Coffee is the most commonly consumed beverage in the world, aside from water. It helps millions of people wake up first thing in the morning or stay awake during an afternoon slump. In fact, the caffeine that’s such an essential ingredient in coffee, is a natural substance that works by stimulating the brain and central nervous system, helping you stay alert and preventing the onset of tiredness.
So, where do you find caffeine, aside from your local coffee shop?
Caffeine is naturally found in the seeds, nuts, or leaves of certain plants. These natural sources are then harvested and processed to produce caffeinated foods and beverages, usually as coffee.
Here are the amounts of caffeine expected per 8-ounce (240-mL) serving of some popular beverages:
- Espresso: 240–720 mg
- Coffee: 102–200 mg
- Energy drinks: 50–160 mg
- Brewed tea: 40–120 mg
- Soft drinks: 20–40 mg
- Decaffeinated coffee: 3–12 mg
- Cocoa beverage: 2–7 mg
- Chocolate milk: 2–7 mg
Both the U.S. Department of Agriculture (USDA) and the European Food Safety Authority (EFSA) consider a daily intake of 400 mg of caffeine to be safe. This amounts to 2 to 4 cups of coffee per day.
Some foods also contain caffeine. For instance, 1 ounce (28 grams) of milk chocolate contains 1–15 mg, whereas 1 ounce of dark chocolate has 5–35 mg.
Once consumed, caffeine is quickly absorbed from the gut into the bloodstream where it travels to the liver and is broken down in various compounds, affecting the body’s different organs, most notably the brain.
Eighty percent of the world’s population consumes a caffeinated product each day, and this number goes up to 90 percent for adults in North America.
Drinking coffee has been associated with a decreased risk of cancers, diabetes, Parkinson’s disease, liver disease, cardiovascular disease, suicide, and better memory and alertness, along with a host of other health benefits.
Caffeine and Hearing Loss
But what about the connection between caffeine and hearing loss/tinnitus? Does drinking coffee have any impact on the risks for those conditions?
That’s what researchers wanted to know when they evaluated hearing and tinnitus data from the 2009 to 2012 Korean National Health and Nutrition Examination Survey and their relationship with a coffee consumption survey.
All patients underwent a medical interview, physical examination, hearing test, tinnitus questionnaire and nutrition examination. The researchers evaluated 13,448 participants over 19 years old. The frequency of coffee consumption had a statistically significant inverse correlation with bilateral hearing loss in the 40 to 64-year-old age group.
This study showed that daily coffee consumers had 50 to 70 percent less hearing loss than those who rarely drank coffee, which tended to be a dose-dependent relationship. In addition, the frequency of coffee consumption had an inverse correlation with tinnitus in those 19 to 64 years old, but its association was related with hearing. Brewed coffee had more of an association than instant or canned coffee in the 40 to 64-year-old age group. These results suggest coffee has a protective effect on hearing loss and tinnitus.
Bottom line? Add the reduced risk of hearing loss/tinnitus to the many reasons to start your day with a “cup of Joe.” Just don’t overdo it. Drinking coffee, or any beverage that contains caffeine, may be safe, but habit forming. Side effects linked to excess coffee consumption include anxiety, restlessness, tremors, irregular heartbeat, trouble sleeping, headaches and high blood pressure. Caffeine also can interact with some medications.