How Fish Oil Can Harm Your Brain

Omega-3 fatty acids have many benefits for the health, including for the brain!

We wrote about some of them, here: What Omega-3 Fatty Acids Really Do For Us

There are even some less well-known benefits, such as: Why Healthy Teeth May Depend On Omega-3 & Exercise

Now, the press has not been all positive, for example: Fish Oil Can Backfire Without This Enzyme

But what’s this about omega-3s harming the brain?

Brain recovery impediment

Researchers (Dr. Eda Karakaya et al.) examined how omega-3 fatty acids from fish oil affect brain recovery, and the results were not happy ones.

In few words: the fish-derived omega-3 fatty acid EPA (eicosapentaenoic acid) accumulated in the brain and was linked to reduced recovery capacity after injury.

Further, EPA altered cortical gene programs by suppressing pathways involved in vascular repair* and extracellular matrix organization while increasing lipid metabolism activity.

*And this is critical. Regular 10almonds readers will remember that we often say “what’s good for your heart is good for your brain”, and it’s because the former feeds the latter, with nutrients, oxygen, etc, and also ultimately takes away detritus (yes, it’s the glymphatic system that does it directly, but without good blood flow, there’s nowhere for it to usefully drain to). So all this means that if cerebrovascular repair is impaired, then ultimately, brain maintenance will be impaired too.

More than just that, in human brain microvascular endothelial cells, EPA reduced the ability to form repair networks under conditions promoting fatty acid use.

And while no ethics board would let the researchers take brain slices from living human volunteers to look at under the microscope, postmortem brain samples from humans with chronic traumatic encephalopathy showed disrupted fatty acid balance and vascular-related gene changes consistent with EPA-linked effects.

In other words: a further smoking gun that strongly suggests (albeit does not outright prove, in this case) “EPA did this”.

There is one thing that’s not completely bad news for fish oil here, which is that DHA (docosahexaenoic acid), another omega-3 fatty acid, did not show the same negative effects and remains associated with normal brain structure.

But since fish oil contains both EPA and DHA in generous amounts, there’s a limit to how helpful this is:

❝Fish oil supplements are everywhere, and people take them for a range of reasons, often without a clear understanding of their long-term effects

But in terms of neuroscience, we still don’t know whether the brain has resilience or resistance to this supplement. That’s why ours is the first such study in the field.❞

~ Dr. Onder Albaryam, a colleague of Dr. Karakaya, and part of the “et al.” in this study

You can read the paper in full, here: Eicosapentaenoic acid reprograms cerebrovascular metabolism and impairs repair after brain injury, with relevance to chronic traumatic encephalopathy

Want to do better for your brain?

You do have other options!

For example, as well as the difference between EPA and DHA that we talked about above, there are also plant-based omega-3s that just have ALA (and not EPA or DHA) which the body can convert to whatever omega-3 form it needs (just like the fish did, for we too are animals that can do that, and for this reason our liver fats would, if healthy, also be a good source of EPA/DHA if something were to predate on us).

For more on that, check out: Omega-3s: Different Sources, Different Benefits?

Enjoy!