Longevity & NAD
Made in the body but not always in enough: shortfalls show up in glutathione, collagen — and in homocysteine.
Not yet investigated
Made in the body but not always in enough: shortfalls show up in glutathione, collagen — and in homocysteine.
This star is on the map because the show intends to take the question apart properly — the trials, how it is actually tested, whether the thing sold is the thing studied. That work is not done yet, and nothing here should be read as a conclusion. When the investigation is published it will appear on this page.
What we are reading
Gathered for the investigation and not yet written up. Each note says what the paper does and does not show.
Recent review, and it connects three of this map's nodes in one sentence: glycine deficiency raises HOMOCYSTEINE, alongside impaired synthesis of glutathione, collagen, nucleotides and one-carbon units. Deficiency states listed are ordinary ones — low protein intake, malnutrition, late pregnancy, diabetes, insulin resistance, xenobiotic load. The practical argument is the interesting part: because serine hydroxymethyltransferase links the two, the author argues glycine should be co-administered with L-SERINE rather than given alone, to avoid losing methylenetetrahydrofolate to the SHMT flux and to avoid ammonia from the glycine cleavage system. He also states plainly that no study has compared glycine alone against glycine plus serine, and that controlled studies in people WITHOUT deficiency are still needed.
Connected on the map
Also in Longevity & NAD
The letter
The full citation list for each investigation, the studies that didn't make the episode, and any corrections — sent the morning it publishes.
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