Lift Weights to Lower Blood Sugar?

Red-White_muscleSRxA’s Word on Health was interested to read that researchers in the Life Sciences Institute at the University of Michigan have overturned a long-held belief that whitening of skeletal muscle in diabetes is harmful.  Instead, they found that the white muscle that increases with resistance training, age and diabetes actually helps to keep blood sugar in check.

The insights identified in the study may point the way to potential drug targets for obesity and metabolic disease.

We wanted to figure out the relationship between muscle types and body metabolism, how the muscles were made, and also what kind of influence they have on diseases like type 2 diabetes,” said Jiandie Lin, Life Sciences Institute faculty member.

Much like poultry has light and dark meat, mammals have a range of muscles: red, white and those in between. Red muscle, which gets its color in part from mitochondria, prevails in people who engage in endurance training, such as marathon runners. White muscle dominates in the bodies of weightlifters and sprinters – people who require short, intense bursts of energy.

lifting-weightsWhen you exercise, nerves signal your muscles to contract, and the muscle needs energy. In response to a signal to lift a heavy weight, white muscles use glycogen to generate adenosine triphosphate (ATP) – energy the cells can use to complete the task. While this process can produce a lot of power for a short time, the glycogen fuel soon depletes.

However, if the brain tells the muscle to run a slow and steady long-distance race, the mitochondria in red muscles primarily use fat oxidation instead of glycogen breakdown to generate ATP. The supply of energy lasts much longer but doesn’t provide the burst of strength that comes from Paula_Radciffe_NYC_Marathon_2008_croppedglycolysis.

People with diabetes see whitening of the mix of muscle.

For a long time, the red-to-white shift was thought to make muscle less responsive to insulin, a hormone that lowers blood sugar,” Lin said. “But this idea is far from proven. You lose red muscle when you age or develop diabetes, but is that really the culprit?”

To find out, the team set out to find a protein that drives the formation of white muscle. They identified a list of candidate proteins that were prevalent in white muscle but not in red.

mouse weight liftingFurther studies led the team to focus on a protein called BAF60c, a sort of “zip code” mechanism that tells the cells when and how to express certain genes. The Lin team made a transgenic mouse model to increase BAF60c only in the skeletal muscle. One of the first things they noticed was that mice with more BAF60c had muscles that looked paler.

“That was a good hint that we were going in the white-muscle direction,” said lead author Zhuo-xian Meng, a research fellow in Lin’s lab.

They used electron microscopy to see the abundance of mitochondria within the muscle, and confirmed that muscle from BAF60c transgenic mice had less mitochondria than the normal controls.

We saw predicted changes in molecular markers, but the ultimate test would be seeing how the mouse could run,” Lin said.

treadmill mouseIf the BAF60c mice could run powerfully for short distances but tired quickly, the scientists would be able to confirm that the BAF60c pathway was a key part of the creation of white muscle.

Using mouse treadmills, they compared the endurance of BAF60c mice to a control group of normal mice, and found that the BAF60c transgenic mice could only run about 60% of the time that the control group could before tiring.

“White muscle uses glycogen, and the transgenic mice depleted their muscles’ supplies of glycogen very quickly,” Lin said.

After some follow-up experiments to figure out exactly which molecules were controlled by BAF60c, Lin and his team were confident that they had identified major players responsible for promoting white muscle formation.

Now that they knew how to make more white muscle in animals, they wanted to determine whether white muscle was a deleterious or an adaptive characteristic of diabetes.

obese mouseThe team induced obesity in mice by feeding them a “Super Size Me” mouse diet. On a high-fat diet, a mouse will double its body weight in two to three months. They found that obese mice with BAF60c transgene were much better at controlling blood glucose.

The results are a bit of a surprise to many people,” Lin said. “It really points to the complexity in thinking about muscle metabolism and diabetes.”

In humans, resistance training promotes the growth of white muscle and helps in lowering blood glucose. If future studies in humans determine that the BAF60c pathway is indeed the way in which cells form white muscle and in turn optimize metabolic function, the finding could lead to researching the pathway as a drug target.

We know that this molecular pathway also works in human cells. The real challenge is to find a way to target these factors,” Lin said.

Until we know for sure SRxA’s Word on Health recommends a healthy mix of running and weight training.

