Low-Glycemic-Index Foods Can Decrease Systolic and Diastolic Blood Pressure in the Short Term

Background. We aimed to compare the effects of low- and high-GI foods on 24-hour ambulatory blood pressure. Methods. This longitudinal study was performed on 30 women, aged 18 to 40 years, during 24 hours. In the first leg of study all recruited subjects were assigned to LGI period for 24 hours and, after a 2-week washout period, all subjects were assigned to HGI period. BP was measured every hour during the 24-hour monitoring. Results. After the intervention, there were significant decreases in SBP and DBP in the LGI period (102.26 ± 14.18 mmHg versus 112.86 ± 9.33 mmHg for SBP and 66.96 ± 10.39 mmHg versus 74.46 ± 7.61 mmHg for DBP) (P = 0.00 and P = 0.002, resp.). However, in the HGI period, there was no significant change in SBP or DBP (110.66 ± 9.85 versus 111.80 ± 9.57 for SBP and 71.16 ± 9.16 versus 74.26 ± 10.09 for DBP) (P = 0.6 and P = 0.06, resp.). Conclusion. The results suggest that LGI foods may be beneficial in reducing 24-hour BP.