Monday, October 28, 2013

Health Research Recap (10/21/2013-10/27/2013)


In Alzheimer's research, researchers found an association between poor sleep duration/quality and an increase in beta-amyloid plaque burden in subjects with a mean age of 76.

In a study on mice, researchers found a possible link between why quality sleep may improve brain function and why poor sleep may increase the amount of plaques in Alzheimer's patients.  The study found that, in sleeping mice, the clean up system of the brain went in to overdrive and removed toxins that are a natural byproduct of brain cell use, including beta amyloid plaque.  During sleep, the cells even shrink to make it easier to clean up the spaces between cells. 

Another link between sleep quality and brain function may be mediated through the immune system.  Researchers restricted the sleep of young healthy men to 4 hours for 5 nights and measured gene expression.  They found an increase in the activity of genes associated with producing antigens and inflammation as well as a host of other immune system related genes.

Another study found a link between high blood glucose and memory function.  What is interesting about this study is that people with blood glucose levels that would be considered within the normal range but at the higher end were associated with poorer performance on a memory test as well as reduced size of the hippocampus.  This confirms a previous study that also found a relationship between high blood glucose and hippocampal volume.  The hippocampus plays a crucial role in memory, and this research can link back to the studies on Alzheimer's and sleep as poor sleep duration and quality are both linked to poor blood glucose control.

Also in Alzheimer's news, researchers found a link between a gene associated with Alzheimer's and an "anti-aging" gene targeted by reseveratrol, the powerful antioxidant found in red wine. While this doesn't mean that drinking tons of red wine or taking resveratrol will prevent Alzheimer's, it gives us a look at a potentially interesting mechanism of the disease.

In more brain news, researchers found an association between teens who regularly exercised moderately to vigorously and better brain performance.  Researchers in the UK used an accelerometer to measure daily movement characteristics and compared those to performance in Math, Science, and English.  The effect of regular intense exercise at age 11 was associated with better performance in all 3 subjects.  At age 13, 15, and 16, academic performance was associated with the amount of intense exercise the child had at age 11.  There was a dose-response meaning that the more intense exercise a child partook in, the greater the benefits.  The benefit appeared to be boost girls science performance the most.


Here's another good reason to dine out with people with good dietary habits.  A study found that people tended to order the same food choices at restaurants when they state their choices out loud.  The study used 3 different menu types with differing types of information (No info, calorie counts, calorie counts and a traffic light green:400cals or less, yellow:401-800 cals, red:>800 cals).  The study found that eaters were happier when they ate the same foods as others in their group, regardless of their initial percepton of the food item.  Previous studies have shown that when people don't order aloud, they just get what they want.

In obesity news, researchers found a transgenerational effect of DDT exposure to mice and obesity in mice 3 generations later.  Researchers injected pregnant rats with DDT and followed them for multiple generations.  While the pregnant rat, her offspring, and her offspring's offspring showed no signs of obesity.  However, the more than half of the great grandchildren of the exposed mouse were obese.  Michael Skinner, the lead researcher, has found similar effects in other environmental pollutants including other pesticides and BPA, but the effect of DDT was far greater.  The effects are due to epigenetics, the silencing and activating of certain genes due to enviromental factors.  Often times, these epigenetic changes can be forced on future generations through lifestyle choices or exposures that occur in older generations long before the affected are born.

The Gut/Bacteria

In gut news, researchers found that obesity may increase the risk of C. Difficile infection.  This study backs up an earlier study this year that found the same relationship.  While this relationship is very interesting, what is more interesting is why this study came about.  The amount of C. Difficile infections has more than doubled from 139,000 to 336,600 over the past 10 years, and physicians are seeing people with C. Difficile infection that do not have the traditional risk factors (being in a hospital, lowered immunity, antiobiotic exposure).  What may be the culprit?  A change in gut bugs.  Both obesity and C. Difficile infection are related to an increased Firmicutes/Bacteroidetes ratio.

Finally, in the "Gross, you shoulda brushed" category, researchers found that the bacteria in people's mouth create a fingerprint that could predict a person's ethnicity.  In addition, no 2 people had the same bacterial make up.  What is even more interesting is that, despite common nutritional and environmental exposure over many generations, African Americans and white Americans had different oral bacteria "fingerprints".