Familiar components to several weight-loss regimens, dietary proteins are no strangers to appetite suppression. An explanation as to why proteins perform in this manner has been curiously absent from the health and medical realms — until now.
A research team fronted by Gilles Mithieux, director of Inserm’s Unit 855 “Nutrition and the Brain” in Lyon, has emerged from the aforementioned teeming uncertainty equipped with a blueprint which describes more fully the biological mechanism of protein properties. Published in the July 5 edition of the Cell review is the explicit outline of the chain reactions prompted by protein ingestion that Mithieux’s team was able to drum up. According to the results, a ‘satiety’ message is sent to the brain post protein-rich meal, allowing for the sensation of fullness to be felt long after the food has been eaten. An extensive set of cues instigated by the dietary proteins (mainly found in meat, fish, eggs, and some cereal-based products) permit the brain and digestive system to remain in correspondence several hours following consumption.
Prior studies have shown that consuming dietary proteins generates a sweetness — a glucose synthesis in the intestines following a period of food assimilation referred to as gluconeogenesis. Glucose disperses into blood circulation through a portal vein where the nervous system senses its presence and transmits an appetite suppressing notice to the brain. The recent research elaborates on this type of function further, describing how the digestion of proteins incites a double-loop chain reaction incorporating the ventral and dorsal peripheral nervous systems via the vagus nerve and the spinal cord respectively.
The initial phase of the process involves the agitation of the oglio-peptides upon the μ-opioid receptors, while the second phase occurs when the brain sends a return-message that propels gluconeogenesis through the intestine. The process can be broken down into the following six steps:
- Consumption of dietary proteins
- Protein residues (oligo-peptides) travel to the intestine in the portal vein
- Recognition of oligo-peptides by μ-opioid receptors
- Receipt of peripheral signals
- Gluconeogenesis induction
- "Appetite-suppressing" message sent to brain
Understanding this schema is the first major push for the discovery of new methods to use when treating obesity. Further research must be conducted on the actions of the μ-opioid receptors to distinguish completely how the sensation of fullness can be elongated without promoting desensitization. Mithieux, the lead author of the report, explained the importance of this practice as such: "If used too intensely, these receptors may become insensitive. A means of activating them 'moderately' must be found, thus retaining their long-term beneficial effects on controlling food intake."