Energy Drinks: Can a Single Serving Harm Your Heart?

What do energy drinks really contain?

Energy drinks (not to be confused with isotonic sports drinks, used by sportspeople to compensate for water and electrolyte losses during exercise) are designed to temporarily boost energy, alertness and concentration. To this end, they contain a cocktail of stimulating ingredients. As a general rule, they contain caffeine (at varying, but often high, levels depending on the brand), combined with taurine, B vitamins and/or plant extracts (1). To this base is added a significant amount of refined sugar, or sweeteners for the so-called 'zero' versions.

Mainly consumed by young people, sometimes at a very early age (68% of teenagers and 18% of 3-10 year olds drink them regularly, according to data provided by EFSA in 2013), these energising concoctions raise questions as much for the variability of their formulations as for their obvious lack of transparency: vague compositions, the combination of several stimulants in undisclosed quantities, misleading marketing, unspecified side effects and interactions, etc. While their benefits remain largely undocumented to this day, their impact on heart function is causing growing concern within the scientific community.

Even a single can of energy drink can alter cardiovascular function

An American study presented at the 2018 American Heart Association (AHA) conference highlights the harmful effects of these stimulant drinks on the cardiovascular system, from the very first can (2).

To back up their claims, the researchers measured the blood pressure and heart rate of 44 young adults in good health, with an average age of 24.7 years, before and after consuming a 680 ml can of Monster Energy. They also performed an ultrasound scan of the heart, both before and after, to assess the ability of the arteries to dilate properly.

After ingestion, the participants showed a visible alteration in endothelial function, which regulates the diameter of blood vessels, among other things. In particular, there was a reduction in vasodilation of around 50%, which persisted significantly after 90 minutes. Their heart rate and blood pressure increased transiently (+12 bpm and +2 mmHg systolic pressure in the 5 minutes following consumption), before gradually returning to their baseline values. It should be noted that another similar study, this time involving 11 young people with an average age of 24.5, came to similar conclusions, namely a negative impact on the arterial endothelial component (3).

These results therefore suggest that energy drinks have a direct and immediate effect on the endothelium of young, healthy adults, resulting in less effective vasodilation. These disruptions open the way to potentially serious complications, particularly during concomitant, sustained physical activity, where the brain, heart and muscles require increased oxygenation. There have been isolated reports of serious cardiovascular and neurological effects, including cardiac arrest. And yet it is precisely before or after exercise that these drinks are regularly consumed.

Other studies carried out on children and adolescents suggest possible explanations. Caffeine is thought to increase left ventricular inotropism (or, in other words, the force of contraction of the left ventricle), hence the vasoconstriction and rise in blood pressure observed (4).

Although the scientific community is in broad agreement that energy drinks are dangerous, more limited studies, based in particular on microvascular conductance, point to a supposed vasodilatory effect at rest in young male subjects (5).

How can we limit the impact of energy drinks, and what can we replace them with?

To prevent the undesirable effects associated with the consumption of energy drinks, it is essential to observe the following precautionary principles:

• do not give energy drinks to children or teenagers
• avoid them if you are pregnant or breastfeeding, if you are sensitive to caffeine, if you suffer from cardiovascular disease or if you are already taking stimulants
• do not combine them with alcohol
• never consume them before or during physical exercise (hydrate with water, or electrolyte drinks if necessary)

Want to boost your energy levels? Fortunately, there are healthier alternatives, such as ginseng (Panax ginseng). Devoid of stimulant molecules, this key root of Chinese medicine, rich in ginsenosides, acts as a general tonic. It helps to maintain optimal alertness and combat fatigue, as well as supporting cognitive processes and brain reactivity (6-7).

Discover Super Ginseng, ginseng extract standardised to 30% ginsenosides.

Found in many energy drinks, taurine is an amino acid derivative present in significant quantities in the brain and heart muscle, where it modulates contractility. Taken on its own (without sugar or caffeine), it is thought to have a positive effect on endurance and performance, both physical and mental (8).

Taurine is a pure formula with no excipients, optimally dosed at 1,000 mg per capsule.

A substance naturally present in all animals, carnitine is involved in energy metabolism, more specifically in the transport of long-chain fatty acids into the mitochondria (9). These can then be converted into adenosine triphosphate (ATP), the preferred fuel for muscles. L-Carnitine has no stimulating effects, but provides invaluable support during physical effort.

L-Carnitine combines two optimised forms of carnitine (one water-soluble and one fat-soluble) for enhanced effectiveness.

Coenzyme Q10, or CoQ10 for short, is another component that acts at the mitochondrial level to support ATP synthesis. It is particularly concentrated in cardiac cells, which are particularly energy-hungry (10).

The Coenzyme Q10 supplement combines CoQ10 with tocopherols and lipids to maximise its absorption.

Ashwagandha (Withania somnifera), which has been part of Ayurvedic medicine for 3,000 years, has recognised adaptogenic properties. By promoting relaxation and cardiovascular health, it effectively supports the body during periods of nervous tension and anxiety, as well as stressful or excessive demands (abuse of energy drinks, for example) (11).

Super Ashwagandha uses an organic ashwagandha extract that is particularly rich in active ingredients (5% withanolides).

The relaxing and psychoactive effects of green tea are largely attributable to one of its molecules: L-theanine. Whereas caffeine 'excites', L-theanine balances relaxation with alertness. Several studies confirm that it improves the brain's ability to concentrate while stimulating the synthesis of tranquillising neurotransmitters, such as GABA (12-13).

A 100% natural extract of green tea, L-Theanine is highly concentrated, containing 100 mg per capsule.

Previous studies have clearly shown that drinking energy drinks results in a temporary but very real increase in blood pressure. Consumers who already have high blood pressure should therefore be extremely vigilant. On the advice of a doctor, they may be better advised to turn to hypotensive compounds such as olive leaf, which helps maintain normal blood pressure, or vasculoprotective compounds such as hawthorn, which supports the heart and circulatory system (14-15).

Tensix combines the best ingredients for lowering blood pressure in a single formulation: olive leaf, hawthorn, potassium...