A recent study, Biomarkers of Dietary Omega-6 Fatty Acids and Incident Cardiovascular Disease and Mortality, has been floating around social media.
As the title suggests, the study found that higher intakes of omega-6 polyunsaturated fatty acids aligned with a lower risk of cardiovascular disease. This study looked at 68,659 participants from thirty pooled studies.
Some claim it is a win for PUFAs and a nail in the coffin for saturated fat. Others aren’t so quick to hop on the seed oil bandwagon.
Unilever, which owns many food brands you may recognise, partially funded the study to better understand the appropriate recommendations for dietary consumption of omega-6 fatty acids.
In this article, we’ll dive into the implications of these controversial findings to understand if you should prioritise (or avoid) omega-6 polyunsaturated fat.
As you’ll see, omega-6 fats may align with lower rates of heart disease. However, you likely needn’t go out of your way to prioritise them, especially if they’re from refined oils or as ingredients in ultra-processed foods and you aren’t already getting plenty of omega-3 (which most people aren’t).
- What Are Omega-6 Fats?
- What is the Recommended Intake of Omega-6 Fatty Acids?
- What Foods Contain More Omega-6 Polyunsaturated Fat?
- How Has Our Intake of Omega-6 Changed?
- What About Saturated Fat?
- What Foods Have the Least Omega-6?
- Managing Your Omega-3:6 Ratio
- Should You Eat More or Less Omega-6 Polyunsaturated Fat?
- Principal Component Analysis
What Are Omega-6 Fats?
Omega-6 fatty acids, or n-6 polyunsaturated fatty acids (PUFAs), are a type of ‘essential’ fatty acid the human body must get from the diet because it cannot produce its own.
Omega-6 fats are found in various plant-based foods, like vegetable oils (e.g., soybean, corn, safflower, cottonseed, canola, sunflower, nuts, and seeds). They are also found in smaller quantities in animal products with monounsaturated and saturated fat.
Omega-6 fats come as linoleic acid (LA) and arachidonic acid (AA).
What is the Recommended Intake of Omega-6 Fatty Acids?
As stated by the introduction to the study, “Recommendations for dietary consumption of omega-6 (n-6) polyunsaturated fatty acids (PUFA) for cardiovascular disease (CVD) prevention remain controversial and inconsistent. For example, the American Heart Association and the Academy of Nutrition and Dietetics recommend 5% to 10%, the United Nations Food and Agriculture Organization recommends 2.5% to 9%, whereas the French national guidelines recommend 4%.” Meanwhile, others advocate for much lower intakes of omega-6 oils in the diet.
Because omega-6 fatty acids have only contributed to a small proportion of energy in the diet in the past, there is not a lot of data on our requirement for polyunsaturated fat. Hence, there is no minimum Dietary Reference Intake (DRI) for what we should consume.
A recent workshop on the Essentiality of and Recommended Dietary Intakes for Omega-6 and Omega 3 Fatty Acids recommended reducing the Adequate Intake of linoleic acid by 2% of energy and an upper limit of 3% due to concerns around the omega-6:3 ratio.
Others, like Dr Cate Shanahan and Dr Michael Edes, have raised concerns about the inflammatory effects of high intakes of refined vegetable oils. For a deep dive into the possible mechanisms behind omega-6 oils and increased heart disease, you can check out this video by Dr James Dinicaltonio.
What Foods Contain More Omega-6 Polyunsaturated Fat?
Higher-fat foods generally contain a blend of saturated, polyunsaturated, and monounsaturated fats. Some sources of omega-6 polyunsaturated fat include nuts and seeds, such as:
- Walnuts (58%),
- Sunflower seeds (47%),
- Hemp seeds (41%), and
- Poppy seeds (30%).
It’s hard to overconsume omega-6 from nuts and seeds in their whole food form. As well as energy from omega-6, you’ll also be getting the vitamins, minerals and fibre that come from nuts and seeds.
However, we see a higher concentration of omega-6 in plant oils that we often use in cooking and as ingredients for processed foods, such as:
- Safflower oil (78%),
- Sunflower oil (60%),
- Soybean oil (51%), and
- Corn oil (54%).
