It is common knowledge that if you have high blood sugar or diabetes, you are at a high risk of suffering from heart disease, stroke, kidney disease, metabolic disorders and vision problems. High blood sugar levels are known to not just cause sudden and unexpected weight loss or gain but also affect the functioning of the entire body. High blood sugar has a deep impact on the brain, brain health, and may even lead to early cognitive decline.
Sugar and brain connection
Decades of research studies indicate that the functioning of the brain depends on blood sugar and any fluctuations in it — whether it’s high or low — can affect the brain. A study published in Trends in Neuroscience in 2013 points out that the human brain accounts for about 2 percent of the entire body weight but consumes around 20 percent of glucose-derived energy. This makes the human brain the body’s main consumer of glucose.
The metabolism of glucose by the brain provides this vital organ with the fuel it needs to maintain physiological function through the generation of the adenosine triphosphate (ATP), which is the main cellular currency for energy. This lays the foundation for all neuronal and non-neuronal cellular processes as well as the production of neurotransmitters, which are the brain’s chemical messengers that carry orders to the rest of the body. Tight regulation of glucose metabolism is, therefore, critical because any disturbance in its balance can not only affect the brain but also the entire body’s functioning through the nervous system.
How glucose imbalance affects the brain
An article in Harvard Medical School’s newsletter, On the Brain, explains the effects of this imbalance. A low level of glucose in the brain means that the brain isn’t producing enough neurotransmitters, which suggests that the communication between the brain and the body can break down. Hypoglycemia (very low levels of blood sugar) can lead to loss of energy for brain function and is also linked to a decline in attention and cognitive function.
Too much glucose can be an equally bad thing. An excess of glucose in the brain can cause brain atrophy or shrinking, as well as memory and cognitive deficiencies. This is the reason why diabetes, which is chronic and destroys the body’s ability to maintain glucose levels through insulin, can have a profound effect on the brain, its function and health. A 2015 study in Psychosomatic Medicine suggests that controlling their blood sugar levels by any viable means is crucial for diabetics to reduce the risk of neuropathic problems, early ageing and more exacerbated cognitive decline.
Enhancing blood sugar control in diabetics
A new study published in the Journal of Clinical Endocrinology and Metabolism further underlines the importance of controlling blood sugar levels in patients with diabetes to improve brain health. The researchers collected data from 1,089 diabetic participants aged 45-76 years from the Action for Health in Diabetes (Look AHEAD) study, which studies the effects of intensive lifestyle interventions (ILI).
One group of participants was guided to focus on blood glucose management via diet, physical activity and social support while the other group was recommended to change their diet and physical activity to lose at least 7 percent of their body weight in a year. Two to three cognitive tests were given to the participants between eight and 13 years since they adopted either of these two ILIs.
The researchers found that the group which focused on weight loss had mixed results in their cognitive scores, indicating that if you have diabetes, weight loss alone is not going to improve either brain health or overall health status. On the other hand, it was observed that participants who focused on better blood sugar control and made greater improvements in this regard had much better cognitive scores. The study, therefore, concluded that active intervention to lower blood sugar levels from diabetes range to prediabetes range can help diabetes patients offset brain damage and cognitive or neurological health issues in the long term.
