The study, published in the journal Science, reported that the addition of niacin (vitamin B3) to the diets of young mice that are genetically predisposed to glaucoma prevented early signs of disease onset – and blocked further development of the disease in aged mice that already showed signs of the disease.
“Thus, healthy intake of vitamin B3 may protect eyesight,” wrote the authors – led by Professor Simon John from the The Jackson Laboratory, Tufts University of Medicine and The Howard Hughes Medical Institute.
“Glaucomas are neurodegenerative diseases that cause vision loss, especially in the elderly,” noted the team. “Studying glaucoma-prone mice, we show that mitochondrial abnormalities are an early driver of neuronal dysfunction, occurring before detectable degeneration.”
John and collagues revealed that administration of vitamin B3 I nthe form of nicotinamide was protective both prophylactically and as an intervention.
“At the highest dose tested, 93% of eyes did not develop glaucoma,” the authors reported. “This supports therapeutic use of vitamin B3 in glaucoma and potentially other age-related neurodegenerations.”
Glaucoma is one of the most common neurodegenerative diseases, affecting an estimated 80 million people worldwide.
In most glaucoma patients, harmfully high pressure inside the eye or intraocular pressure leads to the progressive dysfunction and loss of neuronal cells that connect the eye to the brain via the optic nerve – known as retinal ganglion cells.
Increasing age is a key risk factor for glaucoma, contributing to both harmful elevation of intraocular pressure and increased neuronal vulnerability to pressure-induced damage.
"We wanted to identify key age-related susceptibility factors that change with age in the eye (…) and that therefore increase vulnerability to disease and in particular neuronal disease,” commented Professor John.
He commented that in essence, the treatments of vitamin B3 (nicotinamide, an amide form of vitamin B3) boosted the metabolic reliability of ageing retinal ganglion cells, keeping them healthier for longer.
"Because these cells are still healthy, and still metabolically robust, even when high intraocular pressure turns on, they better resist damaging processes,” added study first author Pete Williams.
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