Study Spotlight:
How does ingested DHA get into the brain? When it does, what effect does APOE4 have? These were the questions asked in a recently published study titled “Associations of APOE4 status and DHA supplementation on plasma and CSF lipid profiles and entorhinal cortex thickness.” Welcome to this month’s newsletter, we’re excited to share our new research and its implications.
In this collaboration with Dr. Laila Abdullah’s team at the Roskamp Institute and Dr. Alfred Fonteh at Huntington Medical Research Institutes, our team examined the distribution of docosahexaenoic acid (DHA) within the blood and spinal fluid following DHA supplementation. We sought to understand the relationship between the Apolipoprotein E4 (APOE4) gene variant, supplemental DHA, and two important aspects of brain health: the fats in our body and the thickness of the entorhinal cortex.
Let’s break it down in simpler terms:
- APOE: a gene involved in making the apolipoprotein E protein—a protein that helps carry cholesterol and other fats in the blood. Having 1 or 2 copies of the APOE4 variety of this gene increases the risk of Alzheimer’s Disease.
- DHA: a fatty acid naturally occurring in cold water fish. DHA is necessary to maintain good brain health.
- Fats in our body: our body contains different types of fats that are essential for our cells and overall health. In this study, we examined the fats found in blood and spinal fluid. By studying these fats, they were able to gain insights into brain health.
- Entorhinal cortex: a part of the brain that plays a role in memory formation and navigation. Its thickness is an indicator of brain health.
Here’s a summary of the study:
Over the course of 2 years, participants between the ages of 55 and 80 were recruited based on minimal seafood consumption, absence of dementia, and willingness to perform two lumbar punctures. Half of these participants were APOE4 carriers. Participants consumed either 2 grams of algal DHA per day or a placebo for 6 months. Participants underwent MRI scans before and after treatment to image the entorhinal cortex. Following treatment, researchers analyzed the blood and spinal fluid to measure fat profiles and DHA levels and used MRI data to measure the thickness of the entorhinal cortex.
Here’s what we discovered:
- APOE4 and fats: People with the APOE4 gene variant had different fat profiles in their blood and spinal fluid compared to those without the gene. This suggests that APOE4 influences how our body processes fats.
- DHA supplementation: Taking DHA supplements led to positive changes in fat profiles—including increased DHA levels in the blood—particularly in individuals with APOE4. This suggests that DHA helps improve how the body handles fats, which might in turn improve brain health.
- Entorhinal cortex thickness: Interestingly, individuals who took DHA supplements had a thicker entorhinal cortex compared to those who received the placebo. This result was seen in both APOE4 carriers and non-carriers. This suggests that DHA has a protective effect on brain structures associated with memory and cognitive function, which could be especially beneficial for individuals at a higher risk of developing Alzheimer’s Disease.
It is important to note that this study had only 22 participants so we cannot draw conclusions on the effects of DHA on cognition or dementia. But these results are a promising step forward. We are actively doing a larger study (PreventE4) with 368 participants to examine the effects of APOE4 on brain DHA levels, brain imaging, and cognition. PreventE4 will be reported at the end of 2024 and provide more clues on the benefits of DHA supplementation.
These findings are significant because they provide valuable insights into how APOE4 and DHA supplements interact to affect our brain health. Understanding these associations can help researchers develop strategies to promote brain well-being and potentially reduce the risks associated with Alzheimer’s and related diseases. As always, it’s important to consult with healthcare professionals before making any significant changes to your diet or supplementation routine.
Thank you and Until Next Time,
The Yassine Lab