Taking combined oral contraceptives can relieve menstrual pain, a Swedish longitudinal study confirmed.

The study published on Wednesday comes from 30 years of health research with data of more than 1,400 Swedish women born in 1962, 1972 and 1982.

"By comparing women at different ages, it was possible to demonstrate the influence of [combined oral contraception] on the occurrence and severity of dysmenorrhea, at the same time taking into account possible changes due to increasing age," lead author Ingela Lindh of the Institute of Clinical Sciences at Gothenburg University in Sweden, said in a statement. "We found there was a significant difference in the severity of dysmenorrhea depending on whether or not the women used combined oral contraceptives."

Participants filled out a questionnaire when they were enrolled in the study at the age of 19 and again at the age of 24.

Women who took birth control reported significant drops in two measurements of pain. Researchers also noted that age was also a factor because as pain decreases as a woman ages, however this effect was independent from the Pill and much smaller, according to researchers.

Doctors sometimes prescribe the pill to reduce period pain, and many women have confirmed the pill’s effectiveness against pain, but scientific evidence of the pill’s efficacy has been mixed.

The study authors said that dysmenorrhea, symptoms of painful menstrual periods, accounts for 600 million hours lost at work and $2 billion worth of output in the U.S. alone.

"[Painful periods] can have a detrimental effect on these women's lives, causing regular absenteeism from school and work, and interfering with their daily activities for several days each month," Lindh explained in the statement. "Therefore effective management of dysmenorrhea is beneficial for both the women affected and society."

The study findings are published online in the European journal Human Reproduction.