People are hearing a lot of this message lately from ads on TV and elsewhere. On the face
of it, granulated sugar (sucrose) and high fructose corn syrup
(HFCS) contain
similar amounts of fructose and glucose. But the devil is in the details. Let's examine the question from the point of view of a FODMAPS-elimination diet for irritable bowel syndrome.
First of all, I think we can agree that fructose is absorbed best in the
presence of an equal amount of glucose, in other words when the sugars
present in the food or beverage are 50% fructose and 50% glucose. For more on this, see my previous post on
fructose:glucose ratio. During
a FODMAPS elimination diet, it is foods with
excess fructose
that need to be avoided. Workers in the field define free fructose in
"excess" of glucose as greater than .5 grams/100 grams of the food. So a
food with 50.5% fructose and 49.5% glucose has enough fructose to be
considered a potential problem.
Granulated sugar (sucrose) is always 50% fructose and 50% glucose.
According to the Corn Refiners Association (
www.hfcsfacts.com), HFCS is
sold to the food manufacturing industry principally in two formulations: 42% fructose and 55% fructose (we will leave 90% fructose formulations out of it for now). So yeah, HFCS is in the same
ballbark
in terms of fructose content--close, but no cigar. In fact, the 42%
fructose version of HFCS, does
not have excess free fructose and would
be permitted during the elimination phase of the FODMAPS elimination
diet. The 55% clearly
does meet the definition of excess free fructose and is
capable of causing symptoms for some individuals.
Since ingredient listings on food labels don't identify which form of
HFCS is in a given food or beverage, my advice is to avoid it all during
the elimination phase of the diet. Feel free to include any and all
HFCS during the fructose challenge phase of your diet.
By the way, "regular" corn syrup is almost 100% glucose (dextrose), so it is allowed on a FODMAPS elimination diet.