Mercury and Alzheimer's: Does Eating Fish Increase the Risk?

Studies show that eating fish protects the brain.  However, studies also show that mercury increases the risk of dementia.  So does eating fish, even if there is some mercury in it, increase or decrease your risk of Alzheimer's disease?  Be sure to continue reading this article to find out the answer...

The Rush University Mercury, Alzheimer's and Fish Study

Dr. Martha Clare Morris and colleagues from Rush University have been at the forefront of brain research.  In fact, Rush University is even home to the MIND Diet which is a way of eating that has been scientifically proven to protect the brain from Alzheimer's disease and other forms of dementia.

In this study, Dr. Morris wanted to understand what mercury from eating fish does to the brain over time.  They also wanted to see if omega 3 fatty acids from fish, plants, or supplements protected the brain.  To answer this question, she studied the brains of 286 people who had already passed away.

These 286 people not only had donated their brains to Rush University but also had provided them with five years worth of food journals.  Armed with this information, Dr. Morris and her team could then connect the dots between Alzheimer's brain changes and mercury from eating fish.

The 5 Findings of the Mercury, Fish, and Alzheimer's Study

To come to their five conclusions, Dr. Morris and coworkers measured the amount of mercury in these donated brains.  Also, they carefully dissected each of these brains not only looking for the plaques and tangles, commonly seen with Alzheimer's disease, but any other sign of brain damage as well.  Here is what they found:

1. The more fish people reported eating while they were alive, the more mercury researchers saw in their autopsied brains.  No surprise here.

2. Eating fish at least once a week correlated with significantly less Alzheimer's changes to the brain in people with the Alzheimer's gene. This finding isn't always consistent with other studies.

For example, some studies show that fish protects everyone's brain whereas other studies show that fish only protects the brains of people without the Alzheimer's gene.  Regardless, there are no credible studies showing that fish is bad for your brain!

3. Plant-based omega 3s, from foods like walnuts, flax or chia seeds, protect you from strokes.  The finding that plant-based omega 3s may prevent strokes is something that has been backed up by other studies.

4. Fish oil supplements offered no protection to the brain.  This Rush University study is just one of many studies now showing that fish oil doesn't help the brain or heart much.

5. Mercury levels in the brain from fish did not correlate with any brain damage.  This finding that moderate levels of mercury from eating fish doesn't cause brain damage had to be the most important, and reassuring, discovery of this study.

Practical Tips

As blog readers know, I have long been interested in anything that can protect the heart and the brain.  Below are my three practical tips based on the findings of this and other studies.

1. Consider eating fish at least once a week.

In my opinion, the scientific data are now robust enough that people should consider eating fish at least once a week.  However, despite the reassuring findings of this Rush University study, mercury should be minimized to the greatest extent possible.

Just because mercury levels didn't correlate with brain damage, doesn't mean it isn't causing any harm.  To minimize your mercury risk from eating fish, always look for wild, small, or ocean fish.

If wild fish is too expensive for your budget, consider shopping at places like Costco.  Given the high price of wild Alaskan salmon,