Coffee accounts for 54% of the caffeine consumption in the world, and caffeine is addictive! However, increasing number of people are avoiding coffee because of an awareness about its negative effects.1 Unfortunately, quitting coffee is not good enough to get rid of caffeine.
Other foods and beverages that you least expect contain caffeine. Some reports say that they are found in foods like energy bars, jelly beans, mints, and peanut butter and even beverages like green tea. Here’s a table of some of the most common products used in our daily lives that contain caffeine.
Common Products That Contain Caffeine
A lot of us switch to tea to cut down caffeine. However, tea also contains caffeine and accounts for 43% of the total caffeine consumption.2 This list could help you figure out what to avoid.
|Products||Serving Size (oz)||Caffeine (mg)|
|Store-bought black tea||8||55|
|Store-bought instant tea (unsweetened)||8||26|
|Store-bought green tea||8||45|
|Store-bought green tea||8||45|
|Energy drinks||16||140–175 (approx)|
|Medications (some drugs that increase alertness and relieve pain)||65–200 (depending on the dosage)|
How Much Is Too Much Caffeine
The European Food Safety Authority and the U.S Food And Drug Administration has cited 400 mg per day of caffeine from all sources as the amount that generally will not result in negative effects. This is approximately three to four 8-oz cups of coffee.34 Doses higher than the recommended intake may have potent effects on the body.
However, this may not be the same for non-coffee drinkers. For instance, an ounce of store-bought green tea contains 45 mg of caffeine. To overdose on caffeine, you would have to drink at least 12 to 13 cups of this green tea.
Although overdosing seems impossible, it should also be noted that eating and drinking other foods and beverages that contain caffeine can increase the caffeine intake. For instance, if you drink 5 cups of green tea and have 3 cans of energy drinks, you’d easily reach the safe caffeine intake limit. Therefore, if you are replacing your daily coffee with other beverages, drink them in moderation to avoid caffeine overdose.
How To Know If You Are Overdosing On Caffeine
Regular consumption of high doses of caffeine, above 400 mg, may cause some side effects to your body. Although these side effects are nonspecific, they may be an indication that you are overdosing on caffeine:5
- Increased heart rate
- Increased breathing rate
- Muscle tremors
If you’ve experienced some of these symptoms, it may be a sign of caffeine overdose. However, if you decide to cut down on your caffeine intake immediately, you may face withdrawal symptoms. This is especially true for those who are dependent on high caffeine doses. Some of the withdrawal symptoms include the following:6
- Decreased energy levels
- Decreased alertness
- Depressed mood
- Difficulty concentrating
Negative Effects Of Too Much Caffeine
- Disrupts sleep: Too much caffeine can reduce sleep quality, especially when the beverage is taken a few hours before bedtime. This is because it hinders the production of melatonin – the sleep hormone.7
- Triggers cortisol production: An overdose of caffeine can trigger the production of the stress hormone, cortisol. When combined with an already stressful lifestyle, the caffeine can result in long-term stress, which can lead to weight gain, diabetes, digestive issues, and poor immune function.8
- Reduces nutrient absorption: Too much caffeine in the body can hinder the absorption of nutrients like iron, calcium, magnesium, zinc, and B vitamins. Over time, this may reduce energy levels and lead to conditions related to nutrient deficiencies.9
- Impacts hormone levels: Increased levels of caffeine may cause adrenals to produce more epinephrine and norepinephrine – the flight or fight hormones that are produced when the body is under stress. The increased hormone production may weaken the adrenals, causing a hormonal imbalance.
- May worsen GERD symptoms: Large doses of caffeine can stimulate gastric acid secretion and thus worsen the symptoms of gastroesophageal reflux disease (GERD).10
Although rare, research states that caffeine overdose ingested over short periods of time can be fatal. One study stated that over-the-counter supplements used to reduce fatigue contain 100–200 mg caffeine per tablet. Caffeine intoxication can lead to death.1112
The bottom line is that light-to-moderate caffeine may not pose a threat to health. However, high doses of caffeine may interfere with day-to-day activities and even cause serious health issues.
|↑1, ↑2, ↑5||Sleep and Caffeine. Sleep Education.|
|↑3||Caffeine and Kids: FDA Takes a Closer Look. U.S Food And Drug Administration.|
|↑4||Guidelines on caffeine intake. Coffee&Health.|
|↑6||Juliano, Laura M., and Roland R. Griffiths. “A critical review of caffeine withdrawal: empirical validation of symptoms and signs, incidence, severity, and associated features.” Psychopharmacology 176, no. 1 (2004): 1-29.|
|↑7||Shilo, Lotan, Hussam Sabbah, Ruth Hadari, Susy Kovatz, Uzi Weinberg, Sara Dolev, Yaron Dagan, and Louis Shenkman. “The effects of coffee consumption on sleep and melatonin secretion.” Sleep medicine 3, no. 3 (2002): 271-273.|
|↑8||Lovallo, William R., Noha H. Farag, Andrea S. Vincent, Terrie L. Thomas, and Michael F. Wilson. “Cortisol responses to mental stress, exercise, and meals following caffeine intake in men and women.” Pharmacology Biochemistry and Behavior 83, no. 3 (2006): 441-447.|
|↑9||Morck, Timothy A., S. R. Lynch, and J. D. Cook. “Inhibition of food iron absorption by coffee.” The American journal of clinical nutrition 37, no. 3 (1983): 416-420.|
|↑10||Cohen, Sidney, and Glenn H. Booth Jr. “Gastric acid secretion and lower-esophageal-sphincter pressure in response to coffee and caffeine.” New England Journal of Medicine 293, no. 18 (1975): 897-899.|
|↑11||Kerrigan, Sarah, and Tania Lindsey. “Fatal caffeine overdose: two case reports.” Forensic Science International 153, no. 1 (2005): 67-69.|
|↑12||Mrvos, R. M., P. E. Reilly, B. S. Dean, and E. P. Krenzelok. “Massive caffeine ingestion resulting in death.” Veterinary and human toxicology 31, no. 6 (1989): 571-572.|