The World of Nutraceuticals and Female Fertility

Can nutraceuticals play a role in conceiving a child?

Infertility is a global health issue affecting 20 to 30 percent of women of reproductive age. World Health Organization (WHO) defines infertility as not being able to conceive after 12 months of unprotected sexual intercourse. It estimates that around 80 million women worldwide are suffering from infertility with a prevalence of 50 percent of all women in developing countries.1,2 Infertility is classified as primary or secondary.3

  • PRIMARY INFERTIITY
    Primary infertility denotes women who have never been able to conceive.
  • SECONDARY INFERTILITY
    Secondary infertility indicates having trouble getting pregnant after at least one successful conception in the past.

Infertility may be caused by a number of different factors, either in male or female or a combination of these.4


Factors responsible for female infertility

Combined factor (40%)

Ovulatory dysfunction (21 to 25%)

Male factor (26 to 30%)

Cervical/uterine/peritoneal factors (10 to 13%)

Tubal factors (14 to 20%)

Unexplained (25 to 28%)


Variety of different causes of female infertility5-7

  1. OVULATION DYSFUNCTION
    • Ageing – female fertility starts to decline by age 35.
    • Diminished ovarian reserve.
    • Endocrine disorder such as:
      • Hypothalamic amenorrhea.
      • Functional pituitary adenomas.
      • Thyroid disorders such as hyperthyroidism, hypothyroidism.
      • Adrenal disorders such as congenital adrenal hyperplasia and Addison’s disease..
      • Ovarian disorder such as Polycystic ovarian syndrome (PCOS) and premature ovarian failure.
  1. TUBAL CAUSES
    • Pelvic inflammatory disease
    • Previous ectopic surgery
    • Hydrosalpinges
  1. Uterine/cervical peritoneal causes
    • Congenital uterine anomaly
    • Fibroids
    • Endometriosis
    • Infection
    • Poor cervical mucus quality/quantity

Similarly environmental conditions such as stressful jobs, unbalanced nutrition and an unhealthy diet interferes with a women’s reproductive health.

Risk factors2,8

Smoking and drinking

Poor nutritional habits

Obesity

Sexually transmitted infections

Increasing age

Chemotherapy or radiation therapy

Stress and antipsychotic medications

Metaboloic disorders like diabetes, obesity and hyperlipeidemia

Apart from a number of gynaecological and systemic metabolic diseases, certain lifestyle related factors, such as age (deterioration of the ovarian reserve and oocyte quality after 30 years of age), excess body weight, smoking, alcohol consumption and chronic exposure to environmental pollutants have adverse effects on female fertility. Similarly environmental conditions such as stressful jobs, unbalanced nutrition and an unhealthy diet interferes with a women’s reproductive health.

Management of infertility

Conventional infertility treatments involve hormonal medications (such as follicle-stimulating hormone, human chorionic gonadotropin and so on), tubal plastic surgery, assisted reproductive technologies (ART), intrauterine insemination (IUI), egg and sperm donation, induction of ovulation and micronutrients supplementation.

The conventional hormonal medications come with unavoidable side effects as well as a high cost and modern fertility treatment procedures. Therefore, nowadays nutraceuticals (dietary supplements, phytochemicals, nutrients, and herbals) have been gaining importance as an alternative or supplemental medication along with pharmaceuticals. These nutraceuticals are considered to be appropriate alternatives to chemical medicines because of their phytoestrogenic, antioxidant and nutritional effects. Various studies have also revealed the role of micronutrients in the treatment of female infertility alone and in combination with other treatments. These micronutrients include B vitamins, vitamin D, vitamin E and fatty acids (saturated fatty acids, monounsaturated fatty acids (MUFS), polyunsaturated fatty acids (PUFAs), omega-3, and omega-6), zinc and selenium.8,9

Role of nutraceuticals in female infertility

Many of the common nutraceuticals that are beneficial to women infertility include melatonin; L‐arginine; myoinositol; L-carnitine; selenium; vitamins E, C, B complex; folic acid; CoQ10; and omega‐3‐polyunsaturated fatty acids.10

Role of micronutrients in fertility18

Micronutrients (vitamins and minerals) have important roles at various stages involved in fertility. Adequate folate levels are necessary for oocyte (immature egg) quality, maturation, fertilisation, and implantation. Zinc has been associated with ovulation and the menstrual cycle. DNA synthesis, which is essential for the development of oocytes, is dependent on zinc and certain B vitamins. Sufficient vitamin A levels are necessary for oocyte quality and blastogenesis. Apoptosis (such as normal cell death) is essential for regulation of follicle atresia, degeneration of the corpus luteum, and endometrial shedding, which is influenced by folate and zinc. Inadequate selenium levels are responsible for luteal phase deficiency, which leads to inadequate progesterone secretion by the corpus luteum thereby making the endometrium less receptive to implantation, putting them at a greater risk of infertility. Vitamins B6, B12, and D, folate and iron have roles in mechanisms that can affect fertility, including homocysteine metabolism, inflammation, oxidative stress, and embryogenesis.

There are few studies suggesting that women who are unable to conceive have lower than recommended levels of certain micronutrients. For example, insufficient vitamin B12 levels have been reported in more than half of infertile women. Women who are infertile appear to have lower vitamin B6 levels than fertile women. Women with low vitamin D levels may be less likely to conceive. Vitamin D has been linked to various health benefits and its deficiency is associated with conditions that decrease fertility, such as PCOS, and can negatively impact the outcome of infertility treatment such as in vitro fertilisation.

Overall, considering the importance of certain micronutrients (like, folate, vitamins B6 and B12 as well as vitamin D) on various aspects of fertility, it is reasonable to restore micronutrients to recommended levels for positive impact on fertility.

The primary causes of female infertility usually include ovulation disorders, fallopian tube problems, uterine lesions, and endometriosis.

Dietary habits and female fertility19

There is an evidence to suggest a link between diet and female fertility. Available data show that diets high in saturated fats and sugars can negatively impact fertility. On the other hand, a mediterranean diet such as diet rich in dietary fibre, omega-3 fatty acids, plant-based protein, and vitamins and minerals, has a positive impact on female fertility. The Mediterranean diet consists of high consumption of vegetables (including pulses), fruits, olive oil, unrefined carbohydrates, low-fat dairy and poultry, oily fish, with a low consumption of red meat and simple sugars. This diet also has been associated with lower prevalence of metabolic syndrome which is a risk factor for infertility.

Conclusion

Infertility is a major public health problem in modern society and recurs in as much as 20 to 30 percent of the female fertile population. The primary causes of female infertility usually include ovulation disorders, fallopian tube problems, uterine lesions, and endometriosis. The conventional treatments of infertility include sex hormone therapy (follicle-stimulating hormone, human chorionic gonadotropin, etc.), tubal plastic surgery, and assisted reproductive technology. There has been growing interest in nutraceutical approaches as an adjuvant treatment in female infertility. Melatonin; L‐arginine; myo‐inositol; L-carnitine; selenium; vitamins E, C, B complex; folic acid; CoQ10; and omega‐3‐polyunsaturated fatty acids are some of the nutraceuticals that have good action in management of female infertility with clinical evidence. In addition, micronutrient supplementation has benefits of improving oocyte and embryo quality and increasing the chances of becoming pregnant in women having difficulties conceiving. Lastly, healthy lifestyle choices can help promote fertility.

References:

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