The power of preconception nutrition

Dietitian Claudia Vavasour explains how eating well can boost fertility – for both him and her! 

Infertility affects up to one in six people, and is usually associated with those who have difficulty becoming first-time parents. However, you may be surprised to learn that secondary infertility is just as common. This is when people who already have one or more children struggle to conceive or carry a baby to term.

Studies show that the causes of secondary infertility are usually 30% attributable to males, 30% to females and 30% to both male and female, while 10% of cases are due to unexplained infertility with no identifiable cause. Secondary infertility affects 25% of New Zealand’s population and, unlike many other health conditions, it doesn’t discriminate between education, ethnicity or socio-economic status.

THE EFFECT OF DEPLETION
Exhaustion, ovulation timing and postpartum nutrient depletion all play key roles in many cases of secondary infertility. For instance, iron deficiency is particularly common postpartum, and long-term it can lead to hypothyroidism, aka an underactive thyroid. The thyroid gland is vital for controlling your heart rate, your body temperature and all aspects of your metabolism. A poorly functioning thyroid gland is a common cause of recurrent miscarriage. This is just one example highlighting how preconception nutrition affects our fertility. It becomes even more critical with subsequent children due to compounding nutrient depletion following pregnancy and breastfeeding.

The power of preconception nutrition for improving fertility has never been more pertinent than it is today. With many fertility treatments facing postponement and cancellation due to the Covid-19 pandemic, we’re left with just the standard advice on getting ourselves ‘fertility fit’: watch your coffee habit, curb the alcohol, keep active and – if you’re one of the lucky ones whose doctor has also suggested this – sticking to or starting a healthy diet.

IS BEING 'PRETTY HEALTHY' GOOD ENOUGH?
Clients often tell me they think their diet is “pretty healthy”, but after a nutrition assessment they are surprised to learn they have an inadequate nutrition intake. An example would be choline, an essential nutrient for pregnancy which (along with folic acid) is involved in brain development and the prevention of neural tube defects. New Zealand doesn’t have data on choline intake but our Australian counterparts have found that only 1% of women of reproductive age do actually meet their choline requirements.

A 2007 Harvard School of Public Health study showed that by making just five changes to your diet, you can improve your fertility by 69%. They also highlighted that the majority of infertility cases caused by ovulation disorders could be preventable through diet and lifestyle changes. These findings were echoed by research from the University of Otago which found maintaining a healthy weight and good nutrition can improve chances of conception for both men and women. Let’s look at these changes and see what can be done to improve sperm and help optimise your chances of conception.

A BOOST FOR SWIMMERS
✔   Brazil nuts
These nuts are an excellent source of selenium. Inadequate or excessive intakes of selenium are linked to reduced sperm size, thought to be due to the antioxidant activity of this essential nutrient. We get our antioxidants by eating a quality diet with plenty of antioxidant rich foods. There’s good news on the selenium front though; you only need to eat two Brazil nuts a day to get your daily dose. Remember that too little or too much can be detrimental, so if you can, getting your nutrients from food is
the best way to go.

✔   Zinc
The fertility superhero! Zinc is particularly important for the ‘swimmers’ as sperm production requires a huge amount of cell division. It’s been shown to improve sperm count and quality and has been found to prevent DNA fragmentation. Meeting your zinc requirements is generally easy for men, provided they have a varied diet. This essential element is found in a variety of different foods, in particular oysters (which is why they’re known as an aphrodisiac), and also in fish, pork, beef, chicken, nuts, seeds, vegetables and dairy foods.

✔   Folate
Folate is most commonly associated with maternal pre-natal nutrition as it plays a role in preventing neural tube defects early in pregnancy. Similar to zinc, folate is mainly responsible for dividing and maintaining new cells and duplicating DNA. Consequently, folate is crucial for male fertility as well. If you want to have healthy and viable sperm, the easiest thing to do is load up on folate-rich foods. Folate is found in dark green leafy vegetables, legumes (such as beans and chickpeas) and whole grains. Be careful if you’re taking folic acid supplements as excessive amounts can have negative effects and potentially mask a vitamin B12 deficiency.

