The United States Department of Agriculture (USDA) has updated the dietary guidelines for Americans to include food rich or rich in zinc and iron, with the goal of reducing heart disease and other chronic diseases linked to the imbalance.
According to the USDA, zinc, one of the three essential minerals needed to grow a healthy brain, can be found in fruits, vegetables, grains and beans.
Zinc can be absorbed through the skin and is found in the skin of many fruits and vegetables, but in lesser amounts in foods such as pasta, rice, bread, pasta sauces, bread crumbs, and baked goods.
The US Department of Health and Human Services recommends limiting the amount of zinc in processed foods.
“The guidelines are about serving more foods with lower zinc content,” said Julie L. Smith, a registered dietitian and senior nutritionist at the Centers for Disease Control and Prevention (CDC).
Smith said zinc intake is a key factor in heart disease, and has been linked to a decreased number of blood clotting factors in the arteries and increased risk of developing certain types of cancers.
“The recommendations do include a recommendation to limit zinc in the foods we eat,” she said.
However, many people don’t consume enough zinc, and many experts disagree about whether the government’s recommendations should be implemented.
According a 2013 report from the USDA published in the Journal of the American Medical Association, a “healthy” amount of calcium intake, the calcium in dairy products and other sources of calcium, is associated with a lower risk of heart disease.
However, the report also found that calcium intake could be increased with supplementation to help balance the diet.
“Most of us don’t get enough calcium in our diets,” said Dr. Sarah M. Lott, associate professor of medicine at the University of Florida and an expert on the effects of dietary zinc and vitamin D on heart disease prevention.
“Most people in the U.S. eat the most nutrient dense foods that contain zinc and other minerals and they have a higher risk of cardiovascular disease.”
Lott said zinc deficiency can be prevented by limiting zinc in foods.
“There are ways to get zinc, but there’s not a way to get all the minerals you need,” she added.
“It’s not just a matter of having more zinc, it’s a matter not just to get more calcium,” said Smith.
“It’s about increasing your calcium intake.”
The US Dietary Guidelines, which were first published in 2000, recommend that all Americans consume 2,000 milligrams (mg) of zinc a day, the amount recommended by the US Centers for Health and Nutrition.
According to Smith, this amount of dietary intake is too low to meet people’s needs, and it is recommended to consume an additional 600 mg a day for people over 65 years old.
Smith said she has not seen a convincing evidence that dietary zinc supplements have been shown to have an effect on heart health.
“We haven’t looked at the research,” she noted.
“If there is a benefit, we’d need to look at it in a randomized controlled trial.”
She said that even if the dietary recommendations are changed, most Americans won’t see any effect because most of the zinc in our diet comes from foods like white bread and rice, which contain a lot of zinc.
In fact, one study published in 2013 in the journal Science found that people who were told to increase their zinc intake by 1,500 mg a week actually did not see a decrease in heart attack risk, but their zinc intakes did decline.
“People should think about the foods they’re eating,” Smith said.
“Foods with more zinc will have more zinc.
And when you consume more zinc in your diet, it will increase your zinc levels.
It will decrease your risk of disease.”
Smith said there are different ways to eat zinc.
“You can eat the right amount of iron, which will increase zinc,” she explained.
“And you can eat more zinc because that will help your body to absorb it.”
However, she said that people need to be aware of the “dangerous” levels of zinc that can be consumed.
“This is a dietary issue, not an environmental issue,” she warned.
“So be aware that if you’re not eating enough zinc or if you are not getting enough zinc in this diet, then it will cause you to develop heart disease.”
Follow Lauren S. on Twitter at @lansayspirit.