By Barry Keate
Hearing loss is the most common sensory disorder, which affects more than 36 million people in the US and 40 percent of Americans over the age of 65. Hearing loss that progresses with age is termed age-related hearing loss, or presbycusis. As we age, we typically lose hearing, which often leads to the development of tinnitus.
There are new studies that show conclusively that increased consumption of Omega-3 fatty acids, found in fish and fish oil supplements have a direct effect on reducing hearing loss in an aging population.
Omega-3 fatty acids are known to be an essential part of a healthy diet. Omega-3's promote health by reducing inflammation, promoting heart health, improving insulin sensitivity in those with Type 2 Diabetes, as a treatment for depression and to reduce the risk of cancer.
Now, two new studies on the effects of Omega-3 fatty acids on hearing loss are adding to the body of knowledge of the health benefits of fish oil. The Blue Mountains Hearing Study is a population-based survey of age-related hearing loss in Australia. The study was begun in 1997 to 1999 and concluded in 2002 to 2004.
The study included 2,956 participants, aged 50 or older, who were given a food-frequency questionnaire from which Omega-3 fatty acids and fish intakes were calculated. The participants also had hearing loss measured at the beginning. Five years later hearing loss was again measured.
Results showed an inverse relationship between total Omega-3 intake and hearing loss; that is, the higher the intake of fish, the lower the hearing loss. Participants who had two or more servings of fish per week had a 42% reduced risk of developing hearing loss compared to those who had less than one serving per week.
A second study was conducted in the Netherlands. In this study 720 men and women, 50 – 70 years old, had Omega-3 fatty acids measured in blood plasma. Hearing thresholds at baseline and after three years were measured. Hearing loss was calculated in the low frequencies (0.5 – 2 kHz) and high frequencies (4 – 8 kHz) over three years.
Results showed that those who suffered the greatest hearing loss were those with the lowest consumption of Omega-3 fatty acids. Most of the hearing loss occurred in the low frequencies.
Why does the consumption of Omega-3 fatty acids reduce hearing loss over time? What accounts for the other numerous health benefits of fish oil? The mechanism of action for these health benefits is not clearly defined but there are some developing theories that may help explain them.
One theory suggests that just as in other areas of health, the positive effect of Omega-3 fatty acids in improving circulation can also increase circulation in the inner ear, which can have a positive effect on hearing.
Another theory of growing popularity posits that age-related hearing loss occurs due to the loss of nerves, sensory hair and membrane cells within the inner ear. Omega-3 fatty acids help protect cell life by slowing down cell aging. They accomplish this by means of preserving telomeres that bind the end of DNA strands.
Telomeres are a region at the end of a chromosome that binds the DNA information together. A good analogy is the plastic tips that hold the end of a shoelace together. Without telomeres, DNA would unravel during cell duplication and all information would be lost.
The lifespan of cells are linked to their telomeres. As the cells duplicate, the telomeres become shorter and shorter and when they are totally consumed, the cell dies. It has been shown that Omega-3 fatty acids prolong the life to telomeres and therefore cell life.
Researchers in California conducted a clinical study on 608 patients with stable coronary artery disease. Telomere length was recorded at baseline and again after five years. Telomere length was compared to intake of Omega-3 fatty acids. Individuals with the lowest consumption of Omega-3 consumption experienced the fastest rate of telomere shortening by a factor of almost 3, compared with those with the highest consumption.
It’s pretty amazing how science is uncovering a wide range of health conditions that can be benefited by Omega-3 supplementation. It now seems clear that everyone should take a daily dose of fish oil, especially those with, or at risk of, hearing loss.