White vegetables are a good source of potassium

WEST LAFAYETTE, Ind. — Colorful vegetables are promoted as key to a healthy diet, but white vegetables, especially potatoes, shouldn’t be forgotten.

“Potatoes are a great source for potassium, and only 3 percent of American adults consume the recommended daily intake for this mineral that’s essential to healthy blood pressure,” said Connie Weaver, Purdue University distinguished professor of nutrition science.

“Potatoes are often discounted from being healthy because of how they are cooked, topped or the amount consumed, but, when prepared in a healthy way, potatoes are nutritious.”

White is in

“People need to remember that white veggies have a place at the table, too,” Weaver said.

In addition to potatoes, other white vegetables often neglected are cauliflower, turnips, onions, parsnips, mushrooms, corn and kohlrabi.

Overlooked

“It’s recommended that the variety of fruits and vegetables consumed daily should include dark green and orange vegetables, but no such recommendation exists for white vegetables, even though they are rich in fiber, potassium and magnesium,” Weaver said.

“Overall, Americans are not eating enough vegetables, and promoting white vegetables, some of which are common and affordable, may be a pathway to increasing vegetable consumption in general.”

The daily recommendation is 4.5 cups of fruits and vegetables in a 2,000-calorie diet, but Americans consume less than half of that, or about 1.8 cups.

Short on potassium

In 2004, the adequate intake for potassium was set at 4,700 milligrams a day, but the average adult intake is about half that amount.

Potassium is one four nutrients identified by the Dietary Guidelines for Americans as lacking in daily diets.

“Western diets have led to a decrease in potassium with fewer fruits and vegetables, and at the same time, there’s been an increase in sodium consumption because people eat more processed foods,” said Weaver, who is an expert in mineral bioavailability, calcium metabolism and bone health.

While potatoes are one of the highest sources of dietary potassium, when processed, they are often higher in salt. While potassium improves blood flow, too much salt increases blood pressure, making the vascular system work harder.

“The relationship between potassium and sodium is interesting because how the two work together may influence risk of cardiovascular disease,” Weaver said. “The human body needs both, but today’s problem is sodium consumption is up and potassium is down.

“Because potassium-to-sodium intake ratios are more strongly related to cardiovascular disease risk than either nutrient alone, more research is needed to understand this relationship.”

Potassium also shows signs of supporting bone health and reducing the risk of cardiovascular disease and stroke, as well as protecting against age-related bone loss and reducing kidney stones, but more research also is needed in these areas, Weaver said.