Whole grains are cereal grains that contain cereal germ, endosperm, and bran, in contrast to refined grains, which retain only the endosperm. Whole grains can generally be sprouted while refined grains generally will not sprout. Whole-meal products are made by grinding whole grains in order to make whole-grain flour. Whole grains are a natural source of protein as well as a source of carbohydrates and are made into many different kinds of foods.
Common whole grains include:
Common whole grain products include:
Common refined-grain products include:
Contents |
Whole-grain products can be identified by the ingredients list. Typically, if the ingredient lists "whole wheat," "whole meal," or "whole corn" as the first ingredient, the product is a whole-grain food item.
"Wheat flour" (as opposed to "whole-grain wheat flour" or "whole-wheat flour") as the first ingredient is not a clear indicator of the product's whole-grain content. If two ingredients are listed as grain products but only the second is listed as whole grain, the entire product may contain between 1% and 49% whole grain.[1] Many breads are colored brown (often with molasses or caramel color) and made to look like whole grain when they are not. In addition, some food manufacturers make foods with whole-grain ingredients, but, because whole-grain ingredients are not the dominant ingredient, they are not whole-grain products. Contrary to popular belief, fiber is not indicative of whole grains. The amount of fiber varies from grain to grain, and some products may have things like bran, peas, or other foods added to boost the fiber content.[2]
In Canada, it is legal to advertise any food product as "whole wheat" with up to 70% of the germ removed.[3] While the resulting product will contain the benefit of fiber in the nutritional information, it lacks the more recently discovered health benefits of antioxidants found in the wheat germ. Canadian consumers can be assured of whole-grain products by a label stating 100% whole-grain whole wheat.
Similar to the distinction between whole and refined grains is that between whole pulses (peas, beans, and other related vegetables) and refined dal (a preparation of pulses or the thick stew prepared from these).
From AACC (American Association of Cereal Chemists) definition: "Whole grains shall consist of the intact, ground, cracked or flaked caryopsis, whose principal anatomical components - the starchy endosperm, germ and bran - are present in the same relative proportions as they exist in the intact caryopsis."
The following names indicate whole-grain products, in accordance with the federal government:[4][5][6]
There are multiple grains such as cereal grains (e.g. wheat, rice, oats, barley, corn, wild rice, and rye) as well as pseudocereals (e.g. quinoa and buckwheat) that may be labeled whole grains.[7]
When wheat is milled to make flour, the parts of the grain are usually separated and then are recombined to make specific types of flour, such as whole wheat, whole grain, white cake and pastry flour, and all-purpose white flour. If all parts of the kernel are used in the same relative proportions as they exist in the original kernel, then the flour is considered whole grain.
Under the Food and Drug Regulations, up to 5% of the kernel can be removed to help reduce rancidity and prolong the shelf life of whole-wheat flour. The portion of the kernel that is removed for this purpose contains much of the germ and some of the bran. If this portion of the kernel has been removed, the flour would no longer be considered whole grain.
Any product made with flour can have the same effect on blood sugar, whether the flour is produced from whole grains or not. For example, wholegrain wheat bread and white bread can have the same glycemic index. Grinding grains into flour increases the surface area upon which enzymes work to more quickly convert starch into glucose. Keeping grains as close to their original form as possible slows or prevents the digestion of starch, and a slower digestion is responsible for preventing spikes in blood sugar (which over time may lead to insulin resistance).[8]
In a 2002 study, consumption of whole grains was found to be associated with lower fasting insulin concentrations when compared to those associated with the consumption of refined grains. This effect as well as improved insulin sensitivity was noticeably more pronounced among obese and hyperinsulinemic subjects, suggesting whole-grain consumption to be an important component of reducing risk factors for type II diabetes when only compared to the consumption of refined grains.[9] Consumption of whole grains has also been consistently linked with a significant decrease in risk factors for cardiovascular disease. Regular whole-grain consumption lowers LDL and triglyceride levels, which contributes to an overall 26% reduction in coronary heart disease-risk factors. In addition, whole-grain consumption is inversely related to hypertension, diabetes, and obesity when compared to refined grains, all of which are negative indicators in total cardiovascular health.[10]
|
|||||||||||||||||||||||||||||||||||
|
|||||||||||||||||||||||||||||||||||