The Dark Side of Polyunsaturated Fats (PUFA's)
For decades, people have been told to embrace a low-carb diet, in large part because of the belief that processed carbohydrates — and specially processed sugars — are the primary driver of chronic disease in Western countries.
But another type of food might have an even more detrimental impact on our health. It’s not saturated fat, as the American Heart Association and other “trusted” sources would have you think. I’m referring to supposedly “heart-healthy” polyunsaturated fatty acids (PUFAs), in particular, Omega 6 PUFAs; that are linked to heart disease, obesity and even cancer.
What Are PUFA’s?
Polyunsaturated fat, also known as PUFA, is a type of unsaturated fat found throughout the diet in both plant-based foods and animal sources.
It’s said there are two types of fat — good or healthy fat, which includes mono-and polyunsaturated fats, and bad or unhealthy fat, which includes trans-fats and saturated fats.
Trans fat is made by chemically altering liquid vegetable oils to make them solid at room temperature and shelf-stable. Often found in highly-processed foods — they negatively impact insulin sensitivity, bringing a risk of developing diabetes, cardiovascular disease and other health issues.
Animal foods like meat and cheese contain high levels of saturated fat, as does coconut oil. We are told this type of fat is unhealthy because it can increase the level of bad cholesterol in the body, developing heart problems and stroke. (WebMD.com)
While I agree about the dangers of trans-fats, I strongly disagree about saturated fats being a health danger. Of course, this runs counter to conventional wisdom:
The top U.S. medical outlets state:
Cleveland Clinic: Saturated fats and trans fats are bad for you, period.
Harvard Health: Good fats include monounsaturated and polyunsaturated fats.
American Heart Association: Eat foods containing monounsaturated fats and/or polyunsaturated fats. Polyunsaturated fats can help reduce bad cholesterol levels.
Yet, other health experts argue that the overconsumption of PUFAs has a greater negative impact on our society than processed carbs and sugar. Linoleic acid is the shortest chain of the common omega-6 fatty acids, and chances are that you’re consuming incredibly high amounts of this substance every day without realizing it.
That’s a major health problem because linoleic acid has been shown in several studies to damage fat cells, leading to inflammation and metabolic dysfunction that will ultimately cause obesity, heart disease, cancer, insulin resistance, Alzheimer’s (also known as Type 3 diabetes) or any of the other chronic diseases that affect most people.
The consumption of linoleic acid also causes hyperphagia — the medical term for excessive hunger. This is likely the reason why you can’t eat just five potato chips (fried in seed oils), emptying the entire bag instead. (MichaelKummer.com)
Substituting dietary linoleic acid in place of saturated fats increased the rates of death from all causes, including coronary heart disease and cardiovascular disease.
The primary issue with PUFAs is that they are highly unstable, quickly becoming rancid or toxic at very low temperatures. This starts during processing when they’re exposed to high heat; during travel when they become more damaged and unstable; and especially during cooking.
These oils are extremely prone to oxidation that leads to free radicals which can cause major cellular damage in the pancreas (producing insulin) and disrupt effective blood sugar handling. Thyroid health is affected, as is general hormonal balance, our digestion and immune system, as well as detoxification from the liver.
Throwing Out Baby With Bathwater
Advice to increase omega-3 fatty acid consumption and radically decrease omega-6 consumption is widespread. But really, should we throw out the baby with the bathwater? By that I mean, are all omega-6s the problem, or just how we process, transport and cook omega-6-rich foods?
Omega-6 has been demonized in the wellness community but this type of polyunsaturated fatty acid (PUFA) is still essential to human health. It’s where we get this food from that’s the problem. In recent decades, consumption of refined omega-6 PUFAs has skyrocketed, as has a dramatic increase in modern chronic disease.
Most consumption of PUFAs is dominated by vegetable oils from soybeans, corn, and sunflower, rather than from fresh, whole foods like nuts, seeds, and pastured meats. And so we have an issue where these corrupted (refined) fatty acids make us sick but of course, all PUFA’s are grouped together, regardless of the source.
It’s the same issue from years ago when all carbohydrates were vilified, regardless of being processed or refined. Yet both have remarkably different effects on the human body.
Whole-food sources of omega-6 come packaged with other nutrients like dietary fibre, nutrients, tocopherols, phytosterols, polyphenols, and more. Can we really discount their effects in protecting unstable omega-6 fatty acids from being oxidized?
