Although age is the most important factor in fertility, there are also genetic, environmental and behavioural aspects that may affect our capacity to procreate.
Reproductive medicine advanced greatly and there are a variety of medical treatments that increase fertility and assist in conception but these can be both invasive and expensive. In many cases, focusing on food, nutrition and maintaining a healthy lifestyle is a simple and effective approach to increase the fertility of both men and women.
However, it is very important to clarify from the start that so far, no single diet or food has been scientifically proven to guarantee conception, implantation and pregnancy in general. Nevertheless, there are several dietary approaches that have proved to be beneficial. When deciding to make changes in your diet, you have to keep in mind that we are all unique, and that whatever worked for your friend may not work for you.
THE MEDITERRANEAN DIET is the diet style of European countries on the Mediterranean coast, such as Spain, Italy, France and Greece. It is characterized by a high intake of cereals, legumes, fruits and nuts, vegetables, fish, and olive oil. On the other hand it counts a low intake of dairy products, meat, poultry and saturated lipids. The intake of alcohol is regular and moderate.
Medical literature has been proving for a long time now the benefits of the Medi Diet for the human health in general. Its effects on decreasing cancer rate, obesity and diabetes as well as general mortality are well known (1). Recently it has been noted that the Mediterranean Diet has a beneficial influence on fertility, with studies performed in Greece showing that it may improve IVF rates (2). Women who followed a Mediterranean diet had higher pregnancy rates (50%) compared to women who did not follow a Mediterranean diet (29.1%). Also, the Mediterranean diet was associated with higher live birth rates (48.8% versus 26.6%).
Being a traditional diet, the Medi Diet was not conceived to promote weight loss. Yet, by being healthy and balanced, it does result in weight loss, especially for those who, by adopting it, make a solid change in their eating habits.
THE KETOGENIC DIET- is the newest trend in terms of fertility diets, happy adepts swear by it, several fertility clinics recommend it, there are some world-renowned experts warning against it. Long story short, it’s quite controversial. First of all, you should know the Keto diet is not new in medicine. It has been used for over 100 years to treat drug-resistant epilepsy, especially in children. Then, in the 70’s, Dr Atkins came up with his very-low-carbohydrate diet for weight loss that started with a very strict two-week ketogenic phase. This is a diet rich in proteins and fats with up to only 20-50 carbs daily, sometimes lower than that. In the absence of carbohydrates and of circulating blood sugar from foods, our body breaks down stored fat in ketone bodies, and will use them to generate energy until we start eating carbs again.
The Keto Diet typically includes meat, fish and seafood, eggs, natural fat and high fat sauces, vegetables growing above ground, high fat diary, nuts and berries (3)
The ketogenic diet has proven to be efficient for overweight patients suffering from insulin resistance and has good results in lowering blood sugar levels for Type 2 Diabetes patients, at least on a short term.
There is proof though that it has a negative impact on patients with kidney disease, and may be worsening their condition. As with any yo-yo diet, the Keto Diet has its risk and shouldn’t be adopted for long periods of time. There are studies showing that low carb diets are unsafe, especially on long term, and that is because people cutting off carbs have a tendency of turning to butter and meat for sustenance. A large study (4) presented at the 2018 Congress of the European Society of Cardiology showed that people who consumed low carbohydrates diets are at greater risk of premature death, including coronary heart disease, stroke and cancer.
“ The results were confirmed in a meta-analysis of seven prospective cohort studies with 447,506 participants and an average follow-up of 15.6 years, which found 15%, 13%, and 8% increased risks in total cardiovascular and cancer mortalities with low (compared with high) carbohydrate diets (see figure for total mortality).
