When it comes to caffeine or coffee, many people think of it as a harmful substance. But in real, caffeine has many health benefits and harms are reported only with very high doses or when consumed in conjunction with alcohol, anti inflammatory medications or ephedrine.
What is Caffeine
Caffeine is a central nervous system (CNS) stimulant of the methylxanthineclass. It is the world’s most widely consumed psychoactive drug. Unlike many other psychoactive substances, it is legal and unregulated in nearly all parts of the world. There are several known mechanisms of action to explain the effects of caffeine. The most prominent is that it reversibly blocks the action of adenosine on its receptor and consequently prevents the onset of drowsiness induced by adenosine. Caffeine also stimulates certain portions of the autonomic nervous system.
How do we consume it
We use caffeine in many different forms like coffee, tea, chocolate, sodas, energy drinks and shots, and wide range of supplements including pain reliever as well as workout supplements.
In our daily life, the main source of caffeine is coffee and tea. According to records today, greater than 80% of the world’s population use caffeine in some form or another.
Interesting fact is that plants also use caffeine as a natural pesticide. Because it is toxic to insects and other pests.
What happens after we consume it
After we consume any drink or beverage containing caffeine, caffeine rapidly enters the blood stream and within just 40-60 minutes reaches all organs of the body.
Due to its lipoholic or fat loving chemical structure, caffeine easily cross the blood brain barrier (BBB). To a nerve cell, caffeine resembles adenosine, a molecule that slows down the nervous system, dilate blood vessels and allow sleep. The nerve’s adenosine receptor cannot tell the difference between the two molecules, so caffeine and adenosine compete for receptor binding.
When caffeine wins, an exaggerated stress response takes hold. The cell activity speeds up, the brains blood vessels constrict, and neuron firing increases. The pituitary gland responds to the increased activity by sending a message to the adrenal glands to produce adrenaline, the “fight or flight” hormone. Pupils and breathing tubes dilate. Heart rate increases. Blood flow shunts to the muscles. Blood pressure rises. Muscles contract. The liver releases extra glucose into the bloodstream to fuel the “fight or flight” response, thus sparing muscle glycogen stores.
That’s how you feel more alert and energetic after caffeine consumption.
Physiological effects of caffeine on organ system
- Central Nervous System – (1) increased alertness and mood. (2) Decreased pain and fatigue.
- Metabolism – (1) Increased oxygen uptake (2) Fat breakdown (3) Glycogen sparing
- Endocrine System – Increased catcholamines, endorphins and cortisol
- Cardiovascular System – (1) Increased Heart Rate (2) Increased Stroke Volume (3) Increased blood pressure
- Respiratory System – Increased respiratory rate
Why caffeine’s effects are lessened after some time
Everyone must have noticed that after some time they need to increase their caffeine intake for the same results they felt when they used it for the first time. This happens because of brain adapts to chronic caffeine use and starts producing more adenosine receptors for adenosine binding. That’s why, after some time same caffeine intake, perceived benefits diminish and the person starts consuming more caffeine for the same desired results.
After that, when we increase our caffeine dosage, brain again sense it after some time and produce more adenosine receptors. As we keep increasing the dosage, risk of severe consequences multiplies.
Caffeine is good for your liver
Liver is the second largest organ in the body after skin. It’s main role is to perform the function of digestion, metabolism and storage of nutrients.
According to journal of clinical and experimental hepatology, the clinical evidence of benefits of coffee consumption in hepatitis B and C as well as non alcoholic fatty liver disease (known as NAFLD) and alcoholic liver disease (damage to the liver and it’s functions due to alcohol abuse) has been presented. Caffeine consumption is associated with improvement in liver enzyme profile (ALT, AST, GGTP – increases when liver is damaged), expecially in individuals with risk for liver disease.
According to studies, more than 2 cups of coffee per day in patinets with pre existing liver disease has been shown to be associated with lower incidence of fibrosis (formation of large amount of scar tissue in the liver) and cirrhosis (chronic liver damage from a variety of causes, leading to scarring and liver failyre) lower hepatocellular carcinomer (most common form of liver cancer) rates as well as decreased mortality.
And many more studies on caffeine proves that “Yes”, caffeine is good for your liver.
Caffeine during pregnancy
Caffeine is hypothesized to cause an increase risk of miscarriage, sudden infant death syndrome, low birth weight at very high doses. But there is insufficient high quality research to determine whether or not caffeine has effects on pregnancy outcomes.
In 2013, department of obstretic and gynecology studies on 60,000 pregnancies over a period of 10 years found no link between caffeine and preterm birth. But it did find a link between caffeine intake and decreased birth weight.
Caffeine is potentially dangerous substance during pregnancy ONLY AT HIGH DOSES. Because of caffeine readily crosses placenta (organ that develops in uterus during pregnancy) and can effect fatal heart rate and breathing. That’s why it would be advisable to reduce overall intake of caffeine during pregnancy.
Note: All the studies are based on caffeine, and caffeine is found in variety of foods like chocolate, cocoa, soft drinks, energy drinks, not only coffee.
Recommended dosage in pregnancy
In 2010, American College of Obstetricians and Gynecologists suggest that moderate caffeine consumption (less than 200 mgs per day) does not appear to be a major contributing factor in miscarriage and preterm birth. But always consult with your doctor.
While research in inconclusive and no one fully understood the true risk of caffeine consumption, most experts recommend caffeine to no more than two cups of coffee in a day.
In addition to it’s toxicity at high doses when combined with other substances like alcohol, ephedrine, or anti inflammatory medication, even moderate caffeine use can be dangerous.