To follow on from last week’s blog ‘male fertility and mitochondrial function’, this blog is focusing on female fertility. Low fertility, which is thought to affect one in six couples trying to conceive, can be a heartbreaking and very stressful situation. Often there is no decisive causative factor leading to infertility or subfertility.
Although this can be the cause of frustration it does mean that if we can optimise health, the chances of conception and a healthy pregnancy can improve. As mentioned in previous blogs, it is advisable to optimise health before attempting to conceive, in order to enhance fertility and support the health of the baby. See blog: Preconception Care.
In order to achieve conception the following things need to happen:
- Production of viable sperm (see blog: male fertility and mitochondrial function)
- Adequate transport of sperm to female genital tract
- Normal oocyte (egg) production
- Transport of sperm and oocyte to fertilisation site in fallopian tube
- Penetration of oocyte by sperm
- Transport to and implantation of uterus
Clearly, both the health of the male and female are equally important for a pregnancy to occur; this blog focuses on female fertility. The production of a normal oocyte relies on adequate hormonal control and a healthy balance of all female hormones particularly oestrogen and progesterone. Interruption to hormonal control can be affected by a number of factors and these should be considered and managed as appropriate. These include:
- Stress and adrenal dysfunction – cortisol inhibits the release of Gonadotrophin Releasing Hormone (GnRH) and therefore can suppress ovulation and sexual activity. Adrenaline can also inhibit the utilisation of progesterone, therefore disrupting hormonal control of the reproductive system. Cortisol is produced from DHEA, as are all of the sex hormones, therefore excess production of cortisol has the ability to deplete production of other steroid hormones. So, if excess stress or adrenal dysfunction is suspected, stress management techniques and adrenal support should be implemented.
- Low thyroid function – hypothyroidism is associated with low fertility, therefore thyroid conditions or sub-clinical hypothyroidism should be considered and supported if fertility is reduced.
- Poor gut and liver function – the liver and gut are responsible for the excretion of oestrogen. If they are not working efficiently oestrogen, which is destined for excretion, can be reabsorbed into the body (particularly in cases of constipation). This can lead to a higher ratio of oestrogen to progesterone, known as oestrogen dominance, which has been shown to have a negative effect on fertility and also increases risk of conditions such as endometriosis and PMS. Therefore, the health of the gut and liver should be considered when supporting fertility. Preconception plans are focused on supporting both the gut and the liver.
- Weight – A low BMI (under 19) or less than 17% body fat, can result in anovulation (a lack of ovulation). A BMI of over 30 can also interfere with ovulation, increase risk of miscarriage and reduce IVF success. Optimum fat percentage for fertility is 20-25% (this is also a healthy BMI).
- Age – after the age of 35 fertility begins to reduce. It is advisable that women over 35 who have been attempting to conceive for over a year should seek potential intervention or investigations to optimise chances of conception.
Other factors associated with poor fertility which should be addressed are:
- Irregular sleep patterns
- Environmental toxins
It is important to consider these external factors however, this blog is focusing on nutrients that are required for fertility and with or without the above factors these dietary principles and nutrient intakes should be implemented to support overall fertility.
Dietary recommendations for fertility are aimed at supporting healthy hormone and oocyte production and mitochondrial function, which is required for DNA replication and cell (oocyte) formation. Dietary characteristics associated with optimal fertility include:
- Avoidance of trans fatty acids (found in heavily processed and baked goods)
- High intakes of healthy fats including omega 3 and monounsaturated fat
- Lower intake of animal protein and high intake of vegetable protein
- Lower intake of high glycaemic load carbohydrates (e.g. white bread, pasta and rice) and sugar
- High intake of fibre from vegetables, fruits and some whole grains
- Subfertility has also been seen in individuals with the coeliac disease and non-coeliac gluten sensitivity. Therefore, avoidance of gluten should be considered
Specific nutrients for fertility
The health of the cell membrane surrounding the oocyte is really important for overall oocyte health and development and also for allowing the sperm to penetrate it. Therefore, cell membrane health should be supported:
Essential Fatty Acids – Omega 3 fats can be incorporated into the cell membrane aiding membrane fluidity and assisting oocyte penetration. EFAs are also associated with supporting normal hormone production, mitochondrial and adrenal function. DHA is particularly important for the cognitive development of the growing foetus.
