PLMI Blog

While a number of factors outside of our control exert influence on fertility, including age and genetics, a multitude of factors in our control also exert profound influence, including nutrition, lifestyle, and environment. A functional and integrative approach to fertility recognizes the various multidimensional influences that can either optimize or impede reproductive health in conjunction with one’s bio-individual makeup.

Impeded Reproductive Function

Infertility is a medical condition defined as the inability to conceive after twelve months of unprotected intercourse that can affect numerous facets of one’s health (1, 2). Aspects of both female and male infertility are integral to the discussion of contributing and underlying causes of impeded reproductive function. Male infertility solely accounts for 20% of cases while being a strong contributing factor in nearly 40% of cases (3). 

The prevalence rates of infertility have been shown to increase from 3.5% to 16.7% in more developed nations, as indicated in a 2021 study (4). Vast changes in food (with the rise in processed and modified foods), environment (increased exposure to toxins and other chemicals), as well as a sedentary and high stress lifestyle may account for this marked increase. 

Factors That Affect Fertility: Omics for Personalized Medicine

Functional medicine recognizes the interconnectedness of the body’s systems in determining underlying causes and multidimensional facets of infertility. Biomarkers, including genomics, metagenomics, and proteomics, can be helpful in identifying variations in genes and biological processes and identifying causes of infertility, while yielding more efficient, targeted treatment modalities and outcomes (5). 

Impeded metabolic, hormonal, and microbiome health can result in inflammation, compromised immune function, and oxidative stress – factors that have been suggested to affect fertility. Poor diet, stress, and exposure to environmental toxins can further compound these underlying physiological processes (6). 

The Relevance of The Microbiome – Epigenetics

Individual variation exists within all of us, particularly relative to the microbiome, which strongly influences the health of its host. The microbiome is integral for regulating homeostasis in the body, playing a pivotal role in modulating metabolism, inflammation, and hormonal and immune health. It is also a central ecosystem for altering genetic expression or epigenetics. In fact, 3.3 million unique genes reside in the gut, underscoring its significance in influencing gene expression (7).

The quality and diversity of the microbiome play a role in metabolism, inflammation, and oxidative stress. Emerging research findings suggest that the composition of the microbiome exerts an influence on reproductive health. Vaginal, semen, and uterine microbiome environments have been studied with the utilization of novel methodologies to provide increased insights into these ecosystems to shed light on fertility status. Sequencing techniques are becoming more widely accessible and implemented to allow for the identification of these microorganisms (8).

Of note, the Lactobacillus crispatus strain of microbiota has been shown to play an important role in influencing fertility. The presence of the following pathogenic bacteria in the genital tract have been found to compromise fertility: Gardnerella vaginalis, Ureaplasma species,  Chlamydia trachomatis, and gram-negative organisms (9). 

A growing body of research suggests that the vaginal microbiome, which is highly unique to each individual, plays a pivotal role in influencing reproductive health (10). Findings also demonstrate a relationship between the microbiome and male infertility. Similar to the vagina, semen and testes contain distinctive microbiomes that have been shown to be associated with the quality of sperm and overall fertility. 

Another study examined the relationship among the microbiome, the genitourinary system, and male infertility utilizing 16s rRNA-based next-generation sequencing on the seminal and testicular microbiome. Various microbiota were suggested to be implicated in sperm dysfunction. This review underscores the importance of the microbiome for fertility, utilizing the microbiota of semen and testes in men (11).

 Nutrigenomics– The Impact of Nutrition & Lifestyle

Nutrigenomics is the study of individual variation in genes and how certain foods can influence genetic expression and other processes in the body that can either impede or support fertility. This underscores the importance of addressing nutrient needs based on bio-individual factors. For instance, genetic variants may exist in enzymes necessary for the reactions of methylation to occur efficiently, such as MTHFR yielding more targeted nutritional support.

Nutrigenomics highlights how food influences what genes become expressed and which ones do not. Compounds in cruciferous vegetables and polyphenols, for example, exert powerful influence on genetic expression, as do nutrients necessary for methylation reactions to occur and foods that nourish the microbiome. The microbiome is plastic and always shifting in response to diet and lifestyle factors. This is encouraging, as we can exert significant influence over it with adequate nutrition and nourishment, stress reduction, sufficient sleep, and regular movement. 

Adhering to a nutrient-dense, low glycemic index diet based on the structure of the Mediterranean diet is recommended for improving reproductive health. This pattern of eating covers nutrients necessary for methylation, essential for fertility as well as mitochondrial function. B vitamins are integral for the methylation process, among other nutrients such as choline, betaine, and zinc (12, 13). Sufficient vegetable and protein consumption,  monounsaturated and polyunsaturated fatty acids, folate, vitamin D, antioxidants, and iron are also important in supporting fertility (14). 

