First of all, what exactly are Polyunsaturated fats?
Pufa’s are an acronym for polyunsaturated fatty acids.
Fats are typically listed under three headings.
They are the polyunsaturated, monosaturated and saturated.
Saturated fat wins class president because of it’s popularity. It’s the one mentioned in lunch rooms, ordering from a menu or while critiquing someone’s eating preferences. It’s had a bullseye on it’s back for 40 years but recent studies have challenged the lipid hypothesis (1,2). Those who have had an above interest in nutrition for even a short time could see the collapse of the saturated fat theory coming.
Examples of saturated fat are butter, cocoa butter, coconut oil, beef and lamb fat.
A distant cousin of saturated fat is trans fat. This fat has deservedly received its fair share of scrutiny (3). This fat fortunately can’t put up the same resistance that saturated fat gave since being exiled to low lipid island.
Trans fat falls under the polyunsaturated heading. If you see partially hydrogenated or hydrogenated oils listed on the product it’s like seeing those warning signs on ski mountain sides.
You’ll find trans fat in doughnuts, baked goods including cakes, pie crusts, biscuits, frozen pizza, cookies, crackers, some cereals, and stick margarines and other spreads. These fats are undeniably recognized as problematic. They have been linked to high blood pressure, obesity, and heart disease. Consumption may also lead to alzheimer’s disease, prostate and breast cancer, type 2 diabetes, liver dysfunction, infertility, and depression (4,5,6,7,8,9,10,11).
Fred Kummerow (who worked in his lab till 102) lobbied the FDA in 1957 to ban trans fats. For 50 years he preached the dangers of these fats. Not until 2015 did the FDA take trans fat off the GRAS (generally regarded as safe) list.
Trans fat is not up for debate on it’s negative health affects.
As mentioned, trans fats is a polyunsaturated fat. Does that hang a question mark on avoiding the other polyunsaturated fats ?
Kummerow, also known as “the man who saved thousands” says this about pufas:
“They oxidize so quickly they become a nuisance in the body, not a help.”
Dr. Broda Barnes, whom I have mentioned before says this about pufas:
“Polyunsaturated fats offer you absolutely nothing except an earlier grave. If you doubt that, go to the autopsies done among the Bantu, among the Japanese and you will find that their arteriosclerosis before the age of thirty is far greater than it is on the American diet, or on the Austrian diet, very similar to ours. Polyunsaturated fats, when this story is finally written is going to make Watergate look like a church social. This is a lie that has been forced on the public.”
The dated reference is funny but the message is not.
“But wait! I thought those fats were good? Canola? Becel? Isn’t Soybean oil in most things? There are green check marks and heart symbols on the label!”
This is where the debate happens. Trans and saturated fat was misunderstood and debated for years with the dust finally settling. Presently, PUFA is slowing leaking oil – rancid oil. Each month more studies surface questioning the efficacy of polyunsaturated fats.
Every oil has a temperature in which it goes rancid or oxidizes. That’s why they put some in dark bottles so light won’t impact. Oxygen, light and heat are the nemesis of these oils.
Guess where you’ll find oxygen and heat plentiful?
That’s right – inside our bodies.
Those oils wouldn’t hurt anybody if they only went rancid while sitting on the shelf but unfortunately they get ingested.
Supplement companies and health experts preach buying antioxidants but wouldn’t it just be better to avoid something that oxidizes so easily and rapidly?
They get stored in the tissues and tend to age the body. They have been linked to inflammation, Alzheimer’s, dementia, diabetes, depression, slowing of the thyroid, cancer, heart damage, and lipofuscin (age spots) to name just a few (12,13,14,15,16,17).
Early 1900’s, a guy named Proctor and his brother in law named Gamble came together and started making candles and soap. Then came the introduction of the light bulb and the need for one of their products was gone. It wasn’t the soap. What to do with all the oil? They bought a patent which turned cottonseed oil into a creamy solid known as Crisco. With a heavy marketing campaign and smearing of lard and butter, Crisco took off. An issue of popular science at the time made this comment:
“What was garbage in 1860 was fertilizer in 1870, cattle feed in 1880, and table food and many things else in 1890.”
Farmers have known for years the affect pufas have on metabolism. They have used soy and corn to fatten livestock. They knew it slowed down metabolism and when selling by the pound it makes economic sense. A slower metabolism and the animal doesn’t have to eat as much to reach optimal weight. That’s a win/win for the farmer.
