Homocysteine is naturally produced by the body during methylation. The body forms homocysteine when it breaks down the amino acid methionine, which is present in many protein-rich foods. Methylation is an essential process in the body. It involves the transfer of a methyl group, comprising one carbon atom and three hydrogen atoms. Methylation supports several key processes in the body, including DNA expression, liver detoxification, and hormone and neurotransmitter metabolism.
The methylation process is dependent on many nutrients, chiefly folate and B12, and therefore when deficiency of these nutrients occurs this can impair methylation leading to an increase in homocysteine levels. Furthermore, other factors such as chronic stress, kidney disease, consuming high amounts of alcohol and genetic variations of genes involved in the methylation process, may further increase risk of having high homocysteine levels. You can learn more about the nutrients involved in controlling homocysteine, including B vitamins that reduce homocysteine.
If you would like to explore the science in more detail, read our comprehensive overview of homocysteine metabolism and health.
Raised homocysteine increases levels of inflammation in the body. It also has a detrimental impact on the structural integrity of blood vessels, and also affects gene expression. Over time, high homocysteine levels may contribute to damage in blood vessels and nervous tissue. These factors may in turn increase the risk of developing chronic diseases. A recent review has suggested that raised homocysteine levels are associated with an increased risk of around 100 diseases or undesirable outcomes. You can explore the research linking homocysteine to disease to understand the growing scientific evidence behind these associations.
These conditions include, in particular:
Emerging evidence also suggests a strong link between homocysteine and dementia risk, highlighting the importance of maintaining healthy levels for long term brain health.
High homocysteine levels can often be improved through diet and lifestyle changes. Learn how to lower homocysteine naturally with practical strategies including nutrition and key nutrients. Research has indicated that increasing intake of folate and B12, as well as omega-3, can help to reduce levels of homocysteine. You can support this process by increasing your intake of green leafy vegetables (folate), chicken and fish (B12), and oily fish (omega-3), and by supplementing these nutrients, particularly B12 and omega-3 for vegetarian or vegan diets.
Other lifestyle factors such as reducing alcohol intake, improving diet quality, and managing chronic stress may also support healthy homocysteine levels.
Always consult your GP and a qualified nutrition practitioner before starting a new supplement regimen.
Most homocysteine tests require a referral from a doctor, nutritional practitioner, or another healthcare professional. They can help interpret the results and support you one to one with making any necessary changes.
Homocysteine is measured through a simple blood test. Our recommendations follow a recent review which considers that, for an adult, values of 10 µmol/L or below are likely to be safe, while values of 11 µmol/L or above may justify intervention.
Normal homocysteine levels are typically considered to be below 10 µmol/L for optimal health. Higher levels may increase the risk of cardiovascular disease and cognitive decline, which is why monitoring and managing homocysteine levels can be important for long term health.
If there are concerns regarding homocysteine, it is important to see a doctor in the first instance. In terms of finding a qualified, registered dietitian / nutrition practitioner, there are a few options:
Individuals who prefer to arrange testing independently can order our Homocysteine (HCY) test directly online to measure their homocysteine levels. This provides a convenient way to measure homocysteine levels and gain insight into factors that may influence brain and cardiovascular health.
Please note that Food for the Brain does not provide medical diagnosis. Consult a GP or qualified healthcare practitioner to interpret your results and provide appropriate guidance.
