alzheimer’s prevention linked to vitamin b3 family

the research confirms what we already know about the prevention of neurodegenerative diseases — that a healthy lifestyle, including exercise and a nutritious diet, is good for our brains.

by dave yasvinski

published mar 01, 2023

4 minute read

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4 minute read

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imagine if we could stop brain disease with lifestyle choices? getty

a new study has found that a supplement belonging to the vitamin b3 family can enter the brain and may even alter the metabolism of biological pathways associated with alzheimer’s and other neurodegenerative diseases. according to the research, published in the journal aging cell, consuming nicotinamide riboside (nr) (found in fruits, vegetables, meat, and milk) causes it to be converted into nicotinamide adenine dinucleotide (nad+), a coenzyme critical to repairing cells and damaged dna. researchers suspect the depletion of nad+ may have wide-ranging consequences for human health.

“nad+ is gradually lost as we get older or develop chronic diseases,” said christopher martens, assistant professor of kinesiology and applied physiology and director of the delaware center for cognitive aging research. “loss of nad+ is linked to obesity and other negative lifestyle habits like smoking. because more nad+ is needed to counteract those negative consequences, it’s more likely to be depleted in the face of negative lifestyle habits.”

there are other reasons we lose nad+, according to the biostation, including overeating, high blood sugar, and alcohol consumption. you can boost nad+ levels naturally by exercising, fasting, restricting calories and consuming fermented foods, milk, green vegetables, fish and whole grains.

what is alzheimer’s disease?

falzheimer’s disease is a chronic condition that is believed to be the result of the accumulation of certain proteins in the brain that leads to the slow death of neurons, according to the alzheimer’s association. this process eventually produces symptoms of memory loss, difficulty thinking or changes in mood and behaviour. the disease is the most common cause of dementia, accounting for 60 to 80 per cent of all cases, and more than 747,000 canadians are currently living with alzheimer’s or another form of dementia.

martens had previously discovered that ingesting nr boosted levels of nad+ in the blood but it was unclear if these benefits extended to the body’s harder-to-reach tissues.

“we had some preliminary signs of efficacy, including lower blood pressure in people who had high blood pressure to begin with,” he said. “but until now, it was unknown whether nr reached targeted organs like the brain to have a real therapeutic effect.”

the reason for the uncertainty is that it is difficult to measure nad+ levels in the brain. new mri techniques provide useful information but are expensive and offer only indirect measurements. instead, the team measured nad+ by looking at extracellular vesicles — tiny particles in the blood that originated from neurons. by using these vesicles as a new form of blood-based biomarker for brain disorders, the team could essentially view a “liquid biopsy” of the brain’s neurons.

“each vesicle has a unique molecular signature on its surface, including proteins that give you clues about its origin,” martens said. “in our case, we selected vesicles that carry markers that are characteristic of neurons, and so we have confidence that the nad+ we measured in them reflects what happens in the neurons and by extension the brain.”

using samples from their first initial clinical trial, they discovered that levels of nad+ increased in vesicles roughly six weeks after ingesting nr. “when nad+ goes up in these vesicles, we see an association with some of the biomarkers of neurodegenerative disease,” martens said. “particularly, in people where we saw an increase in nad+, we also saw changes in biomarkers like amyloid beta and tau, which are both related to alzheimer’s disease.”

they also found a correlation between these neurodegenerative biomarkers and changes in nad+. “if nad+ went up a lot, there was typically a larger change in some of the disease biomarkers,” martens said. “that tells us the nad+ is not only getting into the brain but it’s likely also having some effect on its metabolism and multiple interrelated pathways.”

the team hopes these new blood-based biomarkers will help reveal if nad+ depletion causes alzheimer’s or other neurodegenerative disorders and even open the door to providing a reliable way to test for difficult-to-diagnose diseases.

martens is currently leading a 12-week study to examine the relationship between nr and cognitive impairment in older adults. he hopes to determine if the supplement is more effective in people who are already suffering from impairment.

“they’re coming in with cognitive deficits and as a result are more likely to have an accumulation of some of these biomarkers in their brain, so there’s a chance we’ll see bigger reductions in these biomarkers because they have more of them in their cells,” martens said.

“we’re measuring markers of cognitive function and other things related to functional independence and quality of life but we’re also hoping to gain some insight on the underlying disease process,” martens said. “we’re hoping that the people who take the nr might have preserved function.”

if they are able to prove the efficacy of nr, the team plans to test whether increased use of the supplement can improve cognition and even slow the progression of neurodegenerative diseases.

“we were among the first to do a chronic dosing study in humans, and as a result, we’ve been at the forefront of this field for a few years,” martens said. “now, we’re at a turning point, where we can start to determine whether nad+ increases in other tissues as well and that’s likely where the more important signal will be in terms of resolving disease.”