Monday, January 27, 2014

Health Research Recap (Week of January 21, 2013)

Women who are obese while pregnant have children who are more likely to become obese as they get older.  Until now science hasn't uncovered why this happens, but a recent study indicates that it may be due to improper wiring of the fetus' hypothalamus.  The hypothalamus is important in the regulation of appetite and metabolism, and it makes sense that improper development of the hypothalamus could contribute to the metabolic syndrome.  The problem with this study is that it was done in mice and the effect was produced by feeding the mice a high fat diet.  When using a high fat diet in mice, researchers almost always completely remove fiber from the diet which changes their microbiota and can have a pretty powerful effect on the development of their offspring.

Mother's diet isn't the only epigenetic factor than can affect a child's metabolism.  Another study in rats found that the health and diet of the father at time of conception also has an effect on offspring.  Male rats fed a high fat diet and who were diabetic and obese had female offspring with altered genetic expression in their fat tissue and pancreas that led to poorer blood glucose control.   Of course, this study suffers from the same drawback as the previous study with regard to the high fat diet, but both show how the health status of both parents can have a dramatic effect in offspring. 

A study looking at our good friend lipopolysaccharide(LPS) found that humans can smell immune system activation in other humans when they are injected with LPS.  The T-shirts of people injected with LPS were rated as smelling unhealthy compared to the T-shirts of people not injected with it.  Furthermore, those who had a bigger immune response were reported to have an unhealthier smell than those who had a smaller immune response.

A new study discusses hoe exposure to mildly colder temperatures can significantly impact fat loss.  According to a recent review, people adapt to cold temperatures (Approximately 60 degrees) by increasing brown fat, a type of fat that is metabolically active and helps control body temperature.  Another interesting point of view discussed in the study is that our continued focus on being comfortable may be a fairly strong factor leading to our higher rates of obesity.  Lowering the temperature in your house will not only save you money on your bills, it could also help you stave off obesity.  While there is an initial discomfort phase to the colder temperature, you will eventually adapt to the colder temperature over a couple of weeks.

In fish oil news, in addition to it's positive impact on inflammation and carbohydrate and lipid metabolism, the omega 3 fatty acid DHA appears to be protective of the liver and may help prevent or reverse fatty liver disease.  DHA improved liver function by reducing the damaging effects of inflammation and oxidative stress effect on the organ.

In another fish oil study, researchers found that high blood levels of the omega 3 fatty acids EPA and DHA were associated with larger brain volumes. Of particular interest is that those with higher levels of the fatty acids in their blood had a hippocampus that was 2.7% larger than those with lower blood levels.  The hippocampus plays an important role in memory and those with Alzheimer's experience a shrinking of the hypothalamus that likely contributes to the disease.

Finally, 2 studies identified depression as a common symptom in 2 separate autoimmune conditions.  One study found that those with severe rheumatoid arthritis are more likely to experience depression than previously thought.  The other study found that African American women who reported high levels of symptoms of depression were more likely to experience adult onset asthma than those who were not depressed.  While it certainly makes sense that someone who is sick will be depressed, a messed up gut microbiome is associated with both mood disorders and autoimmune diseases.