Posted on 08/02/2011 11:27:46 PM PDT by neverdem
A report in the August issue of the Cell Press journal Cell Metabolism might help to explain why it's so frustratingly difficult to stick to a diet. When we don't eat, hunger-inducing neurons in the brain start eating bits of themselves. That act of self-cannibalism turns up a hunger signal to prompt eating.
"A pathway that is really important for every cell to turn over components in a kind of housekeeping process is also required to regulate appetite," said Rajat Singh of Albert Einstein College of Medicine.
The cellular process uncovered in neurons of the brain's hypothalamus is known as autophagy (literally self-eating.) Singh says the new findings in mice suggest that treatments aimed at blocking autophagy may prove useful as hunger-fighting weapons in the war against obesity.
The new evidence shows that lipids within the so-called agouti-related peptide (AgRP) neurons are mobilized following autophagy, generating free fatty acids. Those fatty acids in turn boost levels of AgRP, itself a hunger signal.
When autophagy is blocked in AgRP neurons, AgRP levels fail to rise in response to starvation, the researchers show. Meanwhile, levels of another hormone, called -melanocyte stimulating hormone, remain elevated. That change in body chemistry led mice to become lighter and leaner as they ate less after fasting, and burned more energy.
Autophagy is known to have an important role in other parts of the body as a way of providing energy in times of starvation. However, unlike other organs, earlier studies had shown the brain to be relatively resistant to starvation-induced autophagy.
"The present study demonstrates the unique nature of hypothalamic neurons in their ability to upregulate autophagy in response to starvation that is consistent with the roles of these neurons in feeding and energy homeostasis," the researchers wrote.
Singh said he suspects that fatty acids released...
(Excerpt) Read more at sciencedaily.com ...
When I was in college during the early 80s, I was told that the per capita consumption of all sugars combined was around 100 pounds. It’s almost 200 now.
Throwing in the idea that the tongue doesn’t recognize the difference btwn analogs of sugar (artificial sweeteners), and still triggers insulin release when eating ‘diet’ this or that...that’s one reason why ppl get fat on diet stuff.
I think the main reason for obesity is carbs. It’s like we get a ‘carb allowance’, and when we exceed that, insulin resistance/metabolic syndrome/diabetes inevitably results.
I believe the same neurons and biochemical pathways are involved as are with drug addictions.
Try suggesting cutting carbs to almost anyone, and you get that;
“You’ll have to pry my lasagna from my cold, dead fingers” -look.
There’s a reason it’s called “comfort food” - and it’s neurological. (I’m no expert, though).
Cheers.
I’m trying to ingest more of the medium-chain saturated fatty acids...butter, coconut oil, etc. for energy, and quiet down my cravings.
You left out Spam, cabbage, brown rice and lottsa hot sauce. Yeah.
“As for the rats — the only sure thing that can be said about this is that trans fats and HFCS are a lousy diet for rats and should be considered animal cruelty. How many cures for cancer in rats have flopped in humans?”
Agreed, rat studies are third rate evidence, although combined with the (somewhat bad) evidence for trans fat toxicity in humans, and the evolutionary rationale (artifical trans fats are new for our metabolism), I think it might very well be an important part of the story.
Agreed - there is more than sugar to the story (although I reckon that sugar is a big chunk).
I don´t think it´s all carbs that are a problem though. While people might not want to give up lasagna or bread for any price, I would attribute that more to stuff like the opiate-receptor binding gluten exorphins present in wheat, etc.
People don´t get tuber cravings, they get cravings for grain products, glutamate, sugar, etc.
To make my principles regarding food real simple:
Grains + Sugar + Trans Fats = Avoid.
In addition, I’ve come across some evidence that gluten is implicated in many (if not all?) of the so-called auto-immune problems.
And Rocky...Rush just used your line about Hollywood...I laughed again!
Fructose, insulin resistance, and metabolic dyslipidemia
IIRC, Artificial sweeteners were mentioned.
Artificial sweetener tied to weight gain
Check the link in comment# 1.
Yep, Gluten + WGA + Exorphines makes for a pretty nasty (albeit tasty) package. I have tried to get my gluten consumption down to a bare minimum for a while now.
I am flattered beyond belief! I will have to bookmark your comment so I can show it to my grandchildren one day. My fifteen minutes wasn't exactly fifteen minutes, but it still feels great.
Thanks!
But it’s not a 100% certainty that he got it from me. Great minds think alike, you know.
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