Are You Wasting Money On Your Omega-3 Supplements?

Are You Wasting Money On Your Omega-3 Supplements?
Omega-3 supplements are becoming increasingly popular – and rightly so – as another recent UK BioBank study (1) reported a 30% lower risk of dementia in those with higher omega-3 status in their blood.
Another study (2) found a 49% reduced risk for dementia in those with the highest omega-3 DHA level (top fifth) in their red blood cells compared with those having the lowest (bottom fifth).
Oily fish and fish oil supplements contain two types of omega-3 fat, called DHA and EPA. DHA is the main fat found in the brain cells of all animals. What’s more, your omega-3 index predicts both your brain size and cognitive abilities, according to this study (3) from Loma Linda University (featured in the Blue Zones film), so you might want to check that you’re above 8%.
The Benefits Go Beyond Preventing Dementia.
A person’s omega-3 index, which is a composite score of both EPA and DHA bound into red blood cell membranes, predicts both the risk of depression (4) and poorer reading ability, lower IQ, worse memory, sleep difficulties as well as aggression and emotional instability in children – hallmarks of ADHD (5).
It also predicts the risk of heart disease (6) and developmental problems in babies, based on measures taken in women both before and during pregnancy. Pregnant women with a higher omega-3 index have a much lower likelihood of having a baby with developmental problems, according to research from Imperial College London Institute of Brain Chemistry at the Chelsea & Westminster Hospital campus.
The Missing Piece…
However, omega-3s do not act alone. To become biologically active, DHA must be attached to phospholipids – a process entirely dependent on methylation. This, in turn, requires adequate levels of B vitamins: B6, folate, and B12.
A landmark study (7) concluded that the combination of B vitamins and fatty acids improves cognitive function. This is because, during methylation, DHA attaches to a phospholipid, enabling it to be incorporated into the neuronal membrane of the brain. The process of methylation is entirely dependent on vitamins B6, B12, and folate. When omega-3 and B vitamin status are both sufficient, the brain can build new, functional neuronal membranes – literally the structural basis of thought.
So, you need both a high omega-3 status (over 8%) and adequate B vitamins to incorporate DHA into the brain. You can be confident that methylation is working properly if your homocysteine level is below 11 µmol/L. In a large omega-3 study, people with early-stage dementia were given 2.3 grams a day (equivalent to two large fish oil capsules), but only those with lower homocysteine levels benefited (7).
Having a raised homocysteine level, above 11mcmol/L, is extremely common. In the US around 40% of people over the age of 60 have elevated levels. This is often due to poor absorption of vitamin B12 and may require high-dose supplementation to normalise homocysteine. (Read more about homocysteine here.)
Why Testing is Essential
This means two things are critical for protecting your brain:
- A high omega-3 index – ideally over 8%.
- A low homocysteine level – ideally below 11µmol/L, with the optimal level being around 7 µmol/L
If either is lacking, the protective effect is lost. Taking fish oils without ensuring good B vitamin status will not deliver full benefit – and vice versa.
That is why testing both is essential for protecting your brain.
To make this simple, Food for the Brain has launched the DRIFt 5-in-1 home test – a quick pinprick blood test you can do yourself. It measures:
- Omega-3 Index – how much brain-building DHA and EPA are in your cells
- Homocysteine – the key methylation marker, linked to brain shrinkage
- Vitamin D – vital for brain health, mood, and immunity
- HbA1c – the gold-standard measure of blood sugar balance
- Omega-6:3 Ratio – shows whether you’re getting the right fats for your brain
Together, these five markers account for more than half of the modifiable risk for Alzheimer’s disease and dementia.
By testing these markers, you will know exactly what to supplement and what to change in order to protect your brain. And by joining the DRIFt study, you will also become a Citizen Scientist, helping to advance dementia prevention research worldwide.

Order your DRIFt 5-in-1 test today and take the first step towards protecting and upgrading your brain.
Thank you for reading!
Food for the Brain is a non-for-profit educational and research charity that offers a free Cognitive Function Test and assesses your Dementia Risk Index to be able to advise you on how to dementia-proof your diet and lifestyle.
