Which foods or habits effectively raise NAD+ levels?

NAD+ supplements such as NR and NMN demonstrably raise NAD+ levels in the blood. In a randomised, placebo-controlled study of 65 healthy adults, both supplements were effective after fourteen days, whereas nicotinamide (another related compound) was not effective via the same mechanism. NR and NMN are partly converted by gut bacteria, which makes the mechanism more complex than was initially thought.

Exercise has a directly measurable effect on NAD+ in white blood cells. Two separate small studies in young healthy adults (with 24 and 12 participants respectively) showed that even a single training session made the key enzyme that regulates NAD+ production more active. This applied to both high-intensity interval training and more relaxed endurance training. This effect is therefore not exclusive to one particular type of exercise.

Although NR and NMN are also found in common foods such as vegetables, meat, milk and fermented beverages, very little research has been done on how much you actually take in through your diet and whether those amounts do anything meaningful in the body. Researchers describe this as a virtually unexplored area. You therefore cannot yet rely on diet alone to supply sufficient NAD+.

That NAD+ levels rise with supplements is well documented, but whether that actually delivers health benefits is a separate question. In humans, clinical studies so far have produced more disappointing results than animal experiments had led researchers to hope. For cognitive complaints and age-related diseases, most of the positive results still come from animal studies; human trials are scarce and yield mixed outcomes. Safety is less of a concern: multiple reviews and clinical studies confirm that NR and NMN are well tolerated and that no serious side effects have been reported.