September 2026 - Plants Aren’t Brain Food

Metabolic Medical

September 2026 Newsletter

Our brain is our most important organ. It’s also our fattest! It's roughly 60% fat with omega-3s comprising over a third of all the brain's fats! Omega 3s are critical for both brain structure AND function.¹ These unique fats build cell membranes, drive anti-inflammatory signaling and support new brain cell growth (neurogenesis). They are also required for the production of your neurotransmitters such as serotonin, dopamine, GABA, and norepinephrine. Omega 3 is an ESSENTIAL nutrient. “Essential” is defined as you have to consume it because your body cannot make it. You cannot build a brain without fat, and you cannot build a highly functioning brain without omega 3.

Human evolution, brain growth and civilization were enabled by access to fish, our best source for omega 3. However, modern humans are pushed to go plant based on a daily basis. Let me walk you through why a plant based diet is starving our brains of this essential nutrient. Please be patient: there is a little alphabet soup ahead!

Omega-3 are known as PUFAs (polyunsaturated fatty acids) because they have two or more double bonds. Double bonds look like “=” in the chemical structures below. Omega-3 comes in three main forms: alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA). 

ALA — the omega-3 found in flax, chia, and walnuts — has to be converted into DHA and EPA to do anything useful for your brain.² But most people aren’t aware that the human body is terrible at this conversion! That conversion rate in humans is often cited at under 10%. Plant-based omega-3 is not a substitute for the marine kind. If you're relying on nuts and seed to protect your brain, you're relying on a pathway your body barely uses.

Most People Are Deficient — And It's Not Close

Deficiency in omega 3 is the norm. Worldwide, as many as 90% of adults are not meeting recommended omega-3 intake.³ The most common global target for EPA + DHA combined is 250 mg per day — a number most modern diets simply don't hit, because most people aren't eating oily fish regularly.⁴

It's Not Just Your Brain

Omega 3 deficiency reaches far beyond cognition. It protects muscle from wasting, reduces insulin resistance, hydrates skin and lowers inflammation broadly, from arthritis to IBD relief.⁵ Omega 3 also lowers triglycerides by 15-30%, protecting against heart disease: atherosclerosis. 

But it’s the mortality data that has the greatest power of persuasion. A 2021 Framingham study revealed those with a low omega 3 index was as powerful a predictor of early death as smoking!⁶ The red blood cell omega-3 Index (RBC omega 3 Index) is a blood test that measures EPA and DHA directly in red blood cell membranes. This test acts as a reflection of your diet over the last 3 months- just like a HbA1c reflects your blood glucose over 3 months. These red blood cell omega-3 levels carried as much predictive weight for an early death as cholesterol, blood pressure, smoking status, and diabetes combined. People with the highest Omega-3 Index were 33% less likely to die during the study's follow-up period compared to those with the lowest. An index of 8% or higher is considered protective; below 4% is the low range associated with the elevated mortality risk.⁶ Most Americans test below 4%. This is one of the few nutrient markers where you can measure, track, adjust and benefit.

The Brain and Dementia Story 

Omega 3 is a key player in the strategy to protect against cognitive decline and neurodegeneration. Cohort studies looking at fish intake specifically have found associations with a 30–50% lower risk of dementia and Alzheimer's disease.⁷ A large meta-analysis pooling dietary intake data across more than 100,000 participants found a meaningful, but more modest 20% reduction in risk of all-cause dementia or cognitive decline tied to omega-3 intake.⁸ Dietary intake, rather than supplements, carries the clearest, most consistent signal and may provide dose dependent benefits. Omega-3 status looks protective before decline. However, once significant cognitive impairment is already present, supplementation has not been shown as helpful.

Where to Get It

Your best dietary sources are the SMASH fish: sardines, mackerel, anchovies, salmon, herring eaten 1–2 times per week. Cod liver, grass-fed beef, lamb and free-range eggs contribute meaningfully as well.

For anyone who can't hit that through food alone, or who's specifically targeting inflammation, supplementation in the range of 1–3g daily is a reasonable option. The triglyceride form is the natural state found in the fish. Unlike ethyl esters forms which are chemically synthesized, the triglyceride form has better bioavailability: it is easily absorbed, enters the blood and is used by the tissues. 

Take Home Message:

Omega 3 isn't a supplement trend. It's a functional and structural requirement for the organ that makes you who you are! The evidence for omega 3 in mortality risk, inflammation, triglyceride management, dementia prevention and metabolic health is strong. Yet, the dietary gap is real. Omega 3 deficiency is the norm, not the exception. I like intentionally using tins of SMASH fish as a side dish for two meals per week- I leave them on my kitchen counter as a reminder to supplement. I eat grass fed beef as often as I can. And I enjoy a dose of fish oil everyday. 

In building a body of intention, omega 3 is an intentional tool for thriving and prevention.

References

1. Dighriri IM, Alsubaie AM, Hakami FM, Hamithi DM, Alshekh MM, Khobrani FA, Dalak FE, Hakami AA, Alsueaadi EH, Alsaawi LS, Alshammari SF, Alqahtani AS, Alawi IA, Aljuaid AA, Tawhari MQ. Effects of Omega-3 Polyunsaturated Fatty Acids on Brain Functions: A Systematic Review. Cureus. 2022 Oct 9;14(10):e30091 PMID: 36381743

2. Gutierres D, Pacheco R, Reis CP. The Role of Omega-3 and Omega-6 Polyunsaturated Fatty Acid Supplementation in Human Health. Foods. 2025 Sep 23;14(19):3299. doi: 10.3390/foods14193299. PMID: 41097470; PMCID: PMC12524211.

3. Sprague, M., Betancor, M.B., Rolland, A. et al. Evaluating the adequacy of current dietary guidelines for seafood as a source of long-chain omega-3 fatty acids. Sci Rep 16, 15190 (2026).

4.Calder PC, Cawood AL, James C, Page F, Putnam S, Minihane AM. An overview of national and international long chain omega-3 polyunsaturated fatty acid intake recommendations for healthy populations. Nutrition Research Reviews. 2026;39:e6.  

5.Sinha S, Haque M, Lugova H, Kumar S. The Effect of Omega-3 Fatty Acids on Insulin Resistance. Life (Basel). 2023 Jun 5;13(6):1322. PMID: 37374105; 

6. McBurney MI, Tintle NL, Vasan RS, Sala-Vila A, Harris WS. Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort. Am J Clin Nutr. 2021 Oct 4;114(4):1447-1454. PMID: 34134132

7.Godos J, Micek A, Currenti W, Franchi C, Poli A, Battino M, Dolci A, Ricci C, Ungvari Z, Grosso G. Fish consumption, cognitive impairment and dementia: an updated dose-response meta-analysis of observational studies. Aging Clin Exp Res. 2024 Aug 20;36(1):171.PMID: 39162889

8.Wei BZ, Li L, Dong CW, Tan CC; Alzheimer’s Disease Neuroimaging Initiative; Xu W. The Relationship of Omega-3 Fatty Acids with Dementia and Cognitive Decline: Evidence from Prospective Cohort Studies of Supplementation, Dietary Intake, and Blood Markers. Am J Clin Nutr. 2023 Jun;117(6):1096-1109. PMID: 37028557