Section Two: Nutrition

Introduction

“You are what you eat” is one of the most profound statements that you will hear. Unfortunately, few of us realise how important nutrition is to our health. To give yourself the best chance of success with IVF you should pay attention to what you eat and drink. Food is extremely powerful and eating the diet we evolved to eat can make a significant difference to your overall health as well as your chances of IVF success.

A proper, balanced diet can have potent, drug-like effects. In fact, if a pharmaceutical company were to produce a pill that had equivalent effects to a good diet it would transform the world’s health.

When my wife and I asked our fertility doctors for dietary advice they simply told us to “eat a healthy diet”. Ok, great but what it a “healthy diet”? Are there foods that can specifically help or harm fertility? As we researched the subject we found that nutrition is not only important, it is critical to success.

Let’s first take a look at the problems with typical modern diets.

Evolution

Humans evolved over millions of years eating a particular diet. About 10,000 years ago the agricultural revolution began and the human diet changed radically. From an evolutionary perspective 10,000 years is the blink of an eye and certainly not sufficient time to enable us to evolve to cope with a drastically changed diet. Genetically speaking we are still cavemen![1]

Prior to the agricultural revolution we were hunter-gatherers eating foods that could be hunted or fished (meat, fish, shellfish, etc) and foods that could be gathered (vegetables, fruit, nuts, seeds, eggs, mushrooms, herbs, spices, etc). These were of course all wild and organic and as a result full of nutrients and free from chemicals.

During the agricultural revolution humans began to rear animals for meat and to grow various crops, including grains. This is where the problems began. Things got worse during the industrial revolution when foods were processed and refined and the use of unnatural fertilisers and pesticides became prevalent.

Today’s diet

In the Western world today’s diet is typically very different from the diet of our ancestors. In the US the acronym “S.A.D.” has been coined; it stands for Standard American Diet! It is not just a US issue however. The diets in most Western countries have changed dramatically even over the last 200 years. Whereas food used to be fresh and grown locally these days much of the food we eat is processed, contains excessive amounts of sugar together with toxic fats and chemical additives. Many experts believe that the consequence of this is inflammation that slowly damages our bodies and causes a host of chronic diseases.

These are some of the big offenders:

Sugar

Refined sugar is bad for you. I am not talking about the natural sugars that are found in fruit and vegetables, I am talking about the stuff that has been heavily processed and refined. The problems stem from the fact that our bodies are simply not designed to process large amounts of sugar. We cannot deal with it efficiently as we have not evolved to do so. Over the years the amount of sugar in our diets has increased dramatically. One study, for example, showed that in 1700 the average sugar consumption per year was 1.8kg but by 2007 had reached over 67 kg per year[2].

So, what is the consequence of this massive increase? Well it’s not great for our teeth[3] but that is a minor issue in the scheme of things. Excessive sugar intake has been shown to cause liver damage[4], diabetes[5], obesity[6], cancer[7] [8] [9] and heart disease[10]. To make matters even worse, it is highly addictive[11].

It is not just sucrose – the most common form of sugar – that is the problem; sugar comes in many forms and is often hidden in products. Various names are used to describe it including agave syrup, brown rice syrup, corn syrup, fructose, dehydrated cane juice, dextrin, dextrose, fruit juice concentrate, glucose, high-fructose corn syrup, inverted sugar, isoglucose, levulose, malt syrup, maltodextrin, maltose, maple syrup and palm sugar. As a result of this it makes sense to pay attention to food labels.

We will see later the impact sugar intake can have on fertility and IVF.

Processed foods

Virtually all food is processed in some way before consumption; what I am talking about here is overly processed foods that have been highly refined with the result that their intrinsic nutritional value has been removed and/or chemicals (preservatives, flavourings, colourings, etc) have been added.

Our brains love processed foods. We have evolved from times when food could be scarce and so calorie dense foods were a great aid to survival. Highly processed foods tend to be packed with fat and sugar which means they are very calorie dense but our brains have not evolved to recognise that we are no longer in a struggle for survival and so still crave them. This often leads to overconsumption[12] and can lead to addiction[13].

Our love of processed foods is problematic because they are often high in refined carbohydrates, low in nutrients, high in calories, low in fiber, high in trans fats and packed with chemicals. Each of these can cause health issues.

There are not that many studies on the health effects of “processed foods” as a category because the constituents differ substantially. Instead researchers have looked into the effect of specific ingredients. In the studies that have been done processed foods have been linked with an increased risk of cancer[14], asthma, eczema and severe allergic reactions[15].

Of course, as those processed foods often contain things like sugar and trans fats (which we talk about later) the health problems associated with those ingredients are also applicable.

