A new study carried out by Boston University School of Medicine has found out that sugary drinks are linked to pre-clinical Alzheimer’s disease: Poor memory and reduced brain volume in certain areas. This study followed more than 4,200 people, periodically testing them for memory and cognition, and scanning their brains with MRI to measure volume. The participants also filled out questionnaires about their food intake, including sugary drink consumption (including both soda and fruit juices).
The results of this study showed that people who consumed more sweetened drinks had poorer memory and reduced overall brain volume (particularly in the hippocampus, the area that's known to “house” short-term memory), compared to people who didn’t drink sugary drinks. In addition, the authors calculated that one to two sugary drinks per day was associated with 1.6 years of brain aging; more than two drinks per day was associated with two extra years of aging.
“Brain functions such as thinking, memory, and learning are closely linked to glucose levels and how efficiently the brain uses this fuel source. If there isn’t enough glucose in the brain, neurotransmitters, the brain’s chemical messengers, are not produced and communication between neurons breaks down. However, although the brain needs glucose, too much of this energy source can be a bad thing. “- Harvard Medical School, Department of Neurobiology
A 2012 study by researchers of the Department of Neurosurgery at the University of California indicated a positive relationship between the consumption of fructose and the aging of cells. This study was also the first to show how a diet steadily high in fructose slows the brain, hampering memory and learning. Almost the same result was concluded in 2015, when the American Academy of Neurology found that hyperglycemia is associated with subtle brain injury and impaired attention and memory even in young adults.
The bottom line of all this studies is that sugar is just as bad for the brain as it is for other organs, maybe worse, considering that the brain is charged with a lot of critical processes, such as enable cognitive processes like remembering, thinking etc., coordination of bodily activities, internal restoration or involuntary internal processes as basic as the heart beat, between many others.
*Sugary beverage intake and preclinical Alzheimer's disease in the community