Fertility diets: do they work?

IF YOU'VE MANAGED TO AVOID READING ANY FERTILITY DIET ADVICE UNTIL NOW, I APPLAUD YOUR RESTRAINT (OR YOUR ADORBS LACK OF GOOGLING SKILLS).

There’s a LOT of information about how to eat when you’re trying to conceive, but is there evidence that any of it works for people who’ve been diagnosed with fertility problems?

Let’s delve and discover.

Quick intro: the four main types of fertility problems

We can roughly divide female fertility problems into four different categories:

• Ovulatory infertility/dysfunction
• Polycystic ovarian syndrome (PCOS)
• Poor egg quality
• Low egg count (i.e. a small number of eggs)

Each type of fertility problem comes with different implications for how it should be treated. Can a “fertility diet” be used as part of the treatment for any of them? Read on to find out…

Fertility diet for ovulatory infertility/dysfunction

Ovulatory dysfunction is one of the main causes of infertility, and it describes women who don’t ever ovulate, or who ovulate infrequently/irregularly. The main causes are:

• Being overweight or underweight
• Extreme stress
• Eating disorders
• Thyroid issues
• Polycystic ovarian syndrome (PCOS)

Can a fertility diet help with ovulatory dysfunction? The answer is maybe.

If ovulatory dysfunction is caused by your weight…

Women who are severely underweight or overweight often experience hormonal changes that lead to ovulatory infertility. If you find yourself in this category and prioritise becoming a healthier weight, all the evidence indicates that your fertility will improve too.

(To cite just one study, The American Society for Reproductive Medicine states that “more than 70% of women who are infertile as the result of body weight disorders will conceive spontaneously if their weight disorder is corrected”. Admittedly, I can’t find the direct link to the study, but plenty of reputable sources quote the same sentence.)

Even if you still have ovulatory infertility after the required weight gain/loss, you’ll benefit from increased odds of getting pregnant via fertility treatment.

But does it matter what you eat to reach your healthy weight? If you’re overweight, will a diet of Diet Coke and sugar-free Haribo get you ovulating once you reach the required BMI? If you’re underweight, can you gorge on chocolate and cheesecake?

Well, errr… , hate to admit this, but yes, kind of. You don’t want to give yourself a bunch of nutritional deficiencies in your quest to gain or lose weight in the least healthy way possible, but there’s no need to buy up the contents of a “fertility diet” blog post, either.

More important than maca and flax seeds is that the rest of your lifestyle is ovulation-friendly. For example, we know that stress, smoking, excessive exercise and being old can also bring about ovulatory infertility. But if you’re nicotine-free, don’t run daily marathons, are young, and so relaxed that your friends call you “Chilled Jill” (or similar), simply becoming a healthy weight could be all you need.

What about the studies that show a correlation between a “high-quality carb” diet and increased ovulatory fertility, or a “good fats” diet and increased ovulatory fertility, or a “high plant-based protein” diet and increased ovulatory fertility? They’ve been criticised for a number of reasons:

• Small sample size
• Not controlling for the weights of the participants, or the amount of weight they lost
• Not controlling for any other lifestyle changes among the participants
• Lots of different diets seem to lead to increased ovulatory fertility… which gives the impression that it’s the weight loss/gain that matters – not the food you eat (or don’t eat) to lose it

If ovulatory dysfunction is due to stress, thyroid issues, or any reason other than PCOS…

Addressing these underlying issues may help to bring ovulation back. For example, if you start taking medication for an underactive thyroid, you may well find that your absent or sporadic periods return with impressive regularity. Special diets or foods can’t help.

What's proven to help women with ovulatory infertility?

If you're relatively young and you've addressed all the suggestions above (such as getting your weight to a normal level and dealing with any underlying health problems), you've already made it much more likely that you'll get pregnant naturally.

But if you still can't conceive, fertility treatment (IVF, ICSI, Ovulation Induction, etc.) is a potential solution. Fertility treatment takes over your body's natural tendencies and pretty much forces ovulation to occur. While you still aren't guaranteed to get pregnant, you have a very good chance of ovulating.

(Important point: if you're thinking of skipping the weight loss/stress/thyroid/etc. steps and moving straight on to fertility treatment, don't. Fertility treatment is far more likely to be successful if you're a healthy weight and have tackled any underlying health conditions first. It's for that reason many clinics won't treat you unless you have a certain BMI.)

Interested in how fertility treatment works? Read this article on the IVF process from start to finish.

