Magnesium and pomegranate polyphenols in athletes

Nutrition is a fundamental factor in optimizing athletic performance and improving post-exercise recovery. In this context, magnesium and polyphenols from foods such as pomegranate are emerging as important allies in supporting energy functions in the human body, particularly for athletes , at various levels . In the vast sea of ​​nutraceutical options on the market, there is a lot of scientific evidence that has demonstrated the impact of these two nutrients on energy metabolism, with particular attention to mitochondrial function and al athletic performance support .  

Magnesium: A Crucial Mineral for Athletes  

Magnesium (Mg²⁺) is an essential mineral – the fourth most abundant cation in our body – that plays a fundamental role in over 300 biochemical reactions in the human body, many of which are crucial for energy metabolism and the optimal functioning of the muscular and nervous systems . It plays a role in the biosynthesis of lipids, proteins and nucleic acids, in the formation of the second messenger cyclic AMP, in glycolysis and in energy-dependent membrane transport processes. As is known, athletes are subject to greater magnesium consumption due to intense physical activity, which leads to greater loss of this mineral through sweat and urine.  

Functions and biochemical role  

It is present in all cells , influencing various physiological systems and apparatuses , including those consisting of excitable tissues and the neuroendocrine system , as well as cardiovascular and bone. Magnesium deficiency can cause a series of metabolic dysfunctions, therefore it is important to understand its crucial role in many biological processes. In particular, it has been observed that, while a clinically relevant dietary magnesium deficiency is very unlikely in healthy individuals, a subclinical deficit may occur due to insufficient intake , which, in any case, cannot be determined by a simple blood test, since it is an intracellular cation. In athletes, insufficient magnesium intake may cause tachycardia, muscle cramps and weakness .  

In reality, 60% of the magnesium in our body is found in the bones, 39% in the intracellular compartments and only 1% in the extracellular fluids.  

Magnesium Metabolism  

Magnesium is absorbed in the small intestine, at the level of the distal jejunum and ileum, both by an active transport mechanism and by a nonspecific diffusion process. This is the reason why it can compete with the absorption of another cation, calcium. Magnesium homeostasis is guaranteed by renal function and by the modulation of intestinal absorption. Homeostatic mechanisms can be altered in case of genetic defects, diabetes mellitus or alcohol abuse.  

The main sources of magnesium intake through the diet are cereals and their derivatives and vegetables , responsible for 40% of the total magnesium intake.  

Magnesium is mainly known for its involvement as a cofactor in numerous enzymatic reactions. Its functions range from energy metabolism to protein synthesis, from the regulation of nerve transmission to muscle contraction, without forgetting its role in acid-base balance and protection against oxidative stress.  

1. Enzyme cofactor  

A classic example concerns the production of ATP (adenosine triphosphate), the main energy molecule of cells. Magnesium is necessary for the stabilization of ATP molecules, forming a complex with ATP that allows its activation and use , through the neutralization of the negative charges of the macromolecule . Magnesium is also essential for the metabolism of carbohydrates, proteins and lipids, actively participating in processes such as glycolysis and oxidative phosphorylation.  

2. Protein synthesis  

Magnesium is crucial for protein synthesis, as it stabilizes ribosomes, the cellular structures responsible for translating the genetic code into proteins , promoting the adhesion of the two subunits from which they are composed . Furthermore, it is implicated in the correct functioning of tRNAs and in the translation of mRNA.  

3. Regulation of ion channels  

Magnesium regulates numerous ion channels, especially calcium and sodium, exerting a stabilizing effect on the cell membrane. As a calcium antagonist, magnesium can influence processes such as muscle contraction and nerve transmission.  

Role at the muscular level  

Magnesium plays a vital role in muscle function, particularly in muscle contraction and relaxation. Muscle contraction depends on the interaction between actin and myosin filaments within muscle cells, a process that requires energy in the form of ATP.  

