Archive for the ‘genetics and execise’ Category

Lessons unlearned

Thursday, April 18th, 2013

I weighed 153 pounds this morning, so I'm back on my diet plan until I'm under 150 again. Today I had fruit and cereal for two meals and a small amount of Thai leftovers plus a considerably larger amount of spinach for my big meal. I also went to our  health club and rode a recumbent bike for long enough to burn 500 calories and "cover" 15+ miles. I shoveled snow, wet heavy snow at that, for our house and our elderly neighbors place three times (we've had over 20 inches of snowfall in the past three days).  And of course, as I've mentioned before, I quit smoking in 1964.

This is not what we eat.

This is not our typical meal.

After diner I looked at recipes from Martha Rose Shulman's book, The very best of Recipes for Health. Shulman writes a healthy food column in the New York Times online version. I've looked at it frequently and we recently purchased her book. Lynnette made a Quinoa and Tomato Gratin yesterday and we immediately added it to our "Keeper List." A lot of the recipes are vegetarian (about 1/3 of our main meals fit in that category), but she's got some turkey and fish dishes.

What sparked this column was a Pure Study report in JAMA dated April 17, 2013. The title is lengthy: "The Prevalence of a Healthy lifestyle among Individuals with Cardiovascular Disease in High-, Middle-, and Low-Income Countries" In 2009 an article in the American Heart Journal described the PURE Study, the Prospective Urban Rural Epidemiology Study. The World Health Organization defines epidemiology  as the analysis of the distribution and determinants of health-related states or events (including disease), and the application of this knowledge to the control of diseases and other health problems.

The PURE Study began with a premise we're all (hopefully) familiar with; over the past 50-60 years we've seen an epidemic of obesity, diabetes and cardiovascular disease in much of the world, especially in countries, like the United States, where many smoke, eat too much of the wrong foods and exercise too little

Let's start with smoking in this country. The CDC published data online from a 2010 study that said over 19% of adult Americans smoked cigarettes. Over a fifth of those aged 18 to 64 were in this group, but only 9.5% of those over 65. Hispanics (12.5%) and Asian-Americans (9.2%) did better than whites or blacks, but over 30% of American Indians and Alaska Natives were smokers.

Smoking percentages went sharply down with more education: 45.2% of those with a GED smoked, 23.8% of those with a high school diploma, under 10% of people who had graduated from college and 6.3% of those with a postgraduate degree.

Similarly those living below the poverty level were more likely to be smoker (28.9%) than those with incomes at or above that level (18.3%).

There's lots of data linking obesity, low-quality diets, and lack of exercise with cardiovascular disease including heart attacks and stroke. How one defines a low-quality diets varies around the world; living here, I thinks it's lots of fast food and little emphasis on fruits and vegetables.

As a young physician I saw many patients who didn't seem to get the message that their unhealthy lifestyle may well have contributed to their cardiovascular disease. When I was 53 my four-year-older brother died of a heart attack. Almost all of the rest of the family lived to 90 or longer, but he had smoked two to three packs of cigarette a day, gained fifty or so pounds and seldom exercised. If I had a heart attack or a stroke and survived, I'd look closely at my risk factors and try to do something about them.

The PURE study following over 150,000 adults (ages 35 to 70) in over 600 urban and rural settings in 17 different countries. This article discussed 7519 participants who had already had either a stroke or coronary artery disease and determined if they had stopped smoking, altered their eating habits and/or gotten more exercise.

The results were striking, but not at all amazing to me. Guess what proportion improved in all three arenas.

4.3%

Over fourteen percent of these post-cardiovascular-event adults didn't take up any of the three logical behavior changes.

That made no sense to me. Could it be genetic pre-programming? Let's look at data on one of the three behaviors.

A rodent exercise machine

A rodent exercise machine

The New York Times had a recent online article titled, "Why we're motivated to Exercise or Not." Scientists at the University of Missouri took ordinary lab rats and put running wheels in their cages; They bred the males and females who were the most active to each other and did the same to those who ran the least. They continued this over ten generations and ended up with two disparate groups: one ran ten times as much as the other.

They examined the physiques of the rodents to see if one group was fat or had poor muscle tone: no significant differences were found. Then they examined genes in the reward portion of the rats' brains; the part that gives motivation to do things because they cause enjoyment. Lots of differences were noted here.

Does that mean those of us who exercise do so because we're genetically predisposed to do so and the rest are doomed to be sluggards?

The lead investigator, Dr. Frank Booth, thinks it's quite probable that humans have a genetic motivation to exercise or not. But he's quoted as saying his results "are not meant to be an excuse not to exercise."

And that's without having the added incentive of having had a heart attack or a stroke.

What does it take to change our habits of a lifetime?