Professor Banach said: “Low carbohydrate diets might be useful in the short term to lose weight, lower blood pressure, and improve blood glucose control, but our study suggests that in the long term they are linked with an increased risk of death from any cause, and deaths due to cardiovascular disease, cerebrovascular disease, and cancer”
Being a rapid weight loss diet, and being known that in obese and PCOS infertile patients, as little as up to 10% decrease in body weight may improve chances to conceive, the Keto diet gained a well-deserved place in the top 3 of fertility diets. A review of 7 studies trying to determine the extent to which low carbohydrate diets can affect fertility outcomes, concluded that “reducing carbohydrate load can reduce circulating insulin levels, improve hormonal imbalance and resume ovulation to improve pregnancy rates compared to usual diet. However, there has been a lack of research on the benefit of low carbohydrate diets for non-PCOS related infertile women” (5)
THE VEGETARIAN DIET- you may have adopted this one as a way of life, long before ever deciding to have a baby. But does it have any proven benefits for fertility? One thing is certain: cutting meat off your plate reduces inflammation (6) The connection between inflammation and infertility has long been established. Inflammation may throw your hormones out of whack, contributing to Estrogen dominance, which in turn leads to progesterone resistance. There is limited data on vegetarian diets and fertility. What is known though is that menstrual irregularities are more common in women who eat strictly vegetarian/vegan. In diets based exclusively on plants, phytoestrogens found in seeds, grains and legumes can lengthen cycles by lengthening the follicular phase, reduce progesterone which impacts healthy implantation, and may even supress ovulation altogether. As in everything, moderation is key. Studies show that even a low intake of animal foods like goat cheese and eggs make a difference in regards to periods.
PALEO DIET – is probably the newest diet around these days, and it is quite the opposite of the vegetarian diet. Paleo diet, just like the name suggests it, is a meal plan modeled on the diet of the prehistoric human. A Paleo diet typically allows you to eat lean meats, fish, fruits, vegetables, nuts and seeds — foods that could be obtained by hunting and gathering. Dairy products, legumes and grains are limited. Processed foods of any kind are not included in this diet, which of course helps you lose weight rather rapidly. The proven benefits, besides weight loss, are improved glucose tolerance, better blood pressure control, lower triglycerides (7)
Unfortunately, with the diet being so new, there are practically no studies on the way Paleo impacts fertility. Its promoters claim that by being a low carb diet, it has the same benefits as a Keto diet with less fats.
INTERMITENT FASTING- is not so much a diet as it is an eating pattern, which alternates periods of eating with periods of fasting, just like the name suggests it. There is no golden rule for it, and there are several approaches. You can either opt for the 16/8 plan, where you are fasting for 16 hours and eating only during an 8 hour window, or for the 24h plan, where you finish your meal at 8 pm and don’t eat again until 8 pm next day. Of course, both these plans may be adjusted, with people eating during 6 or even 4 hours windows.
But how does intermittent fasting work and what does it do for your body?
The main idea is that, by cutting out one meal a day, you will consume less calories throughout a whole week, even if the other two meals a day you are eating are slightly more copious than what you used to have before.
This eating pattern is supposed to change your insulin production and sensitivity, and therefore helping you lose weight. Intermittent fasting is actually helping your body to consume food more efficiently and burn fat as fuel, when it is deprived of calories during the fasting periods.
There are hundreds of studies performed on humans and animals and showing intermittent fasting improves health conditions such as diabetes, obesity, cardiovascular disease, neurological disorders and even cancers (8)
But how does intermittent fasting impact fertility? Unfortunately the studies connecting fertility and intermittent fasting are very limited and the results are contradictory. Theoretically, when a woman is overweight, a short intermittent fasting period may kick start her metabolism, help her lose some weight, which in itself is good for fertility.
Is this still true for women who are not overweight? Possibly. By regulating blood sugar and pressure, intermittent fasting reduces inflammation, which is good for fertility.
The key, according to the experts, is to make sure you are consuming enough calories during the eating window, so that you don’t enter into “starvation” mode.
It is known that when your pituitary gland senses you are in deprivation mode, it may mess up your ovulation (9) This being said, women did get pregnant even during periods of famine and deprivation, and one just doesn’t get into “starvation” mode overnight. The secret, as with everything, is moderation, adopting this eating pattern for only limited periods of time, while making sure you don’t deprive yourself of healthy nutrients during your eating window.
But what if you’re not really into dieting, you don’t need to lose weight, yet you would like to introduce some fertility super foods into your diet in order to maximize your chances of getting pregnant?
