A recent study attempts to explain the reason why people feel lightheaded and sometimes pass out when they stand up after drinking alcohol, but local doctors said they do not necessarily agree with the findings.
An article published Tuesday in Circulation, an American Heart Association journal, reported that people who drink an average of two to three beers suffer an impairment of the body's ability to maintain a steady blood pressure.
The study found that "people have wider blood vessels and lower blood pressure after drinking alcohol."
The study said because blood pressure can drop after only a few drinks, the body's ability to pump fresh blood to the brain can be impaired. The result is that drinkers tend to feel lightheaded and sometimes faint.
However, Ames doctors said although they understand the concept of the study, they do not see fainting in casual drinkers very often.
Dr. Malhar Gor‚, staff physician at the Student Health Center, said he agreed with the study's findings about feeling lightheaded, but he doesn't personally know of any instances where people have fainted after having only a couple of drinks.
"It is a proven fact that dilation of the blood vessels can lower a person's blood pressure," he said, "and that's an effect of alcohol in general."
Pointing out an example of the dilating effect of alcohol, Gor‚ said a person who has a beer in cold weather often will begin to feel warm because the blood vessels are widening and allowing more warm blood to travel to extremities.
"But at the same time, you're losing blood pressure and body heat, which is bad for you, especially when you're out in the cold," he said.
Gor‚ said assuming a person had no other medical condition, he did not see why the person would pass out after only two or three beers.
Dr. Steven Fisher, physician in the emergency clinic at the Mary Greeley Medical Center, 111 Duff Ave., said patients who have passed out after consuming alcohol often come to the emergency room, but "most of these people lose consciousness because their blood-alcohol level is too high."
"If you were to put an IV in someone and start pumping alcohol into their system, they would eventually pass out because of the alcohol level in their blood," he said.
Fisher said he did not think the part of the study concerning fainting was correct because he often sees patients who have overdosed on alcohol who still have acceptable blood pressures.
"We've had some patients brought in who have passed out after drinking too much alcohol, and their blood pressure is perfectly fine," he said.
In the study, conducted by the University of Iowa College of Medicine and the Mayo Clinic in Rochester, Minn., several of the 19 participants felt lightheaded after two or three beers, but none passed out.