The chart below shows a range of popular foods with our Optimisers in terms of omega-6 (g/2000 calories) vs omega-6 (g/serving). The colouring is based on our satiety index score.
For more detail, you can dive into the interactive Tableau version of this chart (on your computer). Towards the right, we see that plant-based nuts and seeds contain the most omega-6. However, some animal-based foods are not far behind.
How Has Our Intake of Omega-6 Changed?
While correlation doesn’t equal causation, it’s helpful to look at how our intake has changed over the years as our food system has become more processed and obesity rates have increased.
The chart below shows how our energy from PUFAs has risen over the past century. This chart is based on official data from the USDA Economic Research Service. Here, we can see that the amount we consume has increased from 3.4% of total calories in 1910 to 10% in 2010.
For reference, the average intake of our Optimisers—who tend to focus on nutrient density more than the general population and get around half of their energy from fat—obtain an average of 4.6% of their energy from omega-6 polyunsaturated fats (i.e. between the French upper limit and the lower limit set by the American Heart Association and the Academy of Nutrition and Dietetics).
Given that our intake of omega-6 is likely to continue to rise as we consume more processed foods, it makes sense that food manufacturers like Unilever would be eager to see the upper limit for polyunsaturated fat lifted.
But it’s not just omega-6 polyunsaturated fats that are on the rise. The chart below shows that monounsaturated and polyunsaturated fats have each increased by around 300 calories per person daily. Meanwhile, the availability of saturated fat has increased by about 100 calories per person per day over the last century.
Today, we consume an extra 800 calories per person per day more fat than we did a century ago, mainly from increased added vegetable oils.
While many factors have led to increased fat intake, two ingenious inventions appear to have had a major impact.
- In 1910, Procter and Gamble patented the process of hydrogenation, which creates liquid vegetable oils from industrial seed crops. This allowed producers to turn liquid vegetable oils into solids to take on a buttery appearance. Soon after, Crisco and margarine were marketed as healthy options to animal-sourced fats.
- Then, in 1914, Harber and Bosch perfected the process of fixating nitrogen from the air to create synthetic fertiliser in a process fuelled by natural gas. This allowed us to supercharge the agricultural system. We could now essentially inject energy from natural gas (methane) into the soils to grow more food more quickly.
These two ingenious inventions have changed our food system dramatically. Our vegetable oil production, mainly from palm, soybean, sunflower and rapeseed, increased dramatically from 20 million tons in 1961 to more than 160 million tons, leading to increased consumption of both monounsaturated fat and polyunsaturated fat.
During this time, obesity rates have also increased. But it’s not only fat that’s contributed to the obesity epidemic!
In the 1960s, the Second Agricultural Revolution ramped up, leading to an influx in the production of carbohydrates. Food manufacturers used cheap agricultural products like corn, soy, and wheat to create the perfect blend of hyper-palatable carbs and fat we are prone to overeating.
As a result, since the 1960s, our production of carbohydrates has increased by around 500 calories per person per day from carbohydrates, in addition to the increased energy from fat.
What About Saturated Fat?
Meanwhile, our saturated fat consumption has only increased marginally in absolute terms. In fact, our consumption of saturated fat intake has decreased in percentage terms since the widespread use of synthetic fertilisers ramped up. Since the 1960s, we have been getting more energy from monounsaturated fat than saturated fat. However, this decrease in saturated fat intake certainly hasn’t slowed the obesity epidemic, as food manufacturers continue to inject ‘easy’ energy into the food system.
The bottom line is that fat, regardless of the source, is a source of energy. As shown in the chart below from our satiety analysis, we eat more when our diet consists of a higher proportion of energy from fat.
Regardless of any new study findings, obesity is still a significant risk factor for cardiovascular disease and diabetes. But if you have more fat on your body than is healthy for you, consuming more polyunsaturated fat, monounsaturated fat or even saturated fat in their refined forms, separated from their whole food sources, won’t improve your health, help you lose weight or even decrease your risk of heart disease.
But we do know that getting enough protein, fibre and critical nutrients like potassium, calcium and sodium without excess energy will increase satiety, help you lose weight with less hunger and thus reduce your risk for cardiovascular disease, diabetes and all the other adverse outcomes related to obesity.
