Two hundred grams per day of the potato variety called Purple Majesty, a naturally occurring variation developed by the Colorado potato-breeding program, for two weeks led to statistically significant reductions in pulse wave velocity (PWV), according to findings published in Plant Foods for Human Nutrition.
On the other hand, no significant changes were observed for other markers of cardiovascular health, including blood pressure, cholesterol, triglycerides, glucose, insulin and C-reactive protein, reported scientists from Edge Hill University, Queen Margaret University, the James Hutton Institute, and the University of Edinburgh.
“[Purple Majesty] potatoes are relatively inexpensive and commercially available in the UK and could therefore provide a valuable contribution of dietary antioxidants as part of a healthy balanced diet.”
The researchers recruited 14 healthy men and women aged between 20 and 55 to participate in their study. The volunteers were randomly assigned to consumer 200 grams per day of either the cooked purple potato (containing 288 mg anthocyanins) or a white potato (with negligible anthocyanins) for 14 days. This was followed by a seven day “washout” period (with no intervention) and then the men and women were crossed over to the other group for a further 14 days.
Results showed that purple potato consumption was associated with a statistically significant 0.3 m/s reduction in PWV, but no changes in other measures of cardiovascular risk.
Other studies of anthocyanin-rich food consumption had suggested a potential blood pressure-lowering effect, but this was not observed in this study, which may be linked to the timing of the blood pressure measurement, said the researchers: Anthocyanins have been reported to have a transitory reducing effect on blood pressure, which lasts les than four hours. In this study, blood pressure was measured the day after purple potato consumption, and therefore it is conceivable that any effect on blood pressure would be missed.
“Improvements in PWV without any changes in BP (or any other clinical parameter associated with cardiovascular risk) have been reported following interventions with cranberry juice and red clover isoflavones,” they added.
The study is reported to the first to investigate the potential effect of Purple Majesty potatoes on PWV in humans.
“Consumption of [Purple Majesty] significantly improved PWV in apparently healthy subjects without any other changes in cardiovascular markers. Future studies are warranted to validate these findings in longer-term studies, and in populations at risk of CVD to interpret their precise role as potential cardio-protective agents,” concluded the researchers.
Source: Plant Foods for Human Nutrition
Volume 73, Issue 3, pp 203–208, doi: 10.1007/s11130-018-0673-2
“Antioxidant Rich Potato Improves Arterial Stiffness in Healthy Adults”
Authors: C. Tsang et al.