Controversial - Ghrelin is actually a GOOD thing!

The weight loss community (esp the VSG subset) has been told that the hormone ghrelin is a bad thing.  But most of the latest research suggests ghrelin is actually a very beneficial hormone, with substantiated health benefits, as partially summarized below. 

I don't want to upset anyone who has already had bariatric surgery (esp VSG), but I do want to make this post for those considering surgery to be provided with all the information in making their decision.  (And to those who have already had VSG - remember, nothing is more health promoting that losing all that excess weight, so don't fret.)

Benefical aspects of Ghrelin (research in links):

- increases NPY (antidepressant, antianxiety)
http://endo.endojournals.org/content/147/11/5102.full

- defends against stress-induced depression and anxiety
www.ncbi.nlm.nih.gov/pmc/articles/PMC2765052/

- is reduced 60% by VSG and remains low for as long as has been studied (5 years post-op)
www.weightlosstriumph.com/long-term-effect-of-sleeve-gastrec tomy-on-weight-loss-and-ghrelin.html

- fights aging in thymus and thus prevents immune function decline in elderly
www.eurekalert.org/pub_releases/2007-09/joci-hhf083007.php

- protects muscles from atrophy
http://www.news-medical.net/news/20090613/Appetite-stimulati ng-hormone-may-protect-muscle-from-atrophy.aspx

– caloric restriction (but only with full stomach intact) enhances ghrelin levels during aging, which may help extend lifespan
http://www.ncbi.nlm.nih.gov/pubmed/17875344

- stimulates growth hormone secretion (and blocking GH may explain, at least in part, why VSG reduces blood sugar)
http://www.ncbi.nlm.nih.gov/pubmed/15620414

- enhances learning, cognition, and cognitive adaptation)
http://classic.the-scientist.com/news/display/23132/
http://www.ncbi.nlm.nih.gov/pubmed/19652956

– decreases inflammatory responses, improves organ blood flow, attenuates tissue injury following trauma
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2748721

- increases dopamine in substantia nigra and may help slow onset of Parkinson's disease
http://www.ncbi.nlm.nih.gov/pubmed/19906954

- inhibits pro-inflammatory cytokines, reverses age-related thymic involution
http://www.ncbi.nlm.nih.gov/pubmed/17875344

- exerts positive cardiovascular effects and is considered as a direct target for prevention of cardiovascular disease
http://www.hindawi.com/journals/ijpep/2010/248948.html

- exhibits health promoting effects in elderly
http://www.ncbi.nlm.nih.gov/pubmed/18981485

- may be suppressed by either VSG or RNY (though far more consistently by VSG)
http://jcem.endojournals.org/content/88/7/2999.full

Ghrelin itself is a good thing.  Over production is not.

Insulin is a good thing.  Over production is not.

The VSG does not remove ALL places that ghrelin is produced, so it is not absent in a body of a human with a VSG. 

Actually, if anything you may under-produce Ghrelin if you are obese.  Ghrelin levels normally rise as you lose weight, and fall as you gain weight (which accounts for some, but not all of health benefit of weight loss).  So your analogy to excess insulin is simply incorrect.  Getting VSG surgery will immediately remove 80% of Ghrelin production.   And even many years after the surgery, ghrelin levels in the body will be 60% lower than that of a normal weight person without surgery. 

Years ago, the Zoloft commercial taught everyone (esp doctors) that depression is caused by imbalance of neurotransmitters.  It is absolutely certain now, as has been for years, that this is utterly false -- yet the myth will persist for decades probably.   It is not true that obesity is the result of overproduction of ghrelin.  However, it may be the case that producing an imbalance of neurotransmitters (eg, SSRI's) helps with depression, and that slashing ghrelin to far below normal levels may aid in weight loss (eg, VSG).  The devil is always in the details.

And this, is why Medicine is referred to as a Practice. 

Also, I never noticed any significant defense against depression or anxiety pre-op, but I guess thats just me.

Lindsey

 

Yea, me either, but holy crap, can I imagine how depressed or anxious I would have been as a regular weight?

Yike.

LOL That's what I was thinking...I never noticed any benefits, but maybe I just would have needed to be institutionalized without it. Although so far at 10 months post, it's quite the opposite...but stay tuned!!!

Understood in your case, but I think you would agree that the reason many of us gained so much weight is because eating often calms us down and helps with our mood.  This is probably because eating a lot increases something in our brains called neuropeptide-Y (NPY).  Slashing ghrelin levels has been shown to slash levels of NPY.  This has potentially profound implications for WLS because depression after WLS often begins after around 6 months, which is when the bulk of weight loss has already occurred.  DURING weight loss, ghrelin levels will be temporarily boosted as a result of the negative energy balance.  However, once at a stable weight, many people are hit with depression that arguably occurs as a result of ghrelin suppression and associated ramifications on other hormones like NPY.

Just anecdotal from experience, but I have been at a stable weight for 2 months shy of 2 years. and experience none of the depression or associated ramification on other hormones.

I also am an anomaly of sorts because even without a malabsorptive surgery, I do not absorb/retain all of the dense protein I consume - so sometimes the glossy brochure does not cover it all. 

I'm still working out why I would overeat so much, but I would say your theory is more than a fair possibility.

I am still in weight loss mode, so maybe that is why I have only noticed positive differences. I will remember to be on the watch for any signs when my weight stabilizes.

Best of luck,
Lindsey