We repeatedly find that it’s better to prioritise the beneficial essential nutrients—or the vitamins, minerals, amino acids, and essential fatty acids—rather than avoiding ‘bad things’ in food. Many are quick to demonise a single component of the food system, like:
- animal-based foods,
- plant-based foods,
- saturated fats,
- Omega-6 PUFAs,
- Anti-nutrients, etc.
According to someone online, it seems pretty much anything we can eat will kill us.
But when we ensure that we get enough of all the essential nutrients we need without excess energy (i.e., nutrient density), it becomes next to impossible to overdo it on any of those ‘bad things’.
What Foods Have the Least Omega-6?
The chart below shows omega-6 vs fat for popular foods used by Optimisers, showing that foods that contain fat contain some omega-6, so it’s hard to eliminate omega-6. You can dive into the interactive version of this chart in Tabluea here.
An omega-6 intake of 2% corresponds to a total fat intake of 20% which is definitely on the lower end by most people’s standards. Meanwhile, a 5% omega-6 intake corresponds to a total fat intake of 33%.
The chart below shows dairy tends to have less than 5% omega-6 fats. However, eggs contain around 10% omega-6.
Managing Your Omega-3:6 Ratio
While we don’t have a good understanding of how much we need, Omega-6 is an essential fat that is required for many functions in the body! We need some to keep our skin healthy and regulate blood clotting and inflammation.
We also know that it’s important to balance our omega 6:3 ratio. Excessive consumption of omega-6 fats relative to omega-3 fats has been associated with an increased risk of chronic diseases, such as heart disease, diabetes, and cancer.
Omega-6 and omega-3 fatty acids compete for absorption in the body. So, we can’t effectively use omega-3 fatty acids when we have excess omega-6 acids. It’s crucial to maintain a balanced intake of omega-6 and omega-3 fats. The recommended ratio of omega-6 to omega-3 fats is between 4:1 and 1:1. However, the typical Western diet tends to have a much higher ratio of more than 15:1!
Most of these omega-6 fatty acids come from the excess influx of seed oils pumped into ultra-processed foods and the lack of seafood and other omega-3 sources. Thus, it seems most people already consume plenty of omega-6 from added oils and not enough omega-3 fats from foods like seafood.
So, before increasing your omega-6 intake, you should check how much omega-3 you’re getting. Chances are, your omega-6:3 ratio will already be well above the optimal range.
To help you reduce your omega-6:3 ratio (which is likely more important than trying to eliminate omega-6), the chart below shows popular foods in terms of omega-6:3 ratio vs omega 3. Again, you can dive into the detail in the interactive Tableau version of this chart here.
To optimise your omega 6:3 ratio, in addition to minimising added oils like soybean, corn, safflower and sunflower, you may want to keep an eye on your intake of nuts like almonds and peanuts. But more importantly, you can prioritise the seafood shown towards the left.
For more details, see Nutrient Balance Ratios: Do They Matter and How Can I Manage Them?
Should You Eat More or Less Omega-6 Polyunsaturated Fat?
If you’ve made it this far, you can probably see that setting a target range for omega-6 is challenging, and the data supporting what and how much to eat is complex and confusing. There are plenty of passionate advocates on both sides of the debate!
However, we know that overeating leads to obesity, which has many downstream implications, whether it be metabolic syndrome, obesity, diabetes, or any complications arising from these conditions.
We also know that we have increased our omega-6 and energy intake substantially since the 1960s because of the reliance mainly due to the availability of ultra-processed, nutrient-poor, low-satiety foods that combine flavourings, processed seed oils, sugars, and starches.
Over the years, we’ve analysed data from more than forty thousand people who have used Nutrient Optimiser to understand the factors that lead to greater satiety and eating less vs eating more.
As our satiety analysis details, the dominant factors that align with eating less are a higher per cent of total calories from protein (i.e., protein %), more fibre, and more nutrients per calorie (i.e., nutrient density) that are critical for satiety, like potassium, sodium and calcium. Therefore, we satisfy our cravings most effectively when we get more of these essential nutrients with fewer calories.
