Vitamin B-3 has previously been proposed as an alternative for treating Alzheimer's disease.
In an older study, large doses of nicotinamide — also referred to as B-3 — reversed Alzheimer's-related memory loss in mice.
A new study, however, focused on the effect of nicotinamide riboside (NR), which is a form of vitamin B-3, on Alzheimer's-related brain damage in mice.
More specifically, the researchers — who were jointly led by Dr. Vilhelm A. Bohr, the chief of the National Institute on Aging's (NIA) Laboratory of Molecular Gerontology, and Dr. Yujun Hou, a postdoctoral investigator in the laboratory — focused on how NR affects the brain's ability to repair its DNA, a function that is compromised in Alzheimer's disease.
As the scientists explain, a deficiency in the brain's ability to repair its DNA leads to dysfunction in the cells' mitochondria — the energy-creating organelles inside the cells — which, in turn, leads to neuronal dysfunction and lower neuron production.
But NR is "critical for mitochondrial health and biogenesis, stem cell self-renewal, and neuronal stress resistance." Thus, Dr. Bohr and his colleagues wanted to explore the effects of NR supplementation in a mouse model of the neurological disease.
Compared with the controls, the NR-treated mice had less of the protein tau in the brain, less DNA damage, and more neuroplasticity — that is, the brain's ability to "rewire" itself when it learns new things, stores new memories, or becomes damaged.
Also, fewer neurons died or were damaged in these mice. Intriguingly, however, their levels of the beta-amyloid protein stayed the same as those of the control mice.
Finally, the researchers say that in the hippocampi — a brain area involved in memory that often shrinks or is damaged in Alzheimer's — of the mice that received the treatment, NR appeared to get rid of the existing DNA damage or stop it from spreading.