How are memory and omega-3 related?

Memory is as self-evident as breathing or the beating of the heart. You don't feel or even appreciate a memory until you pay attention to it. Or until it breaks.

Memory, like a muscle, can be trained. And you should definitely do it, but it is difficult to train a muscle if its structure is damaged or inferior. This can also happen with memory if there is not enough omega-3 unsaturated fatty acids in the diet.

Docosahexaenoic acid (DHA) makes up more than 90 percent. of polyunsaturated fatty acids in the brain, which is approximately 10-20 percent. of all the lipids that make up the brain. [1] The amount of DHA is highest in metabolically more active parts of the brain, such as the cerebral cortex, mitochondria, and synapses. [2]

Much research is focused on the effect of omega-3 unsaturated fatty acids, especially DHA, on memory and various memory-related diseases such as senile dementia, Alzheimer's disease, etc. prevention and progression.

Supplementing the diet with DHA has been shown to improve memory and reaction time in healthy young adults who normally get little dietary DHA. [3] Other studies report similar results. It has even been found that regular weekly consumption of fish increases the amount of gray matter in the brain. [4]

However, omega-3 is not a miracle substance that improves brain function for everyone without exception. Such an effect is observed in those who lack omega-3. If you want to know if you are one of them, ask yourself the question: how many times a week do you eat wild-caught oily fish? If the answer is 2-3 times, it is likely that you are getting enough of these substances with food. If less, omega-3 food supplements should be included in the diet.

There is growing evidence that adequate omega-3 intake may reduce the risk of developing Alzheimer's disease. in 2018 May. A study of more than 23,000 older adults published in the American Journal of Epidemiology found that those who ate four or more servings of fish per week experienced less memory loss over four to nine years of follow-up compared to people , who typically consume less than one serving per week. According to the researchers, such a result can be described as a four-year younger brain thanks to omega-3. [5]

Regarding Alzheimer's disease and omega-3, it is important to mention that omega-3 does not cure this disease, but slows its progression. This illustrates 2021 very well. published research. During it, it was found that the results of memory tests of Alzheimer's patients in the group that took DHA and EPR (eicosapentaenoic acid) over 6 months. did not deteriorate at all compared to the control group. [6]

An even more telling study came out this year. It looked for links between the amount of omega-3 in red blood cell membranes and the development of Alzheimer's disease. It was observed that those whose erythrocyte membranes contained more than 6.1% DHA. of all erythrocyte membrane fatty acids halved the risk of developing Alzheimer's disease and provided almost five additional years without Alzheimer's disease compared to those whose erythrocyte membranes contained less than 3.8% DHA. of all unsaturated acids. [7]

According to many epidemiological studies, higher consumption of DHA in food or its higher concentration in the blood is associated with protection against Alzheimer's disease or other types of dementia, but more large-scale clinical studies are needed to form firm recommendations.

However, some mechanisms are already known, thanks to which EPR and DHA are beneficial for the structure and activity of the brain:

  • reduces the amount of inflammatory arachidonic acid metabolites and increases the amount of anti-inflammatory EPR and DHA metabolites;

  • improves synapse functions, as it increases the plasticity of synapse membranes and facilitates signal transmission (this affects cognitive abilities); [8]

  • can enhance the action of certain neurotrophic factors and stimulate neuronal growth and metabolism in certain regions of the brain; [9, 10]

  • inhibits the production and accumulation of amyloid β peptide, which is believed to promote Alzheimer's disease, through various mechanisms; [11]

  • improves cerebral blood flow; [12]

  • reduces risk factors caused by blood vessels, manifested by heart attacks and ischemia of small cerebral vessels. [13]

Cole at al. (2009) suggest that DHA may help prevent Alzheimer's disease and other forms of age-related dementia if taken early and in combination with antioxidants. [14]

Another very interesting 2019. study shows that omega-3 polyunsaturated fatty acids (EFA with DHA) protect against memory impairment caused by chronic sleep deprivation.

The study was conducted with rats. They were deprived of sleep and watched as they performed memory tasks and counted the number of errors they made. In terms of memory testing, the number of errors made in both long-term and short-term memory tests was highest in the sleep-deprived group. A very interesting thing was that the rats that were not allowed to sleep but were given extra omega-3 made the same number of mistakes as the control group or the group that got extra omega-3 but were able to get a good night's sleep.

