20+ Harmful Effects of Caffeine


The harmful effects of caffeine are sometimes harder to find information on than all of the reported positives.

Here are a few of the studies that concluded that caffeine could be potentially dangerous to one’s health.

Research Showing Harmful Effects of Caffeine

  1. More than 4 cups of coffee linked to early death. A Mayo Clinic partnered study found that men who drank more than four 8 fl.oz. cups of coffee had a 21% increase in all-cause mortality. However, those that reported that they consumed excessive amounts of caffeine were also likely to smoke and have poor fitness. Dr. Nancy Snyderman from NBC said there were a few discrepancies with the study, but stresses that moderation is still key. See Her Interview Here.
  2. Caffeine consumption may raise blood pressure. Especially in those already suffering from hypertension and those who don’t normally consume caffeine. People with hypertension were given 250 mg of caffeine (about 2 coffees) and the data revealed that their blood pressure was elevated for about 2-3 hours after the caffeine. Src. A second study performed by The Mayo Clinic found similar results from a 160 mg dose. All participants experienced a marked rise in blood pressure and it was the most pronounced in those that didn’t normally consume caffeine. Src.
  3. Increased risk of heart attacks among young adults. A study conducted by Dr. Lucio Mos found that young adults who were diagnosed with mild hypertension had 4 times the risk of having a heart attack if they consumed the amount of caffeine equivalent to 4 cups of coffee.  More moderate consumption showed 3 times the risk. Src.
  4. Caffeine linked to gout attacks. This study showed that people who binge on caffeinated beverages increase their risk for a gout flare-up. Src.
  5. Breast Tissue Cysts In Women. One study showed that “Women who consumed 31–250 mg of caffeine/day had a 1.5-fold increase in the odds of developing fibrocystic breast disease and women who drank over 500 mg/day had a 2.3-fold increase in the odds of developing cysts. Src.
  6. Caffeine could cause incontinence. A study out of the University of Alabama showed that women who consume a lot of caffeine are 70% more likely to develop incontinence. Src.
  7. Caffeine may cause insomnia. Caffeine in a person’s system at bedtime can mimic the symptoms of insomnia. Src.
  8. Caffeine can cause indigestion. People who consume caffeinated beverages often report an upset stomach or indigestion. This mainly occurs when the beverages are consumed on an empty stomach. Src.
  9. Caffeine can cause headaches. While occasional doses of caffeine can relieve headache symptoms, the overuse of caffeine can cause headaches and lead to migraines. Src.
  10. Caffeine could reduce fertility in women. A study from The University of Nevada School of Medicine showed that caffeine can reduce a woman’s chances of becoming pregnant by about 27%. Src.
  11. Caffeine and Miscarriage Risk: In a recent study, both men and women who consumed at least two caffeinated beverages a day during the weeks prior to conception slightly increased the risks of a miscarriage. Src.
  12. Caffeine may not be healthy for type 2 diabetics. A study conducted by the American Diabetes Association showed that caffeine impaired glucose metabolism in those with type 2 diabetes. Src.
  13. Caffeine Overdose. While overdose is rare, it can lead to many adverse symptoms including death, especially in those with underlying medical conditions. Some have a lower tolerance for caffeine than others. Src.
  14. Caffeine Allergies. Some people have over-sensitivity to the caffeine molecule, which causes allergic-like reactions in the body such as hives and pain. Although not a true allergy, many report very negative symptoms after consuming even the smallest amounts. Src.
  15. Caffeine causes more forceful heart contractions. A recent study showed that immediately after energy drink consumption the heart produced more forceful contractions. It is unclear if this has any long-term health implications except for those with known health conditions. Src.
  16. Worse Menopause Symptoms. A recent study published in The Journal of The North American Menopause Society showed that menopausal women who consumed caffeine had a greater degree of vasomotor symptoms. Src.
  17. Caffeine consumption can lead to increased anxiety, depression and the need for anxiety medication. Src and Src. See also our article as to why caffeine causes anxiety and panic attacks.
  18. Caffeine increases the amount of sugary beverages consumed by people, which contributes to obesity and diabetes. Src.
  19. Caffeine inhibits collagen production in the skin. This effect is dose-dependent but really heavy caffeine consumers should be aware. The Study.
  20. Caffeine interferes with ossification and could also lead to greater risk of bone fractures. This is dose dependent, but heavy caffeine consumers should take note. Study 1 (pdf) Study 2.
  21. Caffeine Does Not Help With Prolonged Sleep Deprivation: This can lead to a false sense of security for those that have been sleep deprived for multiple days in a row and choose to get behind the wheel or do some other focus required task, thinking that as long as they have caffeine, they’ll be able to perform. Researchers from the American Academy of Sleep Medicine came to this conclusion after studying caffeine’s effects on their sleep-deprived test subjects. Here’s the study in detail.
  22. Caffeine May Impair Hearing Loss Recovery: For guinea pigs exposed to excessive levels of noise, caffeine was shown to delay the rate at which the guinea pigs recovered from noise-induced hearing loss. Here are the results of a recent study that investigated the problem. A correlation to humans is believed to exist but more research will be needed.

When not managed caffeine can quickly become an out of control problem.

If you are experiencing any tell-tale signs of the risks above, then it’s time to start cutting back. Otherwise, it’s just a matter of time. If cold turkey is no longer a valid approach for you, or if you’ve failed in the past, then we recommend looking at the Wean Caffeine detox. With Wean, you slowly reduce your caffeine intake with their daily supplement protocol and comprehensive caffeine detox book. This may be the best $20 you’ve ever spent.

