by Barry Keate
Oxygen is critical to life, but is also a double-edged sword. While oxygen is necessary to sustain life, too much oxygen in the body’s cells can lead to the production of Reactive Oxygen Species (ROS) molecules. Untold damage is caused to the body by ROS, which we normally refer to as “free radicals”. These dangerous molecules are one of the leading causes of age related disease, being directly responsible for over 100 human diseases including many types of cancer.
Free radicals are produced in normal metabolism when oxygen is used to burn food for energy. They are also produced in certain disease states and in response to environmental pollution and toxins. A free radical is a molecule with an unpaired electron. This makes the molecule unstable and highly reactive, trying to capture an electron that will stabilize it. By capturing electrons from nearby molecules, the free radical converts other molecules to free radicals, thereby initiating a destructive chain reaction.
By producing oxidative damage in DNA, free radicals produce mutations that, over time, can lead to cancer. Oxidative damage begins at birth and is a cumulative risk factor for aging and disease. Stress, infections, inflammation and exposure to pollutants and sunlight all produce free radicals.
The Tinnitus Connection
Antioxidants are chemical substances that donate an electron to the free radical and convert it to a harmless molecule. In this way, antioxidants intercept free radicals and protect cells from the oxidative damage that leads to aging and disease. Antioxidants prevent injury to blood vessel membranes, helping to optimize blood flow to the heart and brain, defend against cancer causing DNA damage and help lower the risk of tinnitus, cardiovascular disease, and dementia.
Antioxidants come in many forms and are produced in the body or supplied from food or supplements. It is much more effective to supply a broad spectrum of antioxidants than taking mega doses of individual ones. Antioxidants work synergistically to reinforce and regenerate each other.
The body produces antioxidants in the form of enzymes, co-enzymes such as co-enzyme Q10 (C0Q10), and sulfur containing compounds such as glutathione. Antioxidants supplied by food or supplements are categorized as vitamins, minerals and flavonoids and carotenoids.
The primary vitamin antioxidants are Vitamins C and E. Vitamin C is the best known and most mainstream antioxidant. It is found in abundance in fruits and vegetables and prevents oxidation of water-based molecules. It is water soluble and active in liquid areas of the body, such as blood plasma and eye fluids. It is responsible for preventing oxidative damage to DNA and blocks the production of cancer causing nitrosamines in the stomach.
Vitamin E is the best known fat soluble antioxidant and works in fat cell membranes and in circulating cholesterol. The richest source of Vitamin E is found in oils, nuts and grain. Vitamin E protects against heart disease. Oxidation of Low Density Lipoprotein (LDL), the “bad” cholesterol, causes it to stick more easily to blood vessel walls, leading to the formation of plaques in arteries, causing atherosclerosis. If plaques detach as clots, they travel in the circulatory system until they eventually cause heart attacks or strokes. Numerous studies have shown Vitamin E to protect against this particular oxidation. It is also associated with low risk of lung, colon, stomach, breast and cervical cancer.
The vitamin-like antioxidant coenzyme Q10 is found in high quantities in the heart and is also protective of cardiovascular disease. CoQ10 also protects against neurodegenerative diseases such as Alzheimer’s and Parkinson’s. CoQ10 works closely with alpha lipoic acid in reducing brain cell damage. Alpha lipoic acid has the ability to regenerate the antioxidant properties of vitamins C and E. It is both water and fat soluble and can eliminate free radicals in any area of the body.
The minerals selenium and zinc serve as components of antioxidants made by the body. Selenium is a critical component of the antioxidant glutathione while zinc is necessary to maintain vitamin E levels. Zinc is very helpful for tinnitus precisely because of it’s antioxidant properties within the inner ear. The largest concentration of zinc in the body is found in the inner ear. Zinc deficiencies have long been associated with tinnitus and zinc supplementation is a very effective way to manage it. A clinical study showing the effectiveness of zinc supplementation for tinnitus can be found at www.tinnitusformula.com/info/articles/stud/zincstudy.asp.
Flavonoids and Carotenoids
Flavonoids are water soluble compounds that give plants their color. The catechins found in black and green tea are powerful antioxidants. They help explain why Japanese men, who smoke more than their American counterparts, have lower lung cancer rates. They also suppress the growth of many types of cancers produced by chemicals and radiation.
Ginkgo biloba contains ginkgo flavonoids that protect against oxidative damage. Ginkgo is very helpful for tinnitus as shown by the clinical study we recently published. This study can be seen here. Recent studies have shown that ginkgo may also help restore some cognitive function in people with dementia.
Grape seed extracts are twice as powerful as vitamin E and four times stronger than vitamin C. This helps explain the so-called “French Paradox.” While the French diet, high in dietary fats, they experience a lower rate of cardiovascular disease due to the effects of the red wine consumption. The tannins in red wine are known antioxidants. However, more than one or two glasses of red wine per day is considered too much of a “good thing.”
Carotenoids are fat soluble compounds. Perhaps the best known is beta carotene, found in carrots, which converts to vitamin A, an antioxidant. A more powerful carotenoid is lycopene, found in tomatoes. Lycopene protects against prostate cancer and cardiovascular disease.
What this means for tinnitus
Glutamate is a neuro-transmitter used by the ear to transmit signals across the synapse leading to the brain. It is produced by the hair cells of the inner ear when converting vibrational sound into electrical signals. When the hair cells are damaged, they produce excess glutamate which floods the neuro-receptors in the auditory nerve and brain. Excess glutamate becomes toxic to the receptors and eventually kills them. This process is known as glutamate neurotoxicity and is responsible for many neurological diseases such as Parkinson’s disease, Alzheimer’s disease, ALS, epilepsy and tinnitus. Tinnitus caused by glutamate toxicity is called Cochlear-Synaptic Tinnitus.
In the biochemical process leading to receptor death, ROS molecules are generated in very large amounts. However, receptors can prevent ROS damage in the presence of antioxidants. Glutathione is the primary antioxidant produced within the cochlea and helps prevent oxidative damage up to a certain point. The glutathione can eventually be overwhelmed, however, and ROS damage continues, eventually leading to the death of the receptor.
Success with NAC
Richard D. Kopke, MD of the Naval Medical Center in San Diego, CA has been working for years developing an antioxidant treatment for hearing loss and tinnitus. Unfortunately, glutathione, taken as a supplement, is not well absorbed into the cells and is degraded by the liver. Dr. Kopke has therefore been working with N-Acetyl-Cysteine (NAC), a precursor to glutathione. NAC can be absorbed by the cells of the inner ear and gives them the ability to produce excess glutathione.
Dr. Kopke has found that if NAC is given to people before noise exposure, their hearing thresholds remain very close to normal compared to those who do not receive NAC. He has also found that giving people NAC shortly after noise exposure also prevents damage to the hair cells. He is now working to determine whether NAC supplementation can be helpful for those who have long lasting hearing impairment.
A diet containing plenty of fruits and vegetables is important for the intake of antioxidants. It is also wise to take a high quality, full-spectrum antioxidant compound to preserve energy and good health. This is especially true for those of us afflicted with tinnitus.
Michael Seidman, MD has done some groundbreaking work in delivering medications directly into the inner ear to reduce tinnitus. He has concentrated on medications that are glutamate antagonists and antioxidants. A paper on his work in this area can be seen here.