Pass the Purple Potatoes to Lower Blood Pressure
Last year, the potato almost received a death sentence in the National School Lunch program. Initially, the government had proposed to limit consumption of starchy vegetable to just one cup per student per week. But thankfully, that moved was blocked because the proposal had “no basis in nutrition science.” The potato, in fact, is a healthful vegetable and new research encourages those who are overweight with hypertension to continue having small helpings to keep blood pressure under control without fear of weight gain.
Nutritionally, potatoes are good sources of vitamin B6, vitamin C, copper, potassium, manganese and dietary fiber. They also contain a variety of phytonutrients. The George Mateljan Foundation for the World’s Healthiest Foods notes that while most of us are only familiar with two or three types of potatoes, there are actually about 100 varieties of the vegetable. A type showing up in more food stores is the purple-skinned potato called Purple Majesty which was the focus of a study funded through a Cooperative Agreement Grant from the United States Department of Agriculture (USDA).
In the Journal of Agricultural and Food Chemistry, Joe Vinson PhD with the University of Scranton in Pennsylvania and colleagues studied 18 volunteers who consumed 6 to 8 small purple potatoes (microwaved) twice a day for four weeks. Most of the study subjects were overweight and had high blood pressure for which they took anti-hypertensive drugs.
Average diastolic blood pressure (the lower number which indicates the pressure on the blood vessels at rest) dropped by 4.3 percent and systolic pressure (the top number representing pressure during each heart beat) decreased by 3.5 percent. None of the study participants gained weight.
Vinson said that other studies have identified substances in potatoes with effects in the body similar to those of the well-known ACE-inhibitor medications, a mainstay for treating high blood pressure. However, pigmented potatoes (ie: purple or red) do have high concentrations of antioxidants including phenolic acids, anthocyanins and carotenoids. These nutritional components are protective against cardiovascular disease, respiratory problems and certain cancers.
One of the phytochemicals found in potatoes is called Kukoamine. This compound, previously only known to be in an exotic herbal plant called Lycium chinense, as noted to be in potatoes as well. These compounds have been shown to lower blood pressure in studies by UK scientists at the Institute for Food Research.
The scientists do not know yet whether ordinary white potatoes have the same beneficial effects, but your basic Idaho potato is high in potassium, an important nutritional component of the “DASH” diet – or Dietary Approaches to Stop Hypertension. Potassium is crucial to heart function and plays a key role in skeletal and muscular function. Studies show that those who eat a diet high in the mineral have lower blood pressure and decreased risk of stroke. Vitamin B6, another vitamin in good supply in potatoes, is also essential for heart health.
Of course, a diet of French fries will up potato consumption, but this isn’t the recommendation for a healthy diet low in fat and rich in unprocessed produce. Roast, steam, bake or boil potatoes and add flavorful ingredients such as fresh herbs or garlic. Remember to eat the edible skin as well – dietary fiber is another important component of heart health as it can help to lower cholesterol.
Source Reference: American Chemical Society
Joe A. Vinson, Cheryil A Demkosksy, Duroy A Navarre, and Melissa A Smyda. High antioxidant potatoes: Acute in vivo antioxidant source and hypotensive agent in humans after supplementation to hypertensive subjects. Journal of Agricultural and Food Chemistry DOI: 10.1021/jf2045262 Publication Date (Web): January 5, 2012
Additional Reference: The George Mateljan Foundation for the World’s Healthiest Foods
Photo Credit: Wikimedia Commons