The landmark Nurses' Health Study is recruiting a new cohort of 100,000 female nurses and nursing students ages 20 to 46 from across the U.S. and Canada.

Described as the world's largest and longest-running set of research on women's health, the Nurses' Health Study has included more than 230,000 participants since the 1970s. By completing confidential lifestyle surveys for more than three decades, the participating nurses have enhanced medical knowledge about nutrition, exercise, cancer and heart disease.

For example, bolstered by evidence from the study, according to a news release, many restaurants ban artificial trans fats. In the study, these fats were shown to contribute to heart disease.

The Nurses' Health Study III will explore important issues in women's health — including those related to the environment, work life, fertility and the effects of lifestyle — on a younger and more diverse group of women.

NHS3 is conducted entirely online, with participants completing brief confidential surveys every six months.

Approximately 20,000 nurses and nursing students have enrolled to date through sponsoring nursing associations, direct mail, social networks, the media and word-of-mouth through current participants. Recruitment will continue until the goal of 100,000 participants has been reached.

Eligible nurses can learn more on the study's website: www.nhs3.org.