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Homocysteine, Hearing Loss and NAD

Friday, June 21, 2019

Hearing loss puts considerable burden on sufferers and those with whom they associate.

The National Institute on Deafness and Other Communication Disorders (NIDCD) reports that more than 37 million American adults have some degree of hearing loss, with more than 30 percent of adults between 65 and 74 years of age being hearing impaired.

The Blue Mountains Hearing Study (BMHS) evaluated hearing in 2,956 subjects who were part of the famous Blue Mountains Eye Study. The subjects were evaluated for serum concentrations of the amino acid homocysteine, folate and vitamin B12. This is the largest community-based cohort to have assessed the association between serum homocysteine concentrations, B vitamins and age-related hearing loss.

The BMHS results showed that nearly two-thirds of the subjects with elevated serum homocysteine suffered hearing loss compared with less than one-third of those with normal serum homocysteine levels.

The study participants with the highest homocysteine levels were 32 percent more likely to have hearing loss.

Homocysteine levels are elevated during B vitamin deficiency and thought to be both a vascular toxin and neurotoxin. It's suggested that poor B vitamin status, particularly folate, could adversely influence the vascular and nervous system structure and function of the auditory system due to the role it plays in cellular metabolism, vascular perfusion and myelin synthesis.

In another US hearing loss study on 55 women over the age of 60, serum vitamin B12 and folate levels were inversely associated with hearing loss in both unadjusted and age-adjusted analyses. However, it’s also important to report that a Danish study on 91 adults aged 67 through 88 demonstrated non-significant associations between serum folate, B vitamins, homocysteine and hearing loss.

Enter NAD: ​​​As we age, peer-reviewed science now suggests that our levels of the coenzyme nicotinamide adenine dinucleotide (NAD) may decrease by as much as 50%.

This matters because NAD does a lot of important things in our bodies. It helps our mitochondria create energy from food. It’s essential to our bodies DNA repair system. It also activates a group of genes called sirtuins, which are so important to the aging process they’ve been nicknamed the “healthy longevity genes.”

​​Interestingly, vitamin B3 (niacin) seems to be the precursor to NAD, again suggesting that B vitamins and possibly homocysteine levels may very well be markers for impending hearing loss, as well as many other diseases of aging. The amino acid tryptophan is also a precursor to NAD.

Those who are particularly interested in NAD science will want to spend some time reading an article published in Nature, as well as in the December, 2018 publication from the Buck Research Institute on Aging. It's titled A perennial molecule that treats pellagra and pauses aging. 

Ellen Troyer ​and the Biosyntrx staff


The ongoing question: Is an elevated homocysteine level a direct cause of diseased eyes, ears, heart and brain, or is an elevated homocysteine level simply a marker for dysfunctional metabolism and B vitamin deficiency?

We vote for the later and strongly recommend homocysteine testing as part of every annual physical. Given that aging is the major risk factor for disease, lifestyle choices and medical technology ​will, no doubt, prove to be t​wo of the most important keys to extending active health span well into our med 90s.