INCREASING COMPLEX CARBOHYDRATE IN THE DIET - ARE THE BENEFITS DUE TOSTARCH, FIBER OR DECREASED FAT INTAKE

'Nutrition Recommendations' suggests that Canadians should consume 30% of the dietary energy as fat and 55% of energy as carbohydrate, from a variety of sources. While much emphasis has been placed on reducing fat intake, less work has been done on changing carbohydrate intake, w ith the result that little change in intake of this nutrient has been seen over the last twenty years. New evidence indicates that there may be direct advantages for health of increasing carbohydrate consumptio n, rather than just as a substitute energy source when fat is removed. Research since 1980 has indicated that not all starch consumed is dig ested and absorbed in the small intestine, but that 8-10% may reach th e colon, where it is fermented by the resident microflora. Fermentatio n of starch results in a higher proportion of the short chain fatty ac id butyrate than fermentation of dietary fibre; this may be of importa nce since butyrate is a preferred energy source for the colonic mucosa l cells, and has been shown to have anticancer properties in vitro. Be nefits for health of starch consumption are emerging with new research ; the public must be informed of these findings and encouraged to cons ume a high starch diet.