Ongoing Clinical Trial Compares Omega-3 Types for Dementia Risk Reduction

Omega-3 fatty acids could aid early dementia symptoms and decrease the risk of Alzheimer disease, offering a cost-effective and well-tolerated treatment option for patients. To evaluate its efficacy, researchers from the University of Cincinnati are conducting a clinical trial comparing 2 types of omega-3 supplements as candidate interventions for older adults at risk for dementia.¹

Image credit: anaumenko | stock.adobe.com

According to the World Health Organization (WHO), more than 55 million individuals have dementia worldwide, with nearly 10 million new cases diagnosed each year. The disease is marked as the seventh leading cause of death globally, and one of the major causes of disability and dependency among older adults. Alzheimer disease is the most common form of dementia and accounts for about 60% to 70% of all cases.²

Omega-3 long-chain polyunsaturated fatty acids (omega-3 PUFAs) are crucial for human organ function, influencing inflammation, immunity, and hormone regulation. They are also essential for brain development and function, serving as a component of neuronal membranes. Since the human body cannot produce omega-3 PUFAs, they are considered essential fatty acids. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most prevalent omega-3 PUFAs.³

“Correcting age-related reductions in brain DHA levels represents a plausible strategy to slow or prevent neurodegenerative processes associated with dementia,” Robert McNamara, PhD, director of the Lipidomics Research Program and professor in the Department of Psychiatry and Behavioral Neuroscience in UC’s College of Medicine, said in a news release. “Fish is a primary dietary source of lysophosphatidylcholine-bound DHA (LPC-DHA), and greater fish consumption by elderly adults has been shown to reduce the risk for developing dementia and AD by 30% to 50%.”¹

Fatty fish high in omega-3 include mackerel, salmon, cod liver oil, herring, oysters, sardines, anchovies, and caviar. Other foods rich with omega-3 include flaxseed, chia seeds, walnuts, and soybeans. Additionally, pasture-raised eggs, omega-3-enriched eggs, meats, and dairy products from grass-fed animals, hemp seeds, and vegetables also contain a source of omega-3.⁴

However, the study authors noted that fish oil supplements offer a convenient alternative to consuming fish, but they contain triglyceride-bound DHA (TAG-DHA), which differs from the DHA found in fish.¹

“Recent evidence indicates that TAG-DHA has very limited entry into the central nervous system and instead accumulates in peripheral tissues, whereas LPC-DHA is significantly more effective for increasing brain DHA levels,” McNamara said in a news release.¹

Previous clinical trials have studied the impact of omega-3 supplementation on symptoms of dementia, but the studies were minor.⁵ The current trial from the University of Cincinnati is the first-of-its kind, including a total of 153 adults aged 62 to 80 years with mild cognitive decline.¹

The individuals included in the study will be randomly assigned to receive a standard fish oil supplement with TAG-DHA, or new supplements with LPC-DHA, or a placebo for 24 weeks. The study authors noted that individuals are required to provide blood and cerebrospinal fluid (CSF) samples, along with a cognitive assessment at baseline and at week 25.¹

“We predict that LPC-DHA supplementation will produce greater increases in CSF DHA levels compared with either TAG-DHA or placebo,” McNamara said in a news release. “We also predict that LPC-DHA will produce greater positive changes in neurodegenerative biomarker levels compared with TAG-DHA or placebo.”¹

The study aims to assess how DHA levels in CSF relate to both neurodegeneration and cognitive function. They will measure DHA and neurodegenerative biomarkers in CSF samples and then examine if changes in DHA levels are associated with improvements in planning, problem-solving, and memory.¹

“Collectively, these results are anticipated to provide novel proof-of-concept evidence in support of future LPC-DHA research in aging at-risk adults,” said McNamara.¹

REFERENCES

1. University of Cincinnati trial compares omega-3 supplements for elderly adults at risk for dementia. EurekAlert!. News release. Published February 24, 2025. Accessed March 11, 2025. https://www.eurekalert.org/news-releases/1074700

2. World Health Organization. Dementia. Published March 15, 2023. Accessed March 11, 2025. https://www.who.int/news-room/fact-sheets/detail/dementia#:~:text=Currently%20more%20than%2055%20million,risk%20of%20developing%20dementia%20include

3. Omega-3 fatty acids for the treatment of dementia. Cochrane Library. News release. Published April 11, 2016. Accessed March 11, 2025. https://pmc.ncbi.nlm.nih.gov/articles/PMC7117565/#:~:text=Omega%E2%80%903%20polyunsaturated%20fatty%20acids,promising%20treatment%20option%20for%20dementia

4. 12 Foods That Are Very High in Omega-3. Healthline. News release. Updated January 26, 2024. Accessed March 11, 2025. https://www.healthline.com/nutrition/12-omega-3-rich-foods

5. Alzheimer’s Society. Diet and dementia. Updated December 2023. Accessed March 11, 2025. https://www.alzheimers.org.uk/about-dementia/managing-the-risk-of-dementia/additional-treatments-for-dementia-risk/diet#:~:text=Do%20omega%2D3%20supplements%20affect%20symptoms%20of%20dementia?&text=Clinical%20trials%20have%20also%20studied,3%20supplements%20have%20no%20effect