Growing up as a nutrition newbie I did everything in my power to avoid saturated fats. Why?
Because I, like everyone else, was warned not to consume them lest we wanted to stare death in the face.
Saturated fats, or as they’re portrayed in the media, ‘artery-clogging’ saturated fats were given the same status as smoking and trans fat when it comes to heart disease and other diseases of the cardiovascular system.
Is saturated fat bad for you?
Saturated fat is public enemy number 1 – for real?
This is the mantra I told my patients and clients in my early days as a dietitian. This is what I learned in my internship; especially reinforced in my diabetes and cardiology rotations and again throughout grad school.
Without knowing, or being exposed to, the other research or expert opinions out there, I never questioned the conventional wisdom. For that, I apologize.
Turns out that the ‘lipid hypothesis’ of heart disease (the single-minded focus on LDL cholesterol levels as the responsible factor for heart disease and stroke) and the ‘diet hypothesis’ of heart disease (focusing on saturated fats and their impact on LDL cholesterol levels) was never universally accepted by all academics, nutrition researchers, nutritional biochemists, or doctors. Who knew?
For more on the idea that LDL is more bad science than bad cholesterol, check out this great article by Anthony Colpo.
Thing is, as an intern and dietitian, I was never exposed to other hypotheses; the information I received was pre-filtered, supporting the medical model/context in which I was trained and use of medications to target LDL cholesterol levels in the blood without regard to the LDL cholesterol size, endothelial function etc, but I’m getting ahead of myself.
Long story short, there is more than enough science, studies and data to show that the overly simplified message to avoid and minimize how much total fat and saturated fat one eats has clearly missed the mark.
This misguided advice has prevented those with diabetes from using an effective way to manage blood sugar: eating a lower/moderate carb diet which requires more fat for energy; natural fats from whole foods.
On the bright side, many in ‘mainstream’ medicine are softening their stance on saturated fat, and dietary fat in general; change is possible.
Facts about saturated fat that most of the public don’t know about
Saturated fats have been part of the human diet for hundreds and hundreds of thousands of years and our bodies produce saturated fat all of the time: every second, minute and hour. Saturated fats are part of the building blocks of all cells and tissues. If you think of human evolution as one, 24 hour day, the notion that saturated fats are bad for our health only came about in the last 60 seconds of the day.
How could something so insidious, so devastating, so life-threatening have been part of the human experience since time began? Isn’t it more likely that we’ve missed the mark?
1. Saturated fats don’t increase the risk for heart disease as we thought
Most of the research that shaped our view of saturated fat and heart disease was conducted decades ago but the bulk of the early research did not separate out the consumption of trans fat (indisputably bad and DO increase the risk for heart disease) and saturated fat.
Trans fats are made from vegetable oils and turned into a solid fat, i.e. shortening. Early researchers considered naturally occurring saturated fat found in whole foods and artificial trans fat to be the same thing.
They are not.
Never the less, the stage was set for a few decades worth of saturated fat bashing. Before enough research was done, ‘we’ jumped the gun and advised everyone to avoid saturated fats. More recently, when a group of researchers got together, privately, in a closed session without representatives from the pharmaceutical or food industry, to review the literature, a different picture emerged.
Once the studies that included trans fat were taken out of the equation, the association of saturated fat and heart disease disappeared.
A recent large analysis of 21 studies involving 347, 747 individuals found no association between saturated fat and heart disease risk (1).
This is in keeping of other systematic reviews that also looked at the association of saturated fat and cardiovascular disease (2, 3, 4).
2. Saturated fat increases HDL a.k.a. ‘good’ cholesterol
Cholesterol is categorized into two simplistic camps, LDL or ‘bad’ because this is the form of cholesterol that, under specific conditions, can lead to heart and vascular disease. HDL is called ‘good’ because it helps to prevent heart and vascular disease by mopping up excess cholesterol deposited in blood vessels and arteries and taking it back to the liver to be eliminated (5, 6, 7).
HDL will also carry a lot of protective antioxidants, like CoQ10, vitamin E, phytonutrients like lycopene, lutein, alpha and beta carotene, and polyphenols from foods like green tea, chocolate, and olive oil, to your blood vessels; these antioxidants help to prevent damage to the blood vessels.
In a nutshell, the higher your HDL level, the better.
For men. > 1.0 mmol/L or 40 mg/dL
For women. > 1.3 mmol/L or 50 mg/dL
Even if LDL [‘bad cholesterol’] is high, HDL will protect you from heart and vascular disease. Think having low LDL cholesterol levels is enough? Nope, as HDL levels drop, the risk for heart disease increases, even if LDL is low!
HDL levels are largely genetically determined but lifestyle can have a profound impact. Traditional advice to raise HDL includes weight loss, exercise, smoking cessation, reducing sugars and refined carbs, and moderate alcohol consumption but these will barely make a difference.
The single best way to boost HDL, and I mean from 0.9 to 1.60 mmol as was in my case, is to eat saturated fat; no other lifestyle or dietary factor will be as effective. My doctor is still shell-shocked to this day. I couldn’t get my HDL to budge despite all the exercise and ‘heart healthy’ monounsaturated-rich foods like olive oil, avocado oils, nuts, seeds and the like.
