Nutritional Qualities of Bread
by Judy Campbell-Gordon, R.D.
Bread, as well as many other nutritious carbohydrate-rich foods, is recommended in Canada's Food Guide to Healthy Eating (Health Canada, 1992) and the Food Guide Pyramid (USDA, 1992) as part of a healthy diet. The main ingredient in bread is flour, which may be derived from a variety of possible grains, the seeds of plants, usually of the grass family. Most popular in Canada and in the US is wheat, however, other grains, such as rye and buckwheat, are also common.
During the milling of grains to produce flour, the refining process eliminates the most nutritious components in exchange for a white color and better keeping qualities. Refined wheat flour, such as white flour, may be enriched with certain vitamins and minerals to supply amounts approaching the content of the original grain. However, many nutrients, found in parts of the kernel that are eliminated during refining, are not replaced. Moreover, antioxidants such as phytochemicals that play a role in preventing the development of many diseases are also lost.
Whole grain flour includes the three parts of the grain kernels: the exterior part of the grain called the bran, the germ and the endosperm. White flour contains just the endosperm, which is the largest part of the grain. The endosperm is rich in carbohydrate and protein, but not nearly as rich in vitamins, minerals and fiber as the bran and germ are. Unfortunately, because the germ is rich in fat it may be removed in making whole wheat flour to prevent it from becoming rancid, so it can be stored for longer periods.
When purchasing bread, the label of a product containing only or mostly unrefined flour will read 'whole wheat flour' as its first ingredient. The first ingredient refers to the item present in the largest quantity.
A diet rich in whole grains, such as bread made from whole grain flour, can have protective qualities against the development chronic diseases including cancer, cardiovascular disease and diabetes.
The following lists the nutrients provided in one cup of whole wheat vs. white flour as compared to daily recommended intake (DRI) of these, in particular, those that are significantly lower in refined flour. Note that one cup of flour may yield 4 - 30 gram slices of bread.
|
Nutrients
or Food Components
|
Whole Wheat Flour
(1 cup)
|
DRI for Women 31-50
|
White, All-Purpose,
Enriched, Unbleached Flour (1 cup)
|
Important Roles of
Nutrients or Food Components
|
|
Fiber (g)
|
15
|
25
|
3
|
Promotes regularity,
reduces risk of heart disease, cancer, diabetes and digestive ailments.
|
|
Calcium(mg)
|
41
|
1000
|
20
|
Promotes bone
strength
|
|
Magnesium(mg)
|
165
|
320
|
28
|
Promotes bone health
|
|
Phosphorus(mg)
|
415
|
700
|
135
|
Promotes bone
strength
|
|
Potassium(mg)
|
486
|
2000-3500
|
134
|
Integral part of
every cell, involved in nerve and muscle function and blood pressure
regulation
|
|
Zinc(mg)
|
3.5
|
8
|
1
|
Many body functions
including reproduction, healing of skin, taste and growth
|
|
Manganese(mg)
|
4.6
|
1.8
|
0.9
|
Many body functions
including tissue development and brain function
|
|
Selenium(mcg)
|
84.8
|
55.0
|
42.4
|
Has antioxidant
properties
|
|
Vit B-6 or
Pyridoxine(mg)
|
0.4
|
1.3
|
0.06
|
Involved in many
biochemical changes including protein,
carbohydrate and fat metabolism
|
|
Vit B-5 or
Pantothenic Acid(mg)
|
1.2
|
5.0
|
0.5
|
Involved in many biochemical
processes including
protein, carbohydrate and fat metabolism, infection and stress
resistance.
|
References
The Wellness Encyclopedia of Food and Nutrition, University of California at Berkeley, 1992
Dietary Reference Intakes (DRI), Food and Nutrition Board - National Academy of Science, 1998
Food Processor Software, Esha
Introductory Nutrition, Helen A. Guthrie, 7th Ed. , 1989, Times Mirror/Mosby College National Academies Press (DRI) www.nap.edu
USDA Nutrient Database for Standard Reference: www.nal.usda.gov
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