NAD+ and cognition
2 papers in the library, strongest Preliminary.
Graded Preliminary · A small pilot trial in which chance assigned 52 older adults to NR or a dummy pill for twelve weeks; too few people to detect small effects.
Papers 2
- NR Doubled NAD+ in Older Adults, but Thinking Did Not ImprovePreliminaryn = 522026Alzheimer's & dementia : the journal of the Alzheimer's AssociationFalling levels of a molecule called NAD+ may raise the risk of Alzheimer's disease. Nicotinamide riboside, or NR, is a building block the body uses to make NAD+. In a small trial, NR doubled blood NAD+ in older adults with memory problems. Their thinking and memory, however, did not measurably improve over twelve weeks. Everyone was 65 or older and had mild cognitive impairment, a stage where memory slips more than usual. Chance decided which of the 52 participants took 1,000 milligrams of NR a day and which took a dummy pill. Forty-two finished the study. Blood flow to the brain as a whole and blood pressure showed no clear change either. Nobody had serious side effects. An extra analysis hinted at more blood flow in the left hippocampus, one specific brain region. That signal is shaky, because when many regions are tested, one hit can easily be chance. The trial was small and lasted only twelve weeks, so smaller effects may have gone unnoticed.
- Nasal NAD Helps Mice With Lost Smell Find Hidden FoodPreliminaryn = 402026Experimental & molecular medicineLosing the sense of smell has no established treatment. In mice, NAD, a molecule cells use to make energy, brought smell back to a large degree when given into the nose. After four weeks the animals found buried food much better than untreated mice. Their damaged smell lining had also largely grown back. The researchers wiped out smell with zinc sulfate in the nose. Groups of ten mice then got NAD on weekdays, a salt solution, or a weekly shot of dexamethasone, a cortisone-like drug. The smell lining in the NAD group measured 52.9 micrometers on average. Untreated mice had 15.2, the dexamethasone group 31.0, and healthy mice 61.6 micrometers. In lab dishes, human stem cells taken from nasal tissue turned into smell nerve cells more often when given NAD. The smell loss here was caused by a chemical and may differ from loss after a cold or with age. The authors note that cells in a dish do not fully mirror the body. Whether an NAD nose treatment restores smell in people was not tested.
How this map is computed
A mark's size is the number of papers we hold on that pairing. It is a count, not a weighting by study design or sample size.
The fill shows the strongest grade in the cell. One Strong paper among four Preliminary ones still fills it dark, so open the cell to see the rest.
Grades and verdicts are assigned by a named person, never by counting.
An empty cell means our library holds no paper on that pairing yet. It is a gap in our library, not proof that nobody has studied it.