In the presence of magnesium, ATP is maintained in its active form, facilitating the binding of ATP to myosin filaments, which is essential for the contraction cycle. In addition, magnesium plays an important role in controlling the release of calcium from intracellular stores, which is essential for the process of muscle contraction. The balance between calcium and magnesium is critical: high levels of calcium stimulate contraction, while magnesium promotes muscle relaxation , inhibiting the release and effect of calcium.  

Furthermore, magnesium is involved in the activation of enzymes of the class ATPases , which catalyze the ATP synthesis reaction . Under magnesium-deficient conditions, muscles may become more susceptible to cramps, spasms, and fatigue, as ATP production and utilization are impaired.  

Role in the central nervous system  

Magnesium also plays a significant role in the function of the central nervous system, acting as a modulator of synapses and membrane potential of nerve cells. In particular, magnesium is involved in the regulation of NMDA (N- methyl -D -aspartate ) receptors, which are essential for synaptic transmission and brain plasticity, including learning and memory processes.  

NMDA receptors are calcium-permeable ion channels that, when activated, allow calcium ions to enter nerve cells. Magnesium, being a natural antagonist of these channels, regulates their activity and prevents excessive calcium entry into nerve cells, which could cause neuronal damage through the phenomenon of calcinosis. Excess intracellular calcium has been associated with neurodegeneration, oxidative stress, and neuronal damage, factors implicated in diseases such as Alzheimer's and Parkinson's.  

Furthermore, magnesium has neuroprotective effects , contributing to the stabilization of the central nervous system and modulating the stress response , which is why it is also classified from a nutraceutical point of view among adaptogens . Magnesium deficiency has been associated with an increase in neuronal excitability, which can lead to disorders such as anxiety, irritability and insomnia.  

Molecular mechanisms  

At the molecular level, magnesium acts primarily as a cation that stabilizes biological structures and facilitates interactions between enzymes and substrates. In many biochemical reactions, magnesium is needed to maintain the active structure of molecules such as ATP, which without it would not be stable , as we have already noted . Additionally, magnesium interacts with phosphates in phosphate group transfer reactions, facilitating processes such as protein phosphorylation.  

In the context of nerve transmission, magnesium regulates ionotropic receptors , such as NMDA receptors, preventing excessive neuronal depolarization, which can be harmful. In essence, it acts as a "filter" that modulates the entry of ions into neurons, protecting the nervous system from excessive electrical activity.  

The ideal magnesium supplement  

When choosing a magnesium supplement, it is important to consider some factors that influence its effectiveness and bioavailability. Bioavailability refers to the body's ability to absorb and utilize magnesium, which can vary depending on the chemical form of magnesium used in the supplement. In fact, the mineral takes on some of the properties of the acid to which it is bound.  

The most commonly used forms of magnesium in supplements can belong to two main categories: organic and inorganic. The fundamental difference between these lies in their bioavailability. Organic forms, such as magnesium citrate , are characterized by high bioavailability and effective absorption at intestinal level, as well as generally being free of unwanted effects such as gastrointestinal disorders . On the contrary, inorganic forms, such as magnesium oxide , have limited bioavailability, but are useful in the treatment of constipation thanks to their laxative action.  

The ideal supplement should be formulated to ensure good bioavailability, preferring forms that promote absorption and minimize side effects such as gastrointestinal disturbances. The optimal dose of magnesium depends on individual needs, but generally ranges between 300 and 400 mg per day for adults, with particular attention to avoiding excessive doses that could cause diarrhea or alterations in the levels of other minerals.  

Italian legislation sets a limit of 450mg of daily magnesium supplementation, while the new LARN (Reference Intake Levels of Nutrients and Energy for the Italian population) of 2024 have raised the recommended daily dose from 240 to 300mg.  

 

Magnesium and Muscle Recovery  

During and after exercise, magnesium helps reduce muscle inflammation and improve post-workout recovery. Studies have suggested that magnesium supplementation can reduce muscle soreness and shorten recovery time after intense exercise , such as resistance and strength training. Magnesium can regulate levels of the stress hormone cortisol , which can increase after intense exercise. It also helps with muscle relaxation , reducing feelings of fatigue and tension.  