As with male fertility, the function of the mitochondria is essential. This is because there is a high rate of cellular replication during oocyte development. The developing embryo also requires optimally functioning mitochondria in order to grow and develop. Some nutrients which support cellular replication and mitochondrial function are:
L-Carnitine – involved in fatty acid metabolism within the mitochondria and therefore supports energy production required for oocyte development, acceptance of spermatozoa and subsequent formation and development of the embryo (embryogenesis).
L-Arginine – a precursor to nitric oxide which has been shown to be required for embryogenesis, hormone secretion, fertility in general and it is also required for cellular replication.
Oxidative stress can have a negative effect on the mitochondria leading to damage and suboptimal function but also may affect the health of the oocyte. If the cell membrane of the oocyte is exposed to oxidative stress it can be more difficult for the spermatozoa to penetrate it. Therefore, it is advisable to reduce environmental oxidative stress (caused by some of the factors mentioned above) and increase a number of antioxidants in order to help prevent damage caused by oxidation. Some antioxidants that have been found to be supportive for reproductive health are:
Alpha Lipoic Acid – powerful antioxidant which also regenerates vitamin C, vitamin E, CoQ10 and glutathione.
Vitamin A – an antioxidant that also is responsible for cellular growth and differentiation and is required for embryonic development. However, caution is needed with supplementation in pregnancy and high vitamin A intakes have been associated with congenital abnormalities. However, beta-carotene (precursor to vitamin A and an antioxidant in its own right) can be taken safely in pregnancy.
Vitamin C – another antioxidant that also has the ability to regenerate glutathione. It has further effects on reproductive health as it has a positive effect on growth and repair of the ovarian follicle and the development of the corpus luteum (essential for maintaining pregnancy). Vitamin C is also associated with a reduced risk of preeclampsia.
Vitamin E – a fat soluble antioxidant which is also important for maintaining ovarian health.
Selenium – supports thyroid hormone production (as mentioned earlier suboptimal thyroid function is associated with low fertility), it is also a powerful antioxidant and involved, again, in glutathione regeneration.
Zinc – a cofactor for enzymes which are involved in the production of DNA and RNA as well as protecting against oxidative damage. Zinc also plays an essential role in the production and transport of reproductive hormones.
Other nutrients that do not have antioxidant properties still play an essential role in fertility these include:
B Vitamins: many of the B vitamins are involved in cellular replication and normal DNA as well as hormone production and specific roles involved in fertility, pregnancy and healthy offspring. These include:
Thiamine (B1) – shown to stabilise membranes of newly generated neural cells.
Riboflavin (B2) – important for mitochondrial energy production as well as antioxidant defence.
P5P (B6) – required for normal production of some hormones and neurotransmitters as well as metabolism. A lack of B6 may be associated with pregnancy-related nausea.
Folate (B9) – required for healthy DNA and RNA synthesis associated with a reduced risk of spinal bifida (ideally women should supplement 400ug for at least 3 months prior to conception).
Methylcobalamin (B12) – works with folate for DNA and RNA synthesis and also protects against neural tube defects. As well as affecting cell replication, sub-optimal levels can lead to high homocysteine levels which can have a negative effect on fertility.
Relevant Cytoplan products
Vitamin D – important for the healthy bone function of developing foetus, modulates immunity (autoimmunity has been linked to poor fertility and miscarriage) and is also involved in cell proliferation and differentiation.
Iodine – major constituent of thyroid hormone.
Iron – formation of red blood cells in mother and developing foetus and is also involved in energy production within the mitochondria.
Relevant Cytoplan products
Pregnaplan – Multivitamin and mineral appropriate for preconception, pregnancy and breastfeeding. Contains range of B vitamins including 400ug methyl folate, vitamin D3, iron, iodine, zinc, calcium, magnesium.
Cyto-Renew – Contains L-Carnitine and alpha lipoic acid as well as other antioxidant nutrients relevant to mitochondrial function.
Omega 3 Vegan – Omega 3 oil high in DHA.
Related Cytoplan blogs
Mitochondrial function and male fertility
have any questions regarding the topics that have been raised, or any other health matters please do contact me (Clare) by phone or email at any time.
firstname.lastname@example.org, 01684 310099
The Cytoplan editorial team: Helen Drake, Clare Daley, Amanda Williams and Joanna Doverman.