Does glycine+NAC work, or only glycine, or only NAC?

[ecstatichamster]

There are great experiments that show glycine + NAC are rolling back many markers of aging. .A speculative theory is that glutathione production is increased by glycone + NAC and that this is responsible by assisting scavenging of ROS, thereby slowing down aging or rolling back some of the many markers of aging.

I and @haidut and others wonder if only glycine may do the trick, and perhaps NAC is unnecessary.

This fish experiment is one I found that seems well constructed and tests a control diet with glycine, and NAC, and both…

Effect of N-acetyl cysteine and glycine supplementation on growth performance, glutathione synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus

An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione…

www.sciencedirect.com

An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione (GSH) synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus. Four practical diets were formulated, control, control +0.2% NAC, control +0.5% glycine, control +0.2% NAC +0.5% glycine.

Each diet was randomly assigned to quadruplicate groups of 30 fish (approximately 9.5 g). The weight gain and specific growth rate were significantly increased with the supplementation of NAC and glycine.

While they had no effect on feed efficiency feed intake and survival. Glutathion peroxidase (GPx) was increased by NAC and γ-glutamine cysteine synthase (γ-GCS) in plasma were increased by glycine.

After the feeding trail, fish were challenged by Streptococcus iniae, fish fed the diet supplemented with NAC obtained significantly higher survival rate after 72 h challenge test. NAC also decreased malonaldehyde (MDA) in liver, increased glutathione S-transferase (GST) activity in plasma, up-regulated mRNA expression of Superoxide dismutase (SOD) and GPx in liver and headkidney.

Dietary supplementation of glycine increased the anti-oxidative ability of tilapia through increase anti-oxidative enzyme activity (SOD, glutathione reductase, myeloperoxidase) and up-regulate anti-oxidative gene expression (SOD).

Immune ability only enhanced by the supplementation of NAC through increased interleukin-1β (IL-1β) mRNA expression. These results clearly indicated that the supplementation of NAC and glycine can significantly improve the growth performance of tilapia, and NAC also enhance the anti-oxidative and immune capacity of tilapia, glycine could only enhance the anti-oxidative ability.

 

[ecstatichamster]

A rat study showing that glycine + NAC has a better effect in this case on lowering TNF-a than just glycine.

Cysteine and Glycine Supplementation Modulate the Metabolic Response to Tumor Necrosis Factor α in Rats Fed a Low Protein Diet

Abstract. Responses to cytokines entail synthesis of substances rich in cysteine and glycine, such as glutathione (GSH), metallothionein and some plasma protein

academic.oup.com

Although glycine improved growth to a limited extent, it had little impact on the impaired response to TNF in animals fed the low protein diets. However, addition of cysteine substantially improved the impaired responses of liver weight increase and zinc and GSH concentration. The enhancing effects of cysteine suggest that these responses are impaired by lack of amino acid substrate. The increases in liver zinc (which represents increased MT synthesis) and glutathione, might be dependent on the supply of glycine and cysteine due to the high content of these metabolically interrelated amino acids in these sub stances. These amino acids comprise 43 and 66% of the total amino acid content of MT and GSH, respec tively (Grimble 1990).

 

[J.R.K]

A rat study showing that glycine + NAC has a better effect in this case on lowering TNF-a than just glycine.

Cysteine and Glycine Supplementation Modulate the Metabolic Response to Tumor Necrosis Factor α in Rats Fed a Low Protein Diet

Abstract. Responses to cytokines entail synthesis of substances rich in cysteine and glycine, such as glutathione (GSH), metallothionein and some plasma protein

academic.oup.com

Although glycine improved growth to a limited extent, it had little impact on the impaired response to TNF in animals fed the low protein diets. However, addition of cysteine substantially improved the impaired responses of liver weight increase and zinc and GSH concentration. The enhancing effects of cysteine suggest that these responses are impaired by lack of amino acid substrate. The increases in liver zinc (which represents increased MT synthesis) and glutathione, might be dependent on the supply of glycine and cysteine due to the high content of these metabolically interrelated amino acids in these sub stances. These amino acids comprise 43 and 66% of the total amino acid content of MT and GSH, respec tively (Grimble 1990).

This is an interesting idea @ecstatichamster, the thing that I have been wondering about since NAC became a COVID wonder supplement is balancing this supplements benefits with Dr Peat’s concerns regarding cysteine being problematic and related to cancer metabolism. Or am I missing a piece of the puzzle here. As haidut has found studies that show restriction of cysteine and the resulting glutathione is a preferred source of energy for cancer cells.

Blocking cystine, and thus glutathione (GSH) synthesis, kills cancer stem cells – To Extract Knowledge from Matter

 

[Perry Staltic]

Cysteine is supposedly the rate limiting factor in glutathione synthesis

 

[chrstn4o]

There are great experiments that show glycine + NAC are rolling back many markers of aging. .A speculative theory is that glutathione production is increased by glycone + NAC and that this is responsible by assisting scavenging of ROS, thereby slowing down aging or rolling back some of the many markers of aging.

