Lethal dose of caffeine
Can caffeine kill? A 37-year-old woman attempted suicide by ingesting 27 grams of caffeine: the immediate toxic effect was cardiac arrest with hypotension, because the caffeine caused a real poisoning. As is easily understood, the ingestion of caffeine in doses equivalent to those contained in 350 cups of coffee has developed a catastrophic reaction on the part of the body.
The average lethal dose of caffeine (LD50) is 150-200 mg per kilo of body mass, but it is practically impossible to reach this threshold with a simple diet.
Caffeine and insomnia
Among the most well-known side effects of caffeine, in first place there is "insomnia: caffeine, in fact, is a methylxanthine that causes effects on the central nervous system, therefore it stimulates concentration, decreases the sense of fatigue and increases the "attention.
Even the caffeine contained in a cup of coffee is capable of causing various side effects and preventing the person from falling asleep; for this reason it is not advisable to drink coffee before going to sleep, especially for individuals who are more sensitive to its action.
Cardiovascular effects
At much higher doses, caffeine can cause seizures, which can be fatal. As for the cardiovascular side effects of caffeine, this substance can have a chronotropic and positive inotropic effect (increase in strength and heart rate): consequently, situations such as increased cardiac output, tachycardia and increased pressure (although mild at normal consumption doses).
It has been seen that in some subjects the habit of consuming coffee has led, as an adverse effect, to slight arrhythmias.
Other side effects
The kidneys are also affected by the side effects of caffeine: there is an increase in glomerular filtration and, at the same time, a decrease in the tubular reabsorption of sodium, which stimulates diuresis.
Methylxanthines in general, including caffeine, could cause bronchodilation, a side effect that affects the smooth muscle of the respiratory system.
Positive effects on the organism
Despite all these side effects, it should not be forgotten that if you take caffeine to benefit from greater concentration, decrease fatigue and improve reflexes, this exciting substance - taken according to the most appropriate doses and methods - can represent a valid help, generally devoid of significant side effects.