This way of eating also supports metabolic, hormonal, and microbiome health. This is significant, as impeded balance in these body systems has been suggested to contribute to infertility. Nutrition can also support the modulation of low-grade chronic inflammation, which has been associated with a number of infertility-related illnesses (15). Nutrient density further supports antioxidant capacity, helping to negate oxidative stress from internal and external factors. 

External Influences 

In addition to chronic stress, nutritional deficiencies, a sedentary lifestyle, and inadequate sleep all further compromise fertility. Lifestyle factors, such as substance use and the extent of exposure to environmental toxins, also play integral roles in influencing fertility (14). Environmental toxins can contribute to oxidative stress, impeding hormonal balance and affecting fertility. Smoking has been shown to be associated with increased rates of infertility (16). Heavy alcohol consumption can also affect fertility by disrupting hormonal and microbiome balance while also making the body more susceptible to increased amounts of oxidative stress. 

These factors are important to consider when deciphering individual nutritional needs and which lifestyle changes to implement over time. It is also valuable to become curious about what these substances serve in terms of stress relief so the individual and provider can explore alternative, more constructive ways of coping conducive to improved fertility for men and women. 

Quality Zzzs for Improved Fertility

Sleep is imperative for modulating countless bodily functions, including hormonal, metabolic, immune, and microbiome balance, playing a pivotal role in fertility. In fact, forty-two studies demonstrated the relationship between sleep habits and female and male reproductive functions. The relationship between sleep dysregulation and fertility was classified according to sleep characteristics, including duration, quality, and regular habits. 

One study highlighted the physio-pathological mechanisms proposed to support the correlation between sleep and fertility, underscoring the profound role sleep plays. Molecular pathways involved in the modulation of circadian rhythm balance, which affect sleep and are integral for reproductive physiology, were identified. A number of mechanisms were found connecting sleep disorders with impaired reproductive health, including adrenal stimulation and dysregulation in circadian rhythm compounding genetic influences (17).

Another study provided evidence of the significance of sleep to reproductive and metabolic health. A cohort of 1603 infertile women enrolled in 2 concurrent randomized clinical trials revealed a relationship between women struggling with infertility and disrupted sleep patterns. Those with PCOS were more likely to report disturbances in sleep than those with unexplained infertility (18). Sleep is also foundational for neurotransmitter synthesis, sufficient digestion and detoxification, helping to rid the body of harmful toxins, as well as promote restoration and support with emotional and psychological forms of stress. 

The Impact of Stress on Reproductive Health

Stress has also been shown to play a central role in impeding fertility. A recent study revealed the potentially hazardous effects of stress on female reproductive function. An association was found in women with impeded reproductive function, increased stress, and reduced overall quality of life. This relationship was more likely to be reported in those struggling with infertility (19).

Chronic stress has been shown to alter reproductive function by impeding various physiological processes in the body, affecting overall homeostasis. In fact, a growing body of research has suggested that oxidative stress is involved in stress-induced male infertility. A 2024 study highlighted the role gonadotropin inhibitory hormone (GnIH), an integral neurohormone, plays in stress-induced infertility in males through a number of mechanisms. 

Research demonstrates that GnIH enhances the release of corticosteroids by activating the HPA axis, and modulates the inhibition of the conversion of thyroxine (T4) to triiodothyronine (T3) by suppressing the hypothalamic-pituitary-thyroid axis. GnIH has also been found to inhibit gonadotropin-releasing hormone, thereby suppressing the hypothalamic-pituitary-testicular axis, and as a result biosynthesis of testosterone. In conjunction, these factors can impede sperm quality and function (20).

Yoga for Improved Blood Flow & Fertility 

A growing body of research demonstrates the mechanistic properties of yoga in supporting improved markers of fertility, such as the reduction of oxidative stress, while positively affecting physiological body systems. Increased oxidative stress is associated with altered methylation, genetic expression, and compromised quality of eggs and sperm. Yoga, in conjunction with meditation, has been shown to significantly reduce oxidative stress, mitigating damage induced to body systems associated with infertility. Through improving blood flow, inducing the relaxation parasympathetic nervous system (PNS) response, improving heart rate variability (HRV), reducing inflammation, and regulating the HPA axis, yoga induces these favorable effects (21). 

Addressing the various multidimensional factors that impede and optimize fertility yields more individualized and effective treatment protocols. In this functional and integrative whole-person approach to health, personalized plans are developed based on specialized data about each unique individual and the multitude of factors that affect their health. 

Join us for this free webinar: The Importance of Lifestyle Genetics in Healthy Aging: Relevance of Genetics from Preconception Across the Lifespan, occurring July 30th from 5 to 7 pm PST. We will delve into personalized, genomic-focused interventions for health in preconception and throughout the entire life span. Experts in this field, Denise Furness, PhD and Leslie P. Stone MD, IFMCP, will lead this thought-provoking discussion along with our own Jeffrey Bland, PhD. This presentation will cover clinical applications of genetic analysis, providing novel insights and improved treatment outcomes for a range of complex issues based on bio-individual and holistic factors. 

References:

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