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| Photo by Casey Hussein Bisson |
Cook with the right kind of fats
Fats & oils are some of the most misunderstood nutrients in today's health community. Conventional wisdom teaches us to cook with 'light' polyunsaturated oils, while saturated fats have been all but demonized. Yet heart disease continues to be the leading cause of death in the US, and chronic inflammation has been identified as a contributor to diseases like arthritis, cancer, diabetes and Alzheimer's.
New research suggests that perhaps not all the blame lies with the type of fats we're eating (saturated or not), but their quality and chemical stability. Free radicals contribute to inflammation, so fats that are susceptible to oxidation are particularly dangerous.
To understand which fats are most easily oxidized, a quick chemistry refresher: each type of fat (saturated, monounsaturated, or polyunsaturated) has a different chemical structure. Saturated fats are structurally rigid because every carbon molecule is "saturated" with a hydrogen molecule. Monounsaturated fats have one "unsaturated" carbon, which forms a double-bond to the next carbon atom on the chain. Polyunsaturated fats have more than one double-bond.
Fats are most susceptible to oxidation at double-bonds. Therefore, the more double-bonds a fat has - the more unsaturated it is - the more easily it will oxidize and create free radicals. And when you eat rancid fats or oils, their free radicals create oxidative stress in your body, contributing to aging, damaging blood vessels, increasing inflammation and setting the stage for many degenerative conditions and diseases.
Exposure to heat, light, and air hastens the rancidification process, so cooking with unsaturated oils just increases the likelihood that those oils will oxidize and cause health problems. Some unsaturated oils are rancid before you even buy them: processing techniques can heat them before they’re bottled, and clear packaging may allow further damage from light. Saturated fats, on the other hand, are more stable and can withstand higher heats. Perhaps this is why Great-Grandma always cooked with butter or lard.
We tend to forget that some saturated fats are healthy and necessary for good health. According to Dr. Jeffrey Bland, “all saturated fat is not the same. …Short-chain fatty acids (like butyric acid, which is highly concentrated in butter) play such a critical role in supporting the healthy of the intestinal cell lining” (Bland et. al., 2004). That said, moderation is key. Saturated fats stiffen our cell membranes and affect their permeability. This is important because cell membrane function directly affects health or disease. According to Dr. Michael Murray, “Alteration in cell membrane function is the central factor in the development of virtually every disease. … Without the right type of fats in cell membranes, cells simply do not function properly” (Murray, Pizzorno & Pizzorno, 2005).
Now, this doesn’t mean that I advocate removing unsaturated fats from your diet. They have many health benefits, such as the anti-inflammatory effects of omega-3 fatty acids found in seafood, chia, flax and walnuts. I recommend getting healthy unsaturated fats from whole foods like avocados, nuts and seeds. And personally, I buy extra-virgin olive oil to drizzle on my salads.
The bottom line: if you’re going to purchase unsaturated oils, ensure that they’re cold-pressed and packaged in dark containers - and don’t use them for cooking. Otherwise, rely on small amounts of saturated fats for cooking, and ensure they're organic to avoid added hormones, pesticide residue, and antibiotics.
Bland, J., Costarella, L., Levin, B., Liska, D., Lukaczer, D., Schiltz, B., … Lerman, R. (2004). Clinical Nutrition: A Functional Approach. Gig Harbor, WA: The Institute for Functional Medicine
Murray, M., Pizzorno, J., & Pizzorno, L. (2005). The Encyclopedia of Healing Foods. New York: Atria.