By completing the Cognitive Function Test you are joining our grassroots research initiative to find out what really works for preventing cognitive decline. We share our ongoing research results with you to help you make brain-friendly choices.
Please support our research by becoming a Friend of Food for the Brain.
References
1 Sala-Vila, A.; Tintle, N.; Westra, J.; Harris, W.S. Plasma Omega-3 Fatty Acids and Risk for Incident Dementia in the UK Biobank Study: A Closer Look. Nutrients 2023, 15,4896. https://doi.org/10.3390/ nu15234896
2 Sala-Vila, A.; Satizabal, C.L.; Tintle, N.; Melo van Lent, D.; Vasan, R.S.; Beiser, A.S.; Seshadri, S.; Harris, W.S. Red Blood Cell DHA Is Inversely Associated with Risk of Incident Alzheimer’s Disease and All-Cause Dementia: Framingham Offspring Study. Nutrients 2022, 14, 2408. https://doi.org/10.3390/ nu14122408
3 Loong S, Barnes S, Gatto NM, Chowdhury S, Lee GJ. Omega-3 Fatty Acids, Cognition, and Brain Volume in Older Adults. Brain Sci. 2023 Sep 2;13(9):1278. doi: 10.3390/brainsci13091278. PMID: 37759879; PMCID: PMC10526215.
4 Yonezawa K, Kusumoto Y, Kanchi N, Kinoshita H, Kanegae S, Yamaguchi N, Ozawa H. Recent trends in mental illness and omega-3 fatty acids. J Neural Transm (Vienna). 2020 Nov;127(11):1491-1499. doi: 10.1007/s00702-020-02212-z. Epub 2020 May 25. PMID: 32451632.
5 Montgomery P, Burton JR, Sewell RP, Spreckelsen TF, Richardson AJ. Low blood long chain omega-3 fatty acids in UK children are associated with poor cognitive performance and behavior: a cross-sectional analysis from the DOLAB study. PLoS One. 2013 Jun 24;8(6):e66697. doi: 10.1371/journal.pone.0066697. Erratum in: PLoS One. 2013;8(9).doi:10.1371/annotation/26c6b13f-b83a-4a3f-978a-c09d8ccf1ae2. PMID: 23826114; PMCID: PMC3691187; see also Raine A, Ang RP, Choy O, Hibbeln JR, Ho RM, Lim CG, Lim-Ashworth NSJ, Ling S, Liu JCJ, Ooi YP, Tan YR, Fung DSS. Omega-3 (ω-3) and social skills interventions for reactive aggression and childhood externalizing behavior problems: a randomized, stratified, double-blind, placebo-controlled, factorial trial. Psychol Med. 2019 Jan;49(2):335-344. Doi 10.1007/s11920-018-0894-y. PMID: 29623453. ; see also Liu, J., Cui, Y., Li, L. et al. The mediating role of sleep in the fish consumption – cognitive functioning relationship: a cohort study. Sci Rep 7, 17961 (2017). https://doi.org/10.1038/s41598-017-17520-w
6 Gutierrez L, Folch A, Rojas M, Cantero JL, Atienza M, Folch J, Camins A, Ruiz A, Papandreou C, Bulló M. Effects of Nutrition on Cognitive Function in Adults with or without Cognitive Impairment: A Systematic Review of Randomized Controlled Clinical Trials. Nutrients. 2021 Oct 22;13(11):3728. doi: 10.3390/nu13113728. PMID: 34835984; PMCID: PMC8621754.
7 Jernerén F, Cederholm T, Refsum H, Smith AD, Turner C, Palmblad J, Eriksdotter M, Hjorth E, Faxen-Irving G, Wahlund LO, Schultzberg M, Basun H, Freund-Levi Y. Homocysteine Status Modifies the Treatment Effect of Omega-3 Fatty Acids on Cognition in a Randomized Clinical Trial in Mild to Moderate Alzheimer’s Disease: The OmegAD Study. J Alzheimers Dis. 2019;69(1):189-197. doi: 10.3233/JAD-181148. PMID: 30958356.