seems to be caused by the lack of special cells (epithe-
lial cells) on the surface of the intestine that are not
available to help digestion. As a result, the body is not
able to absorb fructose efficiently.
Although having different causes, both HFI and DFI
are treated by dietary adjustments. Complete elimination
of fructose and sucrose from the diet is the only effective
treatment for HFI. As for DFI, treatment also involves a
fructose-free diet, with the treating physician allowing
some concessions in mild cases. Some patients may find
a threshold level where they can eat some fructose without
getting symptoms. Close dietary monitoring is important
for good outcome and should include at least semiannual
visits to a biochemical geneticist (for HFI) and monthly
meetings with a nutritionist.DescriptionA strict fructose-free diet involves exclusion of
any beverage or food containing fructose, sucrose, or
sorbitol. Fructose is a monosaccharide, or simple
sugar, that has the same chemical formula as glucose,
the main source of energy for the body, but a different
molecular structure. It is found in all fruits, in some
vegetables and in honey. Fructose and other sugars are
carbohydrates, which are important sources of energy
for the body. The main types of sugars found in bev-
erages and foods are:Lactose: Disaccharide containing glucose and galac-
tose. It occurs naturally in milk.
Maltose: Disaccharide containing two glucoses. It is
obtained from starch.
Dextrose: Other name for glucose, it is obtained from
sugar cane, sugar beets and starches.
Corn syrup: Sugar that consists chiefly of single glu-
cose molecules. It is produced from corn starch.
High fructose corn syrup (HFCS): A mixture of
glucose and fructose sugars, also produced from
corn starch.
The HFI Laboratory at Boston University has
prepared a list of sugars and their tolerance for
patients. Some of the most common food sweeteners
listed include:
Agave syrup: Commonly used in Texan-Mexican
foods, tequila, margaritas, soft drinks. High in fruc-
tose and not tolerated.
Aspartame: FDA-approved sugar substitute sold as
Equal, NutraSweet, NutraTase. Tolerated.
Baker’s sugar: Another name for sucrose, the finest
of all granulated sugars. Not tolerated.
Barley malt syrup: Obtained from sprouted grains of
barley, kiln dried and cooked with water. Tolerated.
Beet sugar: Sucrose. Not tolerated.
Birch sugar: A sugar alcohol, xylitol. Trade name:
The Ultimate Sweetener. Tolerated if pure.
Brown rice syrup: Obtained from brown rice. Possi-
bly contains sucrose. Not tolerated.
Brown sugar: Sucrose coated with molasses. Not
tolerated.
Cane sugar: Sucrose, table sugar. Not tolerated.
Carob powder:Obtainedfrom the carob tree, itis75%
sucrose, plus glucose and fructose. Not tolerated.
Corn starch: Derived from corn, consists of straight
or branched chains of glucose. Tolerated.
Corn sugar: Obtained from corn starch, contains
glucose and maltose. Tolerated.
Corn syrup: Also obtained from corn starch, but in
making the syrup, it usually has either maltose or
fructose or both added. Not tolerated.
Date sugar: Made from dried, pulverized dates and
likely to contain sucrose. Not tolerated.
Dextrin: Glucose molecules linked together in chains
that do not break down to pure glucose. Tolerated.
Dulcitol: Naturally occurring sugar alcohol. Not
tolerated.
Erythitol: Sugar alcohol. Tolerated if pure.Sugars and sweetenersTolerated Not tolerated
Aspartame Agave syrup
Barley malt syrup Baker's sugar
Birch sugar (if pure) Beet sugar
Corn starch Brown rice syrup
Corn sugar Brown sugar
Dextrin Cane sugar
Erythitol (if pure) Carob powder
Glucose Corn syrup
Glucose polymers Date sugar
Neotame Dulcitol
Saccharin Fruit juice sweeteners
Grape syrup
Gur
Honey
Maple syrup
Molasses
Polydextrose
Sorbitol
Stevia
Turbinado
WasanbonThis list of sugars and sweeteners for fruitose intolerant
individuals was prepared by the HFI Laboratory at Boston
University.(Illustration by GGS Information Services/Thomson
Gale.)Fructose intolerance