Gluten

Gluten is found in many grains (including wheat, barley, rye, semolina, and couscous but not buckwheat, quinoa, rice, corn or millet) and contains chemicals called lechtins which are the grains’ self-defensive mechanism against being eaten. The problem with gluten is that we have not evolved with the stomach enzymes necessary to digest it properly. When we eat it inflammatory particles can be released into our bloodstream and transported around the body. The consequence can then be gluten sensitivity and Celiac disease (an extreme reaction to gluten) which have in turn been linked with a number of health issues including irritable bowel syndrome, cancer, fatigue[16], schizophrenia[17], depression[18] and dementia[19].

Gluten consumption has also been linked with increased risk of death. For example, a study[20] of nearly 30,000 patients over 40 years looked at death rates of people with Celiac disease and gluten sensitivity. The researchers found a 39% increased risk of death in patients with Celiac disease, a 72% increased risk in those with gut inflammation related to gluten and a 35% increased risk in those with gluten sensitivity but no Celiac disease.

Excessive calories

It is probably not a surprise given the sections on sugar and processed foods that many people consume too many calories. These are not the only causes however; increased food availability and more aggressive marketing have also been blamed. Various studies have estimated how much calorie intake has increased over the years with one study[21] suggesting that adults eat an additional 500 calories per day. It is interesting to note that levels of obesity have increased alongside the caloric increase[22]. We will look in detail at the impact of bodyweight on IVF success in Section Five: Bodyweight.

Poor quality meat

Let’s start by getting one thing straight: wild and organic meat reared in the way nature intended and eaten in moderation is not the issue here. This issue is meat from animals that have been raised in artificial conditions, fed foods they do not naturally eat, given drugs to keep them free of disease and, in some countries, given hormones to speed up growth.

Take beef as an example. Nature intended for cattle to roam pastures and graze on grass. They are not intended to be intensively reared, kept in a confined cowshed, be fed a grain-based diet and receive antibiotics, growth hormones and other drugs. Cattle reared in this way produces very different meat to cattle raised naturally. The difference is not a good one. Unfortunately, the vast majority of beef is now produced in this way. In the US it is known as “feedlot”.

The saying “you are what you eat” is again very relevant here. By eating meat raised in an unnatural way we ourselves are eating food that we are not by evolution designed to eat. This can lead to health problems. You have no doubt seen news headlines that report on studies that proclaim red meat causes various illnesses. One of the things that these studies do not do is differentiate between naturally reared meat and intensively reared meat. Naturally reared meat is a very different beast (pun intended!). However, the results of these studies are still valid because the vast majority of red meat consumed is intensively reared.

On the other hand, using beef again as the example, naturally raised, grass-fed beef has been shown to have:

  1. higher levels of the healthy omega 3 fats – 2-5 times higher depending on the breed – than grain fed beef and consequently a more healthy ratio of omega 6 fats to omega 3 fats (1.53:1 in grass-fed beef versus 7.65:1 in grain fed beef)[23]. We will look at the importance of this ratio in the section on refined oils below
  2. 2-3 times more conjugated linoleic acid (usually abbreviated to CLA) than grain fed beef, a potent antioxidant shown to protect against various conditions including cancer[24]
  3. carotenoid (a group of antioxidants which includes beta-carotene) levels that are much higher than grain fed beef[25]
  4. more of the antioxidants vitamin E, glutathione, superoxide dismutase and catalase[26]
  5. higher levels of the essential minerals zinc, iron, phosphorus, sodium and potassium[27]

Rather than causing health issues, grass-fed beef is good for us.

Whilst the example above refers specifically to beef, the position is similar with other naturally reared meats[28] [29] [30] [31] [32].

Refined oils

These are oils that have been produced using heavy chemical processes and they are frequently used in food. The content of refined oils is unlike anything humans have been exposed to throughout evolution. This is not a compliment to human ingenuity as they can be extremely damaging to our health.

The first problem is trans fats. I am not going to cover these here except to say that they are so damaging to our health and fertility that I have included them in Section Three: Toxins.

Another problem is the type of fats contained in refined oils. These days most people will have heard of omega 3 fats and the health benefits of consuming them. Fewer people will have heard of omega 6 fats. In themselves there is nothing wrong with omega 6 fats; they are known as an “essential” fat meaning that our body cannot produce them from other sources so we have to get them from our diet. The issues arise when the balance between omega 6 and omega 3 intake becomes out of kilter.

As humans evolved we typically consumed a 1:1 ratio of omega 6s to omega 3s[33]. Today the ratio in Western diets is around 16:1[34]. The position is even more skewed than this ratio suggests because these fats compete with each other so the more omega 6s we consume the more omega 3s we need[35].

So, what’s the problem? When the ratio is out of kilter omega 6s cause inflammation and inflammation, as we have seen, is linked to numerous chronic diseases. Excessive omega 6 intake has been linked with heart disease[36], asthma[37], cancer[38] and depression[39].

