Diet and Lifestyle Either Build Fertility or Burn It Down

One in six couples worldwide can’t get pregnant when they want to. While genetics, anatomy, and unexplained factors all play a role, the research keeps pointing to something most fertility clinics barely mention: daily habits.

A landmark study followed couples trying to conceive over 12 months and found a strict negative correlation between cumulative lifestyle risks and pregnancy rates. 

• Couples with zero adverse lifestyle factors achieved an 83% conception rate.
• Add one bad habit, and it dropped to 71%. 
• Two factors, 62%. 
• Three, 52%. 
• Four or more, just 38%.

These factors include what you eat, drink, smoke, and how you move.

A recent large case-control study out of Korea showed that the top risk factors were heavy drinking, current or past smoking, being underweight, hypertension, diabetes, reduced kidney function, and menstrual disorders.

Here’s what they probably didn’t check.

The Mechanisms Behind the Numbers

Lifestyle factors damage fertility through specific, measurable physiological pathways. And this is where functional medicine changes outcomes.

Alcohol disrupts the hypothalamic-pituitary-gonadal (HPG) axis, the master communication system between your brain and ovaries. When that signaling breaks down, ovulation becomes irregular or stops altogether. Women with infertility in the Korean study had 23% higher odds of being heavy drinkers than women who had given birth.

Smoking accelerates ovarian aging by depleting egg reserves, altering hormone production, and damaging the delicate tissues involved in implantation. Women with infertility had 28% higher odds of being current or past smokers.

Blood sugar dysregulation may be the most underdiagnosed driver of all. Insulin resistance pushes the ovaries to overproduce testosterone and disrupts the estrogen-progesterone balance needed for ovulation and implantation. Women with infertility in the study had 17% higher odds of diabetes and 27% higher odds of hypertension, both commonly related to insulin resistance.

Chronic inflammation, often driven by gut dysfunction, blood sugar swings, or autoimmunity, damages egg quality and creates a hostile uterine environment. Hashimoto’s low thyroid, undiagnosed celiac disease, and leaky gut are all common findings in women labeled with “unexplained infertility.”

And menstrual disorders? The women in the study who later received an infertility diagnosis had 14% higher odds of having been diagnosed with menstrual irregularities two years earlier. The body was sending signals long before the diagnosis arrived.

What Functional Medicine Actually Does

Conventional fertility care tends to skip straight to medