I’m not a big coffee drinker. I get coffee once in a while for the taste, not necessarily for the caffeine effect. I recently started working, and I realize I need the caffeine. At least two a day-- one for getting through the morning and one for after lunch. Now I understand the morning rush at Starbucks and their afternoon special, where you can get a Grande cold beverage for $2 after 2pm if you have that morning’s receipt.
I’ve always heard that coffee is bad for you. So where should you get your daily caffeine? A Coke in the morning doesn’t sound too appetizing. Maybe some Lipton tea will do.
Contrary to belief, coffee may be beneficial to your health. According to various studies, moderate coffee consumption (3-5 cups a day) has shown apparent reductions in the risks of Alzheimer’s disease, Parkinson’s disease, heart, disease, diabetes mellitus type 2, cirrhosis of the liver, and gout. There are also studies that say coffee drinkers are less likely to get certain types of cancer, starting with colorectal cancer.
Other chemical components in coffee other than caffeine are cafestol and kahweol. Cafestol and kahweol are fat-soluble compounds known as diterpenes, which are present in the oil derived from coffee beans. Both compounds are extracted by hot water but are retained by a paper filter. In the 1980s, it was found that these compounds raise serum cholesterol levels in humans. These compounds may be responsible for anti-cancer effect; however the full mechanism is not clear. Both kahweol and cafestol were shown to produce a broad range of biochemical effects resulting in a reduction of the effect of several carcinogens including PAHs (polycyclic aromatic hydrocarbons, a class of chemicals produced by burning organic material), aflatoxin B1 (a mycotoxin) and others. Different mechanisms appear to be involved in these protective effects, but the mechanism has not been elucidated.
Coffee beans come from the Coffee plant. Since it’s a plant, it contains a large and diverse amount of group of compounds including cinnamic acids, benzoic acids, flavonoids, proanthocyanidins, stilbenes, coumarins, lignans and lignins, collectively called plant phenols. Plant phenols are shown to contain strong antioxidant activity. Believe it or not, research shows that coffee is the number one source for antioxidants, due to its high amounts of chlorogenic acid and caffeic acid (also in red wine). It has recently been demonstrated that humans absorb about 33% of ingested chlorogenic acid and about 95% of ingested caffeic acid.
The health effects you hear about coffee is usually due to its caffeine content. Depending on the type of coffee and preparation, the caffeine content can vary greatly. On average, a single shot of espresso (30 mL) can be expected to contain the following amounts of caffeine.
- Drip coffee: 115–175 mg (560–850 mg/L)
- Espresso: 60 mg (2000 mg/L)
- Brewed/Pressed: 80–135 mg (390–650 mg/L)
- Instant: 65–100 mg (310–480 mg/L)
- Decaf brewed: 3-4 mg
- Decaf instant: 2-3 mg
Caffeine is a central nervous system stimulant. Like alcohol and nicotine, caffeine readily crosses the blood–brain barrier that separates the bloodstream from the interior of the brain. Once in the brain, the principal mode of action is as an antagonist of adenosine receptors. The caffeine molecule is structurally similar to adenosine, and binds to adenosine receptors on the surface of cells without activating them (an "antagonist" mechanism of action). Otherwise, brain adenosine acts to protect the brain by suppressing neural activity and by increasing blood flow.
An acute overdose of caffeine, usually in excess of about 300 milligrams, dependent on body weight and level of caffeine tolerance, can result in a state of central nervous system over-stimulation called caffeine intoxication, or colloquially the "caffeine jitters". The symptoms of caffeine intoxication are not unlike overdoses of other stimulants. It may include restlessness, nervousness, excitement, insomnia, flushing of the face, increased urination, gastrointestinal disturbance, muscle twitching, a rambling flow of thought and speech, irritability, irregular or rapid heartbeat, and psychomotor agitation. In cases of much larger overdoses, mania, depression, lapses in judgment, disorientation, disinhibition, delusions, hallucinations, and psychosis may occur, and rhabdomyolysis (breakdown of skeletal muscle tissue) can be provoked.
Now you don’t have to worry about drinking too much coffee. However, you may want to find an alternative caffeine source, like ginseng, if you are worried about the “caffeine jitters.”
