Alzheimer’s disease is one of the most frightening conditions facing our aging population. The idea of forgetting your friends, loved ones, and even yourself is terrifying.
It’s little wonder that more and more research is geared toward finding treatments as well as preventative measures for this disease.
In the natural health world, much attention has been given the use of fish oil in the treatment of dementia and Alzheimer’s. Not only does fish oil appear to slow the progression of mild cognitive impairment, an early stage of dementia, but it also eases depression and joint pain.
This is important because chronic pain can lead to depression. And depression, even mild depression, can push the needle of mild cognitive impairment further down the scale into dementia.
While a few studies have examined the connection between omega-3 fatty acids and dementia and depression, not many have looked at the use of these essential fatty acids in people with mild cognitive impairment. Moreover, few have compared the effectiveness of the two type main types of omega-3s, EPA and DHA, against each other.
This realization led Australian researchers to wonder which type of essential fatty acids worked best at alleviating depression and improving cognitive function.
Does Form Matter?
Researchers worked with 40 participants, all of whom were over the age of 65 and had self-reported memory loss. All participants had normal, everyday functioning, ate fish no more than once a week, and had not taken fish oil supplements in the past three months.
The divided the participants into three groups. The first group took four capsules of an EPA-rich supplement (1.67 grams EPA with 0.16 grams DHA) every day. The second group took four capsules of a DHA-rich supplement (1.55 grams DHA with 0.4 grams EPA) daily. The third group took four capsules of safflower oil per day, which contained 2.2 grams of linoleic acid, a form of omega-6 fatty acids.
All three groups were tested for a variety of variables, including:
- Depression (using a 15-point questionnaire)
- Overall health (measured both physical and mental health)
- Alcohol consumption
- Medication use
- Heart rate
- Blood pressure
Cognition was divided into two areas: memory and executive function. Memory encapsulated things like delayed recall, recognition, verbal expression and the use of mnemonics. Executive function captured things like cognitive flexibility, distractibility and verbal fluency.
At the end of the six-month study period, researchers were quite surprised by their findings. While there was no significant difference among the groups when it came to quality of life, those in the EPA and DHA groups enjoyed significant improvement in depression as compared to the linoleic acid group. But when it came to cognition and pain, DHA seemed to shine.
In fact, the DHA group showed greater improvements in executive function than the EPA group and the linoleic acid group. The DHA group also expressed significantly improved physical functioning and improved body pain.
Researchers concluded, “The present study indicates that DHA may be equally, if not more, effective than EPA for improving mood.” They go on to suggest, “Pure EPA supplements employed in some mental health studies may not be the optimal choice.”
Get Down With DHA
Here’s what I like about this study. It shows, yet again, that omega-3s are simply good medicine. I also like that they attempted to determine if one form of omega-3 is better than the other.
Here’s what I’m less thrilled with: the outcome.
Yes, they showed that both EPA and DHA were quite effective in easing depression. But when it came to slowing the progression of dementia, the results were less impressive. While it is good news that DHA helped ease pain and improve executive function, it didn’t appear to have a significant effect on memory and recall.
I cannot help but wonder what kind of outcome they would have gotten if the participants had taken supplements that were equally high in both EPA and DHA. Science has clearly shown that nutrients work synergistically, and omega-3s are no different.
Don’t wait for the science. Start taking a high-quality fish oil supplement today. Aim for over a gram (1,000 mg) of both EPA and DHA a day. You may have to take several capsules per day to achieve this dosage, but you are worth it!
 Sinn, N et al. Oiling the brain: a review of randomized controlled trials of omega-3 fatty acids in psychopathology across the lifespan. Nutrients. 2010;2:128-70.
 Hurst, S et al. Contrasting effects of n-3 and n-6 fatty acids on cyclooxygenase-2 in model systems for arthritis. Lipids. 2009 Oct;44(10):889-96.
 Sinn, N et al. Effects of n-3 fatty acids, EPA v. DHA, on depressive symptoms, quality of life, memory and executive function in older adults with mild cognitive impairment: a 6-month randomized controlled trial. Br J Nutr. 2011 Sep 20:1-12. [Epub ahead of print.]