Fertile Ground

Every gardener knows that what grows depends on the soil. Long before a seed is planted, the ground is prepared, fed and cared for. Fertility is much the same. The health of the egg and the sperm that come together, and of the body that nurtures a pregnancy, is shaped in the months before conception. And just as importantly, it's a story about two people, not one.

A shared story

Around 1 in 7 couples in the UK have difficulty conceiving. For generations, fertility was seen mainly as a woman's concern, and it's often still the woman who has the first tests. Yet a man's health is involved in around half of all cases where a couple struggles to conceive.¹ Preparing for pregnancy is something to do together.

The quiet decline in sperm

One of the most striking health findings of recent decades concerns sperm. A major review of studies from around the world found that average sperm concentration fell by more than half between 1973 and 2018, and that the decline has been speeding up since 2000, to over 2.5% a year.² Sperm counts are now seen as a marker of men's overall health, and lower counts are linked with a higher risk of illness and earlier death.³

No single cause explains it. Researchers point to the same features of modern life that affect men's testosterone: rising weight, inactivity, poor diet, stress, smoking, and particularly the hormone-disrupting chemicals found in plastics, pesticides and personal care products, some of which affect boys' reproductive development even before birth.⁴ (See Mojo Matters.)

Age and the egg

A woman is born with all the eggs she will ever have, and both their number and their quality gradually decline with age, more noticeably from the mid-30s. Among women having regular unprotected sex, around 94% of those aged 35 conceive within three years, compared with 77% at 38.⁵ Men's fertility also declines with age, more gently: sperm from older fathers carry more DNA damage, which can affect conception and miscarriage risk.

Age can't be changed, but the quality of each egg and sperm is still influenced by how we live, and that's where preparation makes a real difference.

The three-month window

Sperm take around 74 days to develop, and a further couple of weeks to mature.⁶ An egg's final stage of development, before it's released, also takes around three months. This means the egg and sperm that come together are shaped by the food, sleep, stress and exposures of the previous three months or so. It's why it's wise for both partners to begin preparing at least three months before trying to conceive. What we eat and how we live can even influence the chemical marks on the genes passed to a child. (See Not Written in Stone.)

The healthiest pregnancies begin months before conception.

Food for fertility

Diet has a real influence on fertility, for both women and men.⁷

• For women, in the large Nurses' Health Study II, those who followed a "fertility diet" most closely had a 66% lower risk of infertility caused by ovulation problems. Its features included more plant protein from beans and lentils, healthy fats, whole grains, iron from plants and fewer refined carbohydrates and trans fats.⁸
• For men, diets rich in fish, vegetables, fruit, whole grains, nuts and legumes are linked with better sperm quality, while processed meat, sugary drinks and high-fat processed foods are linked with poorer quality.⁹ In one trial, young men who ate 75 g of walnuts a day for twelve weeks, a large handful, saw improvements in how well their sperm moved and how they were shaped.¹⁰
• Fewer pesticides. Men who ate the most fruit and vegetables high in pesticide residues had a 49% lower sperm count than those who ate the least, although eating plenty of fruit and vegetables overall wasn't harmful.¹¹ Choosing organic for the most heavily sprayed produce is a simple step. (See Why Eat Organic?)

In practice, this looks very like a Mediterranean way of eating: colourful vegetables and fruit, beans and lentils, oily fish, nuts, seeds, olive oil and whole grains, with very little sugar or ultra-processed food.

Key nutrients

Alongside the NHS advice on folic acid and vitamin D, naturopathic nutritionists focus on these nutrients for both partners:

• Folate. The NHS advises women to take a 400 microgram folic acid supplement from before conception until 12 weeks of pregnancy, to help prevent neural tube defects such as spina bifida. Some women need a higher dose, so it's worth checking. Leafy greens, beans and lentils provide natural folate. (See Food as Medicine.)
• Vitamin D, which the NHS advises during pregnancy and which matters for both partners' reproductive health.
• Zinc and selenium, essential for healthy sperm. Oysters, pumpkin seeds and Brazil nuts are rich sources.
• Omega-3 fats, from oily fish or algae, which support egg quality, sperm and the baby's developing brain.
• Iodine, vital for the baby's brain development, from fish, dairy and seaweed.
• Iron and B12, especially for women with heavy periods or who eat little or no meat. (See You Are What You Absorb.)
• CoQ10, which helps power the cell's energy factories. In a trial with women who had a low egg reserve, CoQ10 before IVF improved the response of the ovaries and the quality of embryos.¹²

Antioxidant supplements are often sold for male fertility, but a large, well-designed American trial found that a typical antioxidant mix didn't improve sperm or pregnancy rates.¹³ Food first, with targeted nutrients where testing or symptoms show they're needed, is the better approach.

What to avoid

• Smoking and vaping, which damage both eggs and sperm, and cannabis, which lowers sperm count.
• Alcohol. The NHS advises not drinking at all in pregnancy, and alcohol also lowers sperm quality, so cutting it out while trying is wise for both partners.
• Plastics and hormone disruptors. Avoid heating food in plastic, choose fragrance-free products, and drink filtered water from glass or steel. (See Lightening the Load.)
• Heat for men. The testes sit outside the body to stay cooler. Hot baths, saunas, heated car seats and laptops on the lap can all lower sperm production. Keeping a phone in a trouser pocket has also been linked with reduced sperm movement.¹⁴ (See Wired and Tired.)
• Testosterone and steroids. Taking testosterone switches off sperm production, so men on testosterone therapy who hope to become fathers should speak to their prescriber.

Weight, movement, sleep and stress

Both a very high and a very low body weight can disturb ovulation, and in men, excess weight lowers testosterone and sperm quality. Regular, moderate exercise helps both partners, though very intense training can disrupt a woman's cycle. Sleep supports the hormone rhythms of the menstrual cycle and testosterone. (See The Art of Sleep.)

Stress matters too. In an American study that followed couples trying to conceive, women with the highest levels of a stress marker in their saliva were twice as likely to experience infertility.¹⁵ This isn't about being told to "just relax", which can feel unhelpful, but about finding real ways to ease the pressure, from breathwork and time in nature to support from each other. (See The Healing Breath.)

Hormones and hidden causes

Conditions such as polycystic ovary syndrome (PCOS), the most common cause of ovulation problems, endometriosis and thyroid imbalance can all affect fertility, and many respond well to diet and lifestyle alongside medical care. (See The Hormone Web.) Blood sugar balance is particularly important in PCOS. (See Balancing the Sugar Seesaw.)

Herbs and fertility

Herbal medicine has a long tradition of supporting fertility, built on generations of careful observation, and modern research is now lending support to several of these herbs. Ashwagandha improved sperm count and movement in a small trial in men with low counts,¹⁶ and maca has been linked with improved semen quality.¹⁷ For women, vitex (agnus castus) has traditionally been used to support a regular cycle. In Ayurvedic medicine, shatavari (Asparagus racemosus), whose name is often translated as "she who possesses a hundred husbands", is the great tonic for women's reproductive health, used for centuries to nourish fertility and a healthy cycle. It's cooling and moistening, so it particularly suits women who feel dry, depleted or run hot. However, herbs need particular care when trying to conceive: some aren't safe in pregnancy, and the right choice depends on each person's constitution and hormone picture. They're best used with a practitioner's guidance, rather than self-prescribed, and usually stopped once pregnancy is confirmed unless advised otherwise.

At Rootwise, we often work with couples in the months before conception, looking at nutrition, hormones, gut health, stress and environmental exposures for both partners, and supporting those going through fertility treatment. A Rootwise consultation can help you prepare the ground for a healthy pregnancy.