March is Caffeine Awareness Month and Americans love caffeine. About 90 percent of Americans consume caffeine in one form or another every single day. More than half of all American adults consume more than 300 milligrams of caffeine every day, making it by far America’s most popular drug. How does caffeine work? How do we get our caffeine? Are there any health benefits to caffeine consumption? Is caffeine harmful? What is the recommended amount of caffeine?

How Does Caffeine Work?

Caffeine works by blocking an inhibitory neurotransmitter called adenosine. By blocking adenosine, caffeine increases the firing of neurons and stimulates the release of neurotransmitters like dopamine and norepinephrine. This, in turn, makes you feel more energized and awake.

Caffeine Intake

We consume caffeine through various ways. However the most popular way to consume caffeine is coffee. A study commissioned by the National Coffee Association surveyed 3,000 Americans about their coffee drinking habits. The findings show 64 percent of Americans drink a cup of coffee every day, up from 62 percent in 2017, and the highest percentage since 2012. Energy drinks are also a popular way in which Americans consume caffeine. The U.S. energy drink market is mainly dominated by key players such as Red Bull, Monster Beverage and Rockstar, based on 2016 sales. Red Bull generated $3 billion in U.S. sales with its energy drink that “gives you wings.” Monster Energy reported $1.5 billion in U.S. sales. According to a recent consumer survey, about 47 percent of respondents reported consuming energy drinks several times per week. You can also consume caffeine by drinking a soda or tea or eating chocolate.

Benefits of Caffeine

We all know that caffeine can give us a morning jump start. There is some scientific research that shows benefits. In Japan, researchers have shown that caffeine improves memory. Also, a new study out of Johns Hopkins University showed that a 200 mg caffeine pill helped boost memory consolidation. Research shows that those who consume coffee are at less risk of developing Parkinson’s disease, and it even reduces the risk of those who are more likely to develop the condition genetically. Caffeine also reduces kidney stone risk. In a large, 217,883-person study, those who consumed caffeine from any source had less kidney stone formation than those who did not consume caffeine. The researchers believe that this is because caffeine makes urine more dilute.

Exercisers and athletes also benefit from caffeine. Carbohydrates mixed with caffeine replenish muscle glycogen concentrations faster after exercise allowing for a shorter recovery time. It also increases stamina during exercise and relieves post-workout muscle pain by up to 48 percent. Caffeine can also assist with weight loss. The rate at which you burn calories at rest is called resting metabolic rate. The higher your metabolic rate, the easier it is for you to lose weight and the more you can eat without gaining weight. Studies show that caffeine can increase RMR by 3–11 percent, with larger doses having a greater effect. Interestingly, most of the increase in metabolism is caused by an increase in fat burning. Unfortunately, the effect is less pronounced in those who are obese. One study showed that caffeine increased fat burning by as much as 29 percent in lean people, while the increase was only about 10 percent in obese individuals. This benefit appears to decrease with age.

Harmful Effects of Caffeine

Caffeine has a downside as well. 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 two cups of coffee) and the data revealed that their blood pressure was elevated for about two to three hours after the caffeine. A second study performed by The Mayo Clinic found similar results from a 160 mg dose. There is also an 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 four times the risk of having a heart attack if they consumed the amount of caffeine equivalent to four cups of coffee. More moderate consumption showed three times the risk. Caffeine may cause insomnia as well.

How Much Caffeine Do We Need?

According to the Agriculture Department’s latest Dietary Guidelines for Americans, up to 400 milligrams of caffeine per day can be part of a healthy diet for adults. However, adults with certain health conditions may want to consult with their physician regarding the amount of caffeine that is safe for them. The Food and Drug Administration says 600 mg per day is too much. Sticking with 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That’s roughly the amount of caffeine in four cups of brewed coffee, 10 cans of cola or two “energy shot” drinks. Keep in mind that the actual caffeine content in beverages varies widely, especially among energy drinks.

Russ Sohooli, BS, is an exercise physiologist at the Vidant Wellness Center in Washington and can be reached at 252-975-4236.