A recent study on the impact of nutrition on fertility
A recent study published in the journal Reproductive Toxicology examines the current evidence on the link between nutrition and female infertility and poor IVF outcomes.
Infertility is medically defined as the inability to achieve pregnancy after one year of unprotected sexual intercourse. According to current estimates, 15-20% of couples worldwide experience infertility.
Researchers are becoming more interested in identifying lifestyle and environmental factors that may affect reproductive health due to rising infertility rates. Numerous studies have extensively researched the potential effects of certain dietary patterns, such as Mediterranean and Western diets, as well as specific foods, on infertility.
The current study examines the intricate connection between nutrition and fertility, specifically focusing on carbohydrates, proteins, and fatty acids.
Omega-3 polyunsaturated fatty acid (ω-3 PUFAs) and omega-6 (ω-6) PUFAs can be found in various types of food products. ω-3 PUFAs are commonly found in fish such as salmon, mackerel, sardines, and tuna, as well as nuts, seeds, and plant oils. In addition to being found in nuts, seeds, and oils, ω-6 PUFAs can also be found in poultry meat, fish, and eggs.
There is currently no conclusive evidence regarding the impact of these fats on IVF outcomes; however, there seems to be a correlation between increased ω-3 PUFA consumption and improved pregnancy odds.
However, certain foods, such as fish, can lead to higher levels of exposure to persistent organic contaminants, like methylmercury and dioxins. Ingesting vegetables and fruits may also result in an increased risk of pesticide exposure.
Carbohydrates play a crucial role in human energy metabolism by regulating the glucose metabolic pathway and insulin-mediated glucose control. Carbohydrates vary in structure, ranging from simple sugars to complex molecules such as plant cell wall polysaccharides and certain oligosaccharides. The glycemic index (GI) and glycemic load (GL) are measurements that indicate the impact of carbohydrates on blood sugar levels.
Consuming complex indigestible carbohydrates, such as those found in soluble dietary fiber or whole-grain food products, may help reduce GL. There is a correlation between consuming more whole grains and experiencing higher rates of pregnancy and live births. In addition, studies have shown that consuming a higher quantity of vegetables can lead to improved embryo quality after intracytoplasmic sperm injection (ICSI).
There is evidence that suggests carbohydrate intake and its breakdown play a role in regulating ovarian function. According to the Nurses’ Health Study II (NHS II) of 2009, there was a significant increase in the risk of ovulatory infertility among women who consumed higher levels of carbohydrates compared to those with lower levels of carbohydrate intake.
Research has shown that a diet containing less than 45% of total energy intake from carbohydrates can improve symptoms of polycystic ovarian syndrome (PCOS) by increasing levels of follicle-stimulating hormone (FSH) and sex hormone binding globulin (SHBG), while reducing testosterone and insulin levels. There is a correlation between reduced weight and overweight or obese PCOS patients.
In infertile and obese infertile women undergoing IVF, a hypocaloric diet that consists of half of the daily calories from carbohydrates resulted in higher ova retrieval, clinical pregnancy rates, and live birth rates. On the other hand, the consumption of sugary soda was also found to have a weak association with a lower number of ova retrieved and embryos obtained during ovarian stimulation cycles, as well as a reduced live birth rate.
A healthy adult should consume 0.8 g/kg protein for each kilogram (kg) of body mass. There is a positive correlation between animal protein intake and ovulatory disorders when compared to plant proteins. Studies have shown that consuming 5% of energy intake from vegetable proteins instead of animal proteins can reduce the risk of ovulatory disorders by more than 50%.
There is a correlation between dairy and soy consumption and improved outcomes during IVF. This is because soy contains phytoestrogens, which are isoflavones that have a similar structure to estrogen and show weak estrogenic activity by binding to estrogen receptors.
In conclusion, this study emphasizes the importance of considering nutrition in the context of female infertility and IVF outcomes. It suggests that dietary choices, particularly those related to types of fats, carbohydrates, and proteins, may influence fertility and the success of assisted reproductive techniques. However, more research is needed to fully understand the complex interplay between nutrition, environmental factors, and reproductive health.