Dear Dr. Mirkin: Does high fructose corn syrup (HFCS) cause
obesity?
Life-shortening obesity among adult Americans has
tripled from 1960 to the present (to 37 percent). HFCS was
incorrectly blamed because it became widely used in soft drinks
during the same time period. However, Dr. James Rippe of the
University of Central Florida points out that "There are no
measured differences between insulin, leptin, ghrelin, blood
sugar, uric acid, triglycerides, satiety, appetite or calories
consumed at subsequent meals when comparing HFCS to sucrose.
Both contain the same calories and sweetness."
Your body responds in the same way to fruit juices, soft
drinks sweetened with HFCS or sucrose, and any other sugared
beverage such as tea or coffee. Some people think that HFCS is
more harmful than other sugars because they mistakenly believe
that is loaded with fructose. Pure crystalline fructose raises
triglycerides and uric acid higher than glucose does, and it may
increase risk for insulin resistance, obesity, elevated LDL
cholesterol and triglycerides, and metabolic syndrome. However,
despite its name, HFCS is not significantly higher in fructose than
other sugars. Fruit sugar contains 50 percent fructose and
50 percent glucose, while HFCS contains 55 percent fructose and
45 percent glucose, no real difference.
We now understand why all sugared drinks can contribute
to obesity. When you eat sugar in a solid food, your brain
recognizes the calories and you may eat fewer calories from other
sources. However, when you eat the same amount of sugar in
liquid form, your brain fails to recognize these calories and
you are likely to eat more.
Dear Dr. Mirkin: Are artificial sweeteners a good alternative
for weight loss?
They may not be. At the Annual Meeting of the Endocrine
Society on June 11, 2009, researchers from the National Institute
of Aging reported that those who use artificial sweeteners are
twice as likely to develop metabolic syndrome and diabetes.
They are also more likely to be obese and take in more calories,
carbohydrates and fats; have higher fasting blood sugar and
fasting insulin levels;, and have more insulin resistance. This
is supported by two other studies (Circulation, January 2008; and
Obesity, June 2008). Artificial sweeteners affect sweet taste
receptors in the brain and intestines in the same way that sugar
does, causing release of incretin, which increases sugar absorption
from the intestines.