Researchers have found that nicotinamide riboside, a dietary complement, can enter the human brain. This discovery is significant because it confirms that NR can alter the metabolism of biological paths associated with neurodegenerative disorders such as Alzheimer’s.

After consumption, NR easily transforms into nicotinamide-adenine-dinucleotide. NAD+ plays a vital role in repairing DNA damage and repairing damaged cells.

NAD+ decreases with age or chronic diseases. Loss of NAD+ is linked to obesity and other unhealthy lifestyle habits, such as smoking. NAD+ depletion occurs more often when negative lifestyle habits are present, as more NAD+ must be produced to counteract the negative effects.

Researchers found that NAD+ levels in blood could be raised by consuming NR. However, it was not clear if the NAD+ could also reach other tissues.

Initial signs of efficacy included a reduction in blood pressure among individuals with high blood pressure. It was not known whether NR could reach organs like the brain and have a significant beneficial effect.

It is difficult to determine NAD+ levels within the brain. The MRI method is promising, but it’s expensive and difficult to use. It also only provides an indirect measurement. Researchers measured NAD+ instead in tiny particles called extracellular vesicles that were released from neurons. These extracellular microvesicles can be used to detect brain disorders in blood and also function as a “liquid biopsy” of neurons.

Each vesicle’s surface has a unique molecular fingerprint, including proteins that give clues about its origin. Researchers selected vesicles that carried neuron-specific markers. They are therefore confident that NAD+ levels in these vesicles reflect what occurs in neurons and, by extension, the brain.

After 6 weeks, the levels of NAD+ in these vesicles increased.

When NAD+ levels increase in these vesicles, a connection can be made with biomarkers of neurodegenerative diseases. In particular, biomarkers like tau and amyloid Beta, both of which are associated with Alzheimer’s, were altered in those individuals who had an increase in NAD+.

There was also a connection between NAD+ and these biomarkers of neurodegenerative disease.

NAD+ levels that were high caused a greater change in biomarkers. This means that NAD+ doesn’t only enter the brain, but also has an impact on the metabolism and other interrelated pathways.