A new report, published in this month's issue of the Journal of General Internal Medicine, identifies that an estimated 63 million adults have higher LDL (bad) cholesterol levels than the set optimum levels.
And of that group, 38 million are people with health conditions that put them at increased risk for heart disease.
Too much LDL cholesterol can build up on the inner lining of arteries that feed the brain and heart, and in conjunction with other substances form plaques that can clog vessels and cause a stroke or heart attack, say the researchers from Northwestern University Feinberg School of Medicine.
And despite some efforts by food manufacturers to offer more 'heart-healthy' products, the gap continues to grow between ideal and actual cholesterol levels in the nation's consumers.
The recent study, which compared 2001 National Institutes of Health cholesterol level targets with revised, more stringent, optimal targets issued in 2004, found that 10 million more adults had LDL levels above the new targets.
When it comes to the average American's diet, trans fats are one of the major culprits blamed for increasing cholesterol.
Trans fatty acids (TFAs) are formed when liquid vegetable oils go through a chemical process called hydrogenation. Common in a range of food products - biscuits, chips, doughnuts, crackers - the hydrogenated vegetable fat is used by food processors because it is solid at room temperature and has a longer shelf life.
But research suggests that trans fats raise LDL cholesterol levels, causing the arteries to become more rigid and clogged, and increasing the risk of heart disease. This has prompted new labeling rules, which have required manufactures to label the trans fat content of their products since January 1, resulting in an industry-wide response to try to reduce or eliminate trans-fats.
Manufacturers have also been keeping their eyes on a number of ingredients said to help reduce cholesterol, such as barley and oats.
Last month the Food and Drug Administration (FDA) approved a health claim stating that products containing barley may help reduce the risk of heart disease.
Coronary heart disease (CHD) is a global killer responsible for 500,000 deaths per year in the US alone. Risk factors for the disease include high cholesterol levels. And scientific evidence has shown that the consumption of barley could help reduce cholesterol levels.
In a study published in 2003, scientists at the Agricultural Research Service revealed that a diet high in soluble fiber had the greatest effect on reducing LDL (bad) cholesterol levels. Levels of HDL (good) cholesterol either increased or did not change, resulting in an improved total LDL/HDL ratio.
Beta-glucan- found in oats- has also been shown to help lower 'bad' cholesterol levels, when combined with a healthy diet.
And scientists from the US Department of Agriculture's Agricultural Research Service have developed a new oat variety containing high levels of beta-glucan. Writing in this month's issue of Agricultural Research Magazine, the scientists say their variety may soon allow food manufacturers to offer whole oat products that pack the same health benefits as ordinary oats into smaller portions.
On the negative side, a review published last month reveals that soy protein, which has in the past been linked to improved heart health, has little impact on cholesterol levels.
Analysing 22 clinical trials, researchers from the American Heart Association's nutrition committee found that large amounts of isolated soy protein in the diet only lowered LDL cholesterol by about 3 percent on average.
The scientific statement, published in the January 23 issue of the association's journal, Circulation, throws some doubt over the health claim approved by FDA in 1999 and now widely used by makers of soy products.