Study: Marathon Runners Have More Plaque


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

6 thoughts on “Study: Marathon Runners Have More Plaque

  1. Marj

    This is all so very amazing to me. All the studies lately turning so many things upside-down. Saturated fat, running, and even an article I read (don’t recall where) recently that people don’t eat enough salt. All-in-all though, the plant diet seems so realistic and commonsense-y (?). I only wonder how long it will take for such a diet to have consensus as to its merits. I’m now of an age where I’ve seen that change comes about very slowly when it impacts diet and other behaviors.


    1. Bix Post author

      I was really surprised by this study too. I would love to know what these men ate.

      Another thing that got me was that jogging for maybe 20 minutes, 3 times a week, at a slow-to-moderate pace, was more predictive of long life than running marathons!


  2. RB

    The study is interesting to me because I am a life long runner. However, I run to stay healthy; not to run marathons. I probably run about 20 miles a week. I also take walks and ride my bicycle. One of the benefits of my level of training is that I don’t fret about doing physical activities from mowing the lawn, playing basketball with my adult kids or hiking up Mount Yale (over 14,000 feet). I think my training also helps me maintain a high energy level and keeps me trim. I also enjoy running. On days when I can’t run, I feel something is missing from the day.

    I am now much more conscientious about what I eat and try to eat healthy foods most of the time. However, when I was younger, I ate whatever I wanted. My running and active life style kept me trim. As long as I maintained a healthy weight and exercised I thought I was fine. I now think that running alone is not all that is needed to stay fit, healthy and trim. I know a healthy diet is essential. But its easy to get in the habit to chow down on chips, cookies and candies when you are running enough to “burn off the calories.” I suspect diet plays a part in arterial plaque found in marathon runners. A runner training for marathons eat much more than the average person because they may burn 1000 to 2000 extra calories a day.

    I do not think Jim Fixx is the most appropriate picture for this post since he had other issues beside doing long runs everyday. Up until he was 35 he was a two pack a day smoker and overweight (probably obese). He had a family history of heart disease. His father died at 43 of a heart attack. The damage to his body from unhealthy lifestyle aided by his genetic predisposition to heart disease was not totally undone by his running. From what I can determined, he continued to eat unhealthy foods after taking up running. I don’t think it is surprising he died the way he did. If he were a life long runner who never smoked and always maintained a healthy weight, I would be shocked at his early death.

    I certainly think more research is needed to determine why marathon runners have more plaque. Diet has to be part of the equation.


  3. Bix Post author

    Just some thoughts…

    When we eat, or exercise, or perform any activity, even thinking, we produce ROS, reactive oxygen species or free radicals. They are a by-product of metabolism. Radicals are good and bad. Good in that they act as messengers, bad in that they damage cells.

    Lots of exercise produces more radicals. Lots of exercise requires more eating which produces more radicals. An athlete or anyone who does a lot of exercise and a lot of eating has more cell damage. Our bodies heal this damage, and can come back stronger, but they need a lifestyle that supports healing … a good diet, adequate rest and sleep, not smoking, low exposure to chemicals, UV and other radiation, a supportive mental state. Something in these last few variables were acting to inhibit healing in these runners.


  4. RB

    One more comment on Jim Fixx. At age 35, if Mr. Fixx would have maintain his smoking, overweight lifestyle, he may have past away by age 43 like his father. Instead, he quit smoking, lost weight and started running. These lifestyle changes probably prolonged his life made the last 17 years of his life healthier and more enjoyable. So I would say running was beneficial to a longer, healthier life for Mr. Fixx. Perhaps if he followed a heart-healthy diet, he would still be running with us today.


  5. Pingback: Does Long Distance Running Cut A Life Short? | Fanatic Cook

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s