You have probably heard that you want to avoid industrial seed oils because they are highly inflammatory, prone to oxidative stress, and basically bad news all around. I have heard that, too, and I totally get the ideas behind them. But, is it all true?
Information and research are always evolving and uncovering new things. That’s why I want to spend some time today, sharing some new perspectives with you that may change your thinking (and your health, overall).
Assessing Current Ideas
The current narrative is that omega-6 fats are harmful, have created negative effects, and because we have seen higher rates of obesity and diabetes within those who always have high rates of these fats.
So, the thinking goes that these fats are the culprits. Unfortunately, that is no longer congruent with what we know from human studies. So, let me tell you a bit more about why.
Let’s begin with a strong understanding of what fats are, chemically-speaking. Fats are what we call “hydrocarbons.” Basically, they are chains of carbon with hydrogen attached to the sides.
The number of hydrogens present, and how the carbons bond with one another, and their length determine the chemical properties of the fats.
So, in this way, we name fats based upon where they have double bonds. Carbon can bond to itself either once or twice. If it bonds twice it has fewer places where it can bond to hydrogen.
If there are multiple double bonds, this is what we call a polyunsaturated fat. On the other, when it is completely full of hydrogen it is saturated (and, therefore, less flexible).
Based on which carbon atom has the first double bond, this is what we know as the “omega number.” Those are the basics behind fats.
Sources of Fats
Generally, fat is something that is solid at room temperature and (whereas oil is liquid at room temperature). It’s also important to know that all foods have fat.
Fats are not good or bad for this reason, because they are in all foods. And, all foods that have fat have all types of fat within them.
Key Insight: That is why it is a bit misleading when we talk about “omega-3 fat foods.” That’s because, in almost all cases, these foods are blends of different fats and are not typically just one type.
There are also fats which are definitely essential. Some out there are ones that we need, which our bodies are unable to make. That said, there are many, many more fats out there which are non-essential.
While our bodies may use them, but if it does, it can also produce it internally on an as-needed basis. So, of the essential fats, there are only two:
- Linoleic (LA)
- Linolenic (LNA)
That’s it, those are the only two. They’re the only fats that we need that we otherwise could not make on our own. It’s really as simple as that.
How Do We Know These Are Essential?
The truth is we know these are essential not because people get low in them, but due to deficiencies early on in life causing health problems down the road.
Bottom Line: How much does it take to reverse a deficiency, though? Well, believe it or not, it’s only a small amount required (a few grams, per day, for most).
What Do These Fats Do?
Whether essential or non-essential, fats act upon inflammation pathways. The main one is a group of pathways called the eicosanoid pathway. The idea here is that some fats can make compounds that stop inflammation, while others can start it.
In omega-3 acids, LNA converts that down to EPA and DHA (the fats we find, pre-formed, in fatty fish). So, once they are converted, they are attributed to the anti-inflammatory or immune-stopping pathways.
Omega-6 fats can craft things that start, stop, or regulate the immune system. In this way, they have a much greater variety of roles in the body.
Key Insight: Because of this, though, they can make a compound called arachidonic acid, they have been thought to be pro-inflammatory for quite some time.
Now, we know it’s not quite that simple.
There are scenarios in which the body’s ability to convert and use fat does not work correctly. Some of the main enzymes involved include:
- Delta 5
- Delta 6
These are affected by things like:
- Total fat intake
- Micronutrient status
Paradoxically, if someone consumes high amounts of fat in their diet, they use up a lot of these enzymes that regulate the types of fats they have. As well, they cannot control it when there are high amounts of fat present.
Arguments Against Linoleic Acid
The main argument against linoleic acid is that it can make pro-inflammatory prostaglandins. It is true that they can, however, the main issues showing up would involve arachidonic acid.
Arachidonic acid, on its own, is pro-inflammatory and it is present in some negative states. That said, experts have maintained that this view is probably too simplistic because:
- Very little linoleic acid is converted to arachidonic acid
- Arachidonic acid also makes anti-inflammatory molecules
- Linoleic acid can be converted to anti-inflammatory molecules
Animal studies that have been done were looking at very high amounts and in unusual chemical circumstances.
The other thought is that linoleic acid is harmful because we are consuming more of it at a time where we have more obesity (and more metabolic illness).
Preagrarian & Agrarian
The truth is that these correlations do exist. We have had an evolution of fatty acids in the human diet. Before pre-agrarian times, people had very low total fat intake.
