Last month, I had the honour of speaking at the Cruelty Free Festival in Sydney. I titled my presentation ‘Myth-Busting the Vegan Diet’, and boy, are there a lot of myths to bust.
In the Q&A session afterward, several people asked questions relating to fat intake.
This is actually one of the most contentious areas of nutrition, even in the plant-based nutrition world. The Internet is awash with misinformation regarding fat, and a slew of popular pro-fat books released over the last several years has only contributed to people’s confusion about how much fat they should eat, and what type is best.
I’ve been asked so many questions about fat both by clients and members of EmpowerEd, my health and nutrition education program, that I thought I’d gather all the Big Fat Myths together into one post.
Here they are, in no particular order:
Myth #1: Coconut oil is a healthy food
I’ve covered coconut oil in detail in my article Coconut oil: beyond the hype; just to summarise this long and fully-referenced article, coconut oil:
- Does not help you lose weight or belly fat;
- Does raise the ‘bad’ LDL cholesterol, as well as triglycerides, which is associated with an increased risk of heart disease;
- Does impair insulin sensitivity, which raises your risk of type 2 diabetes;
- Does not prevent Alzheimer’s disease; and
- Does dramatically decrease endothelial function (the ability of the inner lining of your blood vessels to regulate blood pressure and stop plaque formation) and impair the antioxidant capacity of HDL for at least 6 hours after consumption.
Again, read my previous article if you want more detail on coconut oil.
Myth #2: Olive oil is heart-healthy
Once again, I’ve already discussed olive oil in great detail in The Mediterranean diet: sorting fact from fantasy. The bottom line is that olive oil is not ‘heart healthy’; it’s just less damaging to cardiovascular health than saturated animal fats such as butter, which is hardly a ringing endorsement of olive oil.
Just like coconut oil, olive oil impairs endothelial function, causing accelerated growth of cholesterol-laden atherosclerotic plaques that cause heart attacks and strokes.
And if you’ve heard that the PREDIMED (Prevención con Dieta Mediterránea) study proved that a Mediterranean diet with either olive oil or nuts is better for cardiovascular disease prevention than a low-fat diet, you’ve been suckered by one of the biggest Big Fat Myths of our time.
You see, the people assigned to the ‘low fat’ diet in the PREDIMED study didn’t eat a low fat diet at all.
As the table below, from the Supplementary Index to the study shows, the control group began the study eating a really high fat diet (39% of energy intake from fat), and ended up eating… a really high fat diet (37% fat).
So what the PREDIMED study actually proved is that a pretty bad diet supplemented with olive oil or nuts, is a bit better for you than a truly god-awful diet. How much better? Well, eating a Mediterranean diet plus olive oil would lower your risk of the primary end point (a composite measure of heart attack, stroke, and death from cardiovascular causes) by 0.6% compared to eating the ‘low fat diet’ that was anything but low fat, and eating a Mediterranean diet plus nuts would lower your risk by 1%.
Excuse me for not being blown away by these outcomes, especially when I compare them to the amazing results that Drs Dean Ornish and Caldwell Esselstyn have obtained, using a low fat plant-based diet to reverse heart disease!
Myth #3: Avocado contains essential fats
Every time someone trots out this particular myth, I get an almost uncontrollable urge to scream at them, ‘Stop taking advice from people who earned their nutrition degree from the Academy of Google!’
As anyone who has actually taken a nutrition course knows, there are only 2 essential fatty acids (building blocks of fat that you have to eat, pre-formed, in your diet because you can’t make them yourself). They are the 2 polyunsaturated fatty acids
- Linoleic acid, an omega 6 fatty acid; and
- Alpha-linolenic acid, an omega 3 fatty acid
That’s it. Every other type of fat that we need, we can make all by ourselves, out of these 2 fatty acids along with non-fat precursors, chiefly carbohydrate.
Avocado contains chiefly monounsaturated fat; in fact out of the 32 g of fat in half an average avocado (flesh only), over 19 g is made up of monounsaturated fat. The remaining fat in an avocado is chiefly saturated (more than 5 g), leaving just over 4 g of polyunsaturated fat. Out of this, most is linoleic acid (the omega 6 fat that most people get too much of anyway) and 0.255 g is alpha-linolenic acid (the essential omega 3 fat). In what universe does this constitute a food high in essential fats?
(For comparison, a heaped tablespoon of ground linseed (flaxseed) contains 2.3 g of alpha-linolenic acid and 0.6 g of linoleic acid, easily fulfilling the Australian RDI of 0.8 g of alpha-linolenic acid for women and 1.3 g per day for men.)
Now, don’t get me wrong, I love avocado and enjoy the rich, creamy texture that it brings to salads and Mexican foods. But I don’t fool myself that it’s making some irreplaceable contribution to my nutritional intake; it’s just a treat that I have in very limited amounts.
Myth #3: Eating fat helps you lose fat
Oh, puh-lease. I know people love to hear good news about their bad habits, but this one is beyond ridiculous. The people pushing this myth are the same ones telling you that eating carbohydrate-rich foods such as rice, potatoes and lentils makes you fat, despite the fact that the slimmest populations of humans on the planet eat a starch-based diet.
Here are some facts about fat:
- Fat contains 9 calories per gram, carbohydrate supplies under 4 calories per gram
- The fat in your meal turns into fat on your body within a few hours.
- It takes virtually no energy expenditure to convert the fat you eat into the fat stored in your body, whereas converting carbohydrate to body fat costs a significant amount of the energy in the carbohydrate. As Dr John McDougall is fond of saying, “The fat you eat is the fat you wear.”
A 2015 study in which obese people were confined to a metabolic ward so that the effect of either carbohydrate or fat restriction on their weight could be precisely measured, clearly showed that it was cutting dietary fat that cut the body fat. The title of the study says it all: Calorie for Calorie, Dietary Fat Restriction Results in More Body Fat Loss than Carbohydrate Restriction in People with Obesity.
Myth #4: Fish oil is good for your heart
This is one of those myths that just won’t die, no matter how much evidence accumulates to disprove it. A major meta-analysis published in 2012 in the Archives of Internal Medicine summed up the state of play in regards to fish oil supplements:
“Supplementation with omega-3 fatty acids did not reduce the risk of overall cardiovascular events…, all-cause mortality, sudden cardiac death, myocardial infarction, congestive heart failure, or transient ischemic attack and stroke.”
Even more worryingly, if you’ve already had a heart attack or suffer from angina, taking fish oil or eating oily fish may actually increase your risk of sudden cardiac death, and certainly won’t prolong your life-span; while eating dark fish may increase your risk of developing atrial fibrillation, an abnormal heart rhythm that increase the risk of stroke, dementia and heart failure.
Myth #5: You need to eat a high-fat diet for hormonal health
I’ve had so many female clients tell me that another naturopath or nutritionist advised them to eat a high-fat diet to ‘balance their hormones’ that I’ve pretty much lost all faith in the institutions that educate and credential such practitioners, whose modus operandi appears to be simply Let’s Make Stuff Up.
Dr Neal Barnard of the Physician’s Committee for Responsible Medicine showed that a low-fat plant-based diet raises SHBG and reduces period pain and PMS. So if your hormones are giving you headaches, it’s time to give high-fat foods the heave-ho!