Many factors can influence female reproductive health, such as being underweight and overweight, obesity, and strenuous physical activity. These are some of the conditions that alter the profiles of specific hormones, such as insulin and adipokines,
thereby impairing women’s fertility. In addition, specific classes of nutrients can affect fertility by acting on specific signaling pathways. Fatty acids, carbohydrates, proteins and components associated with food (such as endocrine disruptors) have physiological activities and their unbalanced intake, both quantitatively and qualitatively, can impair female homeostasis and fertility.
Infertility, defined as the inability to conceive after a year of unprotected sex, is an ongoing problem estimated at 186 million people worldwide. In some regions of the world, such as developing countries, the percentage of infertility can reach an average of 30%. Although male infertility contributes to more than half of all cases of global sterility, infertility remains a social burden on women. The etiologies of female infertility include problems with ovulation, endometriosis and in 20% to 30% of cases remain unexplained. Recently, the effects of lifestyle on female reproductive health have received new attention. Given this, it is possible to observe that weight, body composition, level of physical activity and nutrient intake are factors that can affect female fertility.
Polyunsaturated Fatty Acids and Female Fertility
In women, consumption of trans fatty acids instead of monounsaturated or polyunsaturated fatty acids is positively associated with infertility, regardless of age, BMI, lifestyle, and hormone levels. It has been proposed that the detrimental effects of trans fats on fertility may be due to their different abilities to bind to PPARγ and negatively regulate its expression. In addition, higher intake is associated with altered metabolic parameters such as insulin resistance, risk of type 2 diabetes, and inflammatory markers that can negatively impair ovarian functions.
Consumption of monounsaturated fatty acids has been shown to be associated with a lower risk of ovulatory problems, although these conclusions can only be partially attributed to changes in dietary fats and may be further affected by other nutritional factors, such as protein source (vegetable vs. animal), higher intake of high-fiber carbohydrates, and low glycemic index, dairy products with a high content of fat and other micronutrients.
Polyunsaturated fatty acids, in particular arachidonic acid and its metabolites, influence steroidogenesis in women, exerting direct effects on specific enzymes such as STAR, CYP11A1, and on the regulation of prostaglandin synthesis. In addition, they can also alter the function of nuclear receptors, such as LXRα and PPARs, influencing the transcription of their target genes involved in the synthesis of prostaglandins and ovarian steroidogenesis. The amount and type of polyunsaturated fatty acids can affect various metabolic pathways and the consequent metabolic impairment can cause reproductive outcomes.
Carbohydrates, Sugars and Female Fertility
Some studies have shown that the quality and quantity of dietary carbohydrates may be associated with ovulatory infertility among women. The mechanism can be attributed mainly to reduced insulin sensitivity that leads to increased free IGF-I and androgen levels, thus reproducing some typical clinical features of PCOS.
The main effects of high carbohydrate intake can be mediated mainly by insulin and its signaling pathway, thus affecting the hypothalamic-pituitary-gonad axis. One explanation suggests that the impairment of the ovulatory process is not due to increased carbohydrate intake, but may be linked to the fact that increased carbohydrate intake occurs at the expense of natural fats, which exert a beneficial effect on ovulatory function. Even though the consumption of carbohydrates and sugars, especially fructose in liquids, as found in sugar-sweetened beverages, can affect the reproductive process. Thus, diets high in carbohydrates/sugars lead to dyslipidemia and insulin resistance, causing ovulatory disorders.
Food and Female Fertility
Food is a crucial factor for the overall health and well-being of the female body, and it also has a significant impact on fertility. A healthy, balanced diet can help promote regular ovulation, maintain adequate hormone levels, and reduce inflammation, factors that are important for female fertility.
On the other hand, processed foods, refined sugars, and controlled vitamins should be avoided as they can increase inflammation and impair ovulation. In addition, excessive consumption of alcohol and caffeine can also affect female fertility.
Some foods that may be beneficial for fertility include fruits, vegetables, whole grains, lean proteins, nuts and seeds, as well as a variety of vitamins and minerals, such as folic acid, iron, zinc, and vitamins A, C, and D. Therefore, ensuring a balanced diet can be a key factor for female fertility.
The influence of diet on fertility
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Nutrition and female fertility
– Fontana R, SD Tower. The Deep Correlation between Energy Metabolism and Reproduction: A View on the Effects of Nutrition for Women Fertility. Nutrients. 2016; 8(2):87. https://doi.org/10.3390/nu8020087