Greg Chaffins 
One of my favorite supplements, Omega-3 in the form of fish oil, has now come under the crosshairs as not delivering the protection it was once touted as having. Most people that take the supplement, which also include flaxseed oil and krill oil sources, do so in the hopes that it will aid in maintaining heart, joint, eye, and brain health. But according to a new study it may be doing just the opposite in the long term. Which is probably not exactly what you or I wanted to hear.
Surprising Results
Researchers in China analyzed the data from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) in order to track the effects omega-3 supplements had on related brain biology over time. But the results were unexpected, to say the least.
Matched participants actually showed faster cognitive decline than nonusers across three standard measures: The Mini-Mnetal State Examination (MMSE), the Alzheimer’s Disease Assessment Scale Cognitive Subscale (ADAS-Cog13), and the Clinical Dementia Rating Sum of Boxes (CDR-SB).
Omega-3 Study Details
The study in questions involved 1,814 old participants from the ADNI. Matching omega-3 users with similar non-users based on age, sex, and diagnosis, the final tally included 273 supplement users versus 546 non-users. This gives an almost 2 to 1 ratio between supplement users and non-supplement users. A median followup was set for 5 years.
The participants ranged from the cognitively normal to those with Alzheimer’s disease. The supplement most reported in the study was fish oil (as expected), but there were also flaxseed oil and krill oil users. The researchers found that omega-3 users experienced a faster drop in MMSE and other listed test scores.
The test found that the decline rate for the sample set was smaller than the typical progression for Alzheimers but it was still a measurable quantity for the test results. In other words, it wasn’t a Alzheimer’s specific study but the data was there.
Brain Imaging Key to Findings
The study relied on brain imaging to show the greatest deviation. The faster decline was not from the typical Alzheimer’s markers of amyloid plaques, tau buildup, or gray matter loss. Instead, the study showed reduced glucose metabolism in brain regions vulnerable to Alzheimer’s disease.
The measurement was done using FDG PET scans. These scans can illustrate how well our brain cells and their associated connections are functioning. The resulting reduced glucose metabolism accounted for over 30.8 percent of the MMSE decline, 40.8 on the ADA-COG13, and 19 percent on the CDR-SB issues.
Supplement Implications
On its own, the study does not prove that omega-3 supplements cause cognitive decline. The observational nature of the study meant that researchers could not track exact doses or supplement quality (fish oil products are prone to oxidation.) The sample set of the users were also limited in their racial makeup, so a broader study across differing users under more stringent conditions is probably warranted.
However it does raise a caution flag in that omega-3 supplements should not be assumed as a solid brain health strategy. This is of particular importance in older adults, which is typically the marketing target of choice for such supplements.
Bottom line, more research is needed. There is some question as to what factors influence the omega-3 use outcome, including tighter supplement type data and user specifics. Until then, consider discussing with a medical professional instead of just assuming that such a path is in your best long-term interest.
