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Energy drinks have become increasingly popular among youth these days and that makes the study of their effects on human health very important. In 2014, the global sales of energy drinks reached about US$49.9 billion and the energy drinks market is expected to be worth US$ 85 billion by year 2026.
Energy drinks may contain a variety of ingredients including caffeine, sugars and herbal supplements. They often contain high concentrations of stimulants, and these can be potentially harmful to health and unlike vitamin waters and sport drinks they are not considered beneficial for rehydration. In energy drinks caffeine is often mixed with other powerful stimulants, which adversely affects the cardiovascular and nervous systems.
Several studies suggest that caffeine-laden energy drinks can harm blood vessels and energy drinks are linked to heart, nerve and stomach issues. Although the FDA regulates food and drink in the US, energy drinks manufacturers can get past ingredient restrictions and limits as they energy drinks can be classified as dietary supplements.
What does research say?
A small study by the American Heart Association found that the blood vessel function of young adults notably diminished after consuming just one energy drink. Other studies have also shown how a single beverage can raise blood pressure and cortisol levels, both markers of stress, of the drinker.
A meta-analysis of by the World Health Organization (WHO) on energy drink research noted that the adverse health effects caused after consuming energy drinks are chiefly linked to the content of caffeine in the drink. While caffeine overdose is not necessarily fatal, in worse cases, it can lead to palpitations, vomiting, nausea, convulsions, metabolic acidosis, and hypertension. The WHO study also reported that adults who frequently consume these drinks might be at more risk of hypertension and type 2 diabetes, as caffeine is known to reduce insulin sensitivity.
WHO also warns that the problem is not only with the quantity of stimulant in the drink, but also the speed at which someone drinks them. Although the caffeine levels in some coffee is comparable to that of energy drinks, coffee is usually consumed hot and hence slowly. On the other hand, energy drinks can be swallowed in a matter of minutes and this sudden spike of caffeine can be powerful enough to trigger a heart attack, despite the total dosage being the same as that of a strong cup of coffee. Needless to say, the same risks apply to people who consume cold coffees or multiple double-shot drink with high caffeine content.
Energy drinks and physical activities
Using energy drinks while exercising is common practise. However, this may do more harm than good because energy drinks have been found to reduce the diameter of blood vessels and restrict the flow of blood and oxygen delivery. During exercise arterial function needs to be at its peak and blood circulation should be efficient so that oxygen is transported to cells effectively and quickly.
Hence, consuming energy drinks during activities might not be a good idea as it leads to the heart having to work more while oxygen supply to the heart diminishes, which may account for some cases of cardiac arrest associated with energy drinks and exercise.
Global reports on energy drinks
Reports from Germany indicate that since 2002 energy drinks have been implicated in cases of kidney failure, liver damage, agitation, seizures, psychotic conditions, respiratory disorders, rhabdomyolysis, cardiac dysrhythmias, tachycardia, hypertension, heart failure, and death. Studies from Ireland and New Zealand each report about 15-20 serious complications related to consumption of energy drinks over a period of 4 to 6 years.
Several countries have tried to exclude energy drinks from their drinks market. France managed to ban one energy drink brand containing taurine for twelve years, but the ban was revoked when manufacturers petitioned the European Commission citing the lack of proof that these drinks were unsafe. Countries that have successfully banned high-caffeine beverages to some extent include: Australia, Uruguay, Denmark, and Turkey . In many other countries including the US, energy drinks are still available and accessible to children and teens.