In recent years, caffeine’s approval rating has been rising among the medical community.
The substance has been shown to relieve pain, reduce the risk of more than a few cancers and lower blood pressure, among many other benefits. Of course, too much of a good thing can have consequences and it is important to be mindful of how the drug affects you.
What is caffeine?
Believe it or not, caffeine is the most commonly consumed psychoactive drug according to Mary M. Sweeny, a researcher and instructor in the Department of Psychiatry and Behavioral Sciences at the Johns Hopkins University School of medicine. She goes on to say that, just like any drug, “when we consume caffeine, it has positive effects… and people like these beneficial effects.”
It works by binding to adenosine receptors located in the central and peripheral nervous systems and in various organs such as the heart and blood vessels. Adenosine is a molecule that plays a part in energy transfer and signaling, and is also used in medication to treat irregular heartbeats and during heart stress tests. Like any molecule in the body, too much or too little can be a bad thing, so it is important to maintain an amount that your body reacts safely to.
Because caffeine is a drug, the body reacts and adjusts to the increased adenosine receptor bindings by creating less molecules that organically do so. In its balancing act, the body becomes dependent on the caffeine molecules to participate in the energy transfer and signaling that adenosine naturally does. Because of this, tolerance and symptoms of withdrawal are very real with caffeine consumption.
“Caffeine is so ingrained in our day-to-day habits that we don’t think of it as a source of a potential problem,” says Sweeny, “but it’s important to be aware that it has psychoactive affects, and can interfere with things in ways we don’t expect.”
How does caffeine affect different people?
An 8-ounce cup of brewed coffee can contain 75 to 165 milligrams of caffeine, depending on the source, says a study published in Food and Toxicology. Another study supported consumption of about 400 milligrams daily in adults as not being associated with overt or adverse effects. But of course that varies from person to person. An intake of under 300 milligrams daily was deemed appropriate for pregnant women and an intake of under 2.5 milligrams per kilogram daily in children and adolescents was deemed acceptable.
The American College of Obstetricians and Gynecologists, however, cautions pregnant women to limit caffeine intake to 200 mg/day.
As it turns out, the half-life of caffeine is anywhere between 8.3 to 16 hours longer during pregnancy. This means that the effects of caffeine on the body will be longer lasting and since caffeine may impact brain development, it should be taken into account when considering safety issues. While there will be no damaging effects on a growing fetus, contraceptives can have the same effect on the molecule’s half-life and is important to note.
Other factors that may increase the effects of caffeine on the system are steroid hormones and substantial alcohol intake. Cigarette smoking actually increases the rate that caffeine is metabolized and therefore decreases its effects on the body.
When might it be wise to cut back?
An estimated 90% of the US population regularly consume caffeine, and while it has been enjoyed by many cultures for thousands of years, there may be reasons for you to cut back on your intake, and even cut it completely out of your daily routine.
Dr. Vince Bufalino, a spokesperson for the American Heart Association and senior vice president and senior medical director of Cardiology-AMG, Advocate Health Care, in Naperville, Illinois says that because caffeine can aggravate and accelerate one’s heart rate, it can be a problem for those with an existing heart condition. And if you are sensitive to caffeine, you should cut it out completely.
If you are looking to decrease your daily caffeine consumption or even remove it from your life entirely, there are a few tips CNN Health recommends:
- Keep a caffeine diary.
- Know all of the sources of caffeine in your diet.
- Gradually cut back on the number of cups of coffee you have a day.
- Try coffee alternatives, such as green or black tea.
- Anticipate when caffeine cravings may occur.
When it comes to your daily caffeine intake, simply be smart and aware of your consumption, know how it affects you personally, and react accordingly.