And, most to all of their fats came from nuts and seeds and animal/marine fats. At the time, those same animal fats were pretty lean (not the same as today).
Then, we pivot to agrarian times. This is where more of the food available came from grains (and less of it came from game meats).
At that point, as well, was the first use of concentrated oils. In some areas, then, fat intake went up, but total animal intake went down.
Pre-Industrial & Industrial
In pre-industrial and early-industrial times, diets remained relatively stable. Still consuming amounts of farmed foods, people generally ate less game meat.
The Last Few Decades
This is where we have seen the biggest shift.
What we have seen is that the intake of linoleic acid, specifically from corn and soy oil, has gone up rather dramatically.
The argument is that this did correlate to higher levels of metabolic disease (like diabetes). The pitfall here, though, is that it may seem convincing to suggest these fats were inherently toxic and they caused that.
However, there are other interpretations of these important data points.
Epidemiologic Arguments Against Linoleic Acid
Overall, the Japanese have a lower intake of linoleic acid and lower rates of cardiovascular disease. But, are there other factors at play that are more relevant?
Then, there’s the Mediterranean diet. It has less omega-6 fats than those in the modern American diet and has less chronic disease total.
Key Insight: Is that because these people avoid omega-6? Or, is it because they consume other good things? These are all valid points that introduce some confusion into the mix.
The Omega 3/6 Ratio
There has been a lot of discussion around what has become known as the omega 3/6 ratio. This is the idea that we need some sort of mix between the two to maintain good health.
The difficulty with this is that it may be less about a ratio, and more important that we simply get both. In a lot of cases, what was once thought to be a bad ratio is just low omega-3.
It’s not necessarily that you need specific proportions, but that you need certain amounts of each.
Bottom Line: A huge problem with all of the studies against omega-6 fats is that, up until 2018, these were surrogate markers for trans-fatty acids. They don’t contain them, they merely got caught up in the context.
Pleiotropic & Contextual
The effects of linoleic acid are what we call pleiotropic and contextual (meaning that same molecule could come from almonds as it could come from twinkies).
This means that it would be a mistake to consider the molecule sinister or biologically incompatible with human physiology.
In fact, it is an essential precursor to many molecules that regulate much of our inflammatory pathways. Whether those pathways are creating excessive inflammation or not is based not on the predominance of any one substrate, but the full context of the organisms state.
Some of the larger factors that determine how linoleic acid is metabolized include the overall fuel availability level, micronutrient status, and sympathetic/parasympathetic balance.
Key Insight: The source and the context of linoleic acid ingestion are essential. Is linoleic acid from unprocessed nutrient-rich foods in the context of appropriate fuel balance?
Linoleic Acid and Human Studies
I bring up this whole topic today because there is a lot of data suggesting that linoleic acid is not bad for us. In fact, quite the opposite.
So, let’s dive into some of the recent human studies to illustrate that point:
- Linoleic acid lowers the risk of asthma1
- It lowers the risk of diabetes2
- In humans, it lowered the amount of inflammatory chemicals3
- It can aid in rheumatoid arthritis4
- Those with lupus also have lower rates of linoleic acid5
- It may decrease the risk in men of prostate and other cancers6
- There’s no increase in breast cancer risk, and linoleic acid may even decrease it7
Key Insight: This is what we are seeing: people who have more linoleic acid are more likely to have better health overall.
Here’s some more data to help further that claim:
- Studies have shown that the more linoleic acid you have, the less likely you are to have cardiovascular death (heart death)8(Read: Saturated fats and heart disease )
- Circulating linoleic acid correlated to less occurrence of cardiovascular events9
- Linoleic acid may also be playing a positive role in brain health10
- Linoleic acid may correspond to improved wound healing, too11
Bottom Line: Many population studies show that both dietary intake and serum levels of omega-6 linoleic acid correlate with lower risks of total mortality.
Linoleic Acid: Recap
Sometimes, theories can be at odds with what really happens. In the case of linoleic acid, so much support can be made for it from human studies.
Ultimately, it pushes back on the theory of what linoleic acid could do – with the results of what it does to people.
