Yogurt: A New Antidepressant?

It seems like every week there’s a new reason to stock up on yogurt (well, maybe not too much at once.  It is made from milk, after all).  A recent study suggest that its benefits aren’t limited to just your digestive system!  In fact, the scientists involved say the probiotics that yogurt contains may actually influence your mood and behavior, causing a decrease in both anxiety and depression!

The Study

A group of researchers at University College, Cork, compared the reactions to a stress test by two groups of mice.  One group was fed an ordinary diet, while the other was fed a broth containing Lactobacillus rhamnosus, a bacterium found in yogurt.  The study revealed distinct differences in two areas:

• Behavior: When placed in stressful situations, the mice that were fed probiotics showed signs of being less anxious than the other group. For example: they were more likely to explore open spaces in a maze, which researchers interpreted as a sign of a higher level of confidence.
• Brain Chemistry: The bacteria-fed mice had lower levels of corticosterone (a stress hormone) after going through the stress tests.  Also, their GABA receptors (the receptors that are affected by anti-anxiety medications) were redistributed into a pattern found most commonly in non-depressed animals.

The Connection

While there is much more work to be done to understand exactly what is happening, the researchers believe they have proven the link between the stomach and the brain really does exist.  They’ve done this through experimentation with the vagus nerves of the mice in the study.  When the vagus nerve (an important part of brain-stomach communication) was cut, the differences in stress reaction between the two groups disappeared.  So while we might not know how the bacteria cause these changes, it does appear to be the case that they do something.

If nothing else, the important thing to take from this is that it’s a reminder of just how important diet can be to overall health.  This isn’t the first time that probiotics have been shown to help improve mood.  Studies have shown that patients with chronic fatigue syndrome and irritable bowel syndrome saw noticeable improvements in mood after probiotic treatment.  Will yogurt become a new anti-depressant?  It’s way too early to tell.  But we’ll hear more on the issue as research continues!

 References:

• http://www.economist.com/node/21528214
• http://www.nature.com/news/2011/110830/full/news.2011.510.html
• http://www.dailymail.co.uk/health/article-2031716/Probiotic-yoghurt-help-treat-depression-scientists-say.html