Low Glycemic Diet for Autism?
Intriguing new research suggests that following a diet featuring low glycemic index (GI) foods may alleviate some of the symptoms of autism spectrum disorder (ASD). The research involved an animal model of the disorder that affects increasing numbers of children. ASD is characterized by problems with communication and socialization. The glycemic index is a system for determining how fast sugar calories from a given food are absorbed into the bloodstream after consumption.
In essence, the higher a food’s GI score, the faster it will cause blood sugar levels to rise. In general, the lower a food’s GI score, the better for one’s health. That’s because high GI foods, which are often rich in simple carbohydrates, such as table sugar, tend to cause sharp spikes in blood sugar levels, which trigger steep spikes in blood insulin levels, followed in turn by crashing blood sugar levels. Among other things, this tends to trigger hunger and cravings for still more simple carbohydrates.
High GI foods challenge the body’s ability to keep up with rising and falling blood sugar levels. In contrast, low GI foods tend to release their calories slowly, helping keep blood sugar levels steady. People with type 2 diabetes are often counseled to follow a low GI diet, to help control their blood sugar levels and minimize the need for supplemental insulin. Low GI foods tend to include complex carbohydrates, such as whole grains, and other high-fiber foods, which are digested slowly.
In the present study, mice bred to exhibit autism-like symptoms were fed either a high GI or low GI diet while pregnant. Their offspring were also raised according to the initial diet. The two distinctly different diets seemed to yield distinctly different brains. Mice raised on high GI foods showed more evidence of nerve cell inflammation, and fewer new nerves being formed. Some of the differences may have been related to the diets’ different effects on animals’ gut bacteria, researchers noted. “One thing that's driving a lot of general physiological changes in people is changes in the diet,” said the study's corresponding author, Pamela Maher, with the Salk Institute for Biological Studies.
A low-GI diet tends to be higher in fiber, which encourages the growth of certain strains of friendly bacteria in the digestive tract that may indirectly influence brain health. While there’s a big difference between mice in a laboratory and children in the real world, this research underscores the importance of good nutrition, and suggests possible negative consequences of poor diet that may transcend generations.
A Currais, C Farrokhi, R Dargusch, M Goujon-Svrzic, P Maher. Dietary glycemic index modulates the behavioral and biochemical abnormalities associated with autism spectrum disorder. Molecular Psychiatry, 2015; DOI: 10.1038/mp.2015.64