It’s always important to act on evidence. That said, here are some food sources of linoleic acid:
|Food||Quantity||Linoleic acid||Omega 3 content|
|Walnuts||1 ounce (about 14 half walnuts)||10.7 g||2.6 g|
|Sunflower seeds||1 ounce||10.4 g||0.02 g|
|Pine nuts||1 ounce||9.4 g||0.03 g|
|Tahini||1 tbsp||3.4 g||0.06 g|
|Sesame seeds||1 ounce||5.8 g||0.1 g|
|Brazil nuts||1 ounce (about 6 nuts)||5.8 g||0.005 g|
|Pistachio nuts||1 ounce (about 49 kernels)||3.8 g||0.07 g|
|Almonds||1 ounce (about 22 kernels)||3.5 g||0|
|Flaxseeds||1 ounce||6.3 g||1.6 g|
|Chia seeds||1 ounce||4.9 g||1.6 g|
|Macadamia nuts||1 ounce (10-12 kernels)||0.3 g||0.06 g|
|Safflower oil||1 tbsp||10 g||0|
|Grapeseed oil||1 tbsp||9.3 g||0.01 g|
|Mayonnaise||1 tbsp||7.1 g||0.4 g|
|Sunflower oil||1 tbsp||5.3 g||0.03 g|
|Canola oil||1 tbsp||2.6 g||1.3 g|
|Avocado flesh||100 g (about 1/2 fruit)||1.7 g||0.1 g|
|Avocado oil||1 tbsp||1.7 g||0.1 g|
|Oatmeal||1/2 cup||0.8 g||0.04 g|
|Brown rice, cooked||1 cup||0.6 g||0.03 g|
|Beef, sirloin||100 g (3.5 ounces)||0.2 g||0.03 g|
|Beef, ground grass fed||100 g (3.5 ounces)||0.4 g||0.08 g|
|Bison, grass fed||100 g (3.5 ounces)||0.3 g||0.04 g|
|Beef, strip steak – commercial||100 g (3.5 ounces)||0.2 g||0.04 g|
|Beef, strip steak – grass fed||100 g (3.5 ounces)||0.08 g||0.02 g|
|Salmon, Atlantic – farmed||100 g (3.5 ounces)||0.6 g||2.2 g|
|Salmon, Atlantic – wild||100 g (3.5 ounces)||0.2 g||2.5 g|
|Scallops||100 g (3.5 ounces)||0.004 g||0.2 g|
|Sardines||100 g (3.5 ounces)||3.5 g||1.4 g|
|Cod||100 g (3.5 ounces)||0.008 g||0.3 g|
|Tilapia||100 g (3.5 ounces)||0.2 g||0.2 g|
|Catfish, farmed||100 g (3.5 ounces)||1 g||0.3 g|
|Rainbow trout, farmed||100 g (3.5 ounces)||0.7 g||1.0 g|
|Trout, wild||100 g (3.5 ounces)||0.2 g||0.8 g|
|Butter, commercial||1 tbsp||0.4 g||0.04 g|
|Butter, grass fed||1 tbsp||0.4 g||0.05 g|
|Chicken breast||100 g (3.5 ounces)||0.5 g||0.06 g|
|Chicken thighs||100 g (3.5 ounces)||1.8 g||0.2 g|
|Lamb, trimmed||100 g (3.5 ounces)||0.3 g||0.1 g|
|Pinto beans, cooked||1 cup||0.3 g||0.4 g|
|Spinach, cooked||100 g (3.5 ounces)||0.02 g||0.09 g|
|Coconut oil||1 tbsp||0.2 g||0 g|
|Ghee||1 tbsp||0.003 g||0.002 g|
|Lard||1 tbsp||1.3 g||0.1 g|
|Walnut oil||1 tbsp||7.1 g||1.4 g|
|Cashews||1 ounce||2.8 g||0..2 g|
|Tuna, canned in water||100 g||0.09||0.3 g|
|Wheat berries||100 g||0.6 g||0.03 g|
|Pecans||1 ounce||6 g||0.3 g|
|Flaxseed oil||1 tbsp||1.7 g||7 g|
We often think of grass-fed meat being higher in omega-3 fats. But, grass-fed beef and butter are not significant sources of omega-3 fat. It has some, but it often falls way below our required daily needs.
The foods that are the highest in omega-6 and linoleic acid are walnuts, sunflower seeds, pine nuts, and then they begin to drop a bit.
That said, safflower oil is quite high, and we even look at how these foods compare to their omega-3 content. We can even see that some of them are really rich sources of both.
