What is fertility and how can you improve it?

By Laura Campbell

Fertility is a measure of an individual’s ability to reproduce and conceive to produce fertile offspring. In humans, a male sperm (produced in the male testes) and a female egg (produced in the female ovaries) must fuse in reproduction to produce a fertilised egg. This egg must implant itself in the lining of the female womb. This lining develops into the placenta which supports the development of a baby during gestation, between conception and birth.

Conception is controlled by male and female hormones. Hormones are chemical messengers which tell the cells in the body how to develop. Female fertility hormones include Oestrogen, which leads to the development of the female sex characteristics, Progesterone, which maintains the womb lining, LH (luteinizing hormone), and FSH (follicle-stimulating hormone) and Testosterone, which plays a role in sexual arousal and regulation of the menstrual cycle. FSH controls the release of the egg from follicles.

Male sex hormones include Testosterone, needed for male sex characteristics development, Progesterone and LH, needed for Testosterone production and FSH, needed for sperm production. Men also require Oestrogen for erections and testicular function, as well as for producing sperm. Both female and male sex hormones are produced from Cholesterol via Pregnenolone. Pregnenolone is then converted to DHEA or Progesterone which is converted to Androstenedione. This becomes Testosterone and Oestrogen.

What causes infertility?

Fertility can be caused by numerous reasons. In a female it can be caused by problems in the ovaries (reducing the egg count), problems in the womb or fallopian tubes (reducing the egg release), or polycystic ovaries (PCOS), in which the follicles do not release the egg correctly. It can also be caused by endometriosis, where the womb lining grows inappropriately in the womb.

Female infertility can also be caused by age, as egg cell count and quality decline with age. This is tested for by testing Ovarian reserves. These are a measure of a woman’s reproductive potential and are measured by testing FSH levels and anti-Mullerian levels (AMH) as well as antral follicle count. Female hormone imbalances can also have severe effects.

Stress produces the hormone Cortisol. Our bodies see stress as a threat and priorities defence from stress over reproductive function. Cortisol is made from Pregnenolone, and so high stress can “steal” away the Cholesterol needed to make sex hormones in favour of producing Cortisol. This can lower Oestrogen and Testosterone levels in both males and females.

Cholesterol is made from body and dietary fat, and therefore a body with too much muscle (both male and female) and insufficient body fat percentage, can result in less Oestrogen, Progesterone and Testosterone production. This is especially prominent in bodybuilders and female athletes triad, where high muscle and low body fat percentages (often promoted by the western world with high protein diets and shakes that increase muscle mass) result in impotence in males and a lack of menstruation (amenorrhea) in females.

Too high weight in males can cause infertility as well. This is because fat is stored in fat cells called adipose tissue. Too many fat cells increase Oestrogen production in men. Fat cells lead to increased conversion of Androstenedione to Oestrogen over Testosterone. This lowers male sperm count. Obesity can also elevate body temperature, especially around the Scrotum.

In females, obesity can increase the risk of PCOS. Fat cells also increase Oestrogen in females and this increased Oestrogen acts like the contraceptive pill Oestrogen supplement, ceasing menstruation and preventing ovulation. Infections to the womb can also cause infertility, as can uterine fibroids.

How do I increase my fertility?

A good way to start improving fertility is to reduce stress on both males and females. This can be incredibly hard if you are going through the anxiety and stress of fertility treatment but is essential to improve hormone regulation. Stress also impacts sleep and appetite which themselves impact stress levels. Oestrogen is a mood stabilizer and so the more stressed you are, the more stressed you are likely to become. Activities to reduce stress are essential when attempting to conceive.

Maintaining a healthy body fat percentage in both males and females is also essential for fertility. Too high body weight causes Oestrogen dominance which causes infertility and too low body weight causes low Oestrogen levels, which causes infertility. This is not about weight, but body fat, as a very muscular man may still suffer infertility due to a low body fat percentage.

Diet is also very linked with fertility, though it must be tailored and personalized to your body. Dietary saturated fat is necessary for hormone production as hormones are made of Cholesterol. Too much dietary saturated fat causes Oestrogen dominance, and therefore to increase fertility it would be advised to consume more “healthy” fats such as monounsaturated fats in nuts and seeds, fish and olive oil and lots of dietary fibre from vegetables, which decrease LDL Cholesterol (low-density lipoprotein) levels and decrease saturated fat levels.

Too little saturated fat in your diet causes low Oestrogen levels, and so a diet rich in Cholesterol saturated fat, such as fatty meat, butter, full-fat dairy, eggs, coconut oil and processed foods, increases LDL cholesterol and increases body saturated fat. This is counterculture (which promotes Cholesterol reducing foods to promote heart health in the obesity epidemic) but is necessary for those underweight or too muscular for fertility.

In overweight men and women, a diet high in fibre and complex (vegetable-based) carbohydrates and high in monounsaturated fats, omega-3 and B vitamins, is associated with decreased LDL levels and decreased Oestrogen levels, improving fertility. In underweight individuals, a diet high in fat and low in carbohydrates is necessary to increase Oestrogen levels. Both folic acid (B9) and vitamin D have been shown to increase fertility and a diet high in antioxidant anti-inflammatory foods improve sperm count and egg quality.

Alcohol also reduces fertility. It is a toxin that must be broken down by the liver. Even moderate alcohol consumption has an effect as the liver prioritizes the breakdown of toxins over the breakdown of Oestrogen. Oestrogen must be broken down after day 14 of the menstrual cycle. It is the decrease in plasma (blood) Oestrogen and LH peak that triggers the egg release (ovulation). If Oestrogen levels do not fall, the egg is not released (anovulation) and LH levels are elevated. This has a contraceptive effect. Chronic heavy alcohol use can diminish ovarian reserves. In males, the increased plasma Oestrogen causes hyperestrogenism, Oestrogen dominance which causes decreased testosterone and sperm production in males.

Smoking and drug use (even CBD oil) and even some medications are also toxins that are broken down by the liver. Smoking has been found to decrease sperm volume, total sperm count, semen volume and sperm motility in men. In females, it causes the same effects as alcohol.

Regular exercise also improves fertility, but not to extremes. This is because exercise can help those overweight to lose weight. At a healthy weight, it can reduce stress and cortisol levels and improve insulin levels. However excessive exercise can cause the ratio of body muscle: fat to increase in favour of muscle, reducing body fat and decreasing Oestrogen (athletes triad) in females. Regular moderate exercise improves fertility.

Every man and woman deserves the right to create life.

Our fertility is far more down to lifestyle and our daily choices than we realise. Simple dietary and environmental changes can make a big difference. For anyone trying to conceive, I wish you all the luck in the world and hope you get that magic fusion of egg and sperm to spark the start of a new life.

Copyright Laura Campbell 21/04/2022



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Laurentia (Laura)Campbell

Laurentia (Laura)Campbell

Neuroscience, mental health and nutrition academic and writer. Life-experimenter, trying to add value with an insatiable appetite for actioning positive change.