Conclusion

Are you getting the idea that the modern Western diet is not ideal?! The question now of course is what sort of diet should we follow? Read on. There is a diet that not only avoids the issues created by the modern Western diet it has actually been shown to dramatically improve our chances of IVF success. It is also delicious.

The Mediterranean diet with tweaks)

You may have heard about the Mediterranean diet and its health benefits. If you haven’t, this diet it is, unsurprisingly, the typical diet of people living along the coast of the Mediterranean Sea. There are subtle variations in the diet between countries but it usually comprises some or all of the following:

  1. fresh, local and seasonal fruit, vegetables and herbs
  2. wild fish and shellfish
  3. lean meat
  4. beans/legumes
  5. nuts and seeds
  6. whole grains
  7. extra virgin olive oil

And, importantly, it is low in highly processed foods.

In many ways (grains aside!) this diet closely resembles the diet we have evolved to eat and people that follow it have been shown to have lower rates of heart disease[40], cancer[41], osteoporosis[42], diabetes[43], asthma and strokes[44]. People following a Mediterranean diet also have much lower Body Mass Indexes[45] (for more on the importance of your BMI to IVF success see Section Five: Bodyweight). In fact, it has been shown that people lose weight when eating a Mediterranean diet even if they are not trying[46].

Does the list of illnesses in the paragraph above sound familiar? It should do as it is similar to the list of illnesses we looked at in relation to inflammation and the typical Western diet. Not only is the Mediterranean diet low in many of the causes of inflammation found in the modern Western diet it is abundant in nutrients that actively reduce inflammation, such as antioxidants and healthy fats[47].

The Mediterranean diet is something that has existed for as long as humans have inhabited the region and has not changed much from the caveman days. People living around the Mediterranean Sea simply harvested and consumed what was available and it just so happened that what was available is extremely healthy.

It is not perfect however. Heavily processed foods have not infiltrated the diets of Mediterranean people to anywhere near the extent of much of the Western world but things like pasta, bread and other baked products are consumed. These would not form part of the ideal IVF diet as they are each made from grains which contain gluten and refined carbs which disrupt our blood sugar levels. It is true that the Mediterranean diet often comprises things made from whole grains (which are slightly better) rather than highly refined grains but even then whole grains are still not ideal.

So, if we were to remove grains from the diet where does that leave us? It actually results in something that resembles another healthy diet called the “paleo” (short for paleolithic) or “caveman” diet. This diet aims to replicate the diets of hunter-gatherers, thereby avoiding things like processed foods. The paleo diet has not been studied to the same extent as the Mediterranean diet but the studies that have been done show it improves diabetes indicators[48], blood pressure[49], indicators of heart disease[50] and cholesterol levels[51]. Like the Mediterranean diet it also results in weight loss even where people are not trying to lose weight[52].

What can it help with?

              

How can it help?

So, the Mediterranean diet is good for our health. Does it also increase our chances of success with IVF? Let’s look at the evidence.

In a Dutch study[53] involving 161 couples undergoing IVF researchers looked at the diets of each of the couples and found that those couples following a Mediterranean diet were 40% more likely to achieve pregnancy than those who did not. An interesting footnote is that the increased success rates were only evident where both the male and female partner followed the diet.

Another study[54], this time in Spain, looked at the diets of 2,154 women, some of whom had problems getting pregnant. The researchers divided the women into two groups: one group that followed a Mediterranean diet and the other group followed a typical modern Western diet. The Mediterranean diet group were 46% less likely to have problems getting pregnant than the Western diet group.

A study[55] of 147 women carried out at Harvard looked specifically at intake levels of different types of fat. They found that the women who consumed the highest levels of the type of fats typically found in Mediterranean diets (monounsaturated fats from things like extra virgin olive oil, nuts, seeds and avocados) were 3.45 times more likely to have a live birth following embryo transfer.

Yet another study[56], this time conducted at the University of Athens, categorised women undergoing IVF based on how closely they followed a Mediterranean diet. Those women who followed it most closely had pregnancy rates of 50% compared to only 29% in those that did not follow it. They also had live birth rates of 48.8% compared to only 26.6%.

Finally, it is not only women who can benefit from this diet. A study[57] in 2016, again by the University of Athens, categorised men based on how closely they followed a Mediterranean diet. The men who followed it most closely had much better sperm quality using every measure than those that did not follow it. The researchers calculated the proportion of participants that met the World Health Organisation’s expected levels and found the following:

Measure

Did Not Follow Mediterranean Diet

Followed Mediterranean Diet

Sperm Concentration

16.7%

47.4%

Sperm Count

22.7%

55.3%

Motility

31.8%

65.8%

Morphology

28.8%

50%

 

What can we do?

