World’s Most Popular Drug
Here’s a quick quiz for you: What’s the most popular drug among bodybuilders? It isn’t any type of anabolic steroid or growth hormone, nor does it involve thyroid, beta agonists or any other anabolic substance. The most popular drug among bodybuilders is also the most popular drug world-wide: caffeine.
In the United States about four out of five Americans eat, drink or swallow a product that contains caffeine. Caffeine is ubiquitous in nature, existing in more than 60 known plants. About 75 percent of the caffeine consumed comes from coffee, with the other 25 percent mainly from tea and cocoa. Coffee, at an average 100 milligrams of caffeine per cup, contains twice as much caffeine as tea. A 12-ounce bottle of cola contains between 35 and 55 milligrams of caffeine.
Most people use caffeine to obtain benefits associated with it, including increased mental alertness, faster thought processes and reduced fatigue. Other effects—not specifically sought by most people—include stimulation of the heart, increased secretion of stomach acid and increased urine output.
Caffeine is thought to be an ergogenic aid in that it can enhance athletic performance. A study examined some of the fat-burning properties of caffeine under resting conditions and found that it increased energy expenditure 13 percent.1 Other effects included 24 percent increased fat oxidation, with 76 percent being recycled, likely due to the resting conditions in the study. Most of the effects were attributed to increased sympathetic nervous system activity, or the release of sympathetic hormones, such as epinephrine and norepinephrine, after the subjects took caffeine.
Caffeine-induced fatty acid release can interfere with insulin activity, leading to insulin insensitivity; however, research shows that exercise relieves that particular problem. Indeed, one recent study showed that drinking coffee offers protection against type 2 diabetes and suggested that nutrients besides caffeine, such as magnesium, may be the protective factors in coffee.2
Another recent study found that caffeine protects against Alzheimer’s disease by reducing the toxic effects of a protein called beta-amyloid on brain neurons3; buildup of beta-amyloid is considered a primary event in the onset of Alzheimer’s.
Since caffeine promotes the release of sympathetic hormones that stimulate body processes, it’s not surprising that it can induce severe anxiety in some people. Indeed, “caffeineism” is so distressing that an estimated 20 percent of people cannot tolerate anything containing caffeine. One study, however, found that exercise can relieve anxiety brought on by high doses of caffeine.4
The release of sympathetic hormones by caffeine can stimulate the heart and increase blood pressure. Some drugs prescribed to treat cardiovascular disease, known as beta-blockers, block the effects of sympathetic hormones on the cardiovascular system. Caffeine would appear to be a problem because of the way it affects the cardiovascular system, but most studies have found no significant adverse effects except when excess intake is involved.
For example, one study examined the effects of caffeine on the body’s homocysteine levels.5 A toxic by-product of the metabolism of the essential amino acid methionine, homocysteine is linked to cardiovascular and other diseases. Healthy volunteers drank a liter a day of coffee for a month, and 24 of the 25 participants showed significant elevations of homocysteine in the blood. Vitamin B12, folic acid and vitamin B6 neutralize the effects of homocysteine, converting it into an innocuous substance that’s excreted from the body.
Another recent study found that drinking four cups of filtered coffee a day for one month increased cholesterol levels.6 Previous studies had shown that drinking unfiltered coffee increased cholesterol, an effect scientists traced to elements in coffee called diterpenes. Coffee filters captured the chemicals, making filtered coffee safe—or so they thought. Even so, the increase in cholesterol from coffee is significant only to those who already have elevated cholesterol. To others the effect is insignificant.