Researchers in Sweden have carried out the study and claimed that women who take more than three cups of the caffeine-fuelled drink a day could see their bra size drop, the Daily Star reported.

Tests by cancer researchers found half of all women have a gene linking breast size to coffee intake.

Nearly 300 women were quizzed but Helena Jernstroem, of Lund University, said women should not worry too much.

She explained: "Coffee-drinking women do not have to worry their breasts will shrink to nothing overnight. They will get smaller, but the breasts aren't just going to disappear.”

"Anyone who thinks they can tell which women are coffee drinkers just from their bra measurements will be disappointed. There are two measurements for a bra -- the cup size and the girth, so you wouldn't be able to tell."

While caffeine may shrink women's breasts, the reaction is the reverse for coffee-slurping blokes -- it can make their ‘moobs’ swell, according to the researchers.