Why is salmon good for your brain?

The fish that swims upstream provides more than just a tasty meal

March 5, 2014
Salmon is one of nature's best sources of DHA, an essential fatty acid important for brain health. [Image credit: Flickr user James Bowe]

Salmon is topping the charts as one of the best foods to eat, but what makes this pink-fleshed marine animal a modern mealtime marvel?

Your brain is fat, really fat. Sixty percent of it is composed of fatty acids, the long snake-like building blocks of fat molecules required for proper brain structure and function. Fatty acids come in many varieties, yet the brain has a clear favorite — and salmon is packed with it. More than two-thirds of the brain’s fatty acids are docosahexaenoic acid (DHA), an omega-3 fatty acid found primarily in oily fish, although some vegetarian sources exist as well. Metabolically incapable of making DHA on our own, we must obtain it from our diet.

DHA is like a warm winter coat for your neurons, or brain cells, making up a majority of their cell membrane, the cell’s outer coating. And just like you wouldn’t want to leave your house in the winter without putting on a coat, you wouldn’t want to starve your brain cells of DHA. This essential fatty acid protects neurons from injury, reduces cerebral inflammation, helps produce neurotransmitters that tell cells what to do and is essential for quick information transfer down the axon, the neuron’s highway.

Even though you can’t produce this neuronal insulation on your own, you steal enough of it from your mom while in utero to help you through the first few years of life (that’s why mom’s omega-3 intake during pregnancy is so important). But as you age, DHA levels in your brain decline — imagine your winter coat slowly vanishing the longer you stay outdoors. This deterioration has been linked to memory loss, mood disorders, cognitive decline, attention deficit hyperactivity disorder (ADHD), reduced brain volume and Alzheimer’s disease.

When you’re young, you don’t need to remember your coat when you go outside — a parent never lets you leave the house without it. But as an adult, this responsibility falls on your shoulders. If you don’t adequately layer up before facing the cold, you’ll pay the price. Similarly, if you fail to obtain enough DHA from your diet, your brain will be unable to fire optimally. You’ll leave your neurons exposed to injury, disease, inflammation and reduced cognitive capabilities.

Yet just because you may be feeling chilly now, there’s no need to go overboard with this oily fish. Two servings of salmon a week should do the trick for keeping your brain cells working properly and reducing your risk of neurological disease. So if it’s been a while since you approached the fish counter, you may want to think about paying a visit. I’m making this for dinner.


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About the Author

Hannah Newman grew up playing board games in her basement on Saturday mornings and running to soccer practices. She earned her B.A. in neuroscience at Middlebury College, where she played varsity soccer and created an independent project simplifying science’s puzzles through writing. She loves being active and can often be found running while listening to Radiolab. You can follow her on twitter at @HannahNewmanSci or connect with her on LinkedIn



Lindsay Wilson says:

I just found your website, and was quite surprised to find this quite unbalanced article amongst some really nice answers. While I know that the aim is to simplify the science, I’m afraid that this one seems to miss 3 fairly fundamental points that people should have no problem at all comprehending.

The first is that it’s an imbalance of omega 3 and omega 6 oils that can often lead to problems in Western diets – any article should really talk about this.

The second is that there are a huge number of myths around about the benefits of omega 3s; lots of poorly designed trials that have been jumped on by the press and have turned out not to show anything significant in terms of benefit (e.g. to childhood academic performance).

The third is that any responsible scientist should not really discuss fish consumption without also alerting readers to the long-standing effects that over-fishing has had on global stocks, or the bad wider environmental effects that fish-farms have.

As the article stands, it reads like an advert by a fish company.

If you want to know more about the vegetarian/vegan alternatives for getting omega 3s, and also about getting a healthy diet that has a good balance of omegas, then I would point readers in the direction of the UK Vegan and Vegetarian Societies’ web pages.

For further reading, there are some entertaining articles by Ben Goldacre in his Bad Science article about the long and inglorious history of fish oil research.

Hannah Newman says:

Lindsay. Thank you for these points. This article is a simple explainer with the goal to uncover how DHA — the most essential cerebral omega-3 — works in the brain. I point out that salmon is not the only source of DHA, it simply happens to have one of the highest concentrations of the compound. Your other points regarding the balance of omega 3 and omega 6 as well as the overfishing issue are extremely important. These specifics are better suited for a more in-depth story on omegas and how their acquisition has environmental consequences.

Aika says:

I suggest that you eat salmon with dark greens and bitter herbs such as parsley, cilantro or dandelion to help you grab up any environmental toxins that may be found in the fish. Using herbs with your meal will help you get the most benefit.

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