Pleasure response from chocolate: You can see it in the eyes

June 24, 2013, Drexel University
Chocolate
Chocolate. Credit: Wikimedia Commons

The brain's pleasure response to tasting food can be measured through the eyes using a common, low-cost ophthalmological tool, according to a study just published in the journal Obesity. If validated, this method could be useful for research and clinical applications in food addiction and obesity prevention.

Dr. Jennifer Nasser, an associate professor in the department of in Drexel University's College of Nursing and Health Professions, led the study testing the use of electroretinography (ERG) to indicate increases in the in the retina.

Dopamine is associated with a variety of pleasure-related effects in the brain, including the expectation of reward. In the eye's retina, dopamine is released when the optical nerve activates in response to .

Nasser and her colleagues found that in the retina spiked high in response to a flash of light when a food stimulus (a small piece of chocolate brownie) was placed in participants' mouths. The increase was as great as that seen when participants had received the methylphenidate to induce a strong dopamine response. These responses in the presence of food and drug stimuli were each significantly greater than the response to light when participants ingested a control substance, water.

"What makes this so exciting is that the eye's was considered separate from the rest of the brain's dopamine system," Nasser said. "So most people– and indeed many retinography experts told me this– would say that tasting a food that stimulates the brain's dopamine system wouldn't have an effect on the eye's dopamine system."

This study was a small-scale demonstration of the concept, with only nine participants. Most participants were overweight but none had eating disorders. All fasted for four hours before testing with the food stimulus.

If this technique is validated through additional and larger studies, Nasser said she and other researchers can use ERG for studies of and food science.

"My research takes a pharmacology approach to the brain's response to food," Nasser said. "Food is both a nutrient delivery system and a pleasure delivery system, and a 'side effect' is excess calories. I want to maximize the pleasure and nutritional value of food but minimize the side effects. We need more user-friendly tools to do that."

The low cost and ease of performing electroretinography make it an appealing method, according to Nasser. The Medicare reimbursement cost for clinical use of ERG is about $150 per session, and each session generates 200 scans in just two minutes. Procedures to measure dopamine responses directly from the brain are more expensive and invasive. For example, PET scanning costs about $2,000 per session and takes more than an hour to generate a scan.

Explore further: Taste of beer, without effect from alcohol, triggers dopamine release in the brain

More information: dx.doi.org/10.1002/oby.20101

Related Stories

Taste of beer, without effect from alcohol, triggers dopamine release in the brain

April 15, 2013
The taste of beer, without any effect from alcohol itself, can trigger dopamine release in the brain, which is associated with drinking and other drugs of abuse, according to Indiana University School of Medicine researchers.

Long-term ADHD treatment increases brain dopamine transporter levels, may affect drug efficacy

May 15, 2013
Long-term treatment of attention deficit/hyperactivity disorder (ADHD) with certain stimulant medications may alter the density of the dopamine transporter, according to research published May 15 in the open access journal ...

Reward linked to image is enough to activate brain's visual cortex

March 21, 2013
Once rhesus monkeys learn to associate a picture with a reward, the reward by itself becomes enough to alter the activity in the monkeys' visual cortex. This finding was made by neurophysiologists Wim Vanduffel and John Arsenault ...

High sugar intake linked to low dopamine release in insulin-resistant patients

June 11, 2013
(Medical Xpress)—Using positron emission tomography (PET) imaging of the brain, researchers have identified a sweet spot that operates in a disorderly way when simple sugars are introduced to people with insulin resistance, ...

Feeding hormone ghrelin modulates ability of rewarding food to evoke dopamine release

July 12, 2011
New research findings to be presented at the upcoming annual meeting of the Society for the Study of Ingestive Behavior (SSIB), the foremost society for research into all aspects of eating and drinking behavior, finds that ...

Cocaine vaccine passes key testing hurdle

May 10, 2013
Researchers at Weill Cornell Medical College have successfully tested their novel anti-cocaine vaccine in primates, bringing them closer to launching human clinical trials. Their study, published online by the journal Neuropsychopharmacology, ...

Recommended for you

Evening hours may pose higher risk for overeating, especially when under stress, study finds

January 16, 2018
Experiments with a small group of overweight men and women have added to evidence that "hunger hormone" levels rise and "satiety (or fullness) hormone" levels decrease in the evening. The findings also suggest that stress ...

Bariatric surgery prolongs lifespan in obese

January 16, 2018
Obese, middle-age men and women who had bariatric surgery have half the death rate of those who had traditional medical treatment over a 10-year period, reports a study that answers questions about the long-term risk of the ...

Sugar-sweetened drinks linked to overweight and obesity in children, adults: Analysis of new studies

December 23, 2017
A new review of the latest evidence on sugar-sweetened beverages (SSBs)- which includes 30 new studies published between 2013 and 2015 (and none of them industry sponsored) - concludes that SSB consumption is associated with ...

As income rises, women get slimmer—but not men

December 21, 2017
(HealthDay)—A comprehensive survey on the widening American waistline finds that as paychecks get bigger, women's average weight tends to drop.

Policy and early intervention can curb obesity rates

December 18, 2017
More information and emphasis on dietary lifestyle changes that prevent obesity, and its comorbidities, have not reduced the rise in obesity in U.S. adults and adolescents, according to a recent study in the New England Journal ...

Warning labels can help reduce soda consumption and obesity, new study suggests

December 15, 2017
Labels that warn people about the risks of drinking soda and other sugar-sweetened beverages can lower obesity and overweight prevalence, suggests a new Johns Hopkins Bloomberg School of Public Health study.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.