Nutrition

The PUFA Paradox

Essential… For Profit?

Polyunsaturated fatty acids [PUFAs] are said to be the healthiest fats. In the last century, they have even become “essential” for our health, and it’s almost impossible to avoid ingesting at least some.

Before we suddenly developed a nutritional requirement for these PUFAs, aging was understood as the accumulation of PUFAs in our tissues. Of course, this didn’t sit well with the vegetable oil industry which set out to demonize the saturated fats found in beef and dairy.

When PUFAs accumulate in the retina, it is thought to be the result of aging. Studies have looked at the PUFA content in the tissues of women and children. These also confirm that PUFAs accumulate in our tissues with age.

When the byproducts of PUFA metabolism, like acrolein, are found in the brain, we call it Alzheimer’s. But that’s not going to sell bottles of fish and seed oils.

 

When mercury crosses the blood brain barrier, researchers call it mercury poisoning. Yet, when highly unsaturated fats cross the blood brain barrier, it is said to boost cognitive function.

Consider the fact that many studies have demonstrated a relationship between the degree of unsaturation of tissue fatty acids and longevity. In almost all mammals and birds, maximum longevity is associated with a low degree of fatty acid unsaturation.

In the modern world, as we age, we become less saturated. As non-ruminants, consuming PUFAs leads to them accumulating in our body. And it’s the accumulation of these PUFAs that essentially lowers our life expectancy.

 

Ruminants, like cattle, have rumens which allow them to hydrogenate (saturate) the unsaturated fats from the forage and oils that they consume. So, they can eat a high PUFA diet, yet their adipose will remain almost entirely saturated.

When chickens and pigs are fed a high PUFA diet rich in soy and corn, their fat ends up containing as much PUFAs as canola oil. The same is true for humans. The unsaturation of our adipose tissue is a direct reflection of our dietary fat intake over the past 3 years or so.

 

Marketing & Manipulation

A lot of marketing manipulation was necessary to convince Americans that they should swap the saturated fats from butter with Crisco and other seed oils. Obviously, eating margarine and cottonseed oil was the “patriotic” thing to do. It was also cheaper due to industrialization.

 

Perhaps, the most manipulative scheme was labeling these fats “essential”, despite the fact that becoming deficient in these “essential” fatty acids [EFAs] leads to better health and improved longevity.

As explored here, in 1929, George and Mildred Burr inadvertently found that PUFA consumption slows down the metabolism and thus decreases our nutritional requirements. Later, they found that rats who were deficient in these “essential” fatty acids had substantially faster metabolic rates.

Despite these findings, the Burrs were set out to prove the essentiality of fatty acids such as linoleic acid. So, when their EFA depleted mice developed flaky skin conditions, they attributed it to the lack of dietary EFAs.

A decade or so later, it was discovered that these skin conditions arose from a vitamin B deficiency rather than the absence of dietary EFAs. Perhaps, the introduction of EFAs into the diet only cured the skin condition by slowing down the metabolism and thus lowering the need for B vitamins.

 

Around this time, a volunteer in Burr’s lab went on an extremely low PUFA diet that included plenty of dairy, potatoes, juice, and some vitamin supplements.

His fatigue and migraines disappeared, his blood pressure improved, his metabolic rate increased, and his blood lipids became more saturated. Many people who remove polyunsaturated oils from their diets may experience similar results.

In her defense of low-fat diets, Denise Minger explores incredible stories of weight loss through eating nothing but rice, fruit, sugar, and some vitamins and minerals. These diets proved helpful for heart failure, healing psoriasis, and reducing high blood pressure. They also boosted insulin sensitivity and blood glucose control.

 

One could make the argument that these diets are effective due to their low PUFA content.

Though these diets were also low in saturated fat, once your glycogen stores are topped off, dietary carbohydrates are stored as saturated fat. After all, saturated fats are the fats of mammals.

That’s precisely why we are deficient in EFAs as newborns. The EFA composition of newborns, after a normal pregnancy, depends entirely on the mother’s diet. It has been argued that endogenously produced and supposedly beneficial omega-9s, like mead acid, elevate in place of EFAs.

 

Metabolic Rate & Longevity

There is a general misconception that a slow metabolism confers longevity benefits. This prevailing thought has its roots in Dr. August Weismann’s wear and tear theory of aging as well as Raymond Pearl’s rate of living theory.

Weismann’s theory posits that overtime we wear out from using our bodies. While this theory is intuitively appealing, we are not cars that break down over time. Our bodies are regenerative, restorative machines.

We’re more like a car, with a mechanic driving it, and endless amounts of spare parts and tools. This analogy holds true given that we’re using a high-octane fuel and not filling ourselves with low quality sources of energy like PUFAs.

