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The Truth About Fat
by Sarah Cimperman, ND
Fat has gotten a bad reputation, but it’s a necessary nutrient. Fats help us absorb fat-soluble vitamins and provide our bodies with energy. They protect and insulate our internal organs and regulate our digestion. Fats help build cells, tissues, organs, nerves, hormones, and chemical messengers that allow our cells to communicate with the rest of the body and with the brain. Our brains are 60 percent fat.
The fats our bodies need must come from food. To distinguish the good fats in our diet from the bad, it’s important to understand some basic fat facts. All fatty acids are made up chains of carbon and hydrogen atoms. When every carbon in the chain is saturated with hydrogen atoms, it’s a saturated fat. Saturated fats are stable and they have a regular structure that allows them to pack tightly together, so they’re solid at room temperature. Examples include coconut oil and butter.
When fatty acids have double bonds, not all of the carbon atoms are saturated with hydrogen atoms, so we call them unsaturated. If there’s just one double bond, it’s a monounsaturated fatty acid. If there is more than one double bond, it’s polyunsaturated. Because unsaturated fatty acids are missing hydrogen atoms, they’re always ready to react with other molecules in order to gain some. So they’re naturally unstable. The double bonds in unsaturated fats change their three-dimensional structure, so they don’t pack together as tightly. As a result, they are usually liquid at room temperature, like olive oil and vegetable oil.
Inflammatory Fats
There are two specific types of unsaturated fatty acids that our bodies need but can’t make: omega-3s and omega-6s. (Their names identify the location of double bonds in their chemical structure.) We call them essential because they must be part of our diet. These fats have opposite actions in the body: omega-3s decrease inflammation and omega-6s increase inflammation. Like fat, inflammation is essential. Our immune systems use it to fight infections and heal injuries. But we also want to be able to turn it off once it’s served its purpose. When there is too much inflammation, or if it becomes chronic, it can contribute to cardiovascular disease, diabetes, depression, cancer, autoimmune disease, and neurodegenerative illnesses.
To strike a healthy balance between anti-inflammatory and pro-inflammatory activity in the body, we need both omega-3 and omega-6 fats in our diet, in roughly equal amounts. But most people eat way too many omega-6s and far too few omega-3s. Experts estimate that the average person in the United States eats up to 25 times more omega-6s than omega-3s. So where do they come from?
The parent fatty acid of the omega-3 family, alpha-linolenic acid, is the most abundant fat on the planet. It’s concentrated in green leaves because plants use it for photosynthesis. When animals eat green leafy plants (or algae and plankton in the case of fish and seafood) they become good sources of omega-3 fats themselves. Besides green leafy vegetables, wild seafood, wild game, and grass-fed animal products, other good sources of anti-inflammatory omega-3s are walnuts, ground flax seeds, and olive oil.
The parent fatty acid of the omega-6 family is linoleic acid. Plants use it to store energy in their seeds, which they will later convert to alpha-linolenic acid when they germinate and begin photosynthesis. Here, the term "seeds" refers to the reproductive parts of plants, which includes grains. When we feed grains to animals, they too become sources of omega-6 fats. Other foods high in pro-inflammatory omega-6s include oils extracted from seeds like canola oil, corn oil, cottonseed oil, peanut oil, safflower oil, soybean oil, sunflower oil, and vegetable oil.
Damaged Fats
Besides inflammatory fats, the other group of fats we should avoid is damaged fats. Unsaturated fatty acids are most likely to become damaged because they are unstable and readily react with other molecules. During these reactions, the fats become oxidized, or damaged, and the molecules they react with become free radicals that can damage cells and tissues. Examples of oxidized fats are oils, nuts, and seeds that have gone rancid.
Food processing can damage fats through oxidation by exposing them to high temperatures in the presence of oxygen, and also by altering their structure to extend shelf life. Chemical reactions like hydrogenation and inesterification change the three-dimensional structure of fats, creating trans-fats and other unnatural forms. These fats last longer because they are less susceptible to rancidity, but the disruption to their chemical configuration disrupts the way they work inside our bodies. Damaged fats create inflammation and have been linked to cardiovascular disease, diabetes, obesity, and other chronic illnesses.
Good Fats
Find healthy fats in these foods and make them a prominent part of your diet:
· Green leafy vegetables
· Wild game
· Wild fish and seafood
· Pasture-raised and grass-fed meats, eggs, and dairy products
· Raw walnuts
· Ground raw flax seeds
· Cold-pressed oils: coconut, extra virgin olive, walnut, and flax
· Coconut milk
Because saturated fats are naturally stable and least likely to oxidize, they’re least likely to become damaged. Saturated fats are actually healthy fats, as long as they don’t come from animals that were fed grains or exposed pesticides, antibiotics, or hormones. Despite popular myths, studies show that saturated fats do not cause heart disease.
The fatty acids in oils that are liquid at room temperature are primarily unsaturated and unstable, so always protect them from heat and light. Store olive oil, walnut oil, and flax seed oil in the fridge and never heat them above 300 degrees Fahrenheit. For the same reason, raw nuts and seeds should also be stored in the fridge. When cooking at high temperatures, choose stable saturated fats like coconut oil and butter or ghee from grass-fed cows.
Bad Fats
To get our bodies back in balance, we don’t just need to eat more omega-3 fats, we need to drastically reduce our intake of omega-6s. Start by avoiding these foods:
· Grains and flours including risotto, pilaf, pasta, cereal, bread, and other baked goods
· Grain-fed animal products like meat, eggs, and dairy products
· Roasted nuts and seeds, roasted nut butters
· Processed foods, especially those containing trans-fats or hydrogenated, partially-hydrogenated, or inesterified oils
· Canola oil, corn oil, cottonseed oil, peanut oil, safflower oil, soybean oil, sunflower oil, vegetable oil
· Foods made with these oils like potato chips, French fries, deep-fried foods, crackers, cookies, and other fried or manufactured foods
· Fake butter products like margarine and vegetable oil spreads and sprays
If liquid oils haven’t been cold-pressed, they’ve been extracted with chemical solvents and/or heat that can damage the fatty acids. Not only are the oils listed above pro-inflammatory because they contain too many omega-6s and not enough omega-3s, but they’re likely damaged as well.
Note that all whole foods contain mixtures of saturated and unsaturated fats, of omega-3s and omega-6s. But to simplify the discussion, I’ve categorized these foods based on the types of fat that predominate.
References available upon request. Dr. Sarah Cimperman is a naturopathic doctor in private practice in New York City. For more information, call 646-234-2918 or visit www.drsarahcimperman. com. Read her blogs online at adifferentkindofdoctor.blogspot.com and naturopathicgourmet.blogspot.com.
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