Category Archives: Walking

Study: Marathon Runners Have More Plaque

JimFixxIn1980

Jim Fixx in 1980. He died about 4 years after this photo was taken, of a heart attack during his daily run. He was 52. His autopsy revealed considerable plaque build-up.

Shaun sent this study:

Increased Coronary Artery Plaque Volume Among Male Marathon Runners, Missouri Medicine, March/April 2014

Background: This hypothesis, that long-term marathon running is protective against coronary atherosclerosis, was tested by quantitatively assessing coronary artery plaque using high resolution coronary computed tomographic angiography (CCTA) in veteran marathon runners compared to sedentary control subjects.

Methods: Men in the study completed at least one marathon yearly for 25 consecutive years. All study subjects underwent CCTA, 12-lead electrocardiogram, measurement of blood pressure, heart rate, and lipid panel. A sedentary matched group was derived from a contemporaneous CCTA database of asymptomatic healthy individuals.

Results: Male marathon runners (n = 50) as compared with sedentary male controls (n = 23) had increased total plaque volume (200 vs. 126 mm3, p < 0.01), calcified plaque volume (84 vs. 44 mm3, p < 0.0001), and non-calcified plaque volume (116 vs. 82 mm3, p = 0.04).

Conclusion: Long-term male marathon runners may have paradoxically increased coronary artery plaque volume.

How could this be?

“… an emerging body of scientific data suggests that chronic, excessive, high-intensity exercise may induce oxidative stress and myocardial fibrosis, accelerate atherosclerosis, increase vascular wall thickness, and increase cardiac chamber stiffness.”

So, what constitutes excessive? They cited the Copenhagen City Heart Study which followed 1,878 runners and 10,158 non-runners for up to 35 years. It uncovered a U-shaped curve … those who exercised too little and also too much had increased risk for mortality compared to moderate exercisers.

“… the benefits of running were most significant for those who jogged between 1 to 2.5 hours per week, at a slow to moderate pace, with a frequency of about three times per week. In those runners who were performing higher volume, higher intensity running, the long-term mortality rates were not significantly different from non-runners. In other words, excessive running may have abolished the remarkable improvements in longevity conferred by lower doses of running.”

One hour a week is less than 10 minutes a day. At a slow to moderate pace. That was the best for health and longevity.  Wow.

It looks like running itself may damage blood vessels. But what about diet? You’ll note that both the marathoners and sedentary men had elevated LDL cholesterol (sedentary: 108 mg/dl, marathoners: 112), and, some would say, elevated total cholesterol (sedentary: 183 mg/dl, marathoners 186).  All that running may have been whittling away their weight, but it wasn’t whittling away their cholesterol.

As Dr. Esselstyn famously showed,1 cholesterol is strongly impacted by diet:

“After 5 years on Dr. Esselstyn’s plant-based diet, the average total cholesterol levels of his research group dropped from 246 milligrams per deciliter to 137 mg/dL This is the most profound drop in cholesterol ever documented in the medical literature in a study of this type.”

The Wall Street Journal covered this study and similar ones in Why Runners Can’t Eat Whatever They Want, Studies Show There Are Heart Risks to Devil-May-Care Diets—No Matter How Much You Run, and included this quote from the editor of Runner’s World:

“Ambrose Burfoot, winner of the 1968 Boston Marathon and editor-at-large of Runner’s World magazine, is 67 years old, 6 feet tall and only 147 pounds. A lifelong vegetarian, he subsists mostly on fruits, vegetables and nuts, though he also eats “cookies and all dairy products—cheeses, ice creams etc.,” he wrote in an email.

“Last March I learned that I have a very high coronary calcium,” he said.”

I know several vegetarians with high cholesterol, over 200 mg/dl. A good chunk of their calories come from animal foods – eggs, butter, cheese, yogurt, and other dairy products. “I have to get my protein,” they tell me. Dr. Esselstyn found that when his patients dropped the dairy, their cholesterol dropped along with it.

It may very well be, as Shaun says, that you can’t run from your diet.

By the way, the technology used to measure plaque, coronary computed tomographic angiography (CCTA), was referred to as “noninvasive.” Not true. All radiation is invasive. This report by the National Academies Press says that all ionizing radiation damages cells. There is no level of exposure below which damage to a cell does not occur.

