Diet choices significantly affect health and fertility levels, and adjusting diet to increase the variety of minerals, oils, and vitamins is a potent way to raise conception rates and health. Our diet underpins all bodily processes and makes a big difference to our sexual health, and polycystic ovary syndrome (PCOS), a leading cause of infertility, is usually due to high blood sugar levels from diet choices.
We’re all different, and we provide specific dietary advice as part of the morefertile Personal Fertility Profiles (PFPs), however, it’s fair to say that in an ideal world, eat organic and enjoy a wide variety of fresh fruit and vegetables. If this is balanced with whole grains, essential fats and protein, you’re pretty much there. Of course, this isn’t always possible, but knowing how diet affects fertility can motivate us to do our best!
The general principles of a fertility diet are relatively simple and revolve around “know what you’re eating”, so:
- Avoid processed and packaged foods if possible
- Cook your own when you can
A Mediterranean diet is generally ideal for fertility (not lots of pizza or pasta, though!). It has lots of fresh fish, vegetables, fruit and olive oil, but we think a south-east Asian diet is just as good and adds a bit of variety. These diets are great starting points, and we’re all affected by certain things but bear in mind we’re not all the same, and individual needs vary dramatically, check out the PFP advice for the personal touch.
Women are more fertile when their diet contains all the major food groups. Studies show that:
- Replacing carbohydrates with animal protein reduces ovulation rates
- Adding just one serving of meat (especially chicken or turkey) a day increases the chances of not ovulating by 32%! i
- Replacing carbohydrates with vegetable protein doubles the chances of ovulation
- Trans-fats rather than mono-unsaturated fats in the diet more than doubles the risk of infertility from anovulation ii
The take-home from this is that fried chicken is going to reduce your fertility dramatically, while cutting chips or rice for vegetables or Quorn will improve your fertility.
Fats are an important source of energy, they affect how cells function and are important for oxidative stress. The latest advice is to cook in animal fats (they’re more stable) and to eat vegetable fats cold.
Trans-fats are unsaturated plant fats (generally vegetable oils). Many pre-prepared foods, particularly fast foods, snack food, fried food and baked goods contain them.
- Eating trans-fats instead of carbohydrates increase anovulation rates by 73% iii
Mono-unsaturated fats are found in red meat, milk products and fruits like olives and avocados. Nuts are also a good source (especially cashews and macadamia) and oatmeal. Other important sources of mono-unsaturated fats are oils:
- Olive oil is about 75%
- Sunflower oil (high oleic variety) contains up to 85%
- Canola oil 58%
- Lard is 40%
Women wanting to follow a highly “fertile diet” should concentrate on: iv
- Increasing the quantity and quality of mono-unsaturated fats and reducing trans-fats in the diet
- Eating vegetable protein rather than animal protein
- Avoiding low-fat dairy products
- Reducing the amount of sugar
- Increasing their mineral and vitamin intake (within safe limits)
For vegetarians and vegans, flaxseed oil is an alternative source of omega-3. The fruit and vegetables with the most health benefits are nearly always the most colourful ones, so “eat a rainbow” a day! If you’re not a big fish or shellfish eater, then supplement with fish (or krill) oil in capsules to get your omega-3 fats.
Multivitamins and other supplements are popular options to improve fertility, and when women take multivitamins, they’re less likely to have problems ovulating. The dose may have a significant effect as one study found that women taking six or more tablets are the least likely to experience infertility. Women taking three to five tablets a day, then women on two or fewer tablets also improved. v
The quality of supplements is essential, and severe harm can be done by taking excessive amounts, which means it’s always best to get advice before taking them. Ultimately the best way to get the vitamins and minerals we need is by having a healthy, varied diet, as this also supports a healthy microbiome! If you’re thinking of taking supplements, make sure you’re taking the ones you need with a proper nutritional assessment.
The advice for men is similar to the recommendation for women:
- A diet rich in carbohydrates, fibre, folate, and lycopene improves male fertility vii
- Eating fruit and vegetables improves semen quality
- Lower protein and fat diets (cut down on meat) enhance male fertility
Between 30% and 80% of male subfertility is due to damage from oxidative stress, and semen with oxidative stress/antioxidant imbalances has more DNA damage to their sperm: viii
- Antioxidants reduce free-radicals damaging cells
- High antioxidant levels improve semen quality compared to low or moderate levels of antioxidants ix
- Almost all reviews of antioxidants and male fertility conclude that antioxidants significantly improve male fertility x
- Sub-fertile men who take antioxidants may be up to four times more likely to father a child xi
The best way to get antioxidants is a varied diet with low animal protein levels, while good quality multivitamins and other supplements can help. The diet is the best way to improve antioxidant levels and while taking supplements and eating fast food may seem like balance, it’s not!
Couples trying for a baby should really change their diet at least three months (ideally six months) in advance. We advise six months as it gives time for developing eggs and sperm to benefit from better nutrition and lower oxidative stress. Diets are potent ways to reduce inflammation, balance hormones, or build up substantial energy reserves, which are all crucial for making babies.
While diet is a powerful tool to improve health and fertility, this is especially true when it matches a person’s needs, and not all diet advice is appropriate for everyone, so please:
- Follow the advice for your Fertility Profile
- Bear the general dietary advice here in mind
- Take “food state” supplements over others
- Avoid food you suspect upsets you or get food intolerances tested