Are you still with me?
In part 1 I discussed the history of saturated fatty acids and the research behind it. Turns out naturally-occurring saturated fatty acids in food are not the evil that we were convinced they were over 40 years ago.
In part 2, I discussed the history and science behind linoleic polyunsaturated fatty acids (PUFA), particularly in the form of refined seed and vegetable oils. It turns out these oils, which were considered “heart healthy” over 40 years ago, are actually anything but.
In this post, I will discuss monounsaturated fatty acids (MUFA), which are particularly found in olive oil, avocados, and their pressed oils, and to a lesser degree in nuts, meat, and eggs (1). Then I will put it all together for you.
Monounsaturated fats, or omega-9 fatty acids, are not an essential fatty acid like omega-6 and omega-3. Our bodies are able to create this fatty acid if not eaten in the diet. Therefore, if we don’t eat omega-9 containing foods, it’s not the end of the world.
There does appear, however, to be some beneficial results when monounsaturated fatty acids are added to diets in various studies. Some studies have found that adding olive oil to the diet of diabetics can improve metabolic risk factors including insulin resistance, and reduce liver fat (1-5).
Diets high in MUFA-containing olive oil do not appear to promote weight gain and may have favourable effects on inflammation (1). However, some researchers point out that the favourable effects on weight and liver fat may not be from the olive oil per se, but because the intake of carbohydrates in the studies was reduced to make room for the added MUFA (1, 2).
This is a topic for another post. However, it is important to note that more and more research is exploring the beneficial effects of reducing sugar and starch intake, and replacing it with fats while eating adequate protein.
In terms of omega-9 fatty acids found in olive oil and avocado oil, there is a great deal of debate as to whether it is safe to heat up and cook with olive oil. This article on Kris Kresser’s website provides a great explanation as to why it isn’t necessarily a concern to cook with olive oil (6).
It is important to choose extra-virgin olive oil (EVOO) that is cold-processed (1,6). Otherwise, the oil is likely to have undergone a similar heat and chemical solvent extraction procedure as the industrial seed and vegetable oils I describe later in this article. It has been found that refined olive oil loses most antioxidants and nutrients during the refining process, and is, therefore, less effective in studies than EVOO (1).
Unfortunately, a large amount of EVOO sold in North America is adulterated with other cheaper oils, like canola or soybean oil. My friend owns stores in North Vancouver and in Whistler, BC, called Olives on Tap. Their olive oil is the real deal, and the taste is very very different from the oil I am accustomed to purchasing at the grocery store. Doing your research to find an unadulterated brand is always a great idea (6).
It is also important to consider how you store your oils and fats. Light and oxygen, not only heat, can contribute to oxidation and rancidity; especially oils containing more unstable mono- and polyunsaturated fats. Therefore, store your fats and oils in airtight containers, in a cool, dry place (6).
Putting it together
There are so many pieces to the puzzle, aren’t there?
As I have mentioned, I am only scratching the surface here, but I hope that this will give you enough starting information to help you make better-informed choices.
In part 1, I discussed the history of saturated fatty acids, and how they became demonized. In actuality, this fat isn’t the big hairy green monster we were led to believe it is, and evidence is rolling in that indicates that it could actually be protective.
The key, however, is that if high fat is consumed alongside high levels of sugars and carbohydrates, it won’t have the same positive effects, and could instead become detrimental. This point was also made about omega-9 MUFA (1,2).
Another point to mention about saturated fats is that the food industry that demonized animal-based saturated fatty acids, failed to let us know that some plant-based sources of fats actually contain higher amounts of saturated fatty acids than some meat-based sources! Zoe Harcombe recently posted this pictogram, which shows us the amounts of saturated fat per 100 grams for a variety of meat- and plant-based foods (7). Check it out!
If high levels of fat are consumed alongside high levels of sugars and carbohydrates, it won’t have the same beneficial effects, and could instead become detrimental.
In part 2, I discussed the issues surrounding omega-6 containing polyunsaturated fatty acids (PUFAs) from industrial seed and vegetable oils, such as corn, sunflower, safflower, soybean, canola, and vegetable oils, and how they can contribute to all sorts of inflammatory problems.
Chris Kresser goes into greater detail about omega-6 PUFAs here, explaining that the issue isn’t necessarily with naturally occurring omega-6 fatty acids found in whole foods, such as nuts, seeds and pasture raised meats. The concentrations of omega-6 found in these foods when eaten in moderate amounts can contribute to the optimal 1:1 to 1:4 ratio to omega-3 fatty acids. It is important however to note that it can be easy to overdo it even with naturally occurring omega-6 fatty acids (8).
A small handful of nuts can easily turn into the whole bag if we aren’t paying attention. A tablespoon of almond butter can quickly turn into 4, and almond meal as a flour alternative can very quickly up the amounts of omega-6 fatty acids to a ratio higher than 4:1. Mindful eating is also a very important key here. More on this in a couple of weeks so stay tuned!
The main issue is the industrial seed and vegetable oils. The extraction process uses heat, chemical solvents like hexane, and bleach. This processing removes the naturally occurring nutrients, vitamins, and minerals that help protect the omega-6 fatty acids from turning rancid. The heating process results in oxidation. This rancidity and oxidation are two additional factors that can lead to negative inflammatory processes in the body (8,10).
Therefore, avoiding these industrially processed oils, and getting your omega-6 fatty acids from whole foods seems like the better choice. It is important to note that roasting nuts and seeds can also degrade the protective phenolic compounds and lead to more oxidation and rancidity (1).
