Dietary guidelines recommend eating at least three whole grain servings every day, but surveys have shown that the average American is eating less than one a day, raising the risk of cardiovascular disease (CVD); a disease expected to cost the US $403.1bn in 2006.
The study, performed by Agricultural Research Service (ARS) scientists and published in the March issue of the ARS magazine, Agricultural Research, reports results from a small intervention study of 10 healthy women aged 20 to 45, eating either a whole-grain or refined grain diet.
After five days on either the whole-grain or refined grain diet, blood samples were taken and serum levels of very low density lipoproteins (VLDL), particularly triglycerides. Levels of the protein, apolipoprotein CIII (apoCIII) were also measured. Both of these have been associated with higher risks of CVD.
After eating the refined-grain diet the researchers found that serum levels of both triglycerides and apoCIII were significantly higher than after eating the whole grain diet.
"VLDLs are naturally rich in triglycerides, so you want the lipoprotein lipase - your triglyceride-removing mechanism - to be very efficient," explained lead researcher Nancy Keim.
"If the apoCIII protein on your VLDLs slows down the lipoprotein lipase, triglycerides may spend more time in your VLDLs instead of where they belong-in your muscles or fat tissue. The longer the triglycerides remain in your VLDLs, the more likely they are to be oxidized or to infiltrate your arteries. Neither outcome is good."
Researchers at the University of Maryland published similar results recently for an elderly population. In this instance, people who ate more than three serving of whole grains every day were half as likely to develop metabolic syndrome, and subsequently CVD, as those who ate less than half a serving a day.
The overall US market for whole grain and high fiber foods grew less than one percent between 2000 and 2004, from $4.75 billion to $4.79 billion, says Packaged Facts. But a closer look at the individual categories shows considerably more dynamism.
Cereals still account for the lion's share of the market, but this slipped from 71.2 to 64.4 percent. Of the small-but-growing categories, snacks increased its share the most, from 12.3 to 16.2 percent, and beverages from 1.8 to 3.8 percent.
The initial results from Keim were presented at the last meeting of the Federation of American Societies for Experimental Biology (FASEB), and a larger, longer study is planned for later this year.