When Nixon was trying to get re-elected in early 70’s he wanted to make food cheaper so he subsidized the corn oil industry. Coincidently the lipid hypothesis surfaced around the same time so this set up the perfect climate to run with these oils.
The blame game has fallen on saturated fat, sugar and salt the last 40 years. But as the attached chart shows the rate of pufa increase has been the one thing in our food supply that has changed the most.
I know correlation doesn’t equal causation because that graph could also represent the amount of TV’s in households.
But the one common denominator added to the food supply and increased over the last 100 plus years has been these cheap oils.
Most have heard of the French paradox where the French eat higher percentages of saturated fat than other countries but have lower coronary heart disease(CHD).
The Israeli paradox is also fat related. Susan Allport, author of Queen of Fats, summarizes the Israeli paradox in the following words:
“Israelis eat less animal fat and cholesterol and fewer calories than Americans, but they have comparable rates of heart disease, obesity, diabetes and many cancers. They have an ideal diet, as far as the American food pyramid is concerned, but far from ideal health. Little butter is consumed in Israel, but large quantities of soybean, corn and safflower oil are.”
PUFAs are in most foods. The most problematic are obviously the liquid vegetable and seed oils.
Most restaurants, if not all will use the cheaper oils to increase profit margins.
According to a Boston Consulting Group report, Americans eats out 3.4 times a week. Canadians eat 1 in 10 meals outside the home while Australians eat out more than twice a week.
How much is acceptable?
The best answer would be lower the better.
You would probably have to be in a lab to have complete avoidance. That statement is not meant to cause stress but instead just bring awareness to issue. Becoming worried over which restaurants use lower pufa can be just as unhealthy as the oil. However, there is no reason a person can’t consciously avoid the affecting foods over 20% (see list) when eating at home. Eating under 10% most of the time may take more planning but is achievable.
Please read labels when buying products and try not to be fooled by sleek marketing .
Omega 6 content of common foods by percentage of total calories:
Extremely High (Above 50%):
Grapeseed oil 70.6%!
Corn Oil 54.5%
Walnuts 52.5% (oil is 53.9%)
Cottonseed oil 52.4%
Soybean oil 51.4%
Very High Omega 6 sources (20-50%)
Sesame oil 42.0%
Peanut Butter 22.5%
High Omega 6 Sources (10-20%)
Chicken Fat 19.5%
Canola oil 19.0%
Flaxseed oil 12.9%
Duck Fat 12.2%
Bacon Grease 10.2%
Moderate Omega 6 Sources (5-10%)
Olive oil 9.9%
Goose Fat 9.8%
Chicken with skin 9.0%
Pork chops 6.2%
Popcorn (Air Popped) 5.8%
Low Omega 6 Sources (2-5%)
Chicken Liver 3.7%
Sunflower Oil 3.7% (High oleic variety – others are very high in omega 6)
Beef Tallow 3.1%
Cocoa Butter 2.8%
Cooked carrots 2.7%
Macadamia Nut oil ~2.5%
Brown rice 2.5%
Beef liver 2.1% Grass-fed Beef 2.0%
Whole wheat flour 2.0%
Extremely low Omega 6 Sources (Less than 2%)
Coconut oil 1.9%
Prime rib 1.8%
Whole milk 1.8%
Half and Half 1.8%
Ground Beef 1.6%
Macadamia Nuts 1.6%
Chicken without skin 1.4%
Corn grits 1.2%
Coconut Milk 1.1%
Foie gras 1.1%
Palm Kernel Oil 0.8%
White rice 0.7%
Sockeye Salmon 0.5%
Canned tuna 0.1%
Blue crab 0.1%
Don’t get me wrong. I’m not an absolutist. It’s not pragmatic to feverishly avoid everything on this list above 2%. Like I mentioned, that may cause more stress than the affecting food. However, it doesn’t take anymore energy to grab a jar of coconut oil from the shelf than a bottle of canola. It is reasonable however to avoid those pufas that are high on the list most of the time. No food is inherently evil – although grapeseed and corn oil are trying 🙂
Supplementing vitamin E and asking for coconut oil or butter when dining out can help counter some effects of these fats.
And for those who know the potential harm and still promote these oils – shame on you.
Fats, Functions and Malfunctions
Suitable Fats ; Unsuitable Fats