Lipids, Omega-3 Fats, and Brain Health

Brain FoodsHealth
Written By Danielle

For optimal brain functioning and for the prevention of future cognitive decline,
it is vital that our brains have a regular source of lipids.

What are lipids?

Lipids are fatty, oily, or waxy biological molecules that are insoluble in water. In terms of diet, we think of these as fats. Lipids are critical for maintaining both the structure and the functioning of our brains. Aside from our adipose fat stores, the brain has the highest lipid content of any structure within the body. Lipids account for 50% of the dry weight of our brains (Bruce et al., 2017; Yoon et al., 2022). Lipids are also responsible for many vital brain functions across the lifespan including encouraging neuronal growth, facilitating neurotransmission, ensuring organ homeostasis, preserving optimal cognition, enhancing memory, maintaining mood, and preventing brain shrinkage and neurodegeneration (Hans et al., 2022; Luchtman & Song, 2013).

Fatty acids are the building blocks of lipids.
These are classified as either saturated or unsaturated.

Fatty acids are comprised of chains of between 12 and 20 carbon atoms. If the chain consists of no double-bonded carbon atoms, with each carbon instead being bonded with a hydrogen atom, the fatty acid is considered to be “saturated” with hydrogen. If the fatty acid contains at least one double-bonded carbon atom, then it is “unsaturated” (Libretexts, 2022).

Which lipids are most important for brain health?

Omega-3 long-chain
polyunsaturated fatty acids
are especially critical
for optimal brain function.

  • Omega-3 fats reduce inflammation levels in the brain by lowering the concentration of pro-inflammatory molecules (Chianese et al., 2018; Corraliza-Gomez et al., 2019; Custers et al., 2022).

  • Omega-3 fats increase blood flow to the brain, improving cognition and enhancing both learning and memory (Dighriri et al., 2022).

  • Omega-3 fats reduce the risk of dementia, encourage neuronal preservation, and protect against neurodegeneration (Dighriri et al., 2022; Wei et al., 2023; Welty, 2023; Yanai, 2017).

  • Low Omega-3 levels are associated with smaller brain size. By contrast, Omega-3 fats delay structural brain aging and hippocampal atrophy, and they help to preserve brain volume (Macaron et al., 2021; Tan et al., 2012).

  • Low levels of Omega-3 fats have been consistently associated with depression, bipolar disorder, ADHD, and autism (DiNicolantonio & O'Keefe, 2020; Healy-Stoffel & Levant, 2018; Lange, 2020; Liao et al., 2019).

  • Supplementation with Omega-3 fats can help to reduce the symptoms of anxiety and depression (DiNicolantonio & O'Keefe, 2020; Healy-Stoffel & Levant, 2018; Liao et al., 2019; Mehdi et al., 2023; Su et al., 2018).

Omega-3 rich avocado toast with pine nuts and walnut ricotta.

In understanding what makes Omega-3 polyunsaturated fatty acids so special and critical to our brain health, it is important to refer back to their chemical structure and shape. Differences in the length and saturation of the fatty acids influence the amount of fluidity in a cell's membrane, or how stiff or rigid that membrane is. Because saturated fats have a straight, unbending structure, they can pack together tightly, which makes the molecule more rigid and unyielding. This is also what causes them to be solid at room temperature.

(Morris, n.d.)

Omega-3 polyunsaturated fats, however, have long chains of carbon molecules with multiple carbon to carbon double bonds, which allows them to curve and bend flexibly. Given their long curving structure, polyunsaturated fats do not compress together as closely. This allows for more fluidity in the cell membrane, with greater movement of proteins and lipids. Greater fluidity increases adaptability and makes the membrane more resistant to injury (OmegaQuant, 2022).

(Morris, n.d.)

Just as maintaining muscular flexibility is important to avoiding physical injury, having flexibility and fluidity in our cell membranes allows them to change shape or "deform" as needed. While deformity may sound like a bad thing, it this instance, it refers to a cell's ability to alter its shape as needed to avoid injury when under stress. The more Omega-3 polyunsaturated fats present in a cell membrane, the more fluidity and deformity that is possible.

In the brain, Omega-3 polyunsaturated fatty acids also help with transmitting signals within a cell (signal transduction), encourage gene expression, and protect against apoptosis or cellular death. These are key features in helping to prevent cognitive loss and neurodegeneration. (Dighriri et al., 2022; Kao et al., 2020; Pinho, 2023; OmegaQuant, 2022; Sokoła-Wysoczańska et al., 2018).

With regard to mood disorders, like depression and anxiety, Omega-3 polyunsaturated fats alter synaptic function, facilitate the transmission of neurotransmitters, and reduce brain inflammation, all of which are critical for supporting optimal mood and healthy brain function. (Bazinet & Layé, 2014).

Omega-3 rich blueberry oats topped with walnuts, dates, and ground golden flax.