In this Section I have tried to summarise numerous complex issues in an easily digestible form (pun again!). It may still seem like a minefield, and it can be, but with a few simple guidelines we can cut through the complexity.

The basis of the ideal IVF diet is, unsurprisingly, the Mediterranean diet so ensure that the vast majority of the food you eat comes from the following groups:

  1. fresh, local and seasonal fruit, vegetables and herbs
  2. wild fish and shellfish
  3. lean meat
  4. beans/legumes
  5. nuts and seeds
  6. whole grains
  7. extra virgin olive oil

You don’t have to eat Mediterranean dishes (although there are some fantastic recipes) but try to cook primarily with these ingredients.

As we have seen the Mediterranean diet is a great starting point but there are a number of tweaks we can make to improve it and further increase our chances of IVF success. You will recognise a number of the tweaks as reactions to the issues created by the modern Western diet. We have touched on these already but we’ll now look specifically at their impact on IVF success.

From now on we’ll refer to the tweaked diet as the MDWT (Mediterranean Diet with Tweaks).

Tweak 1: Avoid gluten

Gluten issues are difficult to test for so whilst around 0.5-1%[58] of the population have been found to have Celiac disease, it is estimated that 29%[59] of us experience issues with gluten. One study[60] suggests that the numbers are actually increasing rapidly: comparing blood tests taken from a group of people between 1948 and 1954 and tests from people 50 years later researchers found a 400% increase in the incidence of Celiac disease.

In addition to the links to health issues generally, gluten also seems to affect fertility. One study[61] showed that women with unexplained infertility are 2.5 to 3.5 times more likely to have Celiac disease than women who are not infertile. Other studies have linked gluten with menstruation issues[62] and increased rates of miscarriage[63] and stillbirths[64].

The traditional Mediterranean diet includes pasta, bread and other baked goods. These are all made from grains and grains, as we have seen, contain gluten. As a result, these and other foods made from grains are best avoided.

Tweak 2: Cut sugar and refined carbohydrates

We saw earlier how the increase in sugar consumption has impacted health in general and the impact is not pretty. Refined carbs are not much better. Refined carbs include bread, pasta, rice, flour and foods containing flour, white potatoes, sweets and processed foods containing sugar. Given the cascade of health issues overconsumption of sugar and refined carbs creates it is not a wild guess to think that it may also impact our fertility. Let’s have a look.

A Danish study[65] looked at certain blood sugar markers in couples trying to conceive and found that women with the highest levels of these markers were only half as likely to become pregnant as women with lower levels.

A Japanese study[66] took 157 women undergoing either IVF or ICSI and, again, examined their blood sugar markers. Women with low blood sugar markers produced more eggs (14.6 compared to 8.4), which led to a higher number of embryos (9 compared to 4.7) and higher pregnancy rates (23% compared to 3.4%).

A 2009 study[67] at Harvard looked at the effect sugar and refined carbs has on ovulatory infertility (an inability to produce eggs). It took 438 women and examined the “glycemic load” of carbohydrates in their diets. Glycemic load is a measure of how foods raise blood sugar, refined carbs having a high glycemic load.

The researchers found that those women eating foods with the highest glycemic load were 92% more likely to suffer ovulatory infertility compared to those who ate foods with the lowest glycemic load.

Eating refined carbohydrates causes spikes in our blood sugar levels which has similar, albeit lesser, effects to diabetes and it has been shown that diabetics (both men and women) suffer from increased fertility issues[68] [69]. Coupled with this is the fact that when diabetic drugs designed to control blood sugar levels are given to women their chances of achieving on-going pregnancy double[70].

To top all this off a Chinese study[71] has shown that another issue linked to high sugar intake, “insulin resistance”, can have a significant impact on our risk of miscarriage. The study took women undergoing IVF or ICSI and found that the women with insulin resistance miscarried in 47.8% of cases whereas women without insulin resistance miscarried in only 9.5% of cases.

How can you ensure that you avoid sugar and refined carbs? By eating foods that have low (10 or less) or moderate (11-19) glycemic loads and avoiding anything with a high (20 or more) glycemic load. There are numerous websites that categorise foods by their glycemic load and they are a useful reference point. We used a brilliant database compiled by the University of Sydney, Australia that is available at www.glycemicindex.com/foodSearch.php.

