We all know that the food choices we make every day affect our general health and wellbeing, and so it is hardly surprising that your diet can also influence your ability to conceive.
While even the perfect diet isn’t a miracle cure for fertility, some relatively simple habits can improve your health and optimize your chances.
About “The Fertility Diet”
Much of the advice below originates from the Harvard Nurses’ Health Study, one of the world’s largest and longest-running studies of factors that influence women’s health.
By studying the correlation between the nurses’ food habits and their fertility, the researchers found that diet can affect the risk of ovulatory infertility, and were able to compile a set of dietary recommendations aimed at preventing this type of infertility.
The recommendations will not help women who are infertile due to “mechanical” factors such as blocked fallopian tubes, and they may or may not help with infertility due to other causes. However, the “fertility diet” is generally well-balanced and may give you multiple other health benefits, and it will prepare you for a healthy future pregnancy.
What to eat and drink when you are trying to get pregnant
A folic acid (vitamin B9) supplement
Folic acid, or vitamin B9, is extremely important for the future baby. If you have a deficiency of folic acid at the time you get pregnant, it increases the risk of your baby being born with spina bifida (neural tube defects) and other serious defects of the nervous system.
In addition, women in the Nurses’ Health Study who took a daily multivitamin containing 400 micrograms of folic acid (vitamin B9) were 40 percent less likely to suffer from ovulatory infertility than those who didn’t.
Green leafy vegetables such as spinach and kale are excellent sources of folic acid, but even if you eat a lot of them it can be difficult to get enough.
It is therefore recommended that all women who are trying to conceive take a folic acid supplement, and ideally you should start taking the supplement three months before you start trying to conceive.
You can buy a simple folic acid supplement, or take a multivitamin. If you prefer a multivitamin, choose a specific prenatal supplement, as some standard multivitamins contain too high doses of a certain kind of vitamin A which may cause birth defects.
More vegetable protein, less meat
Findings from the Nurses’ Health Study indicate that getting more of your protein from plants instead of animals can help protect you from ovulatory infertility.
The researchers found that the women with the highest intake of total protein were 41 percent more likely to suffer from ovulatory infertility than women in the lowest-protein group.
However, the reverse was true for women with the highest intake of plant protein: They were substantially less likely to have reported ovulatory infertility than women who ate little plant protein.
Good sources of plant protein include lentils, beans, quinoa, peas, tofu, and nuts and seeds.
The Nurses’ Health Study researchers found that the quantity of carbohydrates in the diet wasn’t correlated with ovulatory infertility. However, the quality of carbohydrates in the nurses’ diets mattered, and not just a little: Women eating the most “bad carbohydrates” were an astonishing 92 percent more likely to have reported ovulatory infertility than women in the lowest category!
So which carbohydrates are good for your ovulatory fertility, and which aren’t?
The researchers based their conclusion on glycemic load – the amount of carbohydrate in the diet, and how quickly it is turned to blood sugar. Foods with a high glycemic load make your blood sugar and insulin levels spike, which can disrupt hormonal balance and the ovulation process.
Foods with a low glycemic load are digested more slowly, enabling a more gradual (and healthier) rise in blood sugar.
To reduce your risk of experiencing ovulatory infertility, therefore, choose carbohydrates with a low glycemic load. You may also know these foods as “slow carbs”: whole grains, beans, vegetables, and whole fruits are all great sources of healthy carbohydrates. This list indicates the glycemic load for more than 100 common foods.
Researchers found that participants in the Nurses’ Health Study were less likely to have ovulatory infertility if they ate at least one daily serving of whole milk or dairy foods made from whole milk.
Skim and low-fat dairy products had the opposite effect: The more low-fat dairy products in a woman’s diet, the more likely she was to have difficulties getting pregnant.
The researchers warn that a high consumption of full-fat dairy may have negative effects on your weight, your heart and your blood vessels in the long term, so don’t down a bucket of ice cream just yet.
You should aim for one or two servings – no more – of dairy products a day, and both of them should be full fat.
For example, have some whole milk with your breakfast cereal, and then a slice of cheese or a cup of whole-milk yogurt later in the day.
It’s so obvious that it’s easy to forget, but water is your body’s most important nutrient. Virtually every system in your body depends on it to function.
Water is a major component of blood, which carries nutrients and oxygen to your reproductive organs. It is also the main component of saliva and mucus – including cervical mucus. Finally, water enables your body to flush out toxins and waste.
How much water you need depends on your body size, the climate you live in and your level of physical activity, but as a rule of thumb, women should try to get at least 2 liters (about 9 cups) of fluids a day. Drink water with every meal, and keep a bottle of water with you to make sure a sip is always available.
A big glass of grapefruit juice every day for the last week or so before ovulation can give you more abundant and thinner (in other words, more sperm-friendly) fertile cervical mucus, possibly because it alters the metabolic degradation of estrogens (female hormones).
If you don’t like the bitter taste, try mixing it with a sweeter juice.
