgin vs. extra virgin)?
It’s critical to read labels and be careful when choosing oils. In general, look out for the word “blended” on labels—this means the oil contains other vegetable oils or additives.
These label terms indicate how the oil was processed, or the source of the oil.
COLD-PRESSED OILS are produced by crushing or pressing the seed or nut and forcing out the oil without the use of heat. This is considered a much healthier option and tends to taste more like the source of the oil because the oil hasn’t been stripped of its natural nutrients, antioxidants, and flavor.
UNREFINED VS. REFINED: Unrefined processing uses minimal heat and does not include bleaching or deodorizing. Refined oils have been processed through heat, color stripping, and a deodorizing process.
EXTRA VIRGIN is the purest form of olive oil. It has been cold pressed and has not gone through bleaching and deodorizing. However, it has a low smoke point. EVOO is great for consuming raw, but not for cooking.
VIRGIN OLIVE OIL is made using the same process, but with riper olives. It has a lighter flavor and a slightly higher smoke point. Some chefs like using it for cooking at low temperatures.
Another tip, once you’ve bought your oils: They should be stored in dark containers, glass if possible, and the color should resemble the plant it originated from.
Are there non-oil ingredients that you recommend for cooking certain dishes?
Vegetable broth can often be used for sautéing instead of oil. Another oil alternative is ghee or butter from grass-fed cows, which both have a high smoke point.
The goop Guide to Cooking Oils
A note on temperature: In reality, we’re not cooking with thermometers at home. But we included the smoke points of the oils that Tana shared with us—some of which surprised us—because they can serve as good general reference frames. Think of high-temperature cooking as above 400 degrees—this is frying, braising, broiling, or searing on the grill. When you’re cooking with one of these methods, you want to be working with oils and fats that can be heated significantly before they begin to smoke. We also put oil marinades in this category, because if we’re marinating meat, we’re likely throwing it on the grill next. (For marinades, as Tana reminded us, you also want oils that remain liquid at cool temperatures, unlike ghee or coconut oil.)
In the second chart here are the oils recommended for low-temperature sautéing and baking, and for consuming raw, in dressings or as a finish. The biggest standout is probably olive oil—because it oxidizes so fast, Tana actually doesn’t cook with it over heat, instead using broth to sauté vegetables and butter for eggs. If, like us, half of your cooking repertoire starts with onions sweating in olive oil, use Chef Thea’s tip: Coat vegetables in olive oil before you heat them, as olive oil is more likely to smoke if you leave it to preheat alone on a burner.
Best Oils for Cooking at High Temperatures
|Oil||Type of Fat*||Smoke Point||Cooking Tips|
|Avocado Oil||70% MUFA||500° F||Neutral cooking oil, great alternative to canola for roasting or high-heat stir fry.|
|Ghee||63% SFA||450° F||Amazing for homemade Indian food, this brown rice Khichdi, and brined chicken (cover with ghee and put it in the oven—so good).|
|Macadamia Nut Oil||80% MUFA||420° F||This is Tana’s go-to, partly because she finds it amazing for the skin. It has a slightly nutty flavor but isn’t too overpowering, and contains an omega-7. Essentially any recipes (including marinades) you’d traditionally think of using olive oil for, Tana subs in macadamia nut oil.|
|Palm Oil||54% SFA||455° F||Another one that works for curries. Tana uses it sparingly for shortening/as a larder alternative, like for a frosting, because it whips nicely.|
|Rice Bran||38% MUFA to 37% PUFA||415° F||Brilliant for deep frying tortillas…|
|Unrefined Coconut Oil||86% SFA||450° F||Good for cauliflower “fried” rice; an easy, detox-friendly version of green chicken curry.|
*SFA=Saturated, MUFA=Monounsaturated, PUFA=Polyunsaturated
Oils That Are Only for Cooking at Lower Temperatures
|Oil||Type of Fat*||Smoke Point||Cooking Tips|
|Butter||50% SFA||350° F||Butter got a bad rep for a long time, and though we still wouldn’t fry with it, it’s a great base for basics like eggs (and Tana tells us it’s the one dairy product she doesn’t avoid). For those trying to up the fat content of their diet, it works well melted in coffee, bulletproof style.|
|Cacao Butter||60% SFA||370° F||The flavor of cacao butter can be ruined if you heat it too quickly, so we use it mostly for desserts. It’s also solid at room temperature, so it’s great for stickiness—melted and poured over granola bars, it helps hold everything together.|
|Grapeseed Oil||71% PUFA||420° F||Grapeseed oil has a higher smoke point than the other oils in this category, but it’s high in omega-6s, so we try not to lean on it too heavily. That said, it makes a great substitute for canola oil in baking recipes thanks to its neutral taste. It’s also much less expensive than some of the other oils on this list.|
|Olive Oil||73% MUFA||370° F||Your highest quality olive oil (the expensive stuff you receive as a gift, or buy from specialty stores) should be reserved for dressings and finishing. And while Tana has us considering alternative options for sautéing, it’s always going to be the starting point for Mediterranean classics like pesto and cazzimperio.|
|Sesame Seed Oil||43% MUFA to 43% PUFA||450° F||Sesame oil is high in omega-6s, but it has amazing flavor. We use it sparingly: just a tablespoon or two for dipping sauces and soups.|
*SFA=Saturated, MUFA=Monounsaturated, PUFA=Polyunsaturated
Tana Amen, B.S.N., R.N. and VP of Amen Clinics, is the author of six books, including the New York Times bestseller The Omni Diet. She is a highly respected health and fitness expert, and a nationally renowned speaker and media guest.
Daniel G. Amen, M.D., is a double board-certified psychiatrist, professor, and ten-time New York Times bestselling author. He is one of the world’s foremost experts on using brain-imaging tools to help optimize and treat his patients; Amen Clinics have one of the highest published success rates for patients.
The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of goop, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.