Is it just me, or does it sometimes seem as if every product in the world has the potential to kill us? Especially when it comes to food—the more delicious the item, the more likely it is to result in a premature death. The key word here is probably—there’s conflicting information on alcohol, red meat, fat, carbohydrates, chocolate, and just about anything at all that’s even a tiny bit tasty. Sometimes it seems that the only things safe to consume are leafy greens and low-fat water. But not too much, of course!
Caffeine is one of the most oft-maligned substances in our modern diet, stemming from rumors that it stunts growth, causes brain tumors, and leads to other horrible side effects. Considering that it occurs naturally in coffee and chocolate—two of the most delicious things in the entire world—how could it ever be good for you?
Well, the next time you fill your morning cup o’ joe, relax, because it turns out that consuming caffeine regularly is one of the better things you can do for your health.
The Upside to Uppers
Chemically, caffeine is a stimulant. It works by binding to receptors in the brain that are designated for a sleep chemical. With caffeine blocking those receptor sites, the sleep chemical doesn’t get absorbed, so blood vessels constrict, neurons begin firing, and the pituitary gland responds by releasing adrenaline, causing pupils to dilate, the heart to beat faster, and muscles to get ready for action. The result is a burst of energy and wakefulness.
In the past several decades, researchers have done thousands of studies on caffeine, leading to some surprising findings. The most comprehensive one, conducted at Harvard and following more than 125,000 people over the course of eighteen years, found that people who drank coffee every day were 9 percent less likely to develop diabetes, and the more caffeine they consumed, the smaller the risk. Men and women drinking six or more cups of coffee per day reduced their diabetes risk by 54 percent and 30 percent, respectively. The study also found that regular consumers of caffeine are more than 50 percent less likely to develop Parkinson’s disease, possibly because caffeine keeps dopamine molecules active in the brain and thus prevents plaque buildup. New drugs to fight the disease now contain caffeine derivatives. Just a few cups of coffee per day also reduce the risk of colon cancer by 20 percent and the risk of gallstones by 50 percent.
A study at Rutgers University in New Jersey even found that regular administration of caffeine, in conjunction with exercise, helped destroy cancer cells in mice; the findings are being used to develop drugs that could one day fight skin cancer. Caffeine has also been shown to lower people’s risk of Alzheimer’s disease and heart disease, and can help treat headaches and asthma. In fact, some over-the-counter pain relievers, such as Excedrin, contain up to 120 milligrams of caffeine—as much as a cup of coffee contains—because caffeine’s ability to constrict blood vessels reduces the supply of blood to the brain, relieving vascular headaches.
Sip It or Slather It
Some believe that caffeine’s benefits aren’t limited to consumption. It’s also become a hugely popular ingredient in many cosmetics and cosmeceuticals, ostensibly for its ability to constrict blood vessels, flushing water out of cells and reducing inflammation. It’s often used in anti-cellulite creams, potions that target undereye circles, and anti-aging facial treatments. However, there’s no reliable data showing that caffeine is any more effective than other ingredients, and the few studies that seem to demonstrate its effectiveness tend to be endorsed by large cosmetic companies with a financial stake in the findings. Most dermatologists agree that topical products with caffeine can reduce the appearance of cellulite or undereye circles, and that they may be able to brighten and firm skin, but the effects are merely temporary. No topical product can change genetics or alter the way skin functions.
The jolt of energy from caffeine is enough to affect our athletic performance, too. After drinking a cup of coffee, most people find that they have the stamina to work out harder and longer. For elite athletes, caffeine’s impact is huge: it helps them jump higher, run faster, and lift more weight by tricking their bodies into ignoring fatigue. Caffeine’s effect on athletes is so well documented, in fact, that until 2004 the International Olympic Committee banned it from the Olympic Games.
Caffeine may do some great things for the body, but it’s not without its downsides. The biggest problem with it is that it’s ultimately an addictive drug, working on the same neural pathways as cocaine, heroin, and nicotine do. The body quickly becomes less sensitive to regular use of caffeine, requiring more and more to achieve the same results, and what many people mistake as the “rush” of caffeinated coffee or soda is merely relief from withdrawal symptoms. Heavy caffeine use can cause insomnia, anxiety, irritability, headaches, nausea, stomach problems, and irregular heart rhythms; and while it may boost mental energy, many experiments have shown that it does nothing to improve memory or brainpower. A study at the University of California, San Diego, found that participants given caffeine tablets performed worse on tests of their motor skills and word recall than participants who’d been given a placebo, and much worse than participants who’d taken an hour-long nap. The researchers theorized that caffeine worsened memory by blocking the uptake of a neurochemical that assists in creating memories.
For most people, caffeine is harmless in small doses, but those with a history of heart disease or cardiovascular problems should avoid it, since it constricts the coronary arteries and raises blood pressure. Caffeine can also react poorly with certain antibiotic medications and bronchodilators prescribed for asthma, and since it’s a diuretic, it can lead to dehydration. It’s probably smart for pregnant women and those with a family history of osteoporosis to steer clear, too. For anybody who chooses to add a bit of caffeine to her diet, it’s better to get it in the form of chocolate or coffee, not through sugary sodas or other products containing artificially added caffeine.
It’s nearly impossible to track what’s good for you and what’s bad for you in any given week. Today, alcohol is good and red meat is out. Next week, red meat will be okay, but we’ll all be watching our niacin intake. Luckily, scientists seem to agree that caffeine is healthy, and that verdict is probably here to stay. Probably.