Polyphenols  

Polyphenols are a group of substances of plant origin, ubiquitously distributed and fundamental for the physiology of plants. They confer resistance against microorganisms, light and insects or determine the pigmentation necessary for reproduction, in addition to other organoleptic characteristics of plants.  

Pomegranate Polyphenols : Allies of Mitochondrial Function  

Pomegranate is a fruit rich in bioactive compounds, especially polyphenols , which have demonstrated numerous positive health effects. Among these, ellagic polyphenols , found in high concentrations in pomegranate, are particularly known for their antioxidant and anti-inflammatory effects, which can support mitochondrial health and energy metabolism. The main class of polyphenols in pomegranate is represented by ellagitannins , which through a complex metabolic process in the human body are converted into urolithins , bioactive compounds capable of exerting numerous beneficial effects.  

Ellagitannin metabolism and urolithin formation  

Ellagitannins are water-soluble polyphenols found in various fruits, including pomegranates, blackberries, strawberries, and raspberries . Punicalagin is the main ellagitannin of pomegranate ( Punica granatum ) and is present in two isomers: punicalagin α and β . After ingestion of foods rich in punicalagin , these are hydrolyzed in the small intestine , releasing molecules of ellagic acid . Ellagic acid is then converted by the intestinal microbiota into urolithins A and B , compounds that, once produced, enter the bloodstream and reach target tissues, including muscles and the liver. Urolithins , especially urolithin A , are known for their potent biological activities, including the activation of mitophagy .  

Mitophagy is the process of removing damaged or dysfunctional mitochondria, a crucial mechanism for maintaining mitochondrial integrity and efficiency. This process is particularly important in skeletal muscle , where good mitochondrial function is essential for proper energy metabolism during exercise.  

Urolithins and Mitochondrial Function  

Once produced in the colon and liver, urolithins A and B reach the mitochondria and activate cellular mechanisms that promote mitochondrial biogenesis and mitophagy . In particular, urolithin A has been shown to stimulate the production of new mitochondria in muscle cells, thereby improving the ability to oxidize fats for energy. This is particularly relevant for athletes, who depend on mitochondrial capacity to maintain high performance during long-duration physical activities.  

Animal and human studies have shown that ingestion of urolithin A can improve mitochondrial function and enhance muscle endurance , increasing exercise capacity and reducing fatigue. In particular, urolithin A has been observed to increase the activity of AMPK (AMP- activated protein kinase ) , an enzyme that regulates cellular energy production and fat breakdown .  

Additionally, urolithin A has been associated with a reduction in oxidative stress in muscles and protection against muscle damage caused by high physical activity. Reducing oxidative stress is essential for preventing chronic inflammation and cellular damage, conditions common in the muscles of athletes.  

Magnesium and Urolytins in Muscle Recovery  

One of the most important aspects for athletes is post-workout recovery . After intense physical effort, the body needs to recover to repair damaged muscles and restore energy reserves. Magnesium and pomegranate urolithins play complementary roles in this process.  

Magnesium helps reduce inflammation and promote muscle relaxation, while urolithins , by stimulating mitophagy , the process of selective elimination of improperly functioning mitochondria, and mitochondrial biogenesis, support the restoration of energy functions at the cellular level. Together, these two compounds can improve muscle recovery by reducing the time it takes to restore energy reserves and limiting the onset of post-workout muscle damage.  

The combination of magnesium and pomegranate polyphenols: a powerful ally for athletes  

Supplementing with magnesium and pomegranate polyphenols may represent a synergistic approach to improve athletic performance, support mitochondrial health, and accelerate post-workout recovery. While magnesium optimizes ATP production and muscle function, pomegranate urolithins enhance mitochondrial capacity, improving energy efficiency at the cellular level.  

Furthermore, the combination of these two compounds may have antioxidant and anti-inflammatory effects , reducing muscle damage related to oxidative stress, frequently associated with intense physical exercise.