In the modern world, much of our diet may contain high levels of sugar (hidden or otherwise), which can have long and short-term health implications. From obesity and diabetes1 to poor dental health2, the potential risks of excessive sugar consumption are wide-ranging, but what effect does sugar have on our brains?
Sugar and the brain
The brain communicates information using chemicals called neurotransmitters that deliver messages across the synapses of our neurons. When sugar is ingested, it activates the sweet taste receptors in the mouth and releases dopamine, a neurotransmitter3. Dopamine is part of the reward system in our brains, meaning that an influx of dopamine can create a positive feeling, and a deficit the opposite4.
Sugar causes dopamine levels to rise, creating a positive, happy feeling when it is ingested5. Your brain can adapt itself to the frequent stimulation of your reward pathways, and as a result, you develop a tolerance and need more to achieve the same rewarding feeling6. There has been some debate as to the similarities between this response and addiction, however, there is no definitive opinion yet. Some evidence has shown that regular sugar consumption can lead to craving sugar7 and the pleasurable feeling it brings.
Sugar and mental health
When the dopamine stimulation wears off, it may cause you to feel irritable and grumpy [2] , and not perform as well at cognitively demanding tasks 8. Sugar consumption has been linked to higher rates of major depressive disorder (often referred to as depression) in men and is also associated with adverse effects on mental health for all genders9.
What is depression?
Depression is a mental health condition characterised by low mood, feelings of unhappiness and hopelessness, and a loss of interest in the things once enjoyed. It can also manifest through physical symptoms such as constant fatigue, loss of appetite and sex drive, poor sleep, and various aches and pains10.
Sugar can exacerbate any symptoms you might experience from depression. For example, if you are living with depression and experiencing low mood, you may turn to high-sugar food for the dopamine rush it brings. However, this effect is short-lived, and the inevitable crash may lead to intense cravings and the desire to consume increasing amounts of sugar. This can perpetuate a punishing cycle that is hard to break free from, as well as heighten the risk of other conditions such as diabetes or obesity.
If you or a loved one is living with depression, you could help researchers investigate potential new treatments. We are running clinical trials at our clinics across England, and, if eligible, you could receive up to £2,630 or £3,263 for your time and commitment to the study. Eligible participants will also receive travel expenses and a full health check-up.
To find out more and register your interest in taking part in depression research, visit MAC’s current trials webpage.
References
1Harvard Health – The sweet danger of sugar
2WHO – Sugars and dental caries
3PubMed – Orosensory self-stimulation by sucrose involves brain dopaminergic mechanisms
4PubMed – The reward circuit: linking primate anatomy and human imaging
5BBC Food – How to eat yourself happy
6Harvard Health – rain plasticity in drug addiction: Burden and benefit
8PubMed – Carbohydrate ingestion, blood glucose and mood