Tweak 3: Avoid highly processed foods

The Mediterranean diet is low in highly processed foods so how can we ensure we avoid them? There are a number of things that we can do:

  1. look at food labels. Generally, the longer the list of ingredients the more processed the food is likely to be
  2. be wary of common highly processed foods: breakfast cereals, bread and baked goods, pastry-based products, sandwiches, biscuits/cookies, cereal bars, confectionary, crisps, ready-made meals, margarine, take-aways/fast food, ice cream and ready-made sauces
  3. buy and cook with real ingredients: vegetables, meat, fish, eggs, fruit, nuts, seeds, herbs and spices
  4. choose locally grown and seasonal produce where possible
  5. avoid low fat/fat-free products. To replace the fat these products are often loaded with other unhealthy ingredients. Low fat/fat-free dairy products have actually been associated with fertility issues[72]
  6. avoid foods with artificial colours, flavours and preservatives

Tweak 4: Eat between 25% and 35% of your calories from protein

The impact of protein consumption on IVF success was shown in a 2013 study[73]. The researchers looked at the diets of 120 patients undergoing IVF and divided them into categories based on their protein intake: those who got 25% or more of their calories from protein and those who got less than 25% of their calories from protein. There was a significant difference in success rates between the two groups.

In the “high” protein group blastocyst (5 and 6 day old embryos) development was 64% compared to 33.8% in the “low” protein group, pregnancy rates were 66.6% compared to 31.9% and live birth rates were 58.3% compared to 11.3%. The results were even more impressive when patients’ carbohydrate intake was also below 40%. In these cases pregnancy rates were 80%.

This research backs up an earlier study[74] which examined whether changing patients’ diets between cycles could increase their chances of success. In this study women with a history of poor blastocyst development and pregnancy outcomes increased their protein intake from 15% of calories to 27% for a period of at least two months and then underwent another IVF cycle. Blastocyst formation increased from 18.9% to 45.3% and pregnancy rates increased from 16.6% to 83%.

Eggs, wild fish, organic and wild meats are all good sources of protein. If consuming this amount of protein is difficult then you can add a protein supplement. Whey protein isolate from organic, grass-fed, drug free cattle is a good choice here.

Calculating your individual protein requirements is straightforward but a bit time consuming. Start by keeping a food diary for a week, noting down the calorie content of everything you eat and drink. It’s a bit of a pain but worth it given the results of the above studies. You may have to estimate some things but there are lots of websites that list the calorie content of different foods.

At the end of the week add up all the calories consumed and divide the total by 7 to give your average daily calorie intake. To work out your protein requirements multiply the average daily intake by 0.25. This will give you the suggested lowest level of protein intake each day in calories. To work out the upper limit multiply the average daily calorie intake by 0.35. Food labels usually do not list protein quantity in calories, they usually just list the weight, so there is one final step. Divide the lower and upper limits by 4 (there are approximately 4 calories per gram of protein). These numbers are the amount of protein in grams that the studies suggest you should be aiming for each day.

That description is quite involved so an example may be helpful:

Day

Calories

Monday

1,855

Tuesday

1,600

Wednesday

1,899

Thursday

1,767

Friday

1,377

Saturday

1,850

Sunday

2,010

  1. add up total calories = 12,358
  2. divide by 7 to give average daily calorie intake = 1,765
  3. multiply by 0.25 to give lower limit = 441
  4. multiply by 0.35 to give upper limit = 618
  5. divide 441 by 4 to give lower limit in grams = 110
  6. divide 618 by 4 to give upper limit in grams = 155

Using this example the woman should consume between 110 grams and 155 grams of protein per day.

If you don’t want to go through this exercise you could base your protein intake on the recommended daily calorie amounts advised by Government health authorities. This would very much be second best, however, as it would not be tailored to your specific needs. As a guide, the UK National Health Service estimates that women need around 2,000 calories per day which would give a protein range of 125 to 175 grams per day.

Tweak 5: Eat organic where possible

Organic produce is generally more expensive than non-organic produce. The issue is whether it is worth spending the extra money and the answer boils down to two questions:

  1. are the chemicals used in the production of non-organic produce, such as pesticides, damaging to fertility? and
  2. is the nutritional content of organic produce better than non-organic produce?

The first point is covered in detail in the Toxins Section so I will not repeat it here.

On the second point the answer is that organic and non-organic produce have similar levels of some nutrients but organic produce has between 18 and 69% more antioxidants[75]. Antioxidants are important to maintain health by preventing damage to our bodies caused by various internal and external things.

My wife and I tried to eat organic food as much as possible but it was difficult to eat 100% organic. As a result, we made sure that anything we ate that was not organic came from a good source and, for fruit and vegetables, we made sure they were considered “safe” by the Environmental Working Group. For more on this see the Toxins Section.

Tweak 6: Consume healthy fats

For years we have been told that fat is bad for us. This is not true, or at least not completely true. Many fats are good for us and, in fact, are necessary for optimal health.

