Doctors at Brigham and Women's Hospital studied diet data of 150-thousand women over eight years.
They studied two age groups: 27-44 year olds, and 43-70 year olds.
The younger women had a 46-percent reduction in their risk of developing high blood pressure.
The older women saw an 18-percent reduction.
Doctors say before they recommend women increase their intake, they must first do a clinical study.