Once we get further down the list, and into a lot of animal foods, they become less significant sources of linoleic acid. So, they are not nearly as present here.
How Much Linoleic Acid Do You Need?
After all this discussion of numbers, it’s best to ask: how much do you really need?
This is tricky. We have so few examples of people who are overtly deficient in it, which is the first problem.
The other problem is that the amounts needed to reverse deficiencies are so small. The best approximation that we can make, in terms of daily requirements, were based on how much is common in populations that don’t have much of a deficiency.
Key Insight: Crunch all that data together and you get somewhere between 11-17 grams of linoleic acid, per day, to make a difference.
When you do look at the amounts in these food sources, it is easy to see how you might not be able to get that. This is especially true if you follow popular diets that try to avoid omega-6 fats entirely. You could easily be low!
Bottom Line: It turns out that being low in linoleic acid can have many negative effects in terms of inflammation in the body.
Linoleic Acid: Full Recommendations
Let’s look at all the numbers together, comparing them with one another, so that you can have a full understanding of how much you need:
Omega-6 Fat (Linoleic Acid)
- Adult men: 14 – 17 grams per day
- Adult women: 11 – 12 grams per day
- Pregnancy/lactating: 13 grams per day
How much Omega-3 Fat is Essential?
As little as 0.3 grams (300 mg) per day can prevent deficiency symptoms in those on parenteral nutrition. Adequate intake is based on highest median intake.
Omega-3 Fat (Alpha Linolenic Acid)
- Adult men: 1.6 g per day
- Adult women: 1.1 grams per day
- Pregnancy: 1.4 grams per day
- Lactating: 1.3 grams per day
There is no evidence to indicate that saturated fatty acids are essential in the diet. That’s why there is no recommended intake set.
The same applies for monounsaturated fats (omega-9 fats).
Linoleic Acid: Action Steps
Basically, what I want you to know is that linoleic acid is not bad. It is not inherently pro-inflammatory, and there is a lot of strong data out there which suggests it could do a lot of good for your body.
In fact, you may even be getting too little of it. The ability to get it from your food is important, but if you cut out certain things you may be missing out.
Please, consider incorporating some more linoleic acid into your diet today!
Essential Health For Your Life
It’s so important to open our minds to the research, and how that corresponds to what we’re being told amidst all the other information out there.
If you want a clear idea of your health, specifically your thyroid, you should consider taking the Thyroid Quiz today (Click Here: Take The Quiz Now). It’s your chance to learn more about your body, your health, and your life. I hope you’ll try it.
1 – https://academic.oup.com/ajcn/article-abstract/110/3/685/5530097?redirectedFrom=fulltext
2 – https://www.google.com/amp/s/medicalxpress.com/news/2019-06-higher-intake-linoleic-acid-diabetes.amp
3 – https://sci-hub.tw/10.1093/ajcn/nqy287
4 – https://www.ncbi.nlm.nih.gov/m/pubmed/29436473/?i=1&from=High%20erythrocyte%20levels%20of%20the%20n-6%20polyunsaturated%20fatty%20acid%20linoleic%20acid%20are%20associated%20with%20lower%20risk%20of%20subsequent%20rheumatoid%20arthritis%20in%20a%20southern%20European%20nested%20case-control%20study
5 – https://onlinelibrary.wiley.com/doi/abs/10.1002/acr.23925
6 – https://www.semanticscholar.org/paper/Serum-linoleic-and-total-polyunsaturated-fatty-in-a-Laaksonen-Laukkanen/48d052b921df54588c8e91ee93463e3793396555
7 – https://www.ncbi.nlm.nih.gov/pubmed/26434699
8 – https://www.ncbi.nlm.nih.gov/pubmed/25161045
9 – https://www.ahajournals.org/doi/abs/10.1161/CIRCULATIONAHA.118.038908
10 – https://www.alzheimersanddementia.com/article/S1552-5260(17)31568-6/abstract#/article/S1552-5260(17)31568-6/abstract
11 – https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5925018/
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Dr. Alan Glen Christianson (Dr. C) is a Naturopathic Endocrinologist and the author of The NY Times bestselling Adrenal Reset Diet, The Metabolism Reset Diet and The Thyroid Reset Diet.
Dr. C’s gift for figuring out what really works has helped hundreds of thousands of people reverse thyroid disease, lose weight, diabetes, and regain energy. Learn more about the surprising story that started his quest.