Fats are split into saturated and unsaturated and unsaturated fats are further split into monounsaturated fats and polyunsaturated fats. Most foods contain a mixture of different fats. For example, olive oil is primarily monounsaturated fat with a small amount of polyunsaturated fat. Most vegetable oils are high in polyunsaturated fat whereas animal fats are high in monounsaturated and saturated fats. We need a balance of each for optimal health.

Fats have 3 primary functions in the body:

  1. to provide building blocks for cell walls
  2. to provide energy
  3. to be converted into other substances, such as hormones

Without adequate intake of the right fats our bodies simply cannot function optimally so we need to pay close attention to the fats we eat. Some of the best fats to consume are as follows:

extra virgin olive oil: it is first important to note that not all olive oil is created equal. By far the best type is “extra virgin” olive oil which means that it has been extracted by mechanical crushing and not through the use of chemicals. It is best used raw in salads and dressings or drizzled over food after cooking. It can be used to cook with but only at low temperatures. Cooking at higher temperatures can damage its structure and change it from being healthy to unhealthy.

avocados: these have been described as the best food to eat for IVF by Professor Jorge Chavarro, a fertility expert at Harvard University. They contain high levels of monounsaturated fats which has been associated with higher live birth rates.

wild oily fish, wild meat and grass-fed meat: these have a good balance of fats and are the closest thing we have to the meat we have evolved to eat. Steer clear of grain fed fish and meat. This includes things like farmed salmon which is fed an artificial diet that changes its fat profile in a similar way to grain fed cattle. Any good butcher and fishmonger will know the provenance of their produce and it would be a good idea to consult with them.

virgin coconut oil: virgin coconut oil is almost entirely saturated fat but, to get all scientific, it is a “medium chain triglyceride” which is much more easily absorbed by our bodies than “long chain triglycerides”, the typical saturated fat found in Western diets. It has been used for centuries in cultures that have low levels of heart and other disease. One of the key benefits of coconut oil is that it is ideal for cooking at higher temperatures as it is extremely stable.

As with olive oil not all coconut oil is the same. Look for “virgin” oil to ensure you are getting a good product. If it is not virgin it is unhealthy and should be avoided.  

We saw above how refined oils are problematic as they have high amounts of omega 6 fats. It would be wise to avoid these (my wife and I did). The most common are: canola oil, corn oil, soybean oil, “vegetable” oil, peanut oil, groundnut oil, sunflower oil, safflower oil, cottonseed oil, grapeseed oil, margarine and butter substitutes.

Tweak 7: Eat the rainbow

If you follow a Mediterranean diet you will consume lots of fresh fruit and vegetables. It is very easy, however, to get into a rut of eating the same things day in day out, particularly in winter when choice is limited. It is not always easy to do but you should aim to eat a variety of different coloured fruits and vegetables each day. Different coloured produce contains different nutrients and by eating a variety each day we can help ensure we are getting everything we need to function optimally.

Tweak 8: Eat your 5 a day

Actually 5 portions of fruit and vegetables a day is the minimum you should be consuming and if you are not getting 5 a day you are not following a Mediterranean diet! Study after study shows the health benefits of eating fresh fruit and vegetables. For example, eating 7 or more portions a day has been shown to reduce the risk of dying from any cause by 42%[76].

The reason for this is that for our bodies to function optimally they need an array of vitamins, minerals, phytochemicals and other micronutrients some of which are only found in fruit and vegetables. Multivitamin supplements can be very useful but they simply do not replace fruit and vegetables.

If, for whatever reason, you struggle to eat 5 portions of fruit and vegetables a day then a greens powder supplement may be helpful. Greens powders are dehydrated vegetables ground into a powder that can be added to food or simply mixed with water. They do not taste great and they are a poor substitute to eating fresh fruit and vegetables but they are better than not consuming them at all. My wife used these powders on days when she was travelling and was not able to get her 5 a day. It may be something worth considering but, to repeat, should not be seen as a replacement.

Tweak 9: Avoid fruit juices

Fruit juices are not a substitute for eating whole fruits. Whilst they contain many of the vitamins, minerals and other nutrients they do not provide the range of nutrients or the levels found in whole fruit. One reason for this is that edible skins and pulp are typically removed during the juicing process and it is in these where many nutrients are found.

Removal of the skins and pulp also has other negative effects: it takes away most of the fibre which means that fruit juice is less filling than an equivalent size piece of fruit and results in more of the fruit sugars being stored as fat because the fibre is not present to slow down absorption. In fact, it has been shown[77] that drinking fruit juice increases the risk of developing diabetes whereas eating whole fruit actually lowers the risk!

There’s also the issue of many fruit juices not being made from 100% fruit and containing unhealthy additives.

Fresh, whole fruit on the other hand is very helpful to fertility. For example, one study[78] showed that higher fruit intake is associated with getting pregnant more quickly.

