How Omega-3s Support the Aging Brain

Okay, I want to shift gears and talk about another really important area with omega-3 fatty acids and how it basically affects our brain aging, cognition, and the way our brain is aging. Omega-3 plays a very important role in the brain throughout the lifespan. We're talking in utero development, when you're inside of your mom's belly and you're developing. From that point, even pre-conception. I mean, it plays an important role at every life stage. Right now, we're going to talk about more of the end type, or I'm talking about neurodegenerative disease, but I just want you to keep in mind that every stage is very important for brain health.

So, Bill and his colleagues have also published some studies looking at the Framingham cohort, looking at omega-3 index and Alzheimer's disease. And so, again, what Bill found is that individuals that had a high omega-3 index had about a 50% reduced risk of Alzheimer's disease compared to people with a low omega-3 index. So, again, this is correlative data. We're going to talk about strengthening that with some intervention and randomized controlled trials as well. But, I mean, 50% reduction is really, really a big deal when it comes to Alzheimer's disease.

Well, other studies have actually looked at omega-3 fatty acid levels and reducing Alzheimer's disease risk and found a dose-dependent decrease. And this always strengthens data when you can find something that is dose-dependent. So, for every 100 mg per day increase in omega-3 fatty acids, that was associated with lowering the risk of Alzheimer's disease and cognitive decline by 10%. So, as it kept going up 100 mg more, you had a 10% lower risk of Alzheimer's disease. And you went up 10%—100 mg more of omega-3 fatty acid, again, an additional 10% decrease in Alzheimer's disease risk. Again, so that's probably why when you get up to that high omega-3 index, which we'll talk about, it takes about 2 g a day to get to that high omega-3 index if you have a low omega-3 index. You could see where that 50% reduction comes into play because you keep going up in a dose-dependent manner. And this is an analysis of multiple different studies here showing that omega-3 reduces Alzheimer's disease risk in a dose-dependent manner.

We also know that higher omega-3 index is associated with a larger hippocampal brain volume. So, as we reach older adulthood, when I mean the age about 65, we start to lose 1 to 2% of our hippocampus per year. So, our brain is atrophying, and specifically our hippocampus is atrophying. And our hippocampus is very important for a lot of different brain functions, learning and memory being two of the most important. And so, you don't want to lose 1 to 2% of your hippocampal brain mass per year because that's going to affect your memory. It's going to affect your cognition, your executive function. It's going to affect everything, right?

So, there are studies that have found that a higher omega-3 index is associated with larger hippocampal brain volume. And that was also something that was found to be dose-dependent as well. And so, it's basically staving off that losing of the hippocampal volume. So, you're basically going against what happens naturally with age because inflammation plays a role in hippocampal atrophy. And so, if you can negate some of that inflammation, you're going to keep some of your brain mass. And of course, that's probably partly why you see a lower risk of Alzheimer's disease as well.

And there's also been some studies looking at omega-3 fatty acid supplementation in individuals with mild cognitive decline and how that can help improve cognition after taking omega-3 fatty acids versus placebo. So, there've been a few studies. This is a meta-analysis of multiple studies as well. Sorry, no. This is one study. It was a 2-year trial. These patients had mild cognitive impairment, and they took 2 g a day of omega-3 for 2 years. And after the 2 years, they had improvements in cognitive function, executive function. And importantly, they actually had lower plasma biomarkers of Alzheimer's disease. They had lower amyloid beta in their plasma. But they also had increased markers of neuronal autophagy.

So, what that means—so, neurons, you're not constantly making new neurons. They're called post-mitotic. So, basically, what you have is pretty much what you're going to get. And so, our brain has ways to get rid of bad stuff that has accumulated in them, and that is through a process called autophagy. And so, autophagy is very active in the brain because it's very important to keep our neurons healthy. And so, there's biomarkers in the blood that are showing that that's going up in people that supplemented with omega-3 compared to the placebo.

So, I think that this is also just strengthening the whole picture here that I'm trying to present to you, which is that omega-3 fatty acids are very important for brain health. They're very important for preventing inflammation in the brain, which does lead to brain atrophy and also lead to neurodegenerative diseases like Alzheimer's disease, dementia. And so, it's something to keep in mind. As I mentioned, 90% of the US population does not get enough omega-3 from their diet.

So, there's a variety of reasons why omega-3 is improving brain health, inflammation being at the core. We talked about that. But also the cell membranes, in our neurons, the cell membranes are very important. And the fluidity, much like in our cardiovascular system, the fluidity is extremely important because all of our transporters and receptors for neurotransmitters, they're all in that cell membrane. It's very important for the structure and function of our receptors and transporters. And so it's globally affecting neurotransmission.

When you have a cell membrane that's not getting omega-3, and in the brain, what happens is—and there's studies that have shown that, for example, you take animals like mice and you make them omega-3 deficient, their glucose transporters aren't functioning right because they're structurally, like the membrane's too stiff. And so the transporter, it's not right, and so glucose can't get into the brain. And so this, over time, yeah, it's going to affect your cognition in the short term. You're going to feel brain foggy. You're not going to feel sharp. But over time, what's going to happen is low glucose in the brain affects a lot of different processes, right? Neurotransmission, it also leads to the accumulation of tau tangles. This is a hallmark of Alzheimer's disease as well.

And so it's really essential for their cell membranes as well as boosting neurotransmission. So, there have been studies also showing that EPA and DHA are important for dopamine, serotonin. When you have high inflammation, it stops the release of serotonin. You're not able to release serotonin from the presynapse. And so it's really just globally affecting neurotransmission, neuroplasticity. It's affecting the transporters, and it's affecting inflammation. So, there's a lot of ways that omega-3 is really behind the scenes improving the way your brain is aging. And when you don't have omega-3 there, not only is it not countering the inflammation, but it's affecting just global nutrient transport into your brain and global neurotransmission.