The immune system protects the body from “foreign agents”, such as viruses and bacteria. It’s essential to ensure the existence of a strengthened immune system, in order to promote training capacity, maintenance of sports performance, and health. Although there are different factors involved to optimise your immune system, nutrition is a factor of great attention and importance. An insufficient intake, with an inadequate amount of micronutrients, macronutrients and energy, can weaken the immune system, increasing the risk of diseases and infections.
In fact, for athletes, energy availability has been considered of relevance. An insufficient energy intake to meet energy needs for training, daily activities and physiological functions has the potential to decrease the action of the immune system. Special attention should be given to athletes who are engaged in a weight loss process, as this is associated with a caloric deficit. In these cases, it’s important to ensure a sufficient intake of protein, carbohydrates, omega-3s, and micronutrients.
In the literature, it is well defined that an insufficient protein intake can increase the risk of infection. Lean sources of protein from animal sources (such as lean meats, fish, eggs and low-fat dairy), as well as from plant-based sources (such as pulses and amaranth), should be included in athletes’ diets in adequate amounts.
In turn, fats are also involved in altering the immune response. The consumption of saturated and trans fats seems to promote the increase of pro-inflammatory markers; on the other hand, consumption of polyunsaturated fats (particularly omega-3 fats) appears to cause an anti-inflammatory response. Saturated and trans fats can be found in foods such as puff pastry, packaged cakes and pastries, sauces, margarines, sausages, among others. Omega-3, on the other hand, can be consumed through plant foods (such as chia seeds and edamame), and through animal foods (fatty fish).
Dietary fibers, present in foods such as vegetables, legumes, whole grains and fruit, may also play an important role in terms of the immune system. This role may be related to the function of fibers at the intestinal level, or to other factors.
As it is well known, micronutrients are also essential for the “health” of the immune system. Special emphasis has been given to vitamin D, which can be obtained through the ingestion of eggs and fish oils, but whose main source is sun exposure.
Vitamins with a high anti-oxidant power, such as vitamins A, C and E, may be involved in the effectiveness of the immune system. However, high levels of these vitamins may affect training adaptations, so the best way to obtain them is through a high intake of fruits and vegetables, as opposed to supplementation. Polyphenols, similarly to these vitamins, have an anti-oxidant role, and must be consumed through food. Red fruits, teas, cocoa, beets and coffee are examples of foods rich in polyphenols.
Immune function can be impaired by drinking large amounts of alcohol, so it is not recommended for athletes to drink alcohol.
In travel situations, special attention should be paid to preventive measures against food poisoning. Likewise, taking multivitamin supplements, as well as probiotics (in athletes who are more susceptible to diarrhea, for example) can be useful.
The content of this article does not constitute medical advice by a registered healthcare professional. For more advice on how to optimise your immune system for sports, speak to a qualified sports nutritionist near you.