image: Robert McNamara, PhD
Credit: Photo/University of Cincinnati
Prior to the onset of Alzheimer’s disease (AD), there is a prolonged period that provides a window of opportunity to slow or prevent disease progression. Unfortunately, few cost-effective and well-tolerated long-term early interventions are currently available.
A new University of Cincinnati trial will compare two types of omega-3 supplements as candidate interventions for elderly adults at risk for dementia. UC’s Robert McNamara, PhD, and Robert Krikorian, PhD, are leading the study, funded by a five-year, $2.2 million grant from the National Institute on Aging.
Study background
McNamara’s research has focused on understanding the effects of dietary bioactive lipids on human health and disease, specifically essential fatty acids enriched in the brain that decline with age, like the omega-3 docosahexaenoic acid (DHA).
“Correcting age-related reductions in brain DHA levels represents a plausible strategy to slow or prevent neurodegenerative processes associated with dementia,” said McNamara, director of the Lipidomics Research Program and professor in the Department of Psychiatry and Behavioral Neuroscience in UC’s College of Medicine. “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%.”
Fish oil supplements are widely available as an alternative to eating more fish and are purported to have the same effects, but McNamara said these supplements contain a different kind of DHA called triglyceride-bound DHA (TAG-DHA).
“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,” he said.
The effects of LPC-DHA supplements have never been investigated, but newly available capsules enriched with LPC-DHA provide a novel opportunity to learn about its effects and address this knowledge gap.
Trial details
In the first-of-its-kind trial, 153 adults who are between 62 and 80 years old and experiencing mild cognitive decline will be randomized to take either a placebo, standard fish oil supplements with TAG-DHA, or new supplements with LPC-DHA for 24 weeks. Participants will provide blood and cerebrospinal fluid (CSF) samples and complete cognitive assessments at the beginning of the study and at week 24 of the study.
Researchers will primarily focus on the impact of DHA levels in CSF samples but will also measure levels of neurodegenerative biomarkers within CSFu.
“We predict that LPC-DHA supplementation will produce greater increases in CSF DHA levels compared with either TAG-DHA or placebo,” he said. “We also predict that LPC-DHA will produce greater positive changes in neurodegenerative biomarker levels compared with TAG-DHA or placebo.”
Additionally, the team will investigate whether changes in CSF DHA levels correlate with improvements in objective measures of executive functioning such as planning and problem-solving and episodic memory performance.
“Collectively, these results are anticipated to provide novel proof-of-concept evidence in support of future LPC-DHA research in aging at-risk adults,” McNamara said.
For more information on the trial, please contact Dawn Skirpan at skirpadn@ucmail.uc.edu or call 513-558-8621.
Research reported in this publication was supported by the National Institute on Aging of the National Institutes of Health under Award Number 1R01AG084834-01A1. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.