I and @haidut and others wonder if only glycine may do the trick, and perhaps NAC is unnecessary.

This fish experiment is one I found that seems well constructed and tests a control diet with glycine, and NAC, and both…

Effect of N-acetyl cysteine and glycine supplementation on growth performance, glutathione synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus

An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione…

www.sciencedirect.com

An 8-week feeding trial was conducted to evaluate the effect of N-acetyl cysteine (NAC) and glycine supplementation on growth performance, glutathione (GSH) synthesis, anti-oxidative and immune ability of Nile tilapia, Oreochromis niloticus. Four practical diets were formulated, control, control +0.2% NAC, control +0.5% glycine, control +0.2% NAC +0.5% glycine.

Each diet was randomly assigned to quadruplicate groups of 30 fish (approximately 9.5 g). The weight gain and specific growth rate were significantly increased with the supplementation of NAC and glycine.

While they had no effect on feed efficiency feed intake and survival. Glutathion peroxidase (GPx) was increased by NAC and γ-glutamine cysteine synthase (γ-GCS) in plasma were increased by glycine.

After the feeding trail, fish were challenged by Streptococcus iniae, fish fed the diet supplemented with NAC obtained significantly higher survival rate after 72 h challenge test. NAC also decreased malonaldehyde (MDA) in liver, increased glutathione S-transferase (GST) activity in plasma, up-regulated mRNA expression of Superoxide dismutase (SOD) and GPx in liver and headkidney.

Dietary supplementation of glycine increased the anti-oxidative ability of tilapia through increase anti-oxidative enzyme activity (SOD, glutathione reductase, myeloperoxidase) and up-regulate anti-oxidative gene expression (SOD).

Immune ability only enhanced by the supplementation of NAC through increased interleukin-1β (IL-1β) mRNA expression. These results clearly indicated that the supplementation of NAC and glycine can significantly improve the growth performance of tilapia, and NAC also enhance the anti-oxidative and immune capacity of tilapia, glycine could only enhance the anti-oxidative ability.

Very interesting. I've been using rather copious amounts of NAC and glycine for the last 5 years and have felt and seen a lot of benefits. After listening to Haidut talk about cysteine and methionine being inflammatory, I am trying to delve deeper into this stuff to understand it better because I also recommend these to my clients (though not in the amounts I use). Research has shown that NAC on its own raise GSH in the body and that cysteine is the rate-limiting factor of GSH synthesis most often, so that has been my justification for its usage...but I am keeping an open-mind.

 

[ecstatichamster]

I can see the justification for minimizing tryptophan and methionine, although it’s hard to do. But I no longer thing cysteine is bad. I believe it increases zeta potential and since I’ve been using it I have yet to get sick. And I know other people with identical experiences, who were getting sick frequently and haven’t gotten sick since starting NAC and glycine.

 

[CastorTroy]

Shouldn't eating plain gelatin do the job for not needing to get isolated glycine?

 

[chrstn4o]

Shouldn't eating plain gelatin do the job for not needing to get isolated glycine?

Should be fine, same for collagen.

 

[Snicky]

I can see the justification for minimizing tryptophan and methionine, although it’s hard to do. But I no longer thing cysteine is bad. I believe it increases zeta potential and since I’ve been using it I have yet to get sick. And I know other people with identical experiences, who were getting sick frequently and haven’t gotten sick since starting NAC and glycine.

I was taking NAC (and a bunch of other stuff) during Covid and through last year. I don’t know if it specifically helped or not but I was sick a few times and then a lot last year (but also going through some very traumatic **** and likely running on stress hormones).

But my athletic perfprmsnce was really good on that, and some ayurvedic herbs, etc!!

What I can say is that apart from a headache here or there, and still bouts of anxiety due to my ongoing personal situation, I have not had a cold or ‘illness’ at all since incorporating raw milk into my diet in late January.

I’m super curious to see what happens as we enter the darker/colder months, but raw milk seems to have benefitted me a lot.

It did not prevent seasonal allergies, though. Hoping to play more with that next year (more honey maybe and effort to lower histamine more).

 

[Ismail]

But I no longer thing cysteine is bad.

I'm starting to think the same.

@ecstatichamster are you taking NAC + glycine?

 

[Dave Clark]

Glutathione my be a preferred source of energy for cancer cells, but so are some vitamins and other nutrients. Unless you know you have cancer, it may be counterintuitive to restrict these 'good' nutrients due to the fact that they may fuel cancer. Most all disease states show a low ratio of reduced glutathione to oxidized glutathione. It may not be wise to purposefully try to keep your GSH levels down just because cancer uses it. Maybe I will see it differently someday, but I just can't get on board doing anything that keeps GSH low, when aging and disease correlate pretty strongly with low levels. One of the reasons I have not used Pyrucet yet.