Can we digest the cellulose of plant cell walls ?
The correct answer is found in the book ” Sense and Nonsense in Nutrition ” ( 1986 ) by : Jack YETIV , physician and scientist , author of several medical articles
” Cellulose contains some bonds that cannot be broken by human intestinal enzymes , whereas all the bonds in starch and glycogen can be broken ( digested ) by human enzymes “
He continues elsewhere :
” Dietary fibers are defined as plant cell wall materials which are indigestible by human gastrointestinal machinery. Ruminants , like the cow , are able to digest these materials , and as a result of this , to the cow , a piece of cellulose is as fattening as a piece of cake would be to us !
The difference is that we can’t digest cellulose to get the glucose out of it , while cows can . Although human enzymes cannot digest dietary fiber , some of the bacteria in the human gastrointestinal tract produce enzymes which can digest fiber and release gases and volatile fatty acids . The fatty acids can be absorbed and actually used by the human host for energy-requiring processes ( i.e. they constitute calories )
However , not all types of fiber , can be metabolized by bacteria in this fashion , and in reality , the number of calories that can be obtained from fiber in this way is very small , maybe 20 to 30 calories per day “
All this “nutritional scientific stuff” confirms me that blending your vegs is a very good and time-saving eating habit, … and trying to thrive on non-blended vegs will in the long term , lead to nutritional deficiencies and underweight
Wrote this on the Iheartfruit Forum on August 25 , 2011
Edit November 5 , 2013
Just found this very interesting site , and here is an explanation on cellulose :
Cellulose is found in large amounts in nearly all plants, and is potentially a major food source. Unfortunately, human beings lack the enzymes necessary to cleave the linkages between the sugars in cellulose. In fact, crystallite cellulose is added to some foods to reduce the caloric value.