3. Saturated fats increase the size of LDL cholesterol molecule
Unknown to the public is the fact that LDL cholesterol comes in different sizes; basically from small and dense to very large and size DOES matter. When you get your blood test and your doctor looks at your LDL level, he or she knows nothing of the size of it (there are other ways to gauge the size though, more on that in a minute).
You see, if the LDL molecule is small in size, it has a better chance of becoming damaged, or oxidized. Think of oxidation like an apple that browns once it’s exposed to the air, or how an iron nail can rust. Small LDL cholesterol can also easily penetrate the lining of blood vessels,
When LDL is damaged/oxidized and/or of the small kind, it easily penetrates blood vessels and promotes inflammation; setting up the process of atherosclerosis or plaque formation (8, 9, 10, 11, 12).
This is why most people who have their first heart attack, often have normal or low cholesterol levels; just looking at the lab value for LDL isn’t the whole picture because small oxidized LDL has no correlation with blood levels of LDL (13).
In fact, small dense LDL is 3x more likely to lead to heart disease than normal or large-sized LDL cholesterol (14)
Large LDL cholesterol doesn’t increase the risk. It’s better protected from oxidation because it can carry a ton more antioxidants like HDL can and because of its size, doesn’t penetrate the blood vessel wall, but kinda bounces off of it as it travels through the bloodstream.
The best way to ensure your liver produces lots of large LDL cholesterol is to, you guessed it, eat less sugar, refined carbohydrate-rich foods like all the white stuff, eat more saturated fat and, believe it or not, eggs (15, 16, 17, 18, 19).
Can you imagine? Eating eggs actually produces less atherogenic (heart disease-promoting) LDL cholesterol.
The easiest way to gauge if you have large LDL cholesterol is to look at all your blood work, not just the LDL (which is what your doctor does): high HDL, low triglycerides and LDL within a normal range = large LDL (good). The opposite, low HDL, high triglycerides = small LDL even if LDL is within the normal range (bad).
4. Saturated fats don’t oxidize easily like polyunsaturated fats do
It’s an undisputed fact that the more double bonds a molecule has, the easier it is for it to oxidize, or become damaged. Saturated fats don’t have any double bonds whereas polyunsaturated fat, as the name implies, ‘poly’ meaning many, and unsaturated meaning double bonds have lots of them.
Diets high in polyunsaturated fats increase the amount of polyunsaturated fats in LDL cholesterol. The more polyunsaturated fats in LDL, the greater the degree of oxidation; remember, the amount oxidized LDL is a better predictor of atherosclerosis than the total amount of LDL in a blood test.
Already noted, oxidation of LDL is a pivotal first step in atherosclerosis, or plaque formation. Analysis of oxidized LDL cholesterol reveals that they are full of ‘heart healthy’ polyunsaturated fats.
Not only that, analysis of the lipid (fat) portion of plaques, taken from blood vessels, show that they contain a disproportionately high concentrations of the omega-6 fat [not saturated fat], linolenic acid.
The amount of linolenic acid in plaque correlates with dietary intake (20, 21, 22, 23). The major source of linolenic acid is grain and seed oils: corn, soy, sunflower, safflower, grape seed, hemp, walnut, ‘vegetable’, sesame, peanut and canola oils. Too many grain and seed oils also throw off the omega-3 to omega-6 ratio.
These oils are pushed because they can lower total LDL in the short term but long term studies have revealed that they increase the risk of heart disease. Research and promotion of these oils have only focused on their impact on blood levels of LDL and not their impact on increasing LDL oxidation.
5. Many foods with saturated fat are super nutritious
Humans have been eating foods with saturated fat for millennia and we’ve relied on those foods to provide us with an abundance of essential nutrients. Because of the saturated fat debacle, many traditionally nutritious foods have been demonized.
These include liver, eggs, organ meats, and higher fat dairy products. These foods are rich in fat-soluble vitamins A and K2, choline, zinc, iron, and conjugated linolenic acid or CLA.
Many of these nutrients have been shown to reduce fatty liver (choline), anemia (iron), are needed for brain health (choline), improve immunity (zinc, vitamin A), reduce heart disease (K2) and reduce the risk for cancers (CLA)
Bottom line:
None of this means that we should be eating copious amounts of butter, cream, coconut milk, coconut oil, full-fat cheese, yogurt, milk, bacon or necessarily make them the mainstay of our diet. It does mean that the almost obsessive focus on reducing our intake of saturated fat has been misguided.
Eating a variety of nutrient-dense, whole foods that naturally contain different fats will ensure you’re getting a balance of all fats and it is for this reason that I don’t fear or avoid any of the foods listed above.
I enjoy them as part of diet that includes plenty of vegetables, fish, some fruit, nuts, seeds, small amounts of whole grains and pulses [chickpeas, lentils, dried peas & beans]. I have, however, taken steps to reduce my intake of the omega-6 fat, linolenic acid, by removing all grain and seed oils and products made with them and gave up margarine a long time ago.
Doug Cook RDN is a Toronto dietitian and functional nutritionist with a focus on digestive, gut, mental health. Follow me on Facebook, Instagram and Twitter.