Sugary beverages and snacks may be a go-to for college students or busy parents looking for a pick-me-up, but studies have shown that consuming too much sugar can have lasting effects on your brain. Some doctors and scientists have found that sugar can affect memory, mood and energy. Others have performed studies suggesting relationships between sugar, brain atrophy and addiction. However, the relationship between sugar and addiction has been disputed by some.
Memory and Learning
High-fructose corn syrup is one source of sugar in the American diet. Dr. Fernando Gomez-Pinilla, a neurosurgery professor at UCLA, studied the role of high-fructose corn syrup on memory and learning processes in the brain. In his 2012 study published in the "Journal of Physiology," he reported that rats that consumed a high-fructose corn syrup diet experienced memory impairment and cognitive issues. However, a review of studies on this topic, published in the "American Journal of Clinical Nutrition" -- which included studies on humans and on rats -- concluded that specific doses of glucose may positively affect memory in humans, especially in the elderly. However, the study did not include any research investigating the long-term effects of high sugar intake on the human brain.
Mood and Energy
A study published in "The Journal of Personality and Social Psychology" investigated the effects of sugar and moderate exercise on energy, tiredness and tension in women. In this study, the women were asked to self-rate their energy, tiredness and tension at a specific time each day. The study found that women who consumed a sugary snack reported that they felt greater tension one hour after eating the snack. The women also reported that they experienced an increase in energy that quickly dropped off after one hour and gave way to tiredness and reduced energy.
Atrophy and Dementia
Dr. Daniel G. Amen, author and medical director of Amen Clinics Inc. in California, examined several studies that suggested high sugar diets may lead to brain atrophy and dementia. One study, published in "Neurology" in 2012, examined the association between glucose levels and brain atrophy in health adults from 60 to 64 years old. The study found that high glucose levels were associated with atrophied hippocampuses and amygdalas. These areas of the brain deal mostly with memory and mental skills. But the "high" glucose levels were less than 6.1 millimoles per liter, which is within the normal range.
A study published in the journal "PLOS ONE" involved the addictive effects of sugar on rat brains. The study suggests that sugar may be more addictive than cocaine. The rats in the study were given a choice of sugar or cocaine.. Surprisingly, 94 percent of the rats chose sugar. Even more interesting, the rats continued to choose sugar even over higher doses of cocaine -- this includes the rats that displayed signs of cocaine addiction. The results of the study suggest that the pleasure that the brain experiences in response to sugar may override self-control and result in sugar addiction. However, a study published in "Clinical Nutrition" in 2010 rebuts this idea, suggesting that the rats selected sugar over cocaine simply because it tasted better. The scientists behind the 2010 study were unable to find any human data to support the idea that addiction to sugar is possible.