Warning: Grapefruit juice may interact with certain types of prescription medication, increasing the effect of the medication and exacerbating side effects. Consult your physician before drinking grapefruit juice if you take prescription medications.
Foods to avoid when you are trying to conceive
As mentioned above, women in the Nurses’ Health Study whose diets had the highest glycemic load were 92 percent more likely to have ovulatory infertility than those eating healthier carbohydrates.
Cookies, cakes, sugary cereals, white bread, white rice, pasta and similar foods are quickly digested and quickly turned into blood sugar. In order to control the blood-sugar spike, your pancreas must release insulin, and too high insulin levels can inhibit ovulation.
Eating lots of fast carbohydrates can therefore increase your risk of developing ovulatory infertility. Reducing your intake of simple carbohydrates will also bring you other health benefits, and can help you reach or keep a healthy weight.
The Nurses’ Health Study showed that women who consumed more than two portions a day of low-fat dairy foods were a whopping 85 percent more likely to experience ovulatory infertility than those who ate them less than once a week.
Why is this? The effect of different types of dairy is the part of the findings which the researchers understand least. But one hypothesis is that a fat-soluble substance in full-fat dairy, responsible for improving ovarian function, is removed by skimming.
For as long as you are trying to get pregnant, then, it is recommended to swap low-fat for full-fat dairy. As this can increase your daily calorie intake, you may want to look at where you can cut back on a few calories elsewhere.
While the Nurses’ Health study researchers found that the total amount of fat in the diet wasn’t correlated with ovulatory infertility, one particular type of fat stood out: The more trans fat in the diet, the higher was the risk of suffering from ovulatory infertility, and the effect started at as little as four grams a day.
Exactly why trans fats are bad for fertility isn’t clear, but it is possible that they affect insulin sensitivity and inflammation.
Trans fats, also known as partially hydrogenated oils, are used in a large number of foods to improve taste, texture or shelf life.
They are primarily found in processed foods such as cakes, biscuits and crackers, frozen pizza, chips, margarine and cheap take-away foods.
Read the ingredient labels whenever you buy processed foods, and avoid any food items which contain trans fats.
The Nurses’ Health Study found that women who were drinking two or more soft drinks per day had an increased risk of ovulatory infertility. Caffeinated and non-caffeinated, sugared and diet sodas all had similar associations.
A Danish study of pregnancy planners found similar results, with reduced fecundity among soda drinkers compared to those who drank coffee or tea.
None of these studies were able to explain why soft drinks seem to be so bad for fertility, but better safe than sorry. Limit your soda consumption to maximum one serving per day while you are trying to conceive.
What about tea and coffee?
No matter what you may have heard about the harmful effects of caffeine or the miracle properties of tea, there is actually little scientific evidence that regular consumption of either tea or coffee is likely to have much impact on your fertility.
The impact of caffeine on female fertility has been studied extensively, with somewhat inconsistent results.
The Nurses’ Health Study did not find any association between intake of coffee or tea and infertility – soft drinks were the only beverages positively related to ovulatory infertility.
Similarly, the Danish study mentioned above found no impact of total coffee or caffeine consumption on fertility, but some evidence for reduced fertility among soda drinkers and slightly higher fecundity rates among tea drinkers.
It seems safe to conclude that you can happily continue to enjoy your preferred hot beverage while you are trying to conceive. Should you still wish to reduce your consumption of coffee or regular tea, you can try replacing some or all of your daily cups with a herbal tea such as FertiliTea.
Alcohol when you are trying to conceive
Can you safely drink alcohol when you are trying to conceive, and if yes, how much?
Unfortunately, the jury is still out on the question. Studies on alcohol intake and women’s fertility are not conclusive, with some showing adverse affects (for instance, this widely cited study) and others, such as this one, showing little or no impact.
The fact that alcohol can cause damage to your unborn baby once you are pregnant, however, is well documented. Heavy drinking during pregnancy, especially binge drinking (large amounts of alcohol at once), can seriously impair the baby’s brain development.
The effects of light drinking are less established, but most health authorities consider that there’s no safe level of alcohol during pregnancy. And as you may find yourself pregnant any time, it is usually recommended that you stay away from alcohol while you are trying to conceive.
In short, there is no conclusive evidence that moderate amounts of alcohol impair fertility, but there is also no answer to the question of how much alcohol is safe. To optimize your chances of conceiving, reduce your alcohol consumption to a minimum.
Vitamin supplements to improve fertility
An optimal diet will provide all the vitamins, minerals, and other micronutrients needed for good health, including reproductive health.
However, dietary perfection is unrealistic for most of us, and taking a daily multivitamin supplement provides good, affordable insurance against nutritional deficiencies. FertilAid for Women is a good all-round prenatal supplement which includes folic acid, other essential vitamins and minerals, as well as antioxidants.
Don’t forget that nutritional balance is just as important for men’s fertility as for women’s. Key nutrients for healthy sperm production include zinc, folic acid and vitamin B12. Designed to support the healthy formation of sperm and increase both sperm motility and sperm count. FertilAid for Men has been scientifically demonstrated to enhance male fertility.