One of the theories proposed by science is that sex has the ability to significantly increase the levels of a substance in the body called immunoglobulin A (IgA), which does of course to your more efficient immune system. The study that proved this by Carl J. Charnetski done at Wilkes University in Pennsylvania in a group of 112 students between the ages of 16 and 23 (men and women with an average age of 18), divided the sample into 4 groups : 1. Those who did not have sex; 2. Those of infrequent sex (less than 1 time per week); 3. Frequent sex (1 to 2 times per week) and 4. Very frequent (3 or more times per week). So, they found that those who had frequent sex had higher levels of IgA, which are the antibodies that fight many diseases and are regularly found in places like the mucous membranes of the lungs, paranasal or nasal sinuses, stomach or intestines. and that they are also found in fluids such as saliva, tears or blood. This particular group had 30% more IgA than the two with less sex, perhaps because it induced a greater state of relaxation, more level of affection, or perhaps other neuroendocrine influences were present.
In addition to increasing your antibodies, it decreases your stress
It achieves this because sex has the great capacity to decrease the secretion of cortisol by the body What is the stress hormone? A 2019 study, carried out on 133 couples, sought to verify how intimacy may be able to dampen the reactivity produced by biological and psychological stress due to this hormone. They verified that sexual intimacy or the one that is had without sex, is mega good and can help regulate cortisol levels in both men and women, returning them to their normal range. All this is also possible because sex promotes the release of other substances such as neurotransmitters and hormones (oxytocin or endorphins) that give you a feeling of well-being and leave that good taste in your mouth.
Sex could protect you from more serious diseases
That study by Charnetski that we were talking about, according to one of its authors, reported that this increase in the release of IgA could give people a added protection against colds or even the flu. And yet after the pandemic, other studies have emerged trying to associate the protection exerted by sex against more serious infections such as the coronavirus.
A study last year carried out at the University of Baghdad that sought to identify the effect of this on the ability of the immune system to deal with infections such as the coronavirus, in a sample of approximately 16,000 people over 18 years of age (all of them with proof of of positive COVID-19) and from 33 different countries made through interviews on digital platforms for 4 months, had results to suggest that sexual activity has a protective role against this disease despite the sex and age of the person, since 76.6% of people who were in contact with people in group 1 (who had sex 3 times or more a month) were not infected and those who did, presented mild disease compared to those in group 2 (less than 3 times of sex a month) that had approximately half of the people infected with 40.43%.
This 2022, a study by Sean Hughes of the University of Washington School of Medicine in Seattle measured immune changes in young women before and after initiating sexual life to determine if these could have a role regarding an increased vulnerability to suffer from sexually transmitted diseases (STDs). They found that they several proteins were significantly increased that control the immune response during the first year in which they became sexually active and although it is still not clear and more evidence is needed to confirm it, they propose that what they found may be indicative of help that can enhance fertility as well as protection against STDs.
In summary, regular and healthy sex, from what is known so far, prepares and defends your body by secreting substances, activating and enhancing the function of your immune system.