1 January 2013

MRI scans reveal fructose's effects on brain's appetite regulators

by Will Parker

Scans of the human brain after ingesting fructose have provided insights into how the substance affects brain chemistry and increases food-seeking behavior and food intake. The new work, published in JAMA, appears to confirm the much discussed association between fructose intake and bulging waistlines.

Conducted by Kathleen A. Page of Yale University, the study set out to explore possible linkages between fructose consumption and weight gain. The study included 20 healthy adult volunteers who underwent two magnetic resonance imaging sessions in conjunction with either fructose or glucose drink ingestion. The primary outcome measure for the study was the relative changes in hypothalamic regional cerebral blood flow after ingestion.

The scans indicated that ingestion of glucose, but not fructose, reduced cerebral blood flow and activity in the brain regions that regulate appetite; and ingestion of glucose but not fructose produced increased ratings of satiety and fullness.

Specifically, the researchers found that there was a significantly greater reduction in hypothalamic cerebral blood flow after glucose versus fructose ingestion. "Glucose but not fructose ingestion reduced the activation of the hypothalamus, insula, and striatum - brain regions that regulate appetite, motivation, and reward processing; glucose ingestion also increased functional connections between the hypothalamic-striatal network and increased satiety," explained Page.

The findings lend support to the notion that when the human brain is exposed to fructose, neurobiological pathways involved in appetite regulation are modulated, thereby promoting increased food seeking and food intake.

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Source: JAMA