A study published in 2020 aimed to test if increasing brain NAD+ levels might protect against dementia associated with diabetes. The results suggest that introducing a precursor (building block) of NAD+ into the body, specifically through a compound called nicotinamide mononucleotide (NMN), may prevent diabetes-related memory deficits. The study can be found here.
In people with diabetes, higher levels of blood sugar can lead to cognitive decline, which sometimes results in dementia. This cognitive decline has been associated with decreased brain NAD+ levels. The study found that diabetes affected the central nervous system, leading to both acute (short-term) and chronic (long-term) metabolic disorders with the potential to damage the brain's functional and structural integrity.
The precursor NMN was given to diabetic rats which, after three months, increased their brain NAD+ levels. NMN appeared to effectively normalise various biochemical levels and rescued the loss of neurons in a part of the brain called the hippocampus - a region crucial for memory processing.
Furthermore, the study also found that NMN treatment prevented the downregulation (reduction of production or response) of SIRT1 and PGC-1α—known factors in cellular response to stress and regulation of metabolic processes—and promoted the deacetylation of proteins in the hippocampus, which is significant for cell function and response to changes in the cellular environment. The indicated outcome was that NMN supported the brain's ability to remember by improving neuronal health and countering metabolic disruption in the brain caused by diabetes.