The simple answer is coffee's high caffeine content. Whether you get your fix from sodas, coffee or tea, this natural compound is involved in two distinct mechanisms that get your heart racing.
Caffeine blocks the body's natural tranquilizing ability by inhibiting the way brain cells interact with another chemical called adenosine.
Caffeine also increases the amount of dopamine, the 'feel good chemical' in the body.
Dopamine is a member of the class of chemical compounds known as neurotransmitters, which facilitate communication between nerve cells.
"Adenosine acts as a sedative in the brain - it makes you sleepy," said Joel Linden, professor of cardiovascular medicine and biophysics and molecular physiology. "Caffeine, by blocking the adenosine receptor, blocks the sleepiness and has a stimulative effect."
The surfaces of brain cells are covered with adenosine receptors, which are proteins that act like docking stations for chemicals.
Usually receptors are specific - only molecules of a certain size and shape are allowed to dock - but caffeine is able to sneak in and take up the space reserved for adenosine.
Once caffeine interacts with brain cell receptor molecules, a cascade of events occurs that leads to increased levels of alertness.
First, the blood vessels leading to the brain constrict, increasing blood pressure at the surface of the brain.
Caffeine also increases brain cell activity, eventually resulting in an increased production of adrenaline, "the fight or flight" hormone.
Adrenaline affects many parts of the body and is responsible for the increased alertness often experienced after drinking caffeinated beverages.
Caffeine also prevents dopamine uptake in the bloodstream. This leaves more dopamine in the body, often creating a pleasurable euphoria.
"A lot of the things that people use to feel good, alcohol and nicotine, increase the amount of dopamine in your brain," Neurobiology Prof. Barry Condron said. "There's a thought that caffeine may have some of that effect."
Caffeine, however, doesn't always make you feel good. If your morning routine includes downing a few cups of coffee, you might experience withdrawal after forgetting the ritual.
Abnormal blood flow to the brain causes caffeine headaches. According to Linden, one possible explanation is that brain cell adenosine receptors become hyper-responsive after excessive interaction with caffeine.
The super-sensitive receptors overreact, dilating blood vessels leading to the brain and causing a headache.
Is caffeine addiction dangerous?
Caffeine addiction is real but not as severe as other drugs.
"Caffeine is a potentially addictive substance, but I don't think that that is common," Condron said. "I think most people who drink two or three cups of coffee a day don't have any serious side effects if they don't have it."
Caffeine consumption can complicate certain conditions, but for the majority of people it is harmless.
According to Linden, caffeine has some effects that may be a mild health risk to certain individuals, such as those with heart disease or hypertension.
"So people with heart disease are sometimes advised to stay off of caffeine," he said. "But for the general population that is in good health, the effects of caffeine, even of long term usage, are minimal."
- Compiled by Jennifer Neal
(Submit health and science questions to cavdaily@cavalierdaily.com)
Read More
Dean Rucker honored with Z Society’s highest honor, Pale Z Award
By Brendon Bordwine | 16 hours agoThe Society has a storied history of honoring University leaders with the Pale Z.
Students receive free STI testing through U.Va. Health and Wellness
By Jackie Bond | YesterdayThrough funding from Student Council, students are now able to receive free STI testing with SHW which includes tests for HIV, Syphilis, Gonorrhea, Chlamydia and Hepatitis C.
President Ryan signs collective statement condemning Trump administration
By Cecilia Mould | YesterdayWhile the statement claims that signees are willing to enact reforms and cooperate with government supervision, it disagrees with the current administration’s decision to withdraw funding from institutions.