NUTRITION FOR WOMEN
✔   Full fat dairy products
A 2003 Fertility Risk Factor study by researchers at the Marshfield Clinic Research Foundation in the US found those who drank more than three glasses of cows’ milk a day had a 70% lower risk of being infertile than those who didn’t drink milk. When you compared those who had the highest intake with those who had the lowest, the difference was 15% in live births in favour of the highest intake group. My advice? If you can tolerate dairy, continue to enjoy it but opt for unsweetened yoghurts which have the benefit of probiotics. If you can’t tolerate dairy, find a plant-based milk alternative that’s fortified with calcium, such as soy or almond milk. Just watch for hidden sugars in these! 

✔   Folic acid
As well as being an important factor in preventing neural tube defects, taking folic acid is also likely to increase your odds of having a baby in the first place. This vital element can be supplemented by prescription and is also found in prenatal supplements, in varying forms. Some women require higher doses though, so ask your doctor or fertility dietitian about which dose is right for you. 

'HIS AND HERS' NUTRITION
✔   Power up on plant protein
Switching just 25g of animal protein with plant protein a day can improve fertility by 50%. This doesn’t mean you need to turn vegan, but you could simply add a little more legumes, lentils, nuts and seeds to your diet. I add lentils to my bolognaise and halve the amount of mince. It’s delicious and is even a win with my toddler!

✔   Omega-3s
The essential omega-3 fatty acids (EPA+DHA) are famous for their protective role in heart health. There is also mounting evidence that these fats play a role in sperm health, women’s fertility and IVF outcomes. This is thought to be by reducing inflammation, aiding hormonal processes, improving cell membranes to help the sperm fertilise the egg, and improving sperm motility. The easiest way to ensure adequate omega-3 is to have oily fish (such as salmon, sardines or mackerel) at least two or three times a week. For vegetarians or vegans, algae-based supplements are available to help you get adequate omega-3.

✔   Cut down on takeaways
Don’t get me wrong, I love the occasional takeaway – the issue is when they become a habit. Takeaway portion sizes are generally larger than home-cooked meals and they tend to be higher in saturated fat. Substituting saturated fats for poly- and monounsaturated fats, such as oily fish, avocado, nuts, seeds, olives and olive oil, is key for fertility. Also, with less frequent takeaways you’ll likely see a modest reduction in your weight too; excess body weight is a common contributing factor in infertility for both Dad and Mum. I’ve found that having a list of quick and easy meals that I can put on the table in less than 10 minutes, and ensuring I always have their ingredient staples in the pantry, reduces how often my family ends up getting takeaways.

✔   Ditch those sugary drinks
You’d be forgiven for falling into the habit of reaching for pick-me-ups, but sugary drinks are a short-term fix. Sadly, their long-term impact is reduced energy levels and weight gain. A 2018 study found that just one sugary drink a day is associated with a 20% drop in your chance of conceiving for both males and females. It might sound boring, but good old-fashioned water really is the way to go. Dress it up with a squeeze of lemon, some mint or a slice of cucumber, or try sparkling water.

✔   Choose the right supplement/s
Remember the saying, “One man’s trash is another man’s treasure”? Well, the same applies to nutritional supplements. We all have unique requirements based on our family and medical history, our age, sex, height, weight, blood chemistry, medications, lifestyle, sleep, stress levels and how much physical activity we get. What worked for a friend may not work for you. Because too little and too much of any nutrient and antioxidant can impede fertility, it’s a good idea to have your supplement regime customised by a fertility dietitian.

✔   The Mediterranean diet 
The Mediterranean diet is an evidence-based pattern that will give you the best possible chance of optimising conception and having a healthy baby. Base your diet on vegetables and fruit, with plenty of colour, try to have legumes and lentils regularly, enjoy eggs, poultry, full fat dairy, nuts and seeds, plenty of seafood and oily fish, with occasional red meat.

So, a balanced diet is key to fertility, because what’s really clear in the research is that there’s no one magic food, nutrient or supplement that will work. Try these strategies to kick start your fertility and for best results, seek individualised treatment from a fertility dietitian.

Claudia Vavasour is a New Zealand registered dietitian and nutritionist, and an expert in fertility nutrition. Claudia is busy growing her little girl Saskia and her private practice fertilitynutrition.co.nz, where she sees couples or individuals for women’s health, fertility and pregnancy nutrition.