Monday, November 25, 2013

Health Research Recap (Week of 11/18/2013)

New research on people termed the "Healthy Obese" shows that despite being healthy from a metabolic perspective, people with good blood numbers who are also obese are more likely to suffer Type 2 diabetes and heart disease later in life.  Personally, I've never believed that there was such a thing as the "Healthy Obese".  Obese people tend to be more sedentary and eat a diet that is of low nutrient density but high energy density when compared to lean individuals, the same poor lifestyle habits related to heart disease and Type 2 diabetes.  That is not to say that just because someone is lean that they are healthier than an obese person, just that people who tend to partake in these poor lifestyle choices are going to be unhealthy whether they are obese or not.  It just so happens that people who live this lifestyle tend to be obese.

As if reading my mind, another study looked at the association between lifestyle choices and risk for the metabolic syndrome.  The metabolic syndrome is a group of symptoms including high blood pressure, high blood  glucose, and excess body fat that are related to an increased risk of chronic disease including diabetes and heart disease.  In the study, the researchers found that obesity and poor nutrition were the lifestyle factors most significantly linked to an increased risk of the metabolic syndrome.  Participants in the study who were obese had an 8 times greater risk of developing metabolic syndrome and those who ate less than 5 servings per day were 4 times more likely to develop metabolic syndrome.  Recommendations...Increase fruit and vegetable consumption(Increase nutrient density) and lower calorie consumption(Decrease energy density).

In a study in mice, researchers found that severely overweight mice had a reduced ability to detect sweetness due to a decrease in the number of taste cells on the tongue responsible for detecting sweetness.  The mice also had a decreased ability to detect bitter but there was no effect on tastes related to meat consumption.

In a study on sudden cardiac arrest, researchers found that more than half of the men in their study had warning signs up to a month prior, making it not so sudden.  Of the symptoms that appeared, 56% experienced chest pain, 13% shortness of breath, and 4 % had dizziness, faintness or palpitations.  Most of the men had coronary artery disease, but fewer than half had been tested.  It's always a good idea to get checked out by your doctor if you experience any of the above symptoms.

New evidence shows that moderate physical activity can reduce damage to the heart in older sedentary adults.  Researchers placed sedentary people in to a physical activity group and a health education group for one year and measured levels of Troponin T, a blood marker used  to diagnose heart attack.  After a year the non-exercise group had 3 times higher levels of Troponin T in their blood than the exercise group.  This backs up a previous study which showed that elderly people who exercise are less likely to have an increase in Troponin levels than elderly people who are sedentary.

A study on insomnia and mortality risk found that men who had difficulty falling asleep or who had poor sleep quality were more likely to experience a cardiovascular disease related death within six years than people who slept normally.  The study found that men who had difficulty falling asleep were 55% more likely to die from cardiovascular disease and those who had poor sleep quality were 32% more likely when compared to those who slept normally.  Of course, since this is an observational study there is no way to know whether it is the lack of sleep causing cardiovascular disease or cardiovascular disease causing poor sleep.  At any rate, making better lifestyle choices that will improve overall health and making an effort to get quality sleep is always a great idea.

Researchers found a link between screens in the bedroom and shortened sleep time in kids with autism.  Having a television or computer screen in the bedroom is associated with reduced sleep time in all people regardless of whether or not they have autism, but the effect may be stronger in kids with autism.  Kids with autism who also had a screen in their room slept almost 2 hours less than kids who did not have a screen in their room, on average.  Since children with autism tend to have poorer sleep quality than kids without it, it's probably a good idea to remove any television or computer screens from your children's bedroom, especially if they have autism.

In research confirming what most anyone in the fitness field can plainly see, children's cardiovascular fitness has declined since 1964.  Since 1970, children's cardiovascular fitness has declined by 6% per decade between 1970-2000 and kids today are 15% less fit from a cardiovascular perspective than their parents were at the same age.  Less free play time and reduced gym in school are likely contributing factors.

Another study in children found that breaking up sedentary periods with times of activity improved health measures in children ages 8-11.  Children who got up more while sitting at the computer, television, or video games saw improvements in fasting insulin, fasting glucose, triglycerides, HDL cholesterol, C-Reactive Protein, waist circumference, and BMI.  The improvements were related to the number of times they got up, and not the amount of time they spent while up.  I take this to mean that you should focus on limiting how long your children are seated throughout the day.

What would a research review be without some gut bug love?  In a study looking at gut bugs and GI transit time, researchers found that gut bacteria influence food transit time through the gut via the hormone GLP-1.  GLP-1 is mostly associated with insulin secretion and appetite control, but increased GLP-1 levels slow gastric emptying and GI transit time.  Gut bacteria ferment fiber in to short chained fatty acids that suppress proglucagon secretion in the gut which lowers GLP-1 levels in the blood and speeds up GI transit time.

More power to the gut bugs.  In a study looking at how chemotherapy works to fight cancer, researchers found that central among it's effects are the gut bugs.  Researchers found that bacteria from the gut migrate from the gut to lymph nodes during chemotherapy where they stimulate an immune response which helps the immune system better fight the tumor.  To confirm these results, the researchers blocked the bacteria from the gut and the effectiveness of chemotherapy was reduced.  This study was done in mice so we need to see confirmation in human studies, but this study reinforces both the importance of healthy bacteria to the immune response and the importance of gut bacteria research in improving health as well as the effectiveness of therapeutic interventions.

Finally, researchers believe that investing in the biology of aging will pay far more dividends in understanding and treating disease than individually researching each disease.  I think this is a step in the right direction because aging is a risk factor for most of the diseases we see today.  Many people are familiar with chronological age, how many years old you are, but few understand that biological age is far more important.  Biological age is related to how well your body functions and can vary between people who have the same chronological age.  For example, 2 people may be exactly the same age but one may look a decade younger and have a better health status than the other.  Diet, lifestyle factors, and other environmental factors related to epigenetics more than likely underlie the discrepancy between chronological age and biological age and research in this area can tell us how we can slow down biological aging.  The entire National Academy on an Aging Society report can be found here.