1Prevent and Reverse Heart Disease, January 2008

COPD – How To Breathe Better, How To Keep Your Weight Up

COPDCausesI just saw a study on COPD and walking that really popped out at me.

Chronic Obstructive Pulmonary disease, or COPD, is really common, probably the most common lung disease, or set of lung diseases, in this country. There are two main forms, which often occur together:

Chronic bronchitis, which involves a long-term cough with mucus
Emphysema, which involves destruction of the lungs over time

Here’s the prevalence, from CDC:

COPDPrevalence

Look at that concentration just west of the east coast.  CDC says, “The states with the highest COPD prevalence are clustered along the Ohio and lower Mississippi Rivers.” Exposure to cigarette smoke and other air pollutants are the main cause. Symptoms show up sooner and are worse in people with poor general health.

Like other chronic diseases (heart disease, cancer, diabetes) you usually have it for years before a doctor tells you so. One thing that sends a person to a doctor? Unexplained weight loss. COPD patients use more calories for breathing. A healthy person might use about 100 calories/day to expand and contract the lungs. A person with COPD uses between 430 and 720 calories/day for the same purpose, even if they are unaware of it.

Cold air is especially difficult for people with COPD because one job of the lungs is to raise the temperature of inhaled air to 98.2°F or body temperature. Calories.

There’s no cure. But exercise, especially walking, helps. That’s why this study drew my attention:

Influence Of Changes In Physical Activity On Frequency Of Hospitalization In Chronic Obstructive Pulmonary Disease, Respirology, April 2014

“Conclusions: Patients with COPD with a low level of physical activity (PA) or who reduced their PA over time were more likely to experience a significant increase in the rate of hospitalization for eCOPD. Changes to a higher level of PA or maintaining a moderate or high level of PA over time, with a low intensity activity such as walking for at least 3–6 km/day, could reduce the rate of hospitalizations for eCOPD.”

It found that people who regularly walked about 2 miles a day, and gave it up, experienced a 2.5-fold increase in their risk for hospitalization after about 3 years. That’s a big increase over a relatively short time. You can imagine they were feeling pretty lousy in the months prior to their hospitalization.

Crystal Phend, senior writer at MedPageToday, in her article Backing Off Exercise Worsens COPD, wrote:

Those who moved from the highest level of activity* to any lower category also doubled their subsequent risk (OR 2.13, P=0.017).

The associations were independent of age, lung function, and prior hospitalizations for exacerbations.

“This suggests that small changes in physical activity habits could significantly improve an important outcome as hospitalization during exacerbation of COPD in those patients,” the researchers concluded.

However, maintaining a lower level of physical activity also roughly doubled risk compared with sticking to a higher level of physical exercise.

The mechanism could be decreasing systemic inflammation, improving lung efficiency, or strengthening lung muscles, but reverse causation and unmeasured confounding were possible as well, they acknowledged.

* Low physical activity was considered less than 1.9 miles (3 km) per day or less, moderate was 1.9 to 3.7 miles (3 to 6 km) daily, and high was anything above that.

So, not only giving it up, but just reducing how much you walk can worsen symptoms.  Walking seems like an effective, non-pharmacological, and inexpensive way to improve lung function.  As long as you keep with it.

How to Keep Your Weight Up? WebMD offered these suggestions:

  • Mix a teaspoon of butter, margarine or olive oil into hot foods such as vegetables, soups and potatoes; it adds 45 calories
  • Eat mayonnaise instead of salad dressing; mayonnaise has 100 calories which is about twice that of salad dressing
  • Use peanut butter liberally; it has lots of protein and about 90 calories per tablespoon
  • Use honey generously for sweetening and as a snack
  • Drink milkshakes made with high-fat ice cream; try adding protein powder or egg substitutes for added calories and proteins
  • Keep high-calorie, healthy snacks around and easy to grab; examples: olives, walnuts, raw almonds and dried fruits
  • Add flaxseed oil or olive oil to cottage cheese with fruit
  • String cheese is easy and bite-size with 80 calories per stick

I like the dried fruit and nut idea. These are probably great weight loss tips in reverse.