Diabetes increases the risk of cognitive decline, partly due to reductions in NAD+ levels. NMN boosts NAD+ levels and preserves cognition and brain function in diabetic mice.

Defective T cells speed up aging when defective due to mitochondrial dysfunction, which increases risk of infection. Providing NAD+ or inflammation-suppressing drugs improved health markers in mice.

In older adults, high-resolution fMRI brain scans showed stronger hippocampal activity and replay in the cortex in those who had better memory and recall scores, regardless of age.

Lactate is a memory-boosting molecular messenger produced by the gut microbe Lactobacillus (L. reuteri.) Feeding either L. reuteri or lactate to mice improved memory and increased GABA.