Scientists have released a new expert opinion. The article brings together more than 25 researchers from around the world, including clinicians and internationally recognized leaders in the biology of aging and metabolism, particularly in the study of nicotinamide adenine dinucleotide (NAD⁺). Their collective perspective underscores the global effort to understand how this tiny molecule, NAD⁺, could be key to healthier aging and protection against diseases such as Alzheimer's and Parkinson's. NAD⁺ is often described as a cell's "fuel regulator." It helps our bodies produce energy, repair damaged DNA, and keep cells functioning properly. As we grow older, however, NAD⁺ levels...