Glucose, Fructose Affect Cerebral Blood Flow Differently
(HealthDay News) – Ingestion of fructose is associated with a distinct pattern of regional cerebral blood flow compared with glucose, which has implications for appetite regulation, according to a study published in the Jan. 1 issue of the Journal of the American Medical Association.
To examine neurophysiological factors that may be involved in the correlation between fructose consumption and weight gain, Kathleen A. Page, MD, from the Yale University School of Medicine in New Haven, Conn., and colleagues conducted a blinded random-order crossover design study involving 20 healthy adult volunteers (10 men and 10 women) who underwent two magnetic resonance imaging sessions in conjunction with fructose or glucose drink ingestion.
The researchers found that, after glucose ingestion, there was a significantly greater reduction in hypothalamic cerebral blood flow, compared with fructose ingestion. Compared with baseline, ingestion of glucose correlated with increased functional connectivity between the hypothalamus and the thalamus and striatum, while fructose ingestion increased functional connectivity between the hypothalamus and thalamus only. Compared with baseline, glucose ingestion correlated with reduced regional cerebral blood flow in appetite and reward regions within the hypothalamus, thalamus, insula, anterior cingulate, and striatum, while fructose correlated with reductions in the thalamus, hippocampus, posterior cingulate cortex, fusiform, and visual cortex. Compared with glucose, fructose ingestion correlated with lower peak levels of serum glucose, insulin, and glucagon-like polypeptide 1.
"In this study, ingestion of glucose but not fructose reduced cerebral blood flow and thus activity in specific brain regions that regulate appetite and reward processing," the authors write. "In keeping with these data, ingestion of glucose but not fructose produced increased ratings of satiety and fullness."