magnesium in food

Magnesium is an essential mineral for the human body that plays a role in over 300 biochemical processes It is fundamentally important for energy metabolism, the functioning of the heart and muscles, and for bone strength. In its natural form, magnesium is almost always found bound to other elements. This is reflected in the wide range of magnesium supplements available on the market. But which foods actually contain magnesium? How do we absorb magnesium? We provide the answers to these questions in this article.

Which foods contain magnesium?

A considerable proportion of our magnesium requirements are met by our diet. Plant foods such as pumpkin seeds, Brazil nuts and cashews are particularly rich in this essential mineral. However, the exact magnesium content in these foods can vary, as it depends heavily on the soil in which the plants are grown. These fluctuations in the micronutrient content of plants are a well-known phenomenon and also affect secondary plant substances. To give you a better overview, here are the average values ​​of magnesium in foods, based on information from the European Food Safety Authority (EFSA):

How much magnesium do we need per day?

The recommended daily magnesium intake is approximately 350 mg for men and about 300 mg for women, as recommended by the German Nutrition Society (DGE). These values ​​are intended as guidelines and may vary, as the metabolism of magnesium is influenced by various factors.

Can we get enough magnesium from our diet?

In principle, yes, we can get the required daily dose through food. Foods rich in magnesium are plentiful. In this Study The authors looked at the actual absorption of magnesium. They examined 463 people in Austria and about 40% of the participants had a magnesium deficiency.

Absorption of magnesium

Magnesium absorption in the human body is a complex process that is influenced by various Transport mechanisms in the intestine Magnesium is mainly absorbed in the small intestine, with two main mechanisms involved: Some of the magnesium "slips" passively between the cells into the blood, especially if we have consumed a lot of magnesium with our food. However, if there is less magnesium, an active mechanism is activated in which special proteins, like little bouncers, actively transport the magnesium into the blood. These “bouncers” require energy (in the form of ATP)to function and ensure that our body can absorb enough magnesium even when there is less available. It is important to note that the amount of Mg absorbed depends not only on how much we eat, but also on the presence of other substances in our food that can affect absorption.

If this description is too superficial for you, we will explain the two transport mechanisms in a little more detail here.

Passive diffusion

At high concentrations in the intestine, magnesium can diffuse passively along a concentration gradient through the intercellular spaces (paracellular space) of the intestinal wall into the blood. This process is mainly localized in the ileum and jejunum and is facilitated by the opening of tight junctions between the enterocytes (intestinal cells)Passive diffusion depends on the magnesium concentration in the diet and the presence of factors that can influence the permeability of the intestinal wall.

Active transport

The active transport of magnesium requires energy and specialized proteins that act as transporters. This process is particularly important when magnesium concentrations in the intestine are low. Two main types of transporters are involved in active magnesium uptake:

• TRPM6 (Transient Receptor Potential Melastatin 6): This channel plays a crucial role in magnesium absorption in the small intestine and is regulated by intracellular and extracellular magnesium levels. TRPM6 is present not only in the enterocytes of the small intestine, but also in the cells of the renal tubules, where it controls the reabsorption of magnesium. Some forms of hereditary hypomagnesemia are associated with a mutation in this transport. Read more about this in our article on magnesium deficiency.
• TRPM7 (Transient Receptor Potential Melastatin 7): Although similar and closely related to TRPM6, TRPM7 is ubiquitously expressed in various cell types and participates in both cellular magnesium homeostasis and general magnesium uptake, albeit to a lesser extent than TRPM6.

Regulation and influencing factors

The efficiency of magnesium absorption is influenced by various factors, including Nutritional composition, the presence of other nutrients (such as phosphate, fatty acids and proteins) and certain hormones (e.g. parathyroid hormone and Vitamin D). Phytic acid, which is found in many plant foods, can inhibit magnesium absorption, while vitamin D promotes the expression of TRPM6 and thus improves magnesium absorption

Another factor is medication use. Proton pump inhibitors (PPIs) and diuretics can both impair magnesium absorption.

Why do we absorb magnesium so differently?

The bioavailability of magnesium, even in food, varies enormously and is between 4 and 80%. One of the factors is the form of magnesium. It makes a difference whether we magnesia, Magnesiumcitrat or take magnesium bisglycinateIn the latter case, the Mg molecule is bound to the amino acid glycine and can thus be picked up via a separate transporter.

How does cooking food change the magnesium content?

Cooking can affect the bioavailability of magnesium in foods in different ways. On the one hand, the Cooking process changes the structure of food, which can cause magnesium and other nutrients to become more readily available or absorbed. For example, heating plant foods can help break down the cell walls, making it easier to access the nutrients they contain.

On the other hand, cooking can also lead to that some of the magnesium and other water-soluble minerals are lost. When cooking in water, magnesium and other minerals can migrate into the cooking water and may then be discarded if the water is not further used. The degree of nutrient loss depends on several factors, including the cooking method, the length of the cooking process and the amount of water used.

How can magnesium loss be reduced?

To minimize magnesium loss during cooking, some strategies can help you:

• Steaming or microwaving vegetables instead of boiling them in large amounts of water.
• Reuse the cooking water, for example for soups or sauces, to utilize the nutrients dissolved in it.
• Use short cooking times and low temperatures to limit nutrient losses.

Why do we have a magnesium deficiency?

If you look at the magnesium content in food, you might think that we all get enough magnesium from our diet. And yet, studies show that many people are deficient in magnesium. What could that be?

There are several possible explanations for this. On the one hand, the Use of medications (PPIs and diuretics), which affect magnesium absorption, are widespread. On the other hand, longevity doctor Peter Attia speculates in his podcast “Drive” that our soils are no longer as rich in nutrients and therefore the magnesium content in food is also decreasing. There are also datawhich suggest that our soils are no longer rich in micronutrients.

Conclusion

Magnesium is found in abundance in food, but there are many factors that affect the absorption of the mineral. As a result, around 40% of people have a magnesium deficiency. This is most easily compensated by taking a magnesium complex or you adjust your diet.