The results of a recent study show that an aspirin taken at bedtime lowered the blood pressure of pre-hypertensive patients, whereas an aspirin taken in the morning didn't have the same effect. While the exact reasons are unknown, researchers suggest that nighttime aspirin usage could slow the production of clot-producing hormones and other substances that are typically generated at night.

The three-month study followed 244 adults with blood pressure that hovered just below the 140/90 mark. (Consistent readings greater than 140/90 are considered high blood pressure (HBP). Readings that are just below that threshold are considered pre-hypertension -- a warning that the patient is at risk of HBP. The group was divided into thirds: one group followed a blood pressure reducing diet, the second took a 100 mg aspirin at bedtime, the third took an aspirin in the morning.

The group that took the aspirin before bedtime saw the best results -- an average drop of 5.4 points in systolic pressure and 3.4 points in diastolic pressure.