Facts about fructose in food you're not supposed to know...
Fructose in food - also known as high
fructose corn syrup - could be a strong risk factor for a heart
attack among middle-aged and elderly men.
Fructose in food
High fructose corn syrup is added to foods to make them taste
sweeter. Because of its "natural" connotations, fructose in food
is often perceived as a healthy alternative to other sweeteners.
You'll find it in soft drinks, ice cream and frozen desserts, especially
in the low-fat versions.
According to Dr. John Yudkin, former chairman of
the department of nutrition at Queen Elizabeth College in London,
high fructose consumption may be a risk factor for heart disease.
Yudkin first warned of the dangers of fructose in the late 1960's.
Like many others, Yudkin wasn't convinced by the studies
linking animal fat with heart disease, and began searching
for another explanation. At first, he chose to focus on sucrose.
His tests showed that sucrose increased blood levels of cholesterol,
insulin, and triglycerides. All are linked with heart disease.
However, when Yudkin broke sucrose down into its constituent parts
(fructose and glucose), fructose appeared to cause the majority
of the problems.
In 1986, the United States Food and Drug Administration reported
that there was "no conclusive evidence" suggesting that sugars
(such as fructose in food) have a negative effect on your health.
However, a Minnesota research team has shown that just six weeks
on a high fructose diet raises plasma triglycerides in men by
more than one-third [1].
Plasma triglycerides are a type of fat in your blood. There is
a growing body of evidence linking plasma triglycerides to the "clogging"
of your arteries, which may increase the risk of a heart attack
or stroke. In fact, some researchers now think that plasma triglycerides
levels may actually be more important than cholesterol levels in
establishing your heart disease risk.
During the first six weeks of the study, subjects were given a
diet deriving 17% of its total calories from fructose. In the second
stage of the study, the fructose was replaced with glucose. The
rest of the diet remained the same.
• The women showed no significant difference in plasma triglycerides
in response to the changes in diet.
• In contrast, after just 7 days on the high-fructose diet,
the men had significantly higher plasma triglycerides values than
during the glucose diet.
Granted, this study did use large amounts of fructose - twice as
much fructose as found in the typical American diet. However, based
on current estimates, there are approximately 27,000,000 Americans
consuming at least this much fructose on a daily basis.
Although previous research has shown that fructose has no negative
effect on plasma triglycerides, many of these studies compared fructose
with sucrose (table sugar). However, when sucrose is digested, it
is broken down into both glucose and fructose - so the comparison
isn't really valid.
In contrast, when a diet high in fructose is compared with a diet
that contains virtually no fructose, there is a consistent body
of evidence showing that fructose has a negative effect on plasma
triglycerides.
It's also worth pointing out that some groups of people are more
susceptible to the negative effects of fructose. The Minnesota
study, for example, shows that fructose had no significant effect
on triglyceride levels in women. People with high
insulin and triglyceride levels to begin with (such as extremely
overweight individuals) appear more sensitive to the negative
effects of fructose [2].
References
1. Bantle, J.P., Raatz, S.K., Thomas, W., & Georgopoulos,
A. (2000). Effects of dietary fructose on plasma lipids in healthy
subjects. American
Journal of Clinical Nutrition, 72, 1128-1134
2. Henry, R.R., Crapo, P.A., & Thorburn, A.W. (1991). Current issues in fructose
metabolism. Annual
Review of Nutrition, 11 , 21-39
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