Researchers have concluded that omega-3 polyunsaturated fatty acids protect against memory impairment caused by chronic sleep deprivation [15] so if uninterrupted sleep is difficult for you because you are raising young children, caring for the sick, staying up at night, or other reasons , disturbing your sleep, consider adding omega-3 to your diet.

[1] Brenna, J. Thomas, and Guan-Yeu Diau. "The influence of dietary docosahexaenoic acid and arachidonic acid on central nervous system polyunsaturated fatty acid composition." Prostaglandins, Leukotrienes and Essential Fatty Acids 77.5-6 (2007): 247-250.
[2] Morris MC, Evans DA, Bienias JL, et al. Consumption of Fish and n-3 Fatty Acids and Risk of Incident Alzheimer Disease. Arch Neurol. 2003;60(7):940–946. doi:10.1001/archneur.60.7.940
[3] Stonehouse, Welma, et al. "DHA supplementation improved both memory and reaction time in healthy young adults: a randomized controlled trial." The American Journal of Clinical Nutrition 97.5 (2013): 1134-1143.
[4] Raji CA, Erickson KI, Lopez OL, Kuller LH, Gach HM, Thompson PM, Riverol M, Becker JT. Regular fish consumption and age-related brain gray matter loss. Am J Prev Med. 2014 Oct;47(4):444-51. doi: 10.1016/j.amepre.2014.05.037. Epub 2014 Jul 29. PMID: 25084680; PMCID: PMC4171345.
[5] Disease, and Decline in Global Cognition and Memory in 5 Cohorts of Older Persons. Am J Epidemiol. 2018 May 1;187(5):933-940. doi: 10.1093/aje/kwx330. PMID: 29053784; PMCID: PMC5928461.
[6] Tofiq, Avin, et al. "Effects of Oral Omega-3 Fatty Acid Supplementation on Cerebrospinal Fluid Biomarkers in Patients with Alzheimer's Disease: A Randomized Controlled Trial—The OmegAD Study." Journal of Alzheimer's Disease 83.3 (2021): 1291-1301.
[7] Sala-Vila, Aleix, et al. "Red Blood Cell DHA Is Inversely Associated with Risk of Incident Alzheimer's Disease and All-Cause Dementia: Framingham Offspring Study." Nutrients 14.12 (2022): 2408.
[8] Chytrova, Gabriela, Zhe Ying, and Fernando Gomez-Pinilla. "Exercise contributes to the effects of DHA dietary supplementation by acting on membrane-related synaptic systems." Brain research 1341 (2010): 32-40.
[9] Fehér, Ágnes, et al. "Association between BDNF Val66Met polymorphism and Alzheimer disease, dementia with Lewy bodies, and Pick disease." Alzheimer Disease & Associated Disorders 23.3 (2009): 224-228.
[10] Fehér, Ágnes, et al. "Association between BDNF Val66Met polymorphism and Alzheimer disease, dementia with Lewy bodies, and Pick disease." Alzheimer Disease & Associated Disorders 23.3 (2009): 224-228.
[11] Grimm, Marcus OW, et al. "Docosahexaenoic acid reduces amyloid β production via multiple pleiotropic mechanisms." Journal of Biological Chemistry 286.16 (2011): 14028-14039.
[12] Amen, Daniel G., et al. "Quantitative erythrocyte omega-3 EPA plus DHA levels are related to higher regional cerebral blood flow on brain SPECT." Journal of Alzheimer's Disease 58.4 (2017): 1189-1199.
[13] Orr, Sarah K., and Richard P. Bazinet. "The emerging role of docosahexaenoic acid in neuroinflammation." Current opinion in investigational drugs (London, England: 2000) 9.7 (2008): 735-743.
[14] Cole, Greg M., Qiu-Lan Ma, and Sally A. Frautschy. "Omega-3 fatty acids and dementia." Prostaglandins, Leukotrienes and Essential fatty acids 81.2-3 (2009): 213-221.
[15] Alzoubi, Karem H., Fadia Mayyas, and Hamza I. Abu Zamzam. "Omega-3 fatty acids protect against chronic sleep-deprivation induced memory impairment." Life sciences 227 (2019): 1-7.