Fertility diet for PCOS

As mentioned above, PCOS is a type of ovulatory dysfunction, but it deserves a section of its own because it has a unique characteristic: insulin resistance.

If you’re overweight and have PCOS, weight loss can help to bring about regular ovulation and actually decrease all other symptoms of PCOS. Unfortunately, PCOS is linked with insulin resistance (see below), and – long story short – insulin resistance increases the body’s insulin levels, which promotes fat storage and weight gain. It’s therefore often harder for women with PCOS to lose weight – but if you have PCOS and you are able to lose weight, there’s a chance that’s all you need.

As for specific foods? There’s little to no concrete evidence that any sort of diet or food aimed at PCOS sufferers will help: if you go on one of the many advertised PCOS diets and lose weight as a result, that’s probably why your fertility has improved rather than the specific food you’re eating.

There’s one big “BUT” to all this…

As mentioned above, PCOS is related to insulin resistance. Low-carb diets have been shown to reduce insulin resistance – and therefore low-carb diets may improve all symptoms of PCOS, including fertility problems. This is the case even if you’re not overweight to begin with.

But there’s another “BUT”, I’m afraid! PCOS sufferers also tend to have lower-quality eggs – so even if you improve your ovulatory infertility through weight loss and/or a low-carb diet, you may still need fertility help.

Fertility diet for poor egg quality

When an egg is poor quality, it's genetically abnormal – which means it often won't fertilise. If it does fertilise, it won’t implant. If it does implant, it has a higher likelihood of being miscarried. And if it does survive to term, it’s more likely that the baby will have a genetic disorder like Down Syndrome.

There are a number of reasons why women can have poor-quality eggs, but the main one is “advanced maternal age”. Read more about poor-quality eggs here.

Can any kind of “fertility diet” help with poor egg quality?

No. To explain why…

There are two main causes of poor-quality (i.e. genetically abnormal) eggs:

• Lack of energy. Each of your eggs contains mitochondria, which can be thought of as teeny tiny batteries. When an egg is fertilised, it’s the mitochondria that give it the energy it needs to constantly divide and eventually become a foetus. As you age, these mitochondria produce less and less energy. The result? Even if you have a successfully fertilised egg on your hands, it may simply run out of steam before it’s able to divide.
• The “wrong” number of chromosomes. An egg needs to have the correct number of chromosomes in order to develop into a healthy, genetic disorder-free baby. As you age, more and more of your eggs will contain the “wrong” number of chromosomes.

Once an egg becomes abnormal, it can’t be made normal again through diet – or indeed anything else.

Can anything be done to prevent eggs from “going bad” in the first place?

Yes, but not food or diet.

As mentioned earlier, the main reason eggs become abnormal (or poor quality) is “advanced maternal age”. What’s age got to do with it? Well, your body – and therefore your eggs – is exposed to infection, stress, toxins, free radicals and more that cause them harm. The older you are, the longer your body has been exposed to all this unpleasantness – and your eggs inevitably become exposed, too.

Younger people can also have poor-quality eggs because egg quality is also affected by the following:

• Smoking
• Drug use
• Endometriosis
• Ovarian cysts
• Obesity
• Some immunological disorders
• Radiation therapy and chemotherapy

Whatever your age, avoiding all this stuff will help to preserve the quality of any good eggs you have remaining. (There’s not much you can do about many on the list, but stopping smoking and recreational drug use is kind of a no-brainer.)

As I paid for a “no smoking” illustration for another article, let's use it again here. And let's make it huge: 

Fertility specialists also believe there’s no harm in trying the following:

• Get your hormones more balanced by de-stressing, sleeping well, and regulating your blood sugar.
• Give your mitochondria more energy by taking CoQ10 as well as vitamins A and E.
• Have acupuncture to increase blood flow to the ovaries. A good blood flow enables more nutrients to reach the eggs and improve their overall health.
• Start taking a B vitamin called Inositol, which is thought to improve egg quality by increasing insulin sensitivity of the ovaries.
• Talk to your doctor about a hormone called DHEA (dehydroepiandrosterone): recent studies indicate that it may improve egg quality, but it’s a pretty potent hormone and needs to be taken under supervision.

And if you’re REALLY looking for something food-related, some fertility specialists recommend that you try to neutralise free radicals in your body (which speed up the ageing process of your eggs) with a diet rich in antioxidants: brightly coloured fruit and veg, green tea and – in moderation – red wine.

