L-cysteine as an add-on therapy for type-2 diabetes
What it found
In diabetic animals and people, cysteine-rich whey protein improved glucose metabolism, and animal studies found the same for L-cysteine.
The authors say more human trials are needed.
What they found
Studies in people
Whey protein in people
Cysteine-rich whey protein improved glucose metabolism in people with type-2 diabetes, according to the reviewed literature.
Animal and lab studies
Whey protein in animals
Cysteine-rich whey protein also improved glucose metabolism in diabetic animals.
L-cysteine in animals
In animal studies, glucose metabolism improved after supplementation with L-cysteine or with molecules that contain a cysteine part.
Other findings
How it may work
The authors describe biochemical ways in which L-cysteine may boost the insulin-dependent signalling pathways involved in glucose metabolism.
Cost
The authors describe L-cysteine as a relatively low-cost dietary supplement that could be used alongside existing type-2 diabetes treatment.
What the authors conclude
“Further studies are needed to examine whether clinical interventions using L-cysteine as an adjuvant therapy indeed help to control glycemia and vascular inflammation in the diabetic patient population.”
Also in their conclusions
- They say further studies are needed to examine whether clinical interventions using L-cysteine as an adjuvant therapy indeed help to control glycemia and vascular inflammation in the diabetic patient population.
How it was done
Many people with type-2 diabetes struggle to keep their blood glucose tightly controlled with diet and current oral drugs. The authors looked at a low-cost dietary supplement that might help as an add-on therapy.
They reviewed the published literature on cysteine-rich whey protein and L-cysteine in diabetic animals and in people with type-2 diabetes. They also describe the biochemical pathways by which L-cysteine may affect insulin signalling in glucose metabolism.
What it can’t tell you
- We summarised it from the abstract only.
- Most of the evidence on L-cysteine itself comes from animal studies, which cannot show what happens in people.
- The review does not report a human trial testing L-cysteine as an add-on therapy, so it cannot show whether it controls blood glucose or blood vessel inflammation in people with type-2 diabetes.
Who paid
- Funding
- Funded by NIDDK NIH HHS (from the PubMed record).
- Authors work at
- LSU Health Sciences Center, USA
The paper
- Title
- L-cysteine supplementation as an adjuvant therapy for type-2 diabetes
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Abstract only
- Cite
- Jain SK (2012). L-cysteine supplementation as an adjuvant therapy for type-2 diabetes. Canadian journal of physiology and pharmacology. doi:10.1139/y2012-087PubMed 22783875DOI
Summary written 26 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error