We also know that ultra-processed foods that use refined flour, sugar and industrial seed oils have minimal amounts of these critical nutrients that promote satiety. So, one of the best things you can do for your health is to avoid ultra-processed foods that contain some combination of flour, sugar and oil in the ingredient list.
It’s also wise to ensure you’re not adding excessive energy from cooking oils or dressings. When they start tracking their food in our Macros Masterclass and Micros Masterclass, many people are surprised at how quickly these added oils add to their daily calories.
The chart below shows omega-6 vs protein vs satiety for the 1400 recipes in our database of NutriBooster recipes that we use in our classes. Overall, we can see that recipes with omega-6 tend to contain less protein and provide lower satiety.
Principal Component Analysis
To better understand the factors influencing satiety, we ran a Principal Component Analysis (PCA) to understand which factors are dominant and clustered.
The output from the PCA below shows that protein % and calorie intake are on opposite sides of the circle, demonstrating that a higher protein % corresponds with less energy from fat and carbs, greater satiety, and lower energy intake.
To the right of the PCA plot, we can see that net carbs, starch, and sugar are also clustered together. While starch and sugar contribute to eating more, non-fibre carbohydrate is the dominant factor (i.e., the longest line). Hence, you’ll automatically ensure you’re not overdoing starch or sugar if you manage your overall carb intake.
Similarly, we can see that fat, saturated, monounsaturated, and polyunsaturated fat are clustered together on the left-hand side of the chart. Total fat intake is dominant and polyunsaturated fat plays a relatively minor role compared to monounsaturated and saturated fat. Like carbs, this suggests that you won’t be overdoing polyunsaturated fat if you have your total fat intake under control.
In our Macros Masterclass, we guide our Optimisers to find the balance between protein, carbs and fat that align with their goals and increase satiety.
This next iteration of the PCA analysis includes several critical nutrients that align with greater satiety and eating less. We see that consuming foods that contain more potassium, folate, selenium, calcium, sodium and protein per calorie all align with greater satiety and a lower energy intake from fat and carbs.
In our Micros Masterclass, we guide people to identify foods and meals that will fill the micronutrient gaps in their diet while dialling back empty calories, whether from ultra-processed foods, added oils, or starch or sugar.
The bottom line is that if you’re focusing on getting what you need from the food you eat while staying within your energy budget, you won’t need to stress so much about the ‘bad things’.
If you focus on getting more essential nutrients per calorie, which are more plentiful in minimally processed foods, you won’t need to stress about your balance of polyunsaturated, monounsaturated, and saturated fat or even refined starch and sugar. You’ll be getting just enough without overdoing any of these energy sources.
The various fat sources have pros and cons, but it quickly gets complex and murky when you dive into the minutia of which energy source is best or worst!
The debate will likely rage on about which fats are ‘good’ vs ‘bad’ according to different camps with different beliefs, evidence, and motivations.
While it can be argued that polyunsaturated fat has some benefits, prioritising omega-6 could have negative impacts, such as:
- Giving food manufacturers a free pass to increase the use of cheap seed oils as ingredients in processed foods even further while boasting their health benefits;
- Poor satiety and the overconsumption of calories if someone overconsumes nutrient-poor, higher-calorie fats in pursuit of ‘health’;
- A lack of bioavailable protein and other essential nutrients that align with vitality and satiety, and
- Further declining omega 6:3 ratio.
The bottom line is:
- You don’t want to be consuming excess energy from either fat or carbs,
- If you focus on getting what your body needs from your food, omega-6 PUFAs, along with the ultra-processed foods and added oils that contain them, will become a non-issue.
- The Food Satiety Index Score (Updated 2023)
- Monounsaturated Fat: Is It So “Good” After All?
- Does Eating Fat Make You Fat? The Surprising Truth About Cholesterol and Saturated Fat!
- Omega-3 Rich Foods and Recipes: A Practical Guide
- Carbs Make You Fat and 9 Other Nutrition Myths That Need To Die
- Keto Lie #11: You Should ‘Eat Fat to Satiety’ to Lose Body Fat
- Macros Masterclass
- Micros Masterclass