Food seems so complicated sometimes.
And just when you think you've figured it out, someone comes along and tells you you've got it all wrong.
Take, for instance, an article that appeared this month in the journal Open Heart declaring that saturated fats are not the dietary equivalent of the devil incarnate. The article is controversial and goes against the dietary guidelines issued by many major health organizations.
And it just may be on to something.
A fat debate
If you want to eat a healthy diet, avoid red meat, cheese and butter. That's how the conventional wisdom has been dispensed for the last several decades after a few studies showed a connection between saturated fats and elevated levels of low-density lipoprotein, or "bad" cholesterol.
Saturated fats are found in many foods, from meat to dairy to coconut, palm and kernel oils. Health Canada has labelled saturated fats as a "bad" type of fat on its website and advises people to steer clear of it in order to reduce the risk of heart disease.
The idea that saturated fat is unhealthy has been around since the 1950s, when Ancel Keys began publishing research showing a link between saturated fat and heart disease. The results were embraced by the American Heart Association and earned Keys a Time magazine cover. In 1970, Keys published the now-infamous "seven countries study" that found countries where saturated fat consumption was high also had more heart disease. In 1977, the U.S. created Dietary Goals for Americans that recommended higher consumption of carbohydrates and lower consumption of saturated fat and cholesterol.
But the problem is that the evidence backing up this universal condemnation of saturated fat is not exactly rock solid and there are more nuances to the debate than most people realize.
And advising people to lower their fat intake seems to have led to some harmful unintended consequences.
Challenging the accepted wisdom
When Keys published his research, he included data from seven countries that showed a saturated-fats/heart-disease link. But he left out the data from 22 additional countries that largely dispelled that theory.
James DiNicolantonio, author of the Open Heart article that questions the dietary guidance against saturated fats, said there is no good data demonstrating that lowering saturated fat will increase survival or ward off heart disease. In fact, the article points out that mounting evidence shows that lowering saturated fat intake and increasing carbohydrate intake increases the small, dense LDL particles in the blood – particles that promote plaque build-up in the arteries.
Despite this, the public continues to hear the opposite message, likely because it's so difficult to challenge accepted wisdom.
"I think it's because we've all been brainwashed about cholesterol," said DiNicolantonio, a cardiovascular research scientist based in Ithaca, N.Y. "It's just been promoted … but it's not accurate."
What the public needs to understand is that there are several different kinds of saturated fats and they have different effects on the body, said Laurie Wadsworth, associate professor in the department of human nutrition at St. Francis Xavier University in Antigonish, N.S.
Stearic acid is a type of saturated fat found in relatively high amounts in animal fat, which includes red meat and dairy. Wadsworth points out that stearic acid doesn't promote plaque buildup in the arteries and doesn't seem linked to heart disease.
Still, the war on saturated fat persists and this concerns DiNicolantonio because many people have dramatically increased their consumption of refined carbohydrates, including sugar and high-fructose corn syrup, as well as Omega-6 (polyunsaturated) fatty acids, as they lowered their fat intake.
This change in diet has corresponded to skyrocketing rates of type 2 diabetes and obesity, he said.
"Certainly, there's no evidence to lower saturated fat. That needs to be removed [from dietary guidelines]," he said. "I think people need to be more aware of the added sugars that are in almost 80 per cent of the foods that are in supermarkets."
Omega-6 fatty acids are found in corn oil, soybean oil and sunflower oil, as well as nuts and seeds. Fish, such as salmon, are the best sources of Omega-3 fatty acids. The problem is many people consume far more Omega-6 than Omega-3 and that skewed ratio may be linked to some health problems. DiNicolantonio noted that several studies have found an increased risk of death occurs when people consume high amounts of Omega-6, or polyunsaturated, fatty acids.
The bottom line
A shifting view on the health profile of saturated fats isn't a licence to eat a T-bone drenched in butter every night. But the evidence supports the idea that beef and other animal fats can be part of a nutritious diet when used in moderation.
Consumers don't need to get too worked up about the complexities of science, according to DiNicolantonio and Wadsworth. What they should do, if they want to have a healthy diet, is avoid processed, packaged foods and stick to a wide variety of whole, real, nutritious foods – even those that contain animal fats.
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