In addition, Tucker Goodrich reviews results of a study in this article that compares two diets: one with a poor omega-6 to omega-3 ratio of 12:1 (so omega-6 is in excess), compared to a 4:1 optimal ratio diet that had both omega-6 and omega-3 in abnormally high concentrations.
Both diets resulted in the development of obesity, but the rats in the study who ate the 4:1 diet gained even more weight than their 12:1 counterparts, and ended up with liver problems (9). The point is, increasing omega-3 fatty acids to offset high omega-6 in your diet doesn’t work. It’s best to just ensure your omega-6 intake remains at a level similar to that 2-3% intake before all of these industrial seed and vegetable oils entered the picture.
Considering all the information, what are the best choices for fats? From my understanding of the research, the first choice is to consume NATURALLY OCCURRING and minimally processed fats, as opposed to oils that are extracted by heat and chemical solvents in a factory.
Second, while it is important to get SOME omega-6 fatty acids in our diet, we tend to get too much in our modern society. Industrial seed and vegetable oils are used far too widely and found in so many packaged foods (8).
We were led to believe 40 years ago that these seed and vegetable oils were the better alternative to saturated fatty acids, and would prevent heart disease. However, it is becoming more and more apparent that this overconsumption of these industrially processed oils is actually making things worse.
My consensus on omega-6 fatty acids: better to eat sources of omega-6 fatty acids that are unprocessed, in moderate amounts. We can get adequate amounts of omega-6 fatty acids that will provide us with a more optimal ratio of omega-3 fatty acids by consuming meats, eggs, un-roasted nuts, and seeds.
In order to ensure we are getting adequate omega-3 fatty acids to balance out our omega-6 intake, eating regular doses of fish and seafood is a great approach. Eating fish 2-3 times a week can be helpful. Also, pasture-raised, grass-fed meats appear to have small amounts of omega-3 fatty acids, as well. Grain-fed non-pastured meats tend to have higher levels of omega-6 and minimal amounts of omega-3. I will go into detail in another post about this difference.
As we can see from part 1, saturated fatty acids are not the enemy. These fats are also fantastic to cook with, as aldehyde production is extremely low when heated (explained in part 2). Some delicious options include coconut oil, duck fat, tallow, and if tolerated, butter or clarified butter, called ghee.
Lastly, research shows that monounsaturated fats from foods like olives and avocados have several benefits. Choosing pure, unadulterated sources of oils from these foods are key. Even better, get the fat from these foods by eating the whole food directly!
It is best to eat a varied diet, and our consumption of fats should be included in this variety. Therefore, here are a few summarizing points from my ramblings:
- try out different types of fats
- Don’t fear saturated fat
- Aim to get omega-6 fatty acid intake in moderate amounts from whole foods instead of processed oils; avoid industrial seed and vegetable oils as much as possible.
- Also, make sure to get adequate omega-3 fatty acids in your diet
- Monounsaturated fats are also a great choice to include in your variety of fats
What do you think? What kind of fats do you have in your diet?
- Ros E. Dietary cis-monounsaturated fatty acids and metabolic control in type 2 diabetes. Am J Clin Nutr. 2003 Sep;78(3 Suppl):617S-625S. http://ajcn.nutrition.org/content/78/3/617S.long
- Errazuriz I, Dube S, Slama M et al. Randomized Controlled Trial of a MUFA or Fiber-Rich Diet on Hepatic Fat in Prediabetes. The Journal of Clinical Endocrinology & Metabolism. 2017; 102(5):1765-1774. https://doi.org/10.1210/jc.2016-3722
- Bozzetto L, Prinster A, Annuzzi G et al. Liver Fat Is Reduced by an Isoenergetic MUFA Diet in a Controlled Randomized Study in Type 2 Diabetic Patients. Diabetes Care. Jul 2012; 35 (7) 1429-1435; http://doi.org/10.2337/dc12-0033
- Qian F, Ardisson Korat A, Malik V, Hu F. Metabolic Effects of Monounsaturated Fatty Acid–Enriched Diets Compared With Carbohydrate or Polyunsaturated Fatty Acid–Enriched Diets in Patients With Type 2 Diabetes: A Systematic Review and Meta-analysis of Randomized Controlled Trials. Diabetes Care. 2016 Aug; 39(8): 1448–1457. http://doi.org/10.2337/dc16-0513
- Garg A, Bonanome A, Grundy SM, Zhang ZJ, Unger RH. Comparison of a high-carbohydrate diet with a high-monounsaturated-fat diet in patients with non-insulin-dependent diabetes mellitus. N Engl J Med. 1988; 319(13):829-24. https://doi.org/10.1056/NEJM198809293191304
- Marksteiner K. Is it Safe to Cook with Olive Oil? Dec 2014. https://chriskresser.com/is-it-safe-to-cook-with-olive-oil/
- Harcombe Z. Saturated fat. Jan 2018. http://www.zoeharcombe.com/2018/01/saturated-fat/
- Kresser, C. An update on Omega-6 PUFAs. Sep 2016. https://chriskresser.com/an-update-on-omega-6-pufas/
- Goodrich T. “Hello, can we have your liver?: Understanding a high-PUFA diet”. Jan 2018. http://yelling-stop.blogspot.ca/search?q=understanding+a+high-PUFA+diet
- Joseph M. Is canola oil healthier than other vegetable oils? Nov 2016. http://nutritionadvance.com/canola-oil-vegetable-oil/