Omega-3s: The science you need to know
Highlights
• There are at least 3 important omega-3 fatty acids: alpha-linolenic fatty acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA)
• ALA is found in a number of plant foods, but our bodies have a hard time converting it into EPA and DHA
• EPA and DHA are found at higher levels in seafood, but variability in access to and quality of seafood can make getting enough difficult
• Omega-3 intake has been linked to wellness
• Pro-resolving mediators are made from omega-3s, and they are thought to have a powerful role in protecting immune balance
• Choosing specific foods and considering dietary supplements are the most reliable ways to ensure higher levels of daily omega-3 intake
What are omega-3 fatty acids anyway?
Omega-3s are often called fats. But technically, they’re fatty acids, the building blocks for fats. While there are many types of fatty acids, researchers often describe two major groupings. these include unsaturated fatty acids (which have at least one double bond linking their carbon atoms) and saturated fatty acids, which don’t have any double bonds. Omega-3s are unsaturated fatty acids.
Hundreds of scientific papers show big differences between fatty acids. For example, trans fatty acids (also called trans fats) are unsaturated fatty acids strongly linked to a number of issues associated with worse wellbeing. On the flipside, omega-3s have emerged as standout stars in the unsaturated fatty acid group for their role in making up healthy cell membranes, as well as their studied effects on a variety of wellness-related processes.
What are the different types of omega-3s?
The omega-3 family of fatty acids contains a number of different molecules. Some of the most important are ALA (alpha-linoleic acid), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Generally speaking, ALA is found in higher concentrations in plant foods like nuts and seeds while EPA and DHA are more concentrated in animal foods, especially seafood. There are important differences in the function of the different omega-3 fatty acids. For example, EPA has been associated with better mental wellness, while DHA may be more important for overall brain wellness.
Can we get enough omega-3 fatty acids in our food?
One of the key attributes of omega-3s is that our bodies can’t make them on their own. This means we have to consume them in our diet. However, our bodies have the amazing ability to convert certain omega-3 fatty acids into others. For example, ALA consumed in flaxseed, nuts or chia seeds can be turned into EPA. EPA can then be converted into DHA. But there’s an important caveat to this point. That’s because the conversion process in our bodies is very inefficient, which means it’s tough for our bodies to get higher levels of EPA and DHA by eating plant-based foods alone. This aspect of our physiology, along with dietary patterns that tend to prioritize highly-processed foods low in omega-3 fatty acids helps to explain why so many people around the world have low levels of EPA and DHA.
Because of the substantial research connecting higher levels of EPA and DHA to better health outcomes, many now recommend that people who consume meat should consider inclusion of cold-water fatty fish in their diet a few times a week. These fish tend to be among the highest in natural EPA and DHA. However, concerns for variability in fish omega-3 content, the availability of fresh, low-cost and high-quality fish as well as dietary restrictions have led many to look to supplements to get their daily dose of omega-3s.
The omega-6: omega-3 ratio
While most Americans may struggle to prioritize dietary omega-3 fatty acids, we tend to do a great job eating lots of omega-6 fatty acids. Omega-6 fats may serve certain important functions in our bodies. However, research indicates that when we have too many omega-6s and not enough omega-3s, risk for worse wellbeing may increase. Our chronically high omega-6 intake is largely due to consumption of one omega-6 in particular called linoleic acid (LA) which is found in vegetable oils like safflower, corn, sunflower and soy. For many years researchers and health experts alike have recommended paying attention to the ratio of omega-6 to omega-3 fatty acids in the diet and trying to move it from what is typical (around 20-15:1) to around 4:1 or even lower. However, new research suggests there may be a bigger benefit to simply prioritizing more omega-3 fatty acids in our diet.
Omega-3s secret partner: pro-resolving mediators
There are thousands of studies spanning the last several decades looking at omega-3s. Omega-3s are especially thought help by keeping the immune system in balance. Yet very recently researchers have discovered another key piece of the story. Just as ALA can be converted to EPA and then DHA (all of which have different physiological effects), so too can EPA and DHA be converted into another set of molecules. These are called pro-resolving mediators (PRMs).
When it comes to promoting a healthy state of immune balance, PRMs may be even more potent than omega-3 fatty acids. In recently published research, PRMs have been found to limit an overactive immune response, a process linked to a wide variety of aspects of worse wellness. PRMs can be found in the same foods that have the highest concentrations of natural EPA and DHA (for example, cod livers). Yet just as our bodies tend to lose a lot of potential EPA and DHA in the conversion of ALA, it’s also easy to lose natural PRMs when fish are processed before we consume them. In fact, compared to the raw version, simply baking salmon was shown to dramatically lower PRM content.
How to prioritize your daily omega-3s
One of the nice things about omega-3 fats is the diversity of foods they can be found in (like mustard seeds and lentils!) Yet if you’re shooting to get your levels of EPA and DHA consistently higher, it’s probably worthwhile to purposely include certain foods in your diet. Here are some easy (and tasty sources of omega-3s).
If you eat seafood:
Even though other animal products (like ground beef and eggs) contain omega-3 fatty acids, the most concentrated sources of the omega-3 fatty acids EPA and DHA tend to be seafoods, especially cold-water fish. If you eat seafood, consider incorporating the SMASH fish (salmon, mackerel, anchovies, sardines and herring) into your diet, as they tend to be high in omega-3s and lower in contaminants like mercury. Consider choosing sustainably harvested wild fish over farmed fish if and when you can. Shellfish like oysters and mussels are also high in omega-3 fatty acids. If you have trouble regularly getting in enough servings of seafood, omega-3 supplementation with a high-quality fish oil is an easy way to help ensure you reach your daily goals for EPA and DHA.
If you don’t eat seafood:
Omega-3 fatty acids are found in a wide variety of plant-based foods. However, the majority of this will be ALA, which means your body may have a hard time getting to higher levels of EPA and DHA if you only consume plant-based products. Some recent research indicates that certain types of seaweed may be an interesting option due to higher levels of DHA and EPA than non-aquatic plants. This is why many people recommend that vegans consider taking an omega-3 supplement like algae oil.
