Dementia

Nutritional Pearls: Does Omega-3 Combat Dementia Onset?

Tamara is a 63-year-old female who is experiencing the early signs of cognitive decline. She was searching the Internet for ways to combat dementia onset and found articles on both increasing her fish intake, as well as taking omega-3 supplements. Before she makes any dietary changes, she comes to you for advice.


How would you advise her?

What is the correct answer?
(Answer and discussion on next page)

 

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Answer: Eating fish keeps the brain robust.

We already know that following a Mediterranean-style diet can reduce your patient’s risk of developing Alzheimer's disease by as much as 60%. Why is that? Some research suggests that it is the intake of fish that is responsible for this effect, while others specifically focus on the omega-3 fatty acids. 

Past Research

A 2007 prospective study looked at the effect of eating fish on Mini Mental Status Exam (MMSE) scores.1 In a 5-year study of 200 Netherlanders, individuals who ate the least fish had their scores in the MMSE fall 4-times faster than those who ate the most fish—regardless of the type of fish consumed. 

On the other hand, a 2006 study in Sweden focused on participants with mild to moderate dementia, who were either given an omega-3 supplement or a placebo for 6 months. The results: Individuals with Alzheimer's disease saw their cognition decline more slowly if they were taking the supplement.2
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A New Study

With today's research, researchers based in Pittsburgh sought to clarify this distinction. They made use of data gathered through the Cardiovascular Health Study Cognition Study (CHS-CS),3 which is part of the larger Cardiovascular Health Study—a large scale, long-term prospective study of risk factors of heart disease and stroke in persons over the age of 65. Participants in CHS-CS were evaluated for signs of dementia or mild cognitive impairment, and each had an MRI of their brains performed. For their research, the scientists limited their study to those participants who had no sign of dementia or cognitive impairment at the initiation of the research.

Researchers looked at the MRIs of these 260 men and women and measured their brain volume (both overall and at several specific locations), then correlated that volume with the amount of baked or broiled fish the participant had reported consuming in a dietary questionnaire completed the year before the MRI was performed. Blood tests performed that same year confirmed that the participants’ blood levels of omega-3s was consistent with the amount of fish they had reported eating.

The Results

Researchers found that brain volumes in 2 areas of the brain are related to memory and cognition; the right frontal lobe, including the right orbital frontal cortex with extension into the right anterior cingulate gyrus, and the right and left posterior cingulate gyrus and bilateral hippocampus (right greater than left) were larger in those participants who reported eating fish at least once per week. Most interestingly, those volumes were not related to the amount of omega-3s in their blood.

What’s the “Take Home”?

The authors caution the reader to avoid taking these results to suggest that omega-3s have nothing to do with maintaining brain volume. Those participants who ate more fish also tended to have more education, which might mean a better lifestyle in general. This does mean that fish is definitely brain food, to quote that old saying. While taking omega-3 supplements might be a good option for those who are allergic to fish, this study suggests that simply eating fish is best, both for the omega-3s and for the brain.

References:

  1. Harlan T. Eat fish, eat well, think better. Dr Gourmet. www.drgourmet.com/bites/2007/040607.shtml. Accessed October 21, 2014.
  2. Harlan T. Omega 3 fat supplements and Alzheimer’s disease. Dr Gourmet. www.drgourmet.com/bites/2006/1024.shtml. Accessed October 21, 2014.
  3. Raji C, Erickson K, Lopez O, et al. Regular fish consumption and age-related brain gray matter loss. Am J Prev Med. 2014;47(4)444-451.