Keeping in mind that no food ever has been scientifically proven to actually help get people pregnant, there are many foods who are good for fertility, and included in an overall healthy diet they may improve your chances of finding the Golden Egg.
But how can we know a certain food is beneficial for fertility? Based on what?
According to scientists, based on the nutrients they contain, and that are needed in order to prepare the body for conception and pregnancy.
ANTIOXIDANTS - they are essential in fighting inflammation and neutralizing free radicals that damage cellular health and cell DNA.
Sources of antioxidants: bright coloured fruits (all berries, pomegranate, oranges, lemons, grapefruits, watermelon, pineapple) and vegetables (carrots, bell peppers, avocados, spinach)
FATS – the healthy unsaturated ones are a big component of the fertility diet.
They can be found in fatty fish (salmon, herrings, sardines, trout, mackerel, anchovy, oysters and mussels). The Omega 3 fatty acids found in fish should only be acquired from diet or supplements, as the body is unable to produce them on its own.
The monosaturated fats that promote egg health and ovulation can be found in nuts, olive oil, seeds.
VITAMINS AND MINERALS – extremely important for overall health, they have a proven effects on ovarian health and are known for their anti-inflammatory and antioxidant effects.
Vitamin C is found in citrus fruits (orange, lemon, grapefruit, kiwi) and vegetables like broccoli, Brussels sprouts and cauliflower)
Vitamin E can be found in nuts, seeds, vegetable oils and green leafy vegetables
Zinc can be taken from lean meats, poultry, lentils, asparagus, nuts and seeds
Folic Acid, essential in order to prevent neural tube defects is found in asparagus, avocado, whole grains, cauliflower, broccoli, lentils, beans, oranges, grapefruit, berries.
CARBOHYDRATES – because yes, there is such thing as healthy carbs, and they are the complex carbohydrates, the ones that are digested slowly, providing the body with a steady supply of energy and having a gradual effect on insulin production.
Whole rice, whole wheat pasta and bread, quinoa, bulgur, barley, polenta.
PROTEIN is vital for body tissue repair and for the healthy production of hormones and enzymes. Yet it is extremely important to make sure your intake of protein is adequate and high quality keeping a fine balance between animal and plant-based protein. If you are consuming animal protein, you may want to opt for lean meats, grass-fed and free-range whenever possible (avoiding processed meats). Eggs are important when it comes to human eggs health as they provide a great source of choline, a nutrient known to prevent birth defects.
DAIRY- studies show that a moderate consumption of dairy improves fertility. You just want to make sure to go full fat and skip the skimmed products.
If we were to come to a conclusion, there is no magical diet, and no one size fits it all when we are talking food and fertility.
We do know weight is important and even slight improvements in BMI result in success.
We do know what nutrients are important in preconception and pregnancy, and we know we can either get them from our diet, or from supplements, or both.
It is obvious, according to studies that whatever strict diet we decide to try, it has be on a short term, and its good effects have to be maintained by adopting a “as-healthy-as-possible” lifestyle, with reasonable dietary choices and physical activity.
We also know that if we manage to find a good balance, it is only going to benefit us in the long run and keep us healthy and in a good shape for a long time.
Because after all, we supposedly achieve optimal fertility when we achieve optimal health. And in the end, this is where the focus should be: on general health, no matter where we are in our lives.
(1) Sofi F, Abbate R, Gensini GF, et al. Accruing evidence on benefits of adherence to the Mediterranean diet on health: an updated systematic review and meta-analysis. Am J Clin Nutr. 2010;92(5):1189–96.
(5) McGrice, M., & Porter, J. (2017, February 27). The Effect of Low Carbohydrate Diets on Fertility Hormones and Outcomes in Overweight and Obese Women: A Systematic Review. Retrieved from https://www.ncbi.nlm.nih.gov/pubmed/28264433
(6) Haghighatdoost F;Bellissimo N;Totosy de Zepetnek JO;Rouhani MH; (n.d.). Association of Vegetarian Diet With Inflammatory Biomarkers: A Systematic Review and Meta-Analysis of Observational Studies. Retrieved from https://pubmed.ncbi.nlm.nih.gov/28836492/