Eating disorders and infertility are arguably two of the most prominent challenges to the health of the 21st century female and increasingly, 21st century male. Both are a complex weave of a mind and body out of balance and often found to be inextricably linked.

As far back as the early 20th century ‘under-nutrition’ has been shown to interfere directly with cognitive, emotional, and more recently, reproductive function. Regardless of the presentation of an eating disorder, whether it is overeating or under-eating, each one presents a challenge to the bodies fine physiological balance needed for a healthy fertile environment.

How are these linked?

The consumption, or lack of consumption, of beneficial fats (the mono and polyunsaturated versions not the harmful saturated form) is a primary area of interest in the link between eating disorders and sub-fertility. Nature gave women proportionately more body fat for a specific reason and the body needs to maintain this to nourish the next generation. A considerable reduction of body fat, below 17% of total body fat, can bring about amenorrhea – the cessation of periods. Women with anorexia or who exercise to the extreme can experience amenorrhea and is the most regular manifestation of sex hormone imbalance (1). This renders the female technically ‘sub-fertile’. The term ‘sub-fertile’ as is apt as this is, in most cases, a temporary condition until body fat and nutritional balance is restored. However in cases of prolonged neglect it may have an effect for up to 8 years after a healthy nutritional status has returned. Conversely too much body fat, in cases of overeating or obesity, can disrupt sex hormone balance and thereby present an equal challenge for reproduction.

Scientists also know that the appetite centre of the brain is exquisitely sensitive not only to the quantity of beneficial fats and carbohydrates but also the timing at which these are consumed(2,3). This information is then sophisticatedly communicated to the centre that controls sex hormones. Without adequate consumption of these major food groups and/or irregular timing, as is prevalent in cases of binge purging behaviour, the body down-regulates the reproductive function as a means of protection (3). Thyroid function and the sex hormone oestrogen has been found to be especially low in those with bulimia nervosa, the gland in the body that contributes to hormone regulation.

A disordered eating pattern may also disturb key serotonin metabolism and neurotransmitter balance. When neurotransmitters and the key nutrients required for their production such as zinc and the vitamin B family are present in sufficient amounts, mood and emotions are stable. If they are depleted, individuals may starve or overeat to manage mood. Serotonin plays a major role in controlling carbohydrate intake, promoting sleep and regulating impulsive and obsessional behaviours. Dieting has been shown to deplete levels of tryptophan very quickly, particularly in women (5). This reduced level of tryptophan can lower a woman’s sex drive and further perpetuate the challenges that eating disorders pose to fertility.

Dieting, skipping meals and binge eating food that is commonly high in sugar, salt and refined carbohydrates may disrupt blood sugar mechanisms within the body leading to low blood sugar levels, cravings and de-sensitisation of cells to insulin (5,6). This disrupted blood sugar balance as well as anxiety and depression caused by low afore mentioned serotonin levels can lower libido as well as contribute to the development of polycystic ovarian syndrome, a condition that causes the ovaries to produce many follicles containing poor quality eggs. All of these factors combined can make conception, fertilization of an egg, implantation and carrying a pregnancy to full term very difficult and, in some cases, temporarily impossible.

How can nutrition play a role?

A sound and varied diet creates a nourished foundation on which a healthy pregnancy may flourish. This foundation provides the body with those essential nutrients to re-balance hormone and neurotransmitter production, enabling the body to find its equilibrium once again. Experiencing ‘sub-fertility’ can be an emotional journey paved with anxiety and changing moods and a time where there is great demand on the body both physically and cognitively. The body’s need for physiological stability through regular nutritious meals is high during this time. Here are a few ways to allow your body to play the role as facilitator it is so capable of doing if you nurture it:

• Fat is often removed from the diet at an early stage including in this the essential fatty acids omega 3 and 6. These are required for all hormone production and can only be generated via dietary consumption of oil fish, nuts, seeds and in smaller amounts, green leafy vegetables. Taking an Omega 3 supplement containing at least 1000mg of Omega 3 is highly recommended where dietary quantities may not be achieved.

• Reducing sugars, refined products and stimulants such as coffee and colas can support blood glucose control, insulin output and mood. Caffeine has been shown to reduce fertility in both men and women

• Choose complex carbohydrates such as whole-meal bread, wholegrain rice and pasta over white versions. These release slow amounts of glucose so as to provide a longer source of energy and provide fibre to help remove unwanted toxins and surplus hormones from the digestive system. They also contribute important nutrients such as b vitamins, selenium and zinc.

• Foods such as turkey, bananas, eggs, tofu and almonds are high in the amino acid tryptophan that can support serotonin production. Include into the daily diet as frequently as possible.

• Regular meals, such as breakfast lunch and dinner, punctuated by a mid morning and mid afternoon snack of fruit, nuts or seeds not only ensures that the blood glucose levels remain stable it also comforts the body in the knowledge that it is no longer necessary to be in starvation mode. This frees key systems to get back to work.

• Variety is important when eating fruit and vegetables. Choose fruit for a snack and aim for at least one vegetable with each main meal. These are the densest source of nutrients and provide key nutrients such as vitamin A, vitamin C, Vitamin E, selenium and iron and zinc essential for reproductive health in both males and females.

• Consider taking a multivitamin and mineral supplement. Note this is a recommendation as a supplement to an otherwise nutrient dense diet where previous nutritional neglect may have created a greater demand for nutrients than the diet can provide.

• Consider herbs such as agnus castus and saw Palmetto to restore hormone imbalance and increase fertility.

Refs:
1. Fairburn and Harrison, 2003
2. Johnson et al, 1994
3. Kaye 2007
4. Kaye and Weltzin, 1991
5. Cowen et al, 1996; Wolfe et al 1997
6. Naessen 2007