- There are reports that people with mild cognitive impairment (MCI) and others may receive a positive effect on memory.
- The evidence score is 51, and reliability is considered moderate.
- This is a research result relevant to older adults concerned about memory decline.
Omega-3 fatty acid is a type of unsaturated fatty acid.
It is generally treated as an ingredient consumed through diet or supplements in health-related contexts.
There are reports that taking omega-3 fatty acid has a positive effect on various memory-related functions.
Of 14 randomized controlled trials (RCTs: a reliable research method in which participants are randomly divided to compare effects), 10 showed positive results in areas such as memory and information processing speed.
This investigation covered older adults and people with mild cognitive impairment. It is a report based on a systematic review (a method that comprehensively collects and analyzes existing research on a specific topic) that compiled and analyzed multiple past studies. In other words, it can be said that in several high-quality studies, some benefit has been shown for memory-related functions.
On the other hand, it is also known that results differ when examined from a long-term, 3-year perspective.
In a large-scale study involving 1,525 participants, no clear difference was seen in the degree of cognitive decline between the group taking omega-3 and the group taking a placebo (a fake substance containing no substantial active ingredient).
This study was conducted on older adults aged 70 and over who had memory-related concerns. It used a randomized controlled trial (RCT) method with a large number of participants — 1,525. It appears that, under certain conditions or over certain periods, differences from intake do not always appear as a statistically significant difference. In other words, some people may not experience an effect.
Looking at the research data, it is suggested that results may differ depending on the condition of the subjects.
For people in a state of mild cognitive impairment (MCI), there are reports that supplementing with docosahexaenoic acid (DHA: a type of omega-3 fatty acid) has a positive effect on cognitive decline.
This finding was shown by a meta-analysis (a method that statistically combines the results of multiple studies to look at an overall trend), which statistically compiled a large amount of research data to look for an overall trend. However, results also show no effect for Alzheimer's type. In other words, it is known that the effect obtained may differ depending on the condition of the person concerned.
| Study | Design | Number of participants | Duration | Main result |
|---|---|---|---|---|
| Nutricion Hospitalaria (2019, PMID:31215788) | Systematic review | Unknown | Unknown | A positive effect was reported |
| The Lancet. Neurology (2017, PMID:28359749) | Randomized controlled trial (RCT) | 1525 | Unknown | No clear association was found |
| Current Opinion in Lipidology (2023, PMID:36637075) | Meta-analysis | Unknown | Unknown | A positive effect was reported |
The research subjects include 1,525 non-demented older adults aged 70 and over with memory complaints, as well as adults with mild cognitive impairment (MCI), people at high risk of Alzheimer's-type dementia, and healthy people with coronary artery disease.
It is suggested that study results may differ depending on the subjects' age, the presence or absence of memory complaints, or their level of risk related to cognitive function.
3 studies were examined, and the study designs include a systematic review, a randomized controlled trial (RCT), and a meta-analysis.
Differences have been reported between study results, and a consistent trend is not necessarily shown across all studies.
For example, while a benefit has been reported for mild cognitive impairment (MCI), there is also a study report finding no benefit for Alzheimer's-type dementia.
What effect is omega-3 fatty acid said to have on memory?
Studies have reported a positive effect on memory (3 studies, reliability is moderate). However, results differ between studies.
Does omega-3 fatty acid benefit people with Alzheimer's-type dementia?
There is a study report finding no benefit for Alzheimer's-type dementia. Therefore, the same results are not shown in every case.
Does omega-3 fatty acid also affect older adults with memory complaints?
In a study of non-demented older adults aged 70 and over with memory complaints, it was reported that no significant difference from the placebo group was found in cognitive decline over 3 years. This result is from a report under specific conditions.
Several studies show that omega-3 fatty acid may have a positive effect on memory in people with mild cognitive impairment. On the other hand, an effect does not appear uniformly in every case, and results may differ depending on the condition or duration involved. This content is based on multiple studies, but it also includes parts that cannot yet be said to be certain.
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