Diet, Depression, Alzheimer's Disease, and Your Gut

This week I saw two unrelated articles that involved the connection between the health of your gut and brain health.  One discussed the influence of the gut on depression, and the other discussed research in China with seaweed sugars that affect the gut and may improve cognition for people with Alzheimer's disease.   

The first was an article in The Atlantic Monthly regarding how the DASH diet fights depression.  The article was actually published in 2018 but was recycled by Pocket.  We discuss the DASH diet in Beating the Dementia Monster but not for treating depression.  The DASH diet is a modified Mediterranean diet that is intended to lower blood pressure.  Brain health and cardiovascular health are intertwined, so the neurologists like to say, "What's good for the heart is good for the brain."

The Atlantic article posits an interesting coincidence -- that a leading risk factor for death worldwide is poor diet, and depression is a leading cause of disability worldwide.  It refers to research suggesting that poor diet makes us sick, and resulting depression can make us even sicker.  It then cites research finding that the DASH diet reduces depression by 11%.

How is this supposed to work?  The DASH diet is heavy with plant fiber that ferments in the gut microbiome.  The microbiome is the ecological community of microbes in the gut that participates in the digestion of food.  According to the article, fermentation creates short-chain fatty acids which regulate the immune system and influence gene expression in the brain.  It says this contributes to increased production of proteins called neurotrophins, which act like manure to the brain as they promote the growth of new brain cells in the hippocampus.  (We recall that Alzheimer's disease attacks the hippocampus.)

Anything sound familiar here?  In Beating the Dementia Monster we described how much of my improvement can be attributed to production of the brain-derived neurotrophic factor (BDNF) during exercise.  So it seems that you can get BDNF through both exercise and diet.  (But you need them both!)

Then last week's ALZForum carried the article on Chinese research entitled, "China Approves Seaweed Sugar as First New Alzheimer's Drug in 17 Years."

At least from the standpoint of spending, China is emerging as a world leader in Alzheimer's research.

The article discussed research that found some improvement in people with Alzheimer's disease who were given a drug called GV-971, or oligomannate, which is based on seaweed sugar.  This was a stage 3 (final) drug trial.  The results seemed promising, but it didn't look like a game-changer.  Its mechanism of action is said to be that it alters the gut biome in a beneficial way.  While the drug seems to have an open path to approval by the Chinese government, there are some issues with the data.

The biggest issue seems to be some odd behaviors in the placebo group, where their cognitive test scores seemed to improve at first but then plummet.  Some noted that Chinese people don't see doctors regularly, but all of the test subjects needed medical attention during the trial.  They wonder if unusual (for them) medical attention might have influenced cognition.  I speculate, for example, that doctors may have influenced the placebo population to make lifestyle changes, or they may have given them new drugs for ailments they found.  

Some also identified anomalies in the data that bring the results into question.  One (Chinese) scientist at Rutgers University pointed to research showing that GV-971 in mice had promoted inflammation, not helped brain health.  This brings into question the Chinese explanation for it's mechanism of action. 

An open question whether GV-971 does more than donepezil (sold under the trade name Aricept) and the other acetylcholinesterase inhibitors.  These treat symptoms without changing the course of the disease.  And donepezil made me sick.

China will likely approve the drug for use in China and then promote it in the USA and other countries.  They also plan some worldwide studies.  American researchers seem to be skeptical, but they seem to think that if it's safe, well, why not use it?

I probably would/will.