Why fertility patients should consider what they eat before resorting to more invasive fertility treatments
Researchers at Hackney Hospital reviewed the weights of new babies prior to pregnancy and during pregnancy. The results showed that mothers of low birth-weight babies had been eating meat, meat products, white bread, refined sugars and soft drinks in greater amounts, while mothers of the healthy-weight babies had been eating nutrient-rich foods, three regular daily meals (importantly breakfast), wholegrain cereals, muesli, oats, nuts and seeds daily, eggs, egg dishes, wholemeal bread, dairy foods, lots of fresh fruits and vegetables (1). The group concluded that a developing embryo/fetus requires abundant nutrients via the placenta, in order to become a healthy baby and that the high-calorie, nutrient-poor, refined foods were detrimental to the developing baby in the womb. Their hypothesis - that low birth weight may be caused by the mothers having too few nutrients in their diet - was supported (2).
A number of other studies have suggested a link between certain nutrients and fertility levels:
Research shows that a low protein diet causes fewer ova to be ovulated, as does a very high protein intake; with 75 grams of protein considered to be the recommended daily intake. The number of eggs (ova) ripening is reduced or ovulation is stopped if the amount of protein is insufficient (3).
Research shows that an optimum intake of essential fatty-acids from omega 3-6 oils, which form the building blocks of hormone-like molecules known as 'prostaglandins', may be necessary to prevent low birth-weight and decrease premature birth (4). Fish oils, rich in essential-fatty acids, have also been shown to benefit women who experience recurrent miscarriages as a result of blood-clotting disorders (5)(6).
Vitamins such as folic-acid have been shown to be crucial for neural-tube closure, (which occurs twenty-five to thirty days after conception) and helps to prevent spina-bifida. It is recommended that women should take folic-acid up to three months before conception (7). Folic-acid, vitamins B6 and B12 are interlinked together and help to control the amino acid 'homocysteine', high levels of which have been linked to early miscarriages (8)(9).
The mineral iron, found in foods such as dried apricots, vegetables, and beans, has also been shown to be necessary for fertility. In one study, women who regularly took an iron supplement or a multivitamin containing iron (non-haem iron) were 40 per cent less likely to have had trouble getting pregnant than women who did not take iron (10).
Coeliac disease is caused by a reaction to gliadin, a gluten protein found in wheat, rye, oats, barley, and spelt. Deficiencies of zinc, folic-acid, B12 and iron have all been implicated in people with this disease. Being coeliac can affect fertility in both men and women. In women, subclinical coeliac disease disrupts the menstrual cycle, and is implicated in premature-menopause, recurrent abortions and low pregnancy rates (11). In susceptible males, gliadin reduces semen quality. Successful conception was reported after gluten-exclusion with infertility patients (12).
Weight has also been shown to influence fertility in women. At the University of Mississippi, one study suggested counseling by a qualified 'therapeutic dietitian' to promote fertility. 'Fertility was restored in 19 out of 26 women, who conceived spontaneously in due course. All the women had been underweight at the outset but were encouraged to gain half-a-pound per week. No drugs were prescribed' (13).
What should we eat to improve fertility?
These studies highlight the potential for some couples to significantly enhance their fertility by optimising their diet and weight. Women who are having trouble conceiving should therefore consider nutritional counselling before resorting to more invasive treatment options, such as IVF. Nutritional counselling may well enhance treatment outcomes.