Dr. Alexander Sisti, MD/ PhD Candidate

People love to say “sugar is addictive”, and while it’s not addictive in there clinical sense of the word, it definitely has an effect on desire and consumption. Artificial sweeteners have never fully succeeded in impersonating sugar. Now, a Columbia University study in mice has identified a brain mechanism that may explain why. In a scientific first, researchers have shown that the brain responds not only when sugar touches the tongue but also when it enters the gut. Their discovery of this specialized gut-brain circuit offers new insight into the way the brain and body evolved to seek out sugar. And because artificial sweeteners do not activate this circuit, the study also offers compelling evidence as to why these sweeteners are never quite as satisfying as the real thing. PLUS Some of the signs the lock-down is causing more problems.

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SHR # 2516 :: How does sugar drive consumption? Scientists discover gut-brain sugar sensor in mice PLUS More Problems With The Lock-down

Show Notes:

[3:00] Sugar isn’t clinically addictive.

• It is a very powerful dopamine stimulator.

[5:00] It plays into 500 million diseases worldwide.

[6:16] What preceded this research?

• Wanted to understand the insatiable desire to consume sugar.
• 2^nd question: if artificial sweeteners could chemically replace sugar, why hasn’t it?

[15:50] Definition of artificial sweetener.

• Sweet but can’t be broken down into ATP.

[16:40] Study design.

• Made genetically engineered mice without sweet receptors.
• They still preferred sugar over artificial sweeteners, even when the sugar molecule contained no calories.

[19:35] Are the triggers from sugar from interaction with a receptor or a microbe?

[21:36] Table sugar vs. fructose.

• Sugar is transported via SGLT-1 while fructose is not.

[23:39] What is happening in the brain to drive this behavior?

• NST- an area embedded deep within the brain stem.
• Responds to sugar and not artificial sweeteners.

[26:04] Can artificial sweeteners drive overconsumption?

• Possibly because the NST would not be triggered by artificial sweeteners.

[27:22] The vagus nerve.

• It interconnects the various sensory nerves in the body.
• Collects information of diagnostic nature from the body.
• It can cause a mechanical change in heart rate.

[38:20] How the mice were genetically modified.

• Whenever the vagus nerve was silenced, the mice consumed the same amount of sugar vs. artificial sweetener.
• Whenever the NST cells were activated via a drug and receptor implant, the mice preferred the drug-spiked sugar drink.

[49:12] what about the microbiome involvement?

• Entero-endocrine cells communicate directly with the vagus nerve.

[58:30] Future research.

• How does this pathway relate to depression?
• What about other nutrients?
• Other mechanisms to activate these NST cells.

[1:01:07] Satiety.

• Protein and fat cause release of CCK.
• Sugar does not.

[1:09:09] Environmental Co2.

• Higher levels of CO2 will drive higher levels of several molecules in a plant.

[1:11:45] Feeling bad from not training.