According to recent statistics compiled by the Health and Social Care Information Centre, around 24% of men and 26% of women in the UK are classified as clinically obese and it is predicted that these figures are only set to rise. Among such serious health concerns, new research carried out by Dr. Jennifer Nasser, associate professor of Nutrition Sciences at Drexel University could mark an important turning point in worldwide health.
The underlying causes of obesity are often speculated in the media, whether this is easy access to cheap, unhealthy food; lack of understanding about nutrition; a failure in schools; or simply changes in lifestyles. However, two problems remain a constant: poor diet and not enough exercise. Whilst the exercise problem is difficult to tackle, it is hoped that a better understanding of the way we eat will provide helpful clues as to how to prevent obesity and improve our relationship with food.
Dr. Jennifer Nasser’s research is developed around our current understanding of how the organic chemical, dopamine, functions in the brain. It is linked to pleasure responses and acts as a neurotransmitter in the brain. Dopamine is also released in the eye’s retina when activated by the optic nerve in response to light.
It has, until now, been believed that dopamine brain function is entirely separate from dopamine eye function, suggesting that any visual triggers would not affect the brain’s dopamine production.
However, during the research, Nasser asked 9 participants to eat a small piece of food and the results are positive. It was found that a release of dopamine in the eyes was triggered when they ate the food, with the same level of response as when given a drug stimulant called methylphenidate. In fact, dopamine production was even triggered when some participants just saw or smelt the food which could provide helpful clues about food addiction.
The tests were carried out using an inexpensive tool which measures the brain’s response to food with a method called electroretinography (ERG) to observe the dopamine activity in the eye’s retina. The average cost of each session is around $150, compared to current dopamine testing which can cost around £2000.
Understanding how the eyes respond to the sensory qualities of food provides a good indication of how some people experience a strong pleasurable response to food. It may help us to better understand how the relationship between eyesight and dopamine production may play a role in triggering compulsive overeating and, in some cases, obesity.
Unlike ordinary feelings of hunger, dopamine stimulates a sense of needing instant gratification which affects our willpower and may encourage impulsive overeating. According to scientists at Wellcome Trust Center for Neuroimaging at University College London, the effects of dopamine on our appetite may have a significant effect on eating habits.
The results differed between the participants, with some showing a more dramatic response to food through just sight and smell. It is hoped that the results of this new scientific research could provide an important insight into how our eyes and brain respond to food. By better understanding the pleasure responses triggered by sight, smell, and taste of food, we will be able to better understand the causes and thus consider potential new treatments for food addiction.