Epidemiological evidence supports the idea that different sources of omega-6 might have different effects on health. Nuts and seeds contain large amounts of omega-6 and are said to be bad for us because of PUFA’s. Yet they’re consistently associated with less cardiovascular disease, not more, as well as less inflammation, and reduced risk of type 2 diabetes and cancer. Sadly, this type of evidence is not well known because studies on whole foods are really lacking, while marketable food items such as plant oils get all the love in research.
Remember to maintain a healthy omega 3 to omega 6 dietary balance. The ideal ratio of omega-6 to omega-3 is 1:1, but because of food processing, today’s modern diet suffers a 15:1 ratio imbalance (too much omega-6: too little omega-3). This leads to severe health issues, including inflammation, depression, obesity, and cancer.
Foods high in Omega 3 include fatty fish (such as salmon, herring, and mackerel), flax seeds, chia seeds, hemp seeds, walnuts, and navy beans. Omega-3-enriched eggs are also an excellent source of these fatty acids.
Rancid Vegetable Oils
The more concerning form of omega-6 is in vegetable oils. Repeated heating of vegetable oils is common practice in the food industry, particularly in large deep-fryers where the oil is heated to temperatures greater than 400 degrees Fahrenheit. This causes severely unhealthy thermal lipid oxidation associated with CVD risk, increased blood pressure, decreased nitric oxide (20), increased total cholesterol, vascular inflammation and changes to vasculature that predispose to atherosclerosis. In other words, garbage in, garbage out! (DrAxe.com)
But it’s not just the heating process. Even unheated canola, soybean, sunflower and other processed oils cannot be a part of a healthy diet. The majority of oils high in omega-6 PUFAs are produced using heat before they ever make it to your kitchen table. They may also contain trace amounts of solvent from the refining process and lack necessary nutrients and beneficial carotenoids, tocopherols, and sterols. In what world would oils extracted with high heat and chemicals be better for our health than unadulterated saturated fats from animal sources?
Here’s a list of popular cooking oils that I highly recommend you stay away from:
Almond oil, apricot kernel oil, canola oil, corn oil, cottonseed oil, grape seed oil, hazelnut oil, mustard seed oil, oat oil, palm oil, peanut oil, rice bran oil, safflower oil, sesame oil, soybean oil, and sunflower oil.
They all contain incredibly high concentrations of omega-6 (i.e., linoleic acid), have little or no (protective) omega-3 fatty acids, are manufactured using high heat (which causes oxidation and rancidity) or harsh chemicals (e.g., hexane), or are subject to a combination of these factors.
You also want to watch out for hidden sources of refined PUFA exposure, such as:
Snacks - Most energy bars, granola, potato chips, etc.
Commercially raised beef, poultry, and eggs. Animals fed a diet high in PUFA (i.e. corn and soy) contain high levels of tissue PUFA, while with the grass-fed variety, this is not so.
Most restaurants and take-out options use PUFA cooking oils.
Fish Oil - Yes, fish oil is a PUFA because its oil has oxidized before you purchase the bottle.
What To Do?
Take a whole food philosophy. Whole foods are always better than the sum of their parts, especially when grown or raised as naturally as possible and high in nutrients. Then we’ll get PUFAs in natural amounts, the way nature intended, while avoiding industrial oils.
2. Use context. Consider the context of the entire diet and lifestyle. Diets highest in PUFAs are also high in processed food, refined carbohydrates, sugar and tend to be low in produce, fibre and diversity. Also work on foundational lifestyle issues such as exercise, sleep, sunlight and so on to yield greater benefits.
4. Be careful about rancidity. Ultimately, highly processed oils are best to avoid. Other oils, such as omega-3 fish or flax oils, are very sensitive to light and heat and highly prone to rancidity, as discussed. (AnnShippymd.com)
In conclusion, polyunsaturated fats are essential to health, but not all sources are created equal. Foods like nuts, seeds and fish are all sources of polyunsaturated fat that are loaded with important nutrients and health-promoting properties. Meanwhile, highly processed and heavily refined foods like vegetable oils are high in polyunsaturated fat but do not carry the same health benefits.
Additionally, it’s important to keep your intake of omega-6 and omega-3 fatty acids in balance. While your body needs both to function and thrive, most of us get far more omega-6 fatty acids than we actually need. (DrAxe.com)
Try incorporating more omega-3 foods, such as fatty fish, nuts, seeds, natto and egg yolks, into your daily diet to be sure you get enough of this vital form of polyunsaturated fat. Also use healthy cooking fats like olive oil, coconut oil, ghee, and other pastured animal fats to keep a healthy omega-3 to omega-6 ratio to stay healthy.