If you indulge in a fatty meal, you’ll probably be doing your best not to think about all the calories you’re ingesting: but it’s probable that your brain knows anyway. That’s according to new research published recently in Cell.
Researchers based at the Yale University School of Medicine have studied, in rats, the types of molecules produced in the gut and other places after eating. Among the principle discoveries is that a certain type of lipid, normally produced in the gut, rises in concentration after the ingestion of a fatty meal.
The role of the lipid in fat intake control was determined after the researchers screened the blood for lipids which increase in concentration after test rats ate a high-fat meal. Among those metabolites which increase in concentration is a type of phospholipid for which there was no previously known physiological function.
Almost as soon as they are produced these lipids, called N-acylphosphatidylethanolamines (NAPEs for short), enter the bloodstream and travel to the brain, where they begin to congregate in the hypothalamus, a region of the brain which is involved in the control of food intake and energy expenditure.
This discovery means good news for the fight against obesity: NAPE is effective even when administered intravenously over several days.
This is in direct contrast to the effects of most other gut hormones, which tend to lose their effectiveness when administered in a chronic fashion. Another similar type of molecule, called CCK, is a peptide which can cause both animals and people to eat smaller meals – but since the test subjects invariably end up eating more often, there is generally no change in total caloric intake.
NAPE doesn’t seem to cause any of these types of problems, meaning that treatments which are designed to increase levels of NAPE might therefore be useful in treating obesity.
When feed with NAPE over a period of five days, test rats continued to reduce their food intake voluntarily, and their body weight declined accordingly. NAPE or NAPE analogs may work the same way in humans, but more research is needed in test animals before NAPE can be tested in humans.
References
Gillum MP, Zhang D, Zhang XM, Erion DM, Jamison RA, Choi C, Dong J, Shanabrough M, Duenas HR, Frederick DW, Hsiao JJ, Horvath TL, Lo CM, Tso P, Cline GW, Shulman GI. N-acylphosphatidylethanolamine, a gut- derived circulating factor induced by fat ingestion, inhibits food intake. Cell. 2008 Nov 28;135 (5):813-24.