The article mainly focuses in the gaps left by a report published by the American Society for Nutrition last month, in which the consumption of fiber-rich whole grains was said to lower the risk of diabetes and heart disease. According to Scientific American, that isn't always the case.
"[Studies of] whole grains using the currently accepted definition don’t have enough data to support them for preventing these different chronic diseases,” says David Klurfeld, the national program leader for human nutrition in the Agricultural Research Service at the U.S. Department of Agriculture.
Klurfeld explains that the main problem with some of the items labeled as whole-grain foods is that they don't provide enough fiber. According to the article, an adult would have to eat 10 bowls of Multi-grain Cheerios, 16 slices of whole-wheat bread, or nine cups of brown rice to get the daily amount of fiber recommended.
“There’s nothing wrong with eating brown rice, but you can't expect health benefits if you're going to be eating brown rice as your source of whole grains,” Klurfeld explains.
The article also notes the processing of the grains as a contributing factor to the problem as well as many of the additives that sometimes accompany whole-grain items.
Joanne Slavin, a professor of food science and nutrition at the University of Minnesota, explained that whole-grain foods became synonymous with healthy foods when U.S dietary guidelines began recommending that individuals increase their whole-grain intake. She adds that the concept has since been distorted.
"The goal is for Americans to replace half of their refined grains with whole grains, not to eat whole grains in addition to the refined ones they have been eating," the article quotes Slavin as saying.
The professor adds that another reason whole-grain foods are misperceived as healthy is because people who eat them tend to carry healthier lifestyles in general.
"A 2006 study reported that the quartile of people who eat the most whole grains are less than half as likely to smoke and 25 percent more likely to regularly exercise as the quartile of people who eat the least whole grains," reads the article.
In the end, Slavin recognizes that the problem is of about quantity.
“We don’t want people to think that because a food has whole grains, they should eat more of it,” she says. “Grains in general are over-consumed in the U.S.”