 

Pearl’s rate of living theory proposes that the faster the metabolism, the shorter the lifespan. Again, this is intuitive, especially when we look at the very slow metabolisms of animals like crocodiles or giant tortoises. These animals can live well beyond 100 years old and can go for several months without eating.

However, this theory has been widely disproven across all different types of organisms.

For example, rats and bats have the same metabolic rate, but bats live far longer. Metabolic rate was found to have no correlation to longevity in birds or mammals, even when statistical methods make corrections for phylogeny and body size.

Machines that run fast are thought to wear out quickly, but this doesn’t hold true in mammals for many reasons. In mice, for example, metabolic rate is positively correlated with longevity.

Mice with the highest metabolic rate had greater total and resting energy expenditure and also lived the longest. A similar trend is observed among dog breeds. Further discussion suggests that it is the increase in resting energy expenditure, across species, that is protective of aging.

 

PUFAs in Nature

PUFAs are perfect for mammals who hibernate since they slow down the metabolic rate. They increase and prolong torpor, decrease the body temperature, and slow down the rate of fat loss during hibernation.

Native Americans knew when to hunt bears – preferably towards the end of hibernation when their fat content was lowest in PUFAs. Bears accumulate fat in the fall on a high PUFA diet, when the ground is replete with acorns.

Although a fat bear might sound like a delicious snack, unsaturated fats quickly go rancid. If this is confusing, just remember that unsaturated implies unstable – easily oxidized.

And if there are doubts about their knowledge of PUFAs, Native Americans have been reported to remove the acorn oils and replace them with more saturated fat.

The Apache and Navajo tribes, known as fierce warriors and hunter-gatherers, avoided eating fish, bears, pork and other foods. Instead, they preferred buffalo, deer and antelope which all happen to be low PUFA ruminants. It is suspected that they too had knowledge of these fats.

 

What else can we learn from hunter-gatherers? Well, they ate nose-to-tail. When looking at healthy hunter-gatherer populations who happen to consume quite a bit of PUFAs, it is important to look at their other habits.

Vitamin A, D, E, K2, cholesterol and thyroid hormone are all protective against PUFAs. And these are all molecules that we would be getting in an ideal environment or an ancestral setting.

As you may know, the thyroid regulates our metabolic rate. A good proxy for our metabolic rate and thus thyroid function, is our body temperature. While PUFAs decrease our body temperature, thyroid hormone increases our body temperature.

A traditional, nose-to-tail, diet may have been more supportive of the thyroid because of its inclusion of nutrient dense organ meats. Those who are born on traditional diets aren’t plagued by vitamin E deficiency from decades of consuming vegetable oils either.

In the United States, the average body temperature has been decreasing since the industrial revolution. It was the resourceful minds of the industrial revolution that took the wasted oils from the cotton industry and sold them for human consumption.

 

Omega-3 Objections

Even those who readily criticize omega-6s from vegetable oils are hesitant to comment on omega-3s. While omega-3s from whole foods (like salmon) may be a concern when consumed very frequently, the real concern here are the fish, algae and krill oils.

These oils, which were once toxic waste products, now comprise an industry that will be valued at $16.37 billion by 2023. And Google’s extraordinary claims about their health benefits warrant a lot of questions…

 

If you’ve picked up milk at the store, you may have noticed that some milk is now being fortified with omega-3s. Yet, study after study has shown that these oils suppress the immune system. They also leave infants at an increased risk of atopy.

A quick google search into lipofuscin will also reveal shocking results. Lipofuscin is also known as age pigment or liver spots. It accumulates as we age, and it shuts down our ability to perform autophagy.

 

Autophagy cleans out damaged portions of cells and it occurs in the lysosomes of our cells. Lipofuscin degrades this process. In monkeys that were fed fish oil, the presence of lipofuscin was three-fold in the liver and measures of oxidative damage were four-fold.

It turns out that high PUFA diets, especially those supplemented with omega-3 oils, drive lipid peroxidation to abnormally high levels. The downstream effects of lipid peroxidation are a host of chronic diseases.

While vitamin E is thought to be protective against lipid peroxidation, even high doses of vitamin E could not reduce the oxidation posed by fish oil supplementation.

Dr. Brian Peskin, the author of the research cited above, posited that fish oils are more harmful than trans fats. This is particularly concerning since a 1994 study found that trans fats had been responsible for at least 30,000 premature heart disease deaths annually. In 2015, trans fats were finally banned.

Many people find short-term relief from taking these highly unsaturated oils, in the same way that they may find relief from eating less or taking ibuprofen. Instead of addressing the underlying cause, these tactics simply suppress the immune system or the inflammatory response.

 

 

EAT WELL. LIVE WELL.

 

Dan Patterson, Head Writer at Sapien.org

 

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