Homocysteine

Homocysteine is a breakdown product of the amino acid methionine and a sensitive marker of methylation disturbances. Homocysteine is looked at in cardiovascular, memory and bone diagnostics. How your value is to be read is set out in your findings report. Causes: deficiency of folate, B12 or B6, MTHFR variants. Measurable directly in Prevent 360.

How homocysteine is formed and broken down

Homocysteine is formed when SAM has donated a methyl group. It is processed further in two ways: back to methionine with folate and vitamin B12 (in the liver also with betaine) or – with vitamin B6 – on to cysteine, from which glutathione and taurine are made. Homocysteine thus sits at the crossroads of methylation and detoxification; if it builds up, at least one of these pathways is not running sufficiently.

High homocysteine – what happens in the body?

Raised homocysteine irritates the inner wall of the blood vessels (endothelium): production of the vessel-widening nitric oxide falls, oxidative stress increases and clotting is promoted. At the same time SAH builds up and slows methylation reactions. Remodelling processes in bone and the nervous system are also linked to it. Causes are a lack of folate, B12 or B6, MTHFR variants, reduced kidney function, an underactive thyroid and some medications such as metformin or methotrexate.

Low homocysteine – what does it mean?

Low values are usually unremarkable and show that homocysteine is processed promptly. Very low values are rare, for example with a very low-protein diet.