By the end of the college football season, more than half of first-year players in a recent study had developed hypertension (high blood pressure), or were on the verge of developing it.
Linemen were especially likely to have developed prehypertension or stage 1 hypertension, according to the study, which was published in Circulation, a journal of the American Heart Association.
The study of 133 varsity football players at Harvard University over six years was conducted principally by Aaron Baggish, associate director of the Cardiovascular Performance Program at the Massachusetts General Hospital, Boston.
On average, the blood pressure of the players studied rose from 116/64 before the football season began to 125/66 at season's end. Increases were disproportionately greater among linemen, 83 percent of whom developed either prehypertension or stage 1 hypertension. Prehypertension starts at 120/80, stage 1 starts at 140/90 and stage 2 is 160/100 or higher.
Only one of the 133 players had been diagnosed with hypertension before the season began.
"We're definitely seeing an increase" in high blood pressure among football players, said Moira Davenport, a sports medicine physician at Allegheny General Hospital.
Hypertension is more common among those who are overweight, so it makes sense that linemen would be more likely to develop signs of it, Dr. Davenport said.
In addition to being heavier to start with than backs or receivers, young linemen are encouraged to bulk up to play their positions better, she noted.
Teenagers typically don't pay as much attention as they ought to to good nutrition, and "it's hard to eat right when you are trying to put on pounds," Dr. Davenport said.
Football players tend to gain weight in the course of the season, said Srinivas Murali, director of the Division of Cardiovascular Medicine for the West Penn Allegheny Health System. In addition, many football players are African-Americans, who are at higher risk for hypertension.
It isn't good for young people to develop high blood pressure, but the results of his study shouldn't scare players, Dr. Baggish said.
Physicians regard prehypertension more as a warning sign than as a risk factor in itself. On average, the players in Dr. Baggish's study were just barely above normal blood pressure.
But the study indicated there were some changes in the cardiac structure as well, noted Dr. Murali. "The heart muscle got thicker, because the heart was pumping harder" from exertion, he said, adding that a thicker heart muscle is an additional risk factor for hypertension.
If your blood pressure falls within the hypertension range, physicians typically recommend that you lose weight -- studies indicate that for overweight people, even modest weight loss reduces dramatically the risk of developing hypertension -- to eat a diet rich in fruit, vegetables, whole grains and fish, and to cut back on salt, saturated fats and alcohol. A healthy diet has been shown to reduce hypertension risk in those of normal weight.
Physicians also advise you to exercise regularly, but that's not advice college football players are likely to need.
Jack Kelly: email@example.com or 412-263-1476.