Certain Sugars Stimulate Appetite, Study Finds

By Samantha Bonar Thu., Jan. 3 2013 at 6:00 AM

Flickr/DOH4

Corn syrup and sucrose are the first two ingredients in gummy bears

Different kinds of sugar affect the brain differently, specifically the feeling of satiety, according to a new Yale University study.

According to the researchers, "increases in fructose consumption have paralleled the increasing prevalence of obesity, and high-fructose diets are thought to promote weight gain and insulin resistance."

Consumption of fructose, which includes refined table sugar (technically sucrose, a combination of fructose and glucose) and high-fructose corn syrup, led to smaller increases in circulating satiety hormones compared to glucose ingestion, the researchers found. Glucose is found in fruits and vegetables and in starchy foods like bread, pasta and rice. In fact, the study found that administration of fructose actually provokes feeding in rodents, while glucose administration promotes satiety.

The experiment involved 20 healthy adult volunteers who drank either a cherry-flavored fructose or glucose drink in a blind, random study, MedPage Today reports. The subjects were then given brain MRIs. Those who had consumed the glucose drink had significant reductions in cerebral blood flow to the hypothalamus, a region of the brain associated with appetite and reward. Those who drank the fructose concoction, on the other hand, saw a slight increase in activity in this area. Robert Sherwin, MD, of Yale University, and his colleagues reported the results in the January 2 issue of the Journal of the American Medical Assn.

Glucose also reduced activation in the insula and striatum, other brain regions that regulate appetite, motivation, and reward processing, while fructose did not, the researchers wrote.

Participants rated their feelings of hunger and satiety before and after the scan, and the researchers took blood to assess circulating hormone levels. The differences in brain effects between glucose and fructose also appeared to coordinate with ratings of hunger, since there was a significant difference from baseline in terms of fullness and satiety when participants drank glucose, but not fructose.

And the blood tests showed that fructose only weakly stimulates secretion of insulin, a hormone that can increase satiety, and attenuates levels of the satiety hormone glucagon-like peptide-1 (GLP-1) -- which means it could possibly increase food-seeking behavior and intake.

In an accompanying editorial, Jonathan Purnell, MD, and Damien Fair, PhD, of Oregon Health & Science University, said the findings "support the conceptual framework that when the human brain is exposed to fructose, neurobiological pathways involved in appetite regulation are modulated, thereby promoting increased food intake."

Purnell and Fair noted that while some researchers and clinicians warn that the total amount of calories is more important than the type of food when it comes to losing weight, the "reality ... is that hunger and fullness are major determinants of how much humans eat, just as thirst determines how much humans drink. These sensations cannot simply be willed away or ignored."

The upshot: High-fructose corn syrup is bad, mmmkay? But you already knew that.

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Carol2013

@frankcomment - You've got everything backwards! All the lies, fraud and corruption come from the health fascists. They deliberately use defective studies to falsely blame tobacco for diseases that are really caused by infection, which exploit the fact that poorer people including smokers are more likely to have been exposed to those infections. Every Surgeon General report is the proof of this.

http://www.smokershistory.com/SGlies.html

http://www.smokershistory.com/SGHDlies.html

And, all their so-called "independent" reports were ring-led by the same guy, Jonathan M. Samet, including the Surgeon General Reports, the EPA report, the IARC report, and the ASHRAE report, and he's now the chairman of the FDA Committee on Tobacco. He and his politically privileged clique exclude all the REAL scientists from their echo chamber. That's how they make their reports "unanimous!"

For the government to commit fraud to deprive us of our liberties is automatically a violation of our Constitutional rights to the equal protection of the laws, just as much as if it purposely threw innocent people in prison. And for the government to spread lies about phony smoking dangers is terrorism, no different from calling in phony bomb threats.

Carol2013

This is fraudulent science. 75 grams of fructose is three times as much as people could reasonably be expected to absorb. "It appears we can absorb, at any one time, up to 25 grams of fructose. Now what is 25 grams? A glass of orange juice has up to 14 grams of fructose, a can of Coke sometimes has 15 to 16 grams of fructose (Satish Rao at University of Iowa).

http://www.uihealthcare.com/kxic/2008/06/fructose.html

Ability of the normal human small intestine to absorb fructose: evaluation by breath testing. Rao SS, Attaluri A, Anderson L, Stumbo P. Clin Gastroenterol Hepatol. 2007 Aug;5(8):959-63.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1994910/

So, because the fructose wasn't even absorbed, not only did it therefore fail to "promote satiety," it probably also gave them gas and physical discomfort. And this is how the food fascists "educate" people that "High-fructose corn syrup is bad."

david1736

You missed the part of the study where they actually surveyed the people on satiety, fullness and hunger - here is the quote from the study (have removed the numbers to make it easier to read, emphasis mine) - "There was NO significant difference between glucose vs fructose ingestion on predrink-postdrink changes in hunger, fullness or satiety".

Considering that HFCS and sucrose actually contain (almost) equal amounts of glucose and fructose - it is a little hard to extrapolate this study, even if there was differences in the actual physical outcomes. Also consider the serving sizes used, 75g of glucose would require drinking 150g of sucrose or slightly less HFCS (we also don't know if there would be any effect in solid vs liquid food)

A little early to take anything from a study that really only showed changes in blood flow but NOT in actual measures of hunger, fullness and satiety!

frankcomment

A few years ago the World Health Organization said that the US had an obesity problem that began around 1983. My own observation is that soft-drink manufacturers in the US started using High Fructose Corn Syrup in 1980 and corn-poison has been replacing natural sugar ever since.

The same band of lobbyists can be traced going from state to state in the 1930s and lobbying to have "exposure" issues be "based on the preponderance of evidence". Now all the offending industry has to do is produce the preponderance of evidence in order to keep their poisons available - - such as the cigarette industry . . . . they pay for studies that show that their product is harmless.

If the NIH, FDA, etc. would publish the funding source for research that they publish, we would all gain by being able to weigh the possibility of bias into the research.