Key takeaways:
Homocysteine is a naturally occurring amino acid in our body and can spike acutely, such as after staying up all night. In healthy people, homocysteine naturally clears over time. However, at chronic high concentrations, it is associated with various health issues, including heart disease and, notably, cognitive decline. In fact, having blood homocysteine levels over 14 μmol/L is associated with a nearly doubled risk of dementia1. Luckily, there are simple ways to lower your homocysteine levels - most notably B vitamin supplementation.
Brain Atrophy, Aging and Cognitive Decline
As we age, our brains naturally undergo some amount of atrophy, or decrease in size, which involves a loss of neurons and their connections. This process is accelerated in Alzheimer’s dementia2. With a lower brain volume and fewer neural connections, it’s easy to see how atrophy can lead to lasting cognitive impairment. One factor that has a strong influence on the rate of brain atrophy is blood concentration of homocysteine. Several studies3,4 link elevated homocysteine levels are linked with a heightened risk of dementia.
The role of B vitamins
You won’t often hear us say this, but you have an ace up your sleeve in fighting homocysteine: B vitamins. One study2 investigated the effects of using B6, B9, and B12 vitamins over the course of two years, using the same level of rigor that is commonly used for drug clinical trials.
On average, people who used B vitamins lowered their overall homocysteine levels by 32% and experienced a 30% slower rate of brain atrophy. In fact, those who started with very high levels of blood homocysteine (> 14 μmol/L) managed to slow their atrophy rate by 53%. In other words, this study suggests that the simple act of taking a daily B vitamin supplement can cut your dementia risk in half.
The type of B vitamin matters
There are two factors to consider when selecting a B vitamin supplement. The first is what vitamins you are getting. The study mentioned above specifically tested the use of vitamins B6, B9 (also known as folate), and B12. It’s important to get a mix of both. The second is whether or not you select the methylated form of the vitamins. Methylation is a biological process that makes the vitamins more available for your body to use. In other words, the same dose of methyl-B vitamins will be more strongly absorbed than normal B vitamins. This is especially important for people with mutations in the MTHFR gene, since they otherwise have trouble absorbing B vitamins. We generally recommend taking methylated B vitamins since they are perfectly safe, but if you are sensitive to overmethylation, you may want to consider regular B vitamins to avoid side effects like headaches, anxiety, or irritability.
Broader Implications for Dementia Prevention
Homocysteine is a critically important risk factor for dementia. Not only does it accelerate brain atrophy, it also aggravates other conditions through inflammation and oxidative stress. Thankfully, B vitamins are an extremely effective tool to lower homocysteine levels. While there are many other ways of managing your homocysteine levels, most notably through diet, exercise, and stress management, B vitamins are a low-effort high-impact way to keep your brain atrophy at bay.
Get started on managing your homocysteine
- Measure your blood homocysteine levels to learn where you stand. Homocysteine is one of the 50+ biomarkers tested during your BetterBrain Essentials blood draw.
- Consider using B vitamin supplements to lower your homocysteine, ideally below 9 μmol/L. We recommend Pure Encapsulations MethylAssist, but make sure you use an unmethylated alternative if you are sensitive to overmethylation.
- Learn more about homocysteine on the Peter Attia Drive episode on dementia. This episode covers many topics, so if you’re just interested in homocystine, skip ahead to 1:09:00.