Washington: The health benefits associated with eating broccoli or other cruciferous vegetables cannot be obtained via supplements, new research has found.
A key phytochemical in these vegetables is poorly absorbed and of far less value if taken as a supplement, the report said.
And not only do you need to eat the whole foods, you have to go easy on cooking them.
“The issue of whether important nutrients can be obtained through whole foods or with supplements is never simple,” said Emily Ho, an OSU associate professor in the OSU School of Biological and Population Health Sciences, and principal investigator with the Linus Pauling Institute.
“Some vitamins and nutrients, like the folic acid often recommended for pregnant women, are actually better-absorbed as a supplement than through food,” Ho said.
“Adequate levels of nutrients like vitamin D are often difficult to obtain in most diets. But the particular compounds that we believe give broccoli and related vegetables their health value need to come from the complete food.”
The reason, researchers concluded, is that a necessary enzyme called myrosinase is missing from most of the supplement forms of glucosinolates, a valuable phytochemical in cruciferous vegetables.
Without this enzyme found in the whole food, the study found that the body actually absorbs five times less of one important compound and eight times less of another.
Intensive cooking does pretty much the same thing, Ho said. If broccoli is cooked until it``s soft and mushy, its health value plummets.
However, it can still be lightly cooked for two or three minutes, or steamed until it``s still a little crunchy, and retain adequate levels of the necessary enzyme.
The study has been published in the Journal of Agricultural and Food Chemistry.