Tweak 10: Don’t eat “blackened” food

By “blackened” food I mean anything that has been burnt, caramelised or cooked in a way that leads it to become dark or black. Barbequed food is a good example.  

Researchers have found[79] that women who are struggling to conceive have much higher levels of things called “advanced glycation end products” or “AGEs” for short. AGEs occur naturally in our bodies in small amounts but can be consumed in larger amounts through eating burnt/blackened foods.

These AGEs can cause inflammation in the lining of the womb which makes it more difficult for an embryo to implant and develop. If an embryo cannot implant or develop then you will not become pregnant.

On top of this, AGEs can interfere with the development of the placenta which can lead to further complications.

Tweak 11: Avoid sugary drinks

We talked about sugar in Tweak 2 but it is worth mentioning sugar-sweetened beverages specifically. The effect of these drinks on fertility was shown in a recent study[80]. The researchers found that overall men and women who drank sugary drinks had fertility rates that were 20% lower than average. The study also suggested that the more of these drinks you consume the bigger the impact. For example, women who drank at least one sugary drink a day had fertility rates that were 25% lower than average and men who drank at least one sugary drink a day had fertility rates that were 33% lower than average.

Ditch the sugary drinks. If you are not sure if a drink contains sugar check the label. If you are still not sure, don’t risk it.

Tweak 12: Eat nuts

Provided, of course, you are not allergic to them. Nuts are a fantastic source of healthy fats, fibre, protein and a host of other nutrients. It has been shown that people who eat them regularly have far fewer health problems.

They have also been shown to significantly improve sperm quality[81] [82].

The best nuts to choose are raw varieties with their skin on. Almonds and walnuts were used in the above studies so these are a good option.

Whilst I couldn’t find any studies on nuts and female fertility, it has been shown[83] that selenium is important in preventing ovulatory infertility. Brazil nuts are packed full of selenium and are therefore a good choice

Resources

The basis of the ideal IVF diet is the Mediterranean diet. So, ensure that the vast majority of the food you eat comes from the following groups:

– fresh, local and seasonal fruit, vegetables and herbs

– wild fish and shellfish

– lean meat

– beans/legumes

– nuts and seeds

– extra virgin olive oil

Whilst the Mediterranean diet is a great starting point there are a number of tweaks we can make to improve it and further increase our chances of IVF success.

Tweak 1: Avoid Gluten

The traditional Mediterranean diet includes pasta, bread and other baked goods which are made from grains. Grains, as we discuss in the video, contain gluten which can affect fertility so these and other foods made from grains are best avoided.

Tweak 2: Cut Sugar and Refined Carbohydrates

Refined carbs, including bread, pasta, rice, flour and foods containing flour, white potatoes, sweets and processed foods containing sugar, are best avoided.

Tweak 3: Avoid Highly Processed Foods

There are a number of things that we can do to avoid, or at least reduce, the amount of highly processed foods that we consume:

– look at food labels. Generally, the longer the list of ingredients the more processed the food is likely to be

– be wary of common highly processed foods: breakfast cereals, bread and baked goods, pastry-based products, sandwiches, biscuits/cookies, cereal bars, confectionary, crisps, ready-made meals, margarine, take-aways/fast food, ice cream and ready-made sauces

– buy and cook with real ingredients: vegetables, meat, fish, eggs, fruit, nuts, seeds, herbs and spices

– choose locally grown and seasonal produce where possible

– avoid low fat/fat-free products. To replace the fat these products are often loaded with other unhealthy ingredients

– avoid foods with artificial colours, flavours and preservatives

Tweak 4: Eat Between 25% and 35% of your Calories from Protein

Eggs, wild fish, organic and wild meats are all good sources of protein. If consuming this amount of protein is difficult then you can add a protein supplement. Whey protein isolate from organic, grass-fed, drug free cattle is a good choice here. 

Calculating your individual protein requirements is straightforward but a bit time consuming. Start by keeping a food diary for a week, noting down the calorie content of everything you eat and drink. You may have to estimate some things but there are lots of websites that list the calorie content of different foods.

At the end of the week add up all the calories consumed and divide the total by 7 to give your average daily calorie intake. To work out your protein requirements multiply the average daily intake by 0.25. This will give you the suggested lowest level of protein intake each day. 

To work out the upper limit multiply the average daily calorie intake by 0.35. Food labels usually do not list protein quantity in calories, they usually just list the weight, so there is one final step. Divide the lower and upper limits by 4 (there are approximately 4 calories per gram of protein). These numbers are the amount of protein in grams that the studies suggest you should be aiming for each day.

