Caffeine is most commonly used as a stimulant. When fatigue hits, many turn to caffeine for a quick energy boost; whether it's in a cup of coffee, soda, or a more potent energy drink. In fact, some people feel unable to function without the customary morning jolt of caffeine. But just how does caffeine affect the body, and is it wise to rely on it as a stimulant?
Where Caffeine is Found
Caffeine can be found in a natural state in many different plants worldwide. Perhaps the best known are the camellia sinesis plant (from which tea is produced), the coffee bean, and the kola plant. The amount of caffeine present in the foods and beverages derived from these plants can vary widely depending on the concentration of the plant and the processing methods.
Caffeine can also be found in other products as an additive. In many soft drinks only about 5% of the caffeine present is natural, the remaining 95% has been added. Caffeine is also found in painkillers and aspirin, cold medications, diuretics, and some weight control aids.
Is There a Healthy Limit to Caffeine Consumption?
When one considers that caffeine has been billed as one of the top three mood-affecting drugs in the world (right up there with alcohol and nicotine), it's only natural to wonder just how much is "healthy." Most health research has concluded that up to 300 mg of caffeine a day will have no negative side-effects. That's the equivalent of about three cups of coffee. However, it's important to keep in mind that this is not an inflexible standard. Depending on one's age, sex, height, weight, and other issues like nicotine use and pregnancy, caffeine will affect each person differently. Most research does agree that more than 600 mg of caffeine a day is too much. At that point, serious side effects like sweating, insomnia, and anxiety, as well as other health risks, become more likely.
The Effects of Caffeine
Caffeine acts as a stimulant. From the moment one consumes any form of caffeine, the compound enters the blood stream where its peak effects are felt about one hour after consumption. The long-term effects can last for six to eight hours afterward.
Caffeine affects several different body systems. Most noticeably, it affects the central nervous and muscular systems. When the caffeine enters the body, it blocks adenosine, a neurotransmitter that produces a calming effect on the body. The body compensates by releasing adrenaline, resulting in increased heart rate and blood circulation, tightened muscles, and an increased glucose release for extra energy. Caffeine can also boost the metabolism, causing an increase in calories burned for up to three hours after consumption.
The brain is also affected by caffeine consumption. Caffeine raises levels of intropin, a pleasure enhancing neurotransmitter, creating a sense of well-being. It also causes an increase in the level of brain activity often resulting in more focused attention and a quicker response time. Caffeine also raises levels of the neurotransmitter acetylcholine which enable a better short-term memory.
Also documented is the fact that caffeine can have an ergogenic effect (meaning simply that it can aid in increased athletic performance by eliminating many symptoms of fatigue). This is especially true in regard to athletic endurance, although mainly on a purely professional level.
Health Concerns Linked to Caffeine
It's important to keep in mind, however, that caffeine is not a compound meant to be overused. In fact, over-consumption is strongly cautioned against. Even though caffeine's addictive effects are much lower than that of other drugs, it can become addictive over time. In addition, the body can become immune to the effects of smaller doses and constantly feel the need for larger and larger amounts to produce the same effect. Serious addicts to caffeine can experience withdrawal symptoms such as headaches, irritability, and depression if their body is deprived of its daily dose of caffeine.
There have also been concerns over caffeine and increased risk of heart conditions, osteoporosis, and high blood pressure. Excessive amounts of caffeine have also been linked to risks in pregnancy, such as miscarriages and low birth weight. While studies on these issues have had mixed results with no clear conclusions, the mere possibility should caution one against large amounts of caffeine consumption.
While caffeine can indeed cause feelings of well-being and may temporarily increase one's mental acuity, it's also important to keep in mind that moderation is the key. Small amounts of caffeine pose no documented risk to health and may help to provide a morning, afternoon, or evening pick-me-up, but relying on coffee too heavily can have many negative consequences.
Sources:
faqs.org, "Caffeine" (April 28, 2010)
articlesbase.org, "How Does Caffeine Affect the Human Body?" (April 28, 2010)
pe2000.com, "Be Careful with Caffeine" (April 28, 2010)
overcaffeinated.org, "Caffeine and the Effects on the Body" (April 28, 2010)
Sarah Lantz - Sarah Lantz is a freelance musician who enjoys writing on the side. She started piano lessons at the tender age of five and has been ...