SRxA-logo for web

Rethinking Resolutions

Tablet PC computer with 2013 New Year counterNew Year’s resolutions. In previous years SRxA’s Word on Health has provided some great tips to help our readers improve their health. This year’s no different…except we’re telling you not to make resolutions.

Yes! We are officially letting you off the hook.  Why? Because according to new research, thinking of health and fitness goals as “New Year’s resolutions” can actually harm your health and have nasty emotional side effects.   For starters two-thirds of people end up ditching their New Year’s goals within weeks of starting them, less than 20% of people will stay with their resolutions for more than six months and less than 10% will keep them all year. This inability to stay on track, can lead to feelings of failure and inadequacy. Experiencing setbacks such as cheating on your diet or skipping a day at the gym can amplify those feelings, resulting in a downward spiral that can lead you back into old habits faster than if you hadn’t made resolutions in the first place.

New Year Fresh startAlthough cutting back on certain foods can be good for your health, completely depriving yourself of them can be a problem. While most New Year’s resolutions revolve around the idea of deprivation: eliminate fat or carbs or salt…these all have a place, in moderation, in your diet. The only time quitting a habit completely is really good for you is if it is dangerous to your health, like smoking or binge drinking. Even then, quitting cold turkey can be hard; it can take months to wean yourself from bad habits. The key is moderation, not deprivation.

Another problem with resolutions is that diet and fitness targets are often totally unrealistic. Setting over-ambitious goals for yourself can lead to perceived failure which means you’ll be more likely to give up and slip right back into old habits.  The key to improving your health habits is to gradually implement change and incorporate them as a part of your lifestyle.

new-year-resolutio_2384285bFinally, remember that feeding and fueling your body mentally, physically and spiritually should be fun. You should never feel like taking care of yourself is work. New Year’s resolutions often take all of the enjoyment out of the process of change. Improving yourself is not just about the end goal, it’s about overcoming obstacles in between and becoming more confident and aware of who you are. Yes, the destination matters, but so does the journey.

So this year, you have our permission to ditch the resolutions, and forego the guilt.  Instead, why not focus on the present…and each day think of one thing you can do right now, towards your goal?

SRxA-logo for web

Wouldn’t You Like to Know!

If you had a family history of developing Alzheimer’s disease, would you take a genetic test that would give you more information about your chances?

Increasingly it seems, people are saying ‘yes’. The controversial genetic test is based on Apolipoprotein E (APOE).  Having certain variants of the APOE gene has been found to significantly increase a person’s risk of developing Alzheimer’s disease.

However, possession of the APOE variant is neither necessary nor sufficient to cause Alzheimer’s disease. This limitation, along with a general lack of treatment options for Alzheimer’s, has raised concerns that the genetic information could burden rather than benefit patients. Consequently, there are a lot of consensus statements and articles against the use of APOE genotyping for predicting Alzheimer’s risk.

Nevertheless, a recent study has shown that patients want to learn about their APOE test results and are not overtly distressed by them.  The Risk Evaluation and Education for Alzheimer’s disease Study (REVEAL), showed that even if the test does not have clinical utility it has personal utility.  Study participants who discovered they have an elevated risk, not only accepted the news but were more likely to initiative preventative life-style measures and more likely to consider retirement planning and purchase long term care insurance.  Knowing their risk also helped patients to have informed discussions with their partners and families.

SRxA’s Word on Health would like to know:

One less guilty pleasure?!?

The 2010 Easter holiday just got better for chocolate lovers.  A study published this week in the European Heart Journal showed that chocolate is good for you.

The ten-year study of chocolate consumption in almost 20,000 people showed that those who ate the most chocolate got the greatest benefit.  German nutritionists found that eating 7.5 grams of dark chocolate every day could reduce the risk of heart attack or stroke by a staggering 39%. Chocolate eating can also lead to lower blood pressure.

As always, there’s a catch – it’s the most expensive chocolate that’s best for you.  Dark chocolate containing at least 70% cocoa produced the best results.

And before you rush out and stock up, you need to do the math.  7.5 grams is approximately 0.26 ounces, which is less than one small square. Eating more than this can result in obesity, which leads to higher blood pressure, which in turn increases the risk of heart attack and stroke!

Still, chocolate is chocolate, right?

Even so, Word on Health wonders whether it will continue to taste as good now that we know it’s good for us.