A new study published in the scientific journal Cell Metabolism uncovers some of the mysteries behind our food cravings
The research was done by the Monell Chemical Senses Center . This research center is the world’s only independent, non-profit scientific institute dedicated to research on the senses of taste and smell, and how they affect our health and well being. Two important questions that the Monell center poses are
1. What are the cellular underpinnings of taste and smell that contribute to the difference between lifelong health and chronic disease?
2.How do our chemical senses shape human nutrition?
Our modern world is plagued by an excess of unhealthy eating, and the negative effects that are seen both individually and throughout society. Unhealthy eating’s destructive health consequences are seen in the epidemic of chronic diseases which are related to lifestyle choices.
They are finding out how physical reactions to different food choices affects our brains’ centers of desire through nervous system connections that transmit information from the gut to our brain. It is known that the vagus nerve sends internal sensory information from the gut to the brain about the the food we eat. But, exactly how the brains’ reward centers are communicated with has never been completely understood.
The new study published in Cell Metabolism by the research team at the Monell Chemical Senses Center, shows that this internal nervous system, the communication pathway from the gut to the brain has two important separate pathways, one related to fat intake and another for sugar intake. And they have found that when both of these pathways are stimulated it triggers our desire to eat more.
Guillaume de Lartigue, PhD, is the lead author of the study. He explains, “Food is nature’s ultimate reinforcer. But why fats and sugars are particularly appealing has been a puzzle. We’ve now identified nerve cells in the gut rather than taste cells in the mouth are a key driver. We found that distinct gut-brain pathways are recruited by fats and sugars, explaining why that donut can be so irresistible.”
For this research fat and sugar related neuron pathways were manipulated in mice and demonstrated that a release of the brain chemical dopamine was produced by stimulating either and both systems. The dopamine release relates to a reward system in the brain representing satiation when the stimulus is provoked. It appears that when both fat and sugar related stimuli are both triggered there is a multiplying effect. And this would seem to relate to the cravings that people feel,wanting to experience the subjectively positive feelings they get when eating these kinds of foods- both sugar and fat containing. This promotes excess intake of the kinds of food that eating chronically are associated with poor health outcomes. Weight gain as a result of excess sugar and fat in the diet is related to many health problems such as diabetes, high blood pressure and cardiovascular disease, as well cancer. All of these together represent the commonest causes of lifestyle related death in our society and increasingly, throughout the world.
Ultimately this research by the Monell Center suggests that there is a subconscious internal desire to consume a diet high in both fats and sugar. And this is a major impediment to dieting for weight loss and generally to eating a more healthful diet.
Dr Lartigue explains that the synergistic effect of both fat and sugar promoting cravings is quite powerful. “It’s like a one-two punch to the brain’s reward system….Combining fats and sugars leads to significantly more dopamine release and, ultimately, overeating….The communication between our gut and brain happens below the level of consciousness. We may be craving these types of food without even realizing it. Understanding the wiring diagram of our innate motivation to consume fats and sugars is the first step towards rewiring it. This research unlocks exciting possibilities for personalized interventions that could help people make healthier choices, even when faced with tempting treats.”
The Monell Centers is hoping that this research will further our understanding of people’s eating desires to develop anti-obesity strategies and treatments.
Appearing as a mission statement the Monell Center publishes on their website the following:
Our senses shape our lives in ways we are only beginning to understand. Monell’s cutting-edge research focuses on taste, smell, and related senses to provide a framework for advances across many areas of human health and well-being.
They work with psychologists, biophysicists, chemists, behavioral neuroscientists, environmental scientists and geneticists.
The Monell Center Outlines These Strategic Research Aims
The Study of Sensory Nutrition
Monell is exploring how taste, smell, and flavor affects the choice of what we eat, and the consequences for our health.They also study taste and smell across the lifespan. They are involved in current research to understand the role of sweet-taste receptors and bitter-sensing cells.
Diagnosing and Treating Diseases: Advance new technologies related to the immune responses that result from the stimuli sensed by foods as well as other environmental factors such as viruses like Covi-19
Address Loss of Smell and Taste: Restore or prevent loss of human smell and taste throughout life through regenerative medicine and behavioral approaches.
The CDC has identified sudden loss of taste and smell as one of the six primary symptoms of COVID-19. Monell researchers are trying to further understand this phenomenon in the hopes of finding practical solutions.
The Monell Center’s research seeks to refine how an olfactory deficit can be tested and quantified. They are engaged in the Sense of Smell and COVID-19 study
They also have published the Monell review of over 100 smell studies
There are other reasons for loss of taste and smell such as in cancer conditions and the side effects of treatments.These problems pose challenges that need to be addressed. Loss of appetite is a related health problem with potentially severe health consequences, as nutritional deficiencies furthering the disease process are a result of inadequate intake.
Monell is driving the use of new technologies as in
Their work includes their attempt to identify the molecular structure of the nearly 400 smell receptors in the human nose, and map the genetic factors related to how we smell.