The study, carried out by plastic and hand surgeons at the Bundeswehr hospital in Berlin, found that the guards were at greater risk of developing a condition called gynaecomastia, or an enlargement of the mammary gland, on the left side, the Hamburger Morgenpost newspaper recently reported.
Though gynaecomastia is usually a hormonal condition, the study found that serving in the guard battalion can also be a cause, because it requires soldiers to repeatedly slam their rifles into the left side of their chest during military drills.
Of the 211 gynaecomastia patients examined, doctors found that 35 came from the battalion, which appears at official events such as state visits and the "Great Tattoo" ceremonies for outgoing German presidents.
Of these 35 soldiers, 26 showed breast growth on the left side of their chests - an unusually high proportion for any sample of gynaecomastia cases.
According to the study, led by hospital department head Professor Björn Krapohl, there was "a highly significant correlation between the activities of a guard and left-sided gynaecomastia."
Krapohl also said that the correlation had been noticed as long ago as 2009, and that he had been lobbying for the "rifle-chest-slam" to be stopped since then.
The Bundeswehr confirmed that the study results had been passed on to the Defence Ministry. "The soldiers affected are being treated medically and are receiving individual therapy," a spokesman said, before adding that more studies should be carried out.
The battalion consists of nine companies, seven of which are stationed in Berlin. It is considered one of the plum appointments in the German army.