The influence of nutritional status and diet on fertility

There are numerous influences that determine the conception and birth of a healthy child. At the same time, we can control some of these influences, and some cannot. Diet is one of the most important external influences on fertility that we can control. It has been scientifically proven that a woman's diet before and during pregnancy affects fertility and the course and outcome of pregnancy. Also, numerous scientific studies dealt with the influence of diet and lifestyle on male fertility.

During the last decades, numerous studies have tried to shed light on the connection between nutrition, the intake of certain nutrients and fertility. Dietary habits, body weight, intake and physical status of vitamins and minerals, and the therapeutic effects of medicinal plants are discussed. Although nutritional interventions will not prevent or cure infertility in all couples, they are worth a try as they are safe, inexpensive and often underestimated solutions.Infertility caused by nutritional factors is often associated with changes in hormone synthesis and activity or sperm quality.

How does obesity affect fertility?

Obesity negatively affects male fertility. Obese men not only produce less sperm, but it also contains more abnormal sperm. Obesity is associated with an increased number of DNA mutations in sperm, which can reduce fertility. Also, lack of body fat and excessive accumulation of fat in the abdominal area is associated with reduced testosterone synthesis and poor sperm quality. Gaining body weight in undernourished and losing extra pounds in obese improves testosterone levels and fertility.

The general rule is that people who have a body mass index (BMI) of less than 20 kg/m² ili veći od 30 kg/m² malnourished or obese in order to achieve optimal fertility. (reminder: BMI can be calculated by dividing body mass in kilograms by the square of height in meters.) However, it should be kept in mind that BMI is not always the best indicator of nutritional status. For example, people who play sports can have a normal BMI, but a low percentage of body fat, while on the other hand, people who have a sedentary lifestyle can have a normal body mass, but too much adipose tissue (which weighs less than muscle). Therefore, other methods are used to estimate the proportion of fat tissue, such as waist circumference or skinfold measurements. A waist circumference higher than 109 cm in women and higher than 120 cm in men indicates a "very high" level of body fat.

A properly balanced diet has many benefits. It helps maintain an ideal body weight, keeps hormones in balance and improves the health of the reproductive system. When choosing food for the day, it is recommended to reach for food rich in antioxidants - vitamins A, C and E, selenium and zinc, as well as numerous plant compounds. Also, the menu should often include fatty fish, seeds and nuts - foods rich in omega-3 fatty acids.

Do antioxidants affect fertility?

Many scientific studies have dealt with the influence of antioxidants on the fertility of men and women. For example, studies show that even 80% of infertile couples consume foods rich in antioxidants (fruits and vegetables) less than recommended.These findings become even more important in the light of research that has shown that antioxidants play a key role in the fertility of both sexes. A high intake of these substances can improve the number, structure and motility of sperm. In women, they can reduce oxidative stress in eggs and reproductive organs.

Nedostatak cinka također je prepoznat kao uzrok neplodnosti u muškaraca. Nedostatak tog minerala koji se smatra antioksidansom uzrokuje smanjenu sintezu testosterona te smanjenje broja i pokretljivosti spermija.

Therefore, foods rich in zinc, such as oysters, nuts and meat, are popularly considered male aphrodisiacs.

The often-mentioned precious fats, omega-3 fatty acids, participate in the development of eggs and hormone synthesis in women and the production of sperm in men.The results of preliminary studies indicate that an adequate intake of omega-3 fatty acids, especially EPA and DHA, can be a useful preventive measure for infertility related to hormone synthesis disorders and sperm production.

Alcoholism can be a cause of infertility due to the direct toxic effects of alcohol. Regular excessive drinking of alcohol can reduce fertility by as much as 50%. However, moderate alcohol consumption (1-2 drinks per day for women and 1-3 drinks per day for men) does not have a negative effect on fertility. People who want to increase their chances of conceiving should also avoid caffeine in excessive amounts because it affects the fertility of both sexes. It is found in tea, coffee, chocolate and various carbonated drinks. However, enjoying coffee in moderation, i.e. drinking one to two cups a day, should not have a harmful effect.

Studies have shown that infertility is significantly more common among smokers - both men and women. The effect of quitting smoking is already visible after a few days! In men, the sperm count can increase up to 800 percent, while women get pregnant more easily and quickly.

Author: Prof. Dr.Sc. Darija Vranešić Bender, clinical nutritionist