The mark, which last year added a whole grain category to its nutritional certification program, is currently found on 800 products. Around 30 of these feature the association's whole grain version.
An easily identifiable stamp, the red and white heart-check mark identifies products that meet the requirements of the AHA's Food Certification Program. This was established in 1995 as part of ongoing efforts with the Food and Drug Administration (FDA) to help consumers select nutritious foods, and aims to provide consumers with a convenient way to identify heart-healthy foods.
Designed to identify foods suitable for people over the age of two, the program requires that each serving of a product must be low fat (less than or equal to 3g), low in saturated fat (less than or equal to 1g), low in cholesterol (less than or equal to 20mg), low in sodium (less than or equal to 480mg for individual foods) and that it must contain at least 10 per cent of the recommended daily value of either protein, vitamin A, vitamin C, calcium, iron or dietary fiber.
Firms can apply to use one of two versions of the stamp: the original low saturated fat and cholesterol marker; or the newer stamp, introduced in October 2005, which includes a whole grains claim. In accordance with FDA guidelines, this requires that products must contain at least 51 percent whole grains by weight.
Companies currently using the mark on their products include industry leaders General Mills, ConAgra, Campbell, Kellogg and Quaker Oats.
Participation in the Food Certification Program, which claims to be revenue neutral, currently carries a charge of $4,500- $7,500 per product. However, as participation is renewed and volumes are increased, costs fall to around $3,500, said the AHA.
Whole grains have gained increasing popularity since the US government issued its 2005 Dietary Guidelines, which included the advice that Americans should consume upwards of three ounce-equivalents of whole grain products per day. At least half the grains consumed should be whole grains.
Whole-grain foods are a rich source of both insoluble and soluble dietary fiber. Soluble fiber has been shown to help lower LDL (bad) cholesterol levels, and so has been linked to a reduced risk of heart disease. Insoluble fiber also has been associated with decreased cardiovascular disease risk. And an increasing body of scientific evidence is emerging to confirm the link between whole grains and heart health.
In February the FDA issued draft guidelines setting out what it understands to be whole grains - that is, cereal grains consisting of the intact, ground, cracked or flaked fruit of the grains whose starchy endosperm, germ and bran are present in the same relative proportions as in the intact grain.
These definitions were intended to help manufacturers understand what the FDA considers appropriate for food labels making whole grain statements, and for consumers to have consistent guidance on what whole grain entails. However, while the guidance supports manufactures making quantitative statements about the amount of whole grains in their products - such as '100 percent whole grain' or '10 grams of whole grains' - this is often not sufficient guidance for consumers, who often do not understand quantitative statements.
"Identifying products that have a significant amount of whole grains can be confusing, even for dietitians," according to Penny Kris-Etherton, professor of nutrition at Pennsylvania State University.
As a result, markers such as the AHA's stamp have gained an increased presence in grocery stores over the past year.
And it is consumers driving the success of the heart-check mark, said the AHA, adding that many people have come to rely on it. According to a survey conducted last year, 90 percent of consumers said the heart-check mark is important to them as a tool to quickly and reliably pick heart-healthy foods.
According to the Sherry Nielsen, director of the AHA's Food Certification Program, the fiber content of a product is one of the most important criteria linking whole grains to heart health. Each product that applies to carry the association's heart-check mark is tested for its fiber content. Products are also re-examined each year on the renewal of participation, to ensure that formulations have not changed.
Another popular stamp that has come to be associated by many as an indication of a product's whole grain content is the Whole Grain Stamp, introduced by the Whole Grains Council (WGC) last year. The characteristic the black-and-gold stamps, which indicate the number of grams of whole grain ingredients in a serving, currently appear on nearly 800 products seen on shelves in the US.