As coveted as polyunsaturated fats are by the brain, they are delicate and highly vulnerable to a process called oxidation. Oxidation occurs when oxygen (you may have heard of it) reacts chemically with certain molecules to create a new, damaged “zombie” molecule that has a super- reactive extra electron, called a free radical. How reactive is
“super-reactive”? Let’s just say these radicals make the White Walkers from Game of Thrones look like a caravan of pacifist hippies.
That extra electron can then react with another nearby molecule, transforming it into a second free radical and setting off a never-ending chain reaction that leaves utter mayhem in its wake. It’s the biochemical equivalent of the zombie apocalypse, one molecule biting and infecting the one next to it, spawning a horde of the undead. Pioneering Austrian organic biochemist Gerhard Spiteller, who had done much of the eye-opening research on the dangers of oxidized polyunsaturated fats, put it this way:
Radicals are typically four orders of magnitude (10,000x) more reactive than non-radical molecules.
Their action is not under genetic control, they attack nearly all biological molecules, destroying lipids, proteins, nucleic acids [DNA], hormones and enzymes until the radicals are quenched by scavenger molecules.
This is a form of chemical damage that all organic matter is subject to, like rust on iron (iron is actually a catalyst for this same process in the human body, and may partly explain why men get more and earlier heart disease than women: they have more red blood cells, and more iron in circulation) or a sliced apple that has turned brown. Leave an apple slice on the counter for a few minutes and you can appreciate just how quickly these chemical reactions take place. In the body, excessive oxidation equals inflammation and damage to cellular structures and DNA. It’s also thought to be one of the primary mechanisms of aging.
The battle against oxidation is a constant game of tug-of- war for all living creatures. Our own bodies, when healthy, have built-in antioxidant defense capabilities, and ideally, we churn out antioxidants—the aforementioned scavenger molecules—as fast or faster than free radicals can be created. (Many of the Genius Foods are beneficial in part because they increase your body’s production of its own scavenger molecules.) Chronic inflammation or diseases like type 2 diabetes impair our ability to fight the accumulation of oxidative stress, and this is compounded when we absorb excess pro-oxidants from our food. It only takes a small amount of oxidative stress to set off a nuclear chain reaction of biochemical destruction, and the balance is a delicate one.
This places the brain in a unique and precarious situation. Accounting for 20 to 25 percent of your body’s oxygen metabolism, constructed in large part by these delicate polyunsaturated fats, and squeezed into a container the size of a grapefruit, it couldn’t be a larger magnet for
oxidation. When oxidative stress overwhelms our natural antioxidant systems, brain fog, memory loss, DNA damage, and the onset or worsening symptoms of Alzheimer’s, Parkinson’s, multiple sclerosis (MS), Lewy body dementia, and autism ensue.
Intact (let’s call them fresh) polyunsaturated fats are vulnerable to oxidation, but when they appear in their natural state, contained in whole foods, they are bundled with fat-guarding antioxidants like vitamin E. This is not the case when polyunsaturated fats appear in oils that have undergone heat and chemical processing. When these oils are extracted and used to create packaged foods, they represent one of the major toxins in our food supply.5
Sometimes these oils are where you’d expect to find them, like in commercial salad dressings and margarines.
Other times, they are sneakier. Grain-based desserts like cookies and cakes, granola bars, potato chips, pizza, pasta dishes, bread, and even ice cream are among the top sources of oxidized oils in the diet.6 They coat and comprise the
“varnish” on breakfast cereals. “Roasted” nuts are covered with them (unless they explicitly say they are dry-roasted).
And these oils are regularly served to us in restaurants, where processing, poor storage methods (being left out in a warm kitchen environment for months, for example), and heating and reheating make these highly susceptible fats go bad. Most restaurants now fry and sauté foods in them, reusing the oil over and over, further damaging them, and damaging you in the process. French fries? Shrimp tempura? Those delicious beer-battered chicken fingers? All are vehicles for these biochemically mutated oils, and for
massive amounts of dangerous compounds called aldehydes.
Aldehydes are by-products of fat oxidation and have been found in elevated amounts in Alzheimer’s-riddled brains. They may influence the susceptibility of proteins in the brain to cross-link and clump together, thereby forming the plaques that gunk up the brain and are characteristic of the disease.7 These chemicals also serve as powerful toxins to the energy-generating mitochondria of the brain and spinal cord.8 Aldehyde exposure (resulting from consuming rancid oils) directly impairs cells’ ability to generate energy.
This is pretty bad news for your brain, the chief energy consumer in your body.
Even after one polyunsaturated oil–rich meal, circulating markers of fat oxidation skyrocket by about 50 percent in young people, while a fifteen-fold increase in markers of rancid oils has been observed in older subjects.9 Another study noted that arteries become instantly stiffer and less responsive to the demands of exercise after a similar meal.
These fats, far removed from their natural form, fuel the underlying mechanisms of chronic disease, damaging your DNA, causing inflammation in your blood vessels, and raising your risk for several types of cancer.
These are the ominous oils to watch out for:
Canola oil Safflower oil
Corn oil Sunflower oil
Soybean oil Rapeseed oil
Vegetable oil Grapeseed oil
Peanut oil Rice bran oil
The food industry’s search for cheap oil that it could market to the American people resulted in a veritable rogue’s gallery of deplorables. Sure, we eventually found out that trans fats were worse for our health than real butter could ever be, but our veil of ignorance continues to be exploited on butter-yellow tubs with labeling like “no hydrogenated oils,” “non-GMO,” and, of course, “organic.”
In reality, these wellness buzzwords only serve to obscure the few pennies’ worth of mutated, rancid, heat-damaged Frankenfats that have been squeezed into a tub and sold for
$4.99 in the premium health food section of the supermarket.
Cottonseed, canola, safflower, sunflower, and soy oils—
all are bad news and are hidden virtually anywhere manufacturers can squeeze them. In all, our use of these oils has skyrocketed two hundred– to one thousand–fold in the last century (the latter figure being the case for soy), despite an overall 11 percent decrease in total fat consumption by adults in the United States between the years 1965 and 2011.10 These oils now make up 8 to 10 percent of total caloric intake for Americans—up from almost zero at the turn of the century. While a handful of sunflower seeds or peanuts or a corn on the cob may be perfectly healthy, there is no safe level of consumption for any of these oils when
industrially extracted from their original food sources and heated to high temperatures.
FAQ: I thought canola oil was healthy because it contains omega-3s?
A: Canola oil is highly processed. While it does contain a relatively high amount of omega-3s compared to other oils, omega-3s are even more vulnerable to oxidation than omega-6s. The processing of canola oil creates just as many oxidative by-products, including trans fats, which damage your blood vessels and your brain cells.11 More on this later.