So there you go: you now have permission to go wild on the pomegranate juice. (But any other fruit and veg will also do.)

Want to know more about egg quality? Read this article about egg quality and quantity.

Fertility diet for low egg count

Having a low egg count (that is, having a small number of eggs remaining in your ovaries) is different from ovulatory infertility. Women with ovulatory infertility may have a TON of eggs but just don't ovulate. This time we're talking about women who have a small repository of eggs (relatively speaking).

Who's at risk of having a low egg count?

Women over the age of 35 are most at risk of having a low egg count. Some younger women will also have a low egg count, but this is for a variety of niche reasons (such as congenital adrenal hyperplasia or a pituitary tumour) to be discussed with a doctor.

Why are older women likely to have a low egg count?

Women are born with all the eggs they'll ever have (about two million), and you lose loads of them every month. By the time you hit puberty, you’re already down to your final 350,000 or so eggs – and then you’ll lose about 1,000 eggs every month after puberty.

The rate of egg depletion increases as you age – and by the time you’re 30, you’ll have about 12% of your eggs left. When you get to 40, you’ll be down to your final 3%. A few years later and they’ll mostly be all gone. (Menopause is typically between the ages of 48 and 55.)

Of course, not everyone starts with exactly the same number of eggs or loses them at exactly the same rate, but the variation between women isn’t usually significant enough to warrant any feelings of egg-repository-related jealousy.

Want to know more about egg count? Read this article about egg quality and quantity. 

Why should I worry about a low egg count?

Among young people, a low egg count usually isn't anything to worry about: there will still be enough eggs for ovulation to occur each month, and those eggs are likely to be good quality.

But it's a bigger deal for women who are older, because those eggs are also likely to be lower quality.

It's also not ideal for women who have other fertility issues and require IVF or ICSI. With IVF/ICSI, the idea is to collect many eggs from you in one go – so if you don't have many eggs hanging around in the first place… you see the problem.

Read more about having a low egg count here.

Can a fertility diet help to improve my egg count?

No. Nothing can be done to increase the number of eggs you have. Food and diet can’t help, but neither can anything else. If you want more eggs, you’ll need to invent a time machine and become younger.

Can certain foods or diets help to retain the number of eggs I have?

No.

Can anything help to retain the number of eggs I have?

Glad you asked! Yes: quitting smoking. 

Practically all scientific studies show that smoking accelerates the loss (and has an impact on the quality) of eggs – and as a result, it may also bring forward your menopause by several years too.

Oh, go on then… 

In summary…

If you have ovulatory infertility…

• If you’re overweight or underweight, eat more or less to get your weight to a healthy level. What you eat doesn’t really matter: being a healthy weight could be all you need to start ovulating naturally. (And even if you still don’t start to ovulate naturally, fertility treatment is more likely to be successful once you’re a healthy weight.)
• If you have PCOS, you may benefit from a low-carb diet (regardless of whether you’re overweight or underweight). But your PCOS also has an impact on egg quality, which means you may still need fertility treatment.
• If you have ovulatory infertility for any other reason (such as extreme stress and thyroid issues), no special foods or diets will help. You need to address the underlying cause of your ovulatory infertility and/or get fertility treatment.

When it comes to egg quality…

• There’s nothing you can do about the eggs that have already “gone bad”. For the remaining eggs, you need to quit smoking/recreational drug use. You can also try de-stressing, acupuncture, taking CoQ10, vitamins A and E, Inositol and DHEA (none of which have have been proven to work, but aren’t considered harmful either).
• If you’re desperate to go down the “fertility diet” route to improve the quality of your eggs, some fertility specialists believe that you can try to neutralise free radicals in your body (which speed up the ageing process of your eggs) with a diet rich in antioxidants: brightly coloured fruit and veg, green tea and – in moderation – red wine.
• Also: be young. That’s the most important factor when it comes to egg quality.

As for egg count/quantity…

• Quit smoking.
• Be young (again).
• No special diets can help with egg quantity.

And in conclusion…

Successful IVF treatment has very little to do with your diet.

The annoying truth is that – aside from medical expertise – successful IVF treatment is mostly down to factors outside our control: age and luck. The factors we can control (and which have been proven to make a difference to IVF treatment) are:

• Get to a healthy weight
• Quit smoking and recreational drugs

… And that’s about it. A healthy, well-balanced diet rich in antioxidants is probably a good idea anyway, but there’s no need to stick to any sort of “fertility diet” unless you have PCOS.