Optimizing Nutrition to Promote Fertility
Infertility is defined as the inability to conceive after trying for 12 consecutive months and 6 months for patients above the age of 35. Dealing with infertility can quickly become overwhelming. From the range of treatment options, medications/injections, and the cost of treatments, all of these factors and more can contribute to overall stress and emotional wellbeing during the fertility journey.
Still, research has continued to explore additional treatments which can help support pregnancy and reproductive outcomes. The relative success rate of IVF per cycle still rests under 30% on average in Canada (this number may vary depending on number of embryos transferred, age of patient, and previous fertility treatment history). Some of the modifiable risk-factors which can improve fertility and reproductive health include: physical activity, metabolic health and weight, nutrition, lifestyle, and nutraceuticals. A number of studies have now been published and we are now seeing a clearer image of what an optimal diet can look like for patients struggling with infertility. And more importantly, how an evidence-based nutritional and dietary plan may help optimize fertility for patients trying to conceive naturally or with assisted reproductive technologies (ARTs).
And the numbers did not hold back, in fact, one prospective cohort study following over 18’000 nurses found that following a fertility diet reduced the likelihood of experiencing infertility by 66% due to ovulatory disorders and by 27% for all other causes of infertility! While this is an observational study, the results are significant!
A recently published review looked at over 100 research articles published on optimal fertility diet and nutrition to support fertility and pregnancy. And we will share some of the most important information from these studies for you.
Overall Optimal Dietary Support for Sperm Health:
Consumption of healthy diets has been found to be associated with improved sperm parameters across multiple research papers. Increased consumption of healthier foods and diets have also been shown to support increased levels of Testosterone and decrease DNA-fragmentation rates of sperm cells (very important factor for embryo quality and potentially reducing risk of miscarriages). Consumption of a standard north american diet, with lots of red and processed meats, sugars, refined grains, high energy drinks and snacks did not show any improvement in sperm health. Some studies even found that consumption of a western diet was associated with lower sperm concentration, motility, and normal morphology.
Overall Optimal Dietary Support for Uterine/Ovarian Health:
Various prospective cohort studies found that following a healthy diet was associated with a 44% decreased risk for infertility compared to patients that did not follow this diet. Other studies found that following a healthy prenatal diet was associated with a higher clinical pregnancy rate and live birth rate, and another study found that following a healthy diet was associated with a higher liver birth rate for patients undergoing ART (i.e. IVF).
Types of Protein and Fertility
Various studies have evaluated for various form of protein and their impact on reproductive health outcomes. Some forms of protein have been shown to be associated with lower testosterone, sperm health parameters and reduced antral follicle count (AFC). Some of the saturated fats found in certain forms of protein may be responsible for this, as higher consumption of saturated fats appears to be correlated a lower number of follicles retrieved during fertility treatments (i.e. IVF). The research behind Soy protein is inconclusive and it is unclear if it is beneficial or potentially harmful for fertility.
Recommendations for Omega 3 and its potential benefit for fertility should be limited to servings of fish 3 times a week due to higher risk of contamination from mercury (as per US food and drug administration). Although some studies have found that risk of contamination is outweighed by potential benefits on reproduction from increased omega 3 consumption.
Optimal Fat Intake for Fertility
It is no secret that trans-fatty acids can be detrimental for health. No exception here for reproductive health. High intake of trans-fatty acids is associated with type 2 diabetes, inflammation, and insulin resistance, all of which can negatively affect ovulatory function. Consumption of higher amounts of Omega 3s may be associated with increased fertility and reduced time to pregnancy. One study found that increased consumption of seafood was associated with 47-60% increase in likelihood of conception compared to patients with little seafood intake. However, this study did not account for supplements or other confounding variables.
Optimal Carbohydrate Intake for Fertility
A measure of the impact a specific carbohydrate containing food impacts the blood sugar (glucose) levels is called glycemic index. The total quality and quantity of a carbohydrate-containing food and its dietary fibre content is determined by its glycemic load. Foods that have a higher glycemic load have been shown to be associated with an increased risk for ovulatory dysfunction and infertility related to it, as well as poor sperm motility. Whereas foods with lower glycemic load with whole-grain foods may increase live birth rates. This may partly due to the antioxidants found in whole grain foods and healthier quality of grains.
It is unclear what amount of carbohydrates is optimal or for how long this should be done to see actual improvements in reproductive outcomes or health parameters.
Antioxidants for Fertility
Antioxidants refers to nutraceuticals/supplements of high-dose active compounds that cannot be achieved through dietary sources alone. The effect a compound has in a dietary dose is different from its pharmacological effect when taken in higher doses. The research has evolved greatly behind this topic, from early studies unclear on whether antioxidants actually had an impact on reproductive health or not to more recent studies finding very exciting improvements in sperm health, uterine/ovarian health and function, and increased pregnancy rates.
For sperm health, antioxidants have been shown to help increase semen quality and can increase the likelihood of a clinical pregnancy that leads to a live birth. For uterine/ovarian health and function, the use of high dose and evidence-based nutraceuticals can improve reproductive outcomes for patients trying to conceive. While available studies are smaller and higher powered and quality studies are required, based on the relative low-risk of harm, patients should have a conversation with their licensed Naturopathic Doctor to discuss if certain antioxidants may be of benefit to them.
Alcohol and Infertility
Studies looking at patients consuming alcohol on a daily basis were found to have lower semen volume and lower normal sperm morphology. Patients that consumed alcohol on a daily basis were found to have worse sperm health when compared to patients that had less.
Higher amounts of alcohol consumption also appeared to negatively affect reproductive health in females.
Caffeine Intake and Fertility
There are conflicting studies on this topic. Overall, we see that consumption of 1 or 2+ cans of caffeinated soda was associated with a 23% and 28% decrease in chances of conception, respectively. Some studies fail to find any correlation between caffeine intake and fertility. Higher intake of caffeine is hypothesized to negatively impact the quality of sperm DNA.
For patients going for IVF, consumption of caffeine was associated with poor egg/embryo health but not impact clinical outcomes. Other studies failed to find an association between caffeine intake and fertility. However, the European food safety authority and WHO recommend a maximum of 200-300 mg of caffeine a day for patients trying to conceive.
One case-control population study that followed over 11’000 patients found that consumption of beverages sweetened with sugar was associated with a decrease in conception rates. Patients included in this study were under 40 years of age.
Two other studies also found that Women who consumed sugar-sweetened sodas or energy drinks had lower chances of conceiving compared to patients who did not drink these beverages. The researchers hypothesized the role of sugar potentially interfering with hormone function and follicle growth/ovulation.
Two studies evaluating for the impact of sugary snacks or drinks on sperm health found that higher consumption of these foods was associated with lower sperm concentration and/or lower sperm health (i.e. motility and morphology).
Limitations of the Studies
Many of the studies included in this review were observational studies, meaning that while correlation can be established, causation cannot. There are additional factors, or confounding variables, which may impact the outcomes measured. However, it does start to paint an important picture of what types of lifestyles may be better associated with both increased fertility and a reduction in chronic disease.
This article is in no way a replacement for medical advice or medical care, it is advised that anyone concerned about their Health should speak with their Naturopathic Doctor. Please discuss with your healtcare provider and only make changes to your medications regimen if recommended by your doctor and under their guidance.