Other Claims Against Caffeine

You may have heard or read about other negative health effects from caffeine consumption, but as of now, there just isn’t enough evidence to fully endorse those as legitimate health concerns.

Some of those negatives include:

  • Adrenal fatigue
  • Irregular heartbeat
  • Hallucinations
  • Accelerates bone loss. Src.
  • Tremors

Caffeine is a drug and can affect people differently just like any other substance. It’s important that consumers understand how caffeine interacts with their bodies in regards to their personal health histories.

The food and beverage industry spends millions, if not billions, of dollars worldwide to fund studies and promote caffeinated products as safe or even healthy.

Fortunately, caffeine is one of the most researched substances on the planet and there does exist some unbiased data in which to glean some reliable information from.

While much of the research published does allude to the safety and even potential benefits of caffeine (in moderation), there are a handful of research studies that highlight the potentially harmful effects of caffeine.

The risks of suffering from any of the harmful effects of caffeine are diminished by being aware of how much is personally being consumed daily.

It is also important to be aware of any pre-existing medical conditions that may contribute to caffeine’s negative effects.

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  • zazz82

    Coffee,tea, cocoa, and kola nut all contain caffeine as well as two other stimulants called, theobromine ( formally known as xantheose) and theophylline. Theophylline is used to treat respitory disorders but is a very dangerous substance regardless because of its very narrow therapeutic index. Theophylline is easy to overdose on so it must be closely monitered. Theobromine can induce mutations within the genes. The amounts of these stimulants within these plants that we consume vary from plant to plant, plus each individual person is affected differently who consumes these stimulants. Too much of anything one eats or drinks is never good for you. Some, such as myself ,are extremely sensitive to caffeine and can hardly consume any at all. The fact of the matter is, is that caffeine, theobromine, and theophylline are drugs, and the FDA allows these drugs to be available to any and everyone with no objections, especially caffiene. Caffeine, theobromine, theophylline are the toxins that the plants that contain them use to deter and or kill the creature trying to eat them. These stimulants are corrosive to our health unless used properly for medical reasons. I am no different than anyone else though, I love chocolate, soda, tea, and coffee as much as the next person and would love to enjoy them more often if I could like when I was younger and had a higher tolerance them. My point is caffeine, theobromine, theophylline, are all in the long run just plain bad for you. In my personal opinion, energy drinks ought to be outlawed, that crap is no better than snorting cocaine. It would be great to find a way to completely extract all harmful stimulants from our favorite drinks and foods so we could enjoy them safely. I’ll keep the sugar though, in moderation of course.

  • disqus_973nwf4tHB

    smoke weed get drunk

  • disqus_973nwf4tHB

    smoke weed every day

  • disqus_973nwf4tHB

    who the hell wrote this

  • Mcplayer

    Caffeine is in alot of things we can’t really stop, but i here what you are saying

  • Solon

    ask yourself if you can stop consuming caffeine? Don’t lie. There’s the answer to how powerfully addicted you are. We have used drugs like coffee to fill in laconas in our lives that we don’t even always consciously notice. That’s why some people get more addicted than others. It’s all mental health at the end of the day. Caffeine is so spookily omnipotent; even at AA meetings they give it out!

  • Glodus Mc

    This is bullshit. I don’t believe that

  • Glodus Mc

    Any unnatural Sugar is one which harmful to health

  • Anaiah Jandhi

    Hello. Well, I am still a college student and doing my internship now. I always love to drink coffee since it makes me wide awake whole day. I started drinking coffee since I started my internship (Dec 2014). I drink at least 2 cups a day at first and then I drink 2 50g sachets of coffee in one 500 ml bottle (because I am drinking it cold). Since then, I observe that I cannot go to sleep until 12MN and I always feel my heartbeats fast. I palpitate almost everyday (I have history). But I really feel that coffee releases my stress. Now, I sometimes feel dizzy after I drink that dose of coffee .. But I can’t help. It helps me not to stress out. Do you have any advise ?

  • Ted

    Sounds like you need to cut back. I would suggest not having it after 12 noon and sticking to no more than 2 coffees a day. This is especially important if you have an existing heart arrhythmia.

  • Mark

    Caffen is not good for the body remember how you live with out it, befor you started drinking coffe that’s the life you can get back. but you need to stop drinking coffe to get the benefit

  • Anaiah Jandhi

    Thanks @CaffeineInformer:disqus Yes .. Actually, I have arrhythmia. Is there any difference if I drink my coffee before 12 ?

  • Ted

    Having it only before 12 helps with it not interfering with your sleep.

  • James Day

    I enjoy caffeine, I drink about eight cups of coffee every morning. I drink half a gallon of green tea during the day. I enjoy chocolate especially dark chocolate. I e-vape caffeine juice throughout the day. I sleep perfectly fine, I’m not nervous. I don’t have eating disorders. I don’t have mental problems. I have no health problems. I’m 41 years old.

  • There is a lot of those sources that are not really reliable. Check it before post it.

  • JamesF

    Which medical journal is unreliable? Would be good to know…

  • Anaiah Jandhi

    Thanks for the tip 🙂 .. Call me non-sense but I didn’t know it actually. It’s a big help

  • Ted

    Not at all. That’s why we are here. 🙂

  • Gene E

    What are you interning in? I hope its not medicine!

  • G Erwin

    I like you comments! Very informative!

Last Modified: November 9, 2017