There are Two Types of Omega-3 Fatty Acids:

  • ALA (alpha-linolenic acid), comes from plants, such as flaxseeds, hemp hearts, walnuts, and chia seeds. ALA is considered essential, as our body cannot synthesize it, so we must get it from our food.

  • EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) are the second type of Omega-3 polyunsaturated fatty acids. Our bodies can produce EPA and DHA from the ALA we consume in our foods. However, the body’s ability to convert ALA is limited. Only about 5% of ALA is converted to EPA, while less than 0.5% is converted to DHA.

The long, bending molecular structures of EPA, DHA, and ALA promote fluidity in our cell membranes,
allowing them to alter shape as needed when under stress.


As a society, we are sorely lacking in essential Omega-3 fats. A recent study found that over 95% of children and 68% of adults had Omega-3 concentrations below the established Dietary Guidelines for America. Approximately 89% of adults had such deficient Omega-3 concentrations that they were deemed to be at high risk for cardiovascular disease (Murphy et al., 2021).

Luckily, we can easily add Omega-3 rich foods to our diets. The best sources of ALA include flaxseeds, hemp hearts, walnuts, chia seeds, soybeans, navy beans, tofu, avocados, cherimoya (custard apple), pecans, pistachios, and pine nuts.

According to the National Institutes of Health,
the current daily recommended intake of ALA for adults is
1,100 mg for women and 1,600 mg for men (NIH., n.d.).

We can obtain EPA and DHA through food sources, including seafood (especially wild caught salmon, small oily fish like anchovies, and some shellfish). For those individuals who rarely or never consume seafood, adequate intake can be ensured through a high-quality fish oil or an algae omega supplement. Fish obtain their EPA and DHA by eating algae, and algae supplements have been shown to be viable means of increasing Omega-3 concentrations (Arterburn, 2008; Craddock et al., 2017; Doughman et al., 2007). Please consult your doctor before adding any supplements to your diet. This is not intended as medical advice.

There are no established dietary guidelines regarding the recommended daily intake of EPA and DHA. However, the FDA recommends that daily intake not exceed 3000 mg of EPA and DHA combined, and that no more than 2000 mg come from supplements (Krupa et al., 2023). Other researchers have proposed that 1000 mg daily may be optimal for longevity, cardiovascular functioning, and brain health (Calder, 2023). If you choose to supplement, please discuss dosing with your medical provider.

Here are some of my favorite tricks to increase daily Omega-3 consumption:

Ingredients for Omega-3 rich Spicy Cilantro Sauce including walnuts, ground flax, and hemp hearts.

Here are some additional recipes to add to help inspire your daily Omega-3 intake:

Omega-3 Rich Hemp Crusted Tofu with Celeriac Puree by Feasting at Home

In addition to being critical to our brain health,
Omega-3 fats may also provide the key
to unlocking the Blood Brain Barrier.

When we eat ALA rich plant foods like those shown above, they are synthesized into DHA and EPA in the liver. EPA and DHA (either eaten directly or having been created from ALA) are then carried through the bloodstream to the Blood Brain Barrier (BBB) (DiNicolantonio & O'Keefe, 2020). In the past several years, researchers have come to understand how these molecules can pass through the tight junctions of the BBB and into the brain. Investigators have discovered that a protein located on the single layer of endothelial cells lining the BBB acts as a molecular gateway that transports long-chain fatty acids into the brain (Cater et al., 2021; Zhang et al., 2018). As described by lead researcher Rosemary Cater, "Essential nutrients like Omega-3s require the assistance of dedicated transporter proteins that specifically recognize them and get them across this barrier. The transporters are like bouncers at a club, only letting molecules with invites or backstage passes in" (Columbia, 2021).

Scientists from UCLA and the National Institutes of Health (NIH) have recently developed a 3D model of the transporter protein that provides the gateway for Omega-3s to enter the brain. This transfer of fatty acids into the brain requires three distinct steps shown in the rendering below. The long chain of Omega-3 fatty acids binds to the transporter and is surrounded by the transport protein, it is then flipped within the transport molecule as it crosses through the BBB, where it is eventually absorbed by the brain tissues (Nguyen et al., 2023). 

Step-by-step process of lipid transport across blood-brain barrier. Credit: Image created by Ethan Tyler from NIH Medical Arts (NIH Media Advisory, 2023).

Historically, getting medications to cross the BBB has posed a significant challenge in treating a wide array of neurological and psychological diseases. Scientists hope to use this exciting new information about Omega-3 transport proteins to eventually create medications that can be delivered directly to the brain via this pathway. Being able to cross the BBB could completely alter treatment for some of our most devastating brain-based diseases, such as Parkinson’s, Alzheimer’s, ALS, and Schizophrenia.

Until then, by mindfully including delicious sources of Omega-3 fats into our daily diets,
we can help to ensure that our brains are functioning optimally now and in the future.

Wishing you excellent health and happy eating.
🌱💕



References:

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Danielle
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