Dietary Fiber Further Epidemiological Support for a High-Intake Dietary Pattern

TLDR: The report by Pietinen et al3 of the Alpha-Tocopherol Beta-Carotene (ATBC) Study in this issue of Circulation provides new epidemiological evidence that should have an effect on dietary recommendations for prevention of coronary heart disease.

Abstract: Dietary fiber is prominent in recommendations for prevention of both coronary heart disease and cancer. The National Cancer Institute gives primary emphasis to dietary fiber in its recommended food choices. A range of intake of 20 to 30 g/d is suggested for US adults.1 The National Heart, Lung, and Blood Institute, through its National Cholesterol Education Program, emphasizes reduction in fat intake and compensatory energy replacement through the increased intake of other foods, including those with high fiber content. However, no quantitative target is provided for fiber intake.2 The report by Pietinen et al3 of the Alpha-Tocopherol Beta-Carotene (ATBC) Study in this issue of Circulation provides new epidemiological evidence that should have an effect on dietary recommendations for prevention of coronary heart disease. What is dietary fiber, and how has its role been investigated? Much of the research on dietary fiber through the 1980s is reviewed in Diet and Health: Implications for Reducing Chronic Disease Risk, the encyclopedic 1989 report of the National Research Council.4 Dietary fiber is plant material consisting of nonstarch polysaccharides and lignins (polymers of phenylpropane residues), which are resistant to digestion by enzymes secreted in the human alimentary tract. Components of dietary fiber may be characterized by their specific chemical structures, their properties of solubility or insolubility, and the foods in which they are found. Food composition data for fiber are difficult to compile because of the complexity of their chemical properties and variations in available analytic methods. Quantification of fiber intake in the usual diet has not, therefore, been possible until very recently, and it remains somewhat tentative due to these limitations. Nevertheless, there is agreement that the principal food sources for fiber in general are cereals, fruits, and vegetables, with several foods providing multiple types of fiber. How much fiber …