That description is quite involved so an example may be helpful:

Monday: 1,855 calories
Tuesday: 1,600 calories
Wednesday: 1,899 calories
Thursday: 1,767 calories
Friday: 1,377 calories
Saturday: 1,850 calories
Sunday 2,010 calories

– add up total calories = 12,358

– divide by 7 to give average daily calorie intake = 1,765

– multiply by 0.25 to give lower limit = 441

– multiply by 0.35 to give upper limit = 618

– divide 441 by 4 to give lower limit in grams = 110

– divide 618 by 4 to give upper limit in grams = 155

Using this example the woman should consume between 110 grams and 155 grams of protein per day.

Another option is to base your protein intake on the recommended daily calorie amounts advised by Government health authorities. This would very much be second best, however, as it would not be tailored to your specific needs. As a guide, the US and UK Governments estimate that moderately active women need around 2,000 calories per day which would give a protein range of 125 to 175 grams per day.

Tweak 5: Eat Organic Where Possible

My wife and I tried to eat organic as much as possible but it was difficult to eat a diet that was 100% organic. As a result we made sure that anything we ate that was not organic came from a good source and, for fruit and vegetables, we made sure they were considered “safe” by the Environmental Working Group (www.ewg.org).

Tweak 6: Consume Healthy Fats

Without adequate intake of the right fats our bodies simply cannot function optimally so we need to pay close attention to the fats we eat. Some of the best fats to consume are as follows:

– extra virgin olive oil: it is first important to note that not all olive oil is created equal. By far the best type is “extra virgin” olive oil. It is best used raw in salads and dressings. It can be used to cook with but only at low temperatures

– avocados: these have been described as the best food to eat for IVF by Professor Jorge Chavarro, a fertility expert at Harvard University. They contain high levels of monounsaturated fats which has been associated with higher live birth rates

– wild oily fish, wild meat and grass-fed meat: these have a good balance of fats and are the closest thing we have to the meat we have evolved to eat. Steer clear of grain fed fish and meat. This includes things like farmed salmon. Any good butcher and fishmonger will know the provenance of their produce and it would be a good idea to consult with them

– virgin coconut oil: virgin coconut oil is almost entirely saturated fat but, to get all scientific, it is a “medium chain triglyceride” which is much more easily absorbed by our bodies than “long chain triglycerides”, the typical saturated fat found in Western diets. One of the key benefits of coconut oil is that it is ideal for cooking at higher temperatures as it is extremely stable. Look for “virgin” oil to ensure you are getting a good product. If it is not virgin it is unhealthy and should be avoided

Avoid canola oil, corn oil, soybean oil, “vegetable” oil, peanut oil, groundnut oil, sunflower oil, safflower oil, cottonseed oil, grapeseed oil, margarine and butter substitutes.

Tweak 7: Eat the Rainbow

If you follow a Mediterranean diet you will consume lots of fresh fruit and vegetables. It is very easy, however, to get into a rut of eating the same things day in day out, particularly in winter when choice is limited. It is not always easy to do but you should aim to eat a variety of different coloured fruits and vegetables each day. 

Tweak 8: Eat Your 5 a Day

Actually 5 a day is the minimum you should be consuming and if you are not getting 5 a day you are not following a Mediterranean diet! Study after study shows the health benefits of eating fruit and vegetables. 

If, for whatever reason, you struggle to eat 5 portions of fruit and vegetables a day then a greens powder supplement may be helpful. Greens powders are dehydrated vegetables ground into a powder that can be added to food or simply mixed with water. They do not taste great and they are a poor substitute to eating fresh fruit and vegetables but they are better than not consuming them at all. 

My wife used them on days when she was travelling and was not able to get her 5 a day. It may be something worth considering but, to repeat, should not be seen as a replacement. 

Tweak 9: Avoid Fruit Juices

Fruit juices are not a substitute for eating whole fruits. Whilst they contain many of the vitamins, minerals and other nutrients they do not provide the range or levels of nutrients found in whole fruit. One reason for this is that edible skins and pulp are typically removed during the juicing process and it is in these where many nutrients are found.

Tweak 10: Don’t Eat “Blackened” Food

By “blackened” food I mean anything that has been burnt, caramelised or cooked in a way that leads it to become dark or black. Barbecued food is a good example. 

Researchers have found that women who are struggling to conceive have much higher levels of things called “advanced glycation end products” or “AGEs” for short. AGEs occur naturally in our bodies in small amounts but can be consumed in larger amounts through eating burnt/blackened foods.

Tweak 11: Avoid Sugary Drinks.

Ditch them. End of story. If you are not sure if a drink contains sugar check the label. If you are still not sure, don’t risk it.

Tweak 12: Eat Nuts

Provided, of course, you are not allergic to them. 

They have been shown to significantly improve sperm quality. The best nuts to choose are raw varieties with their skin on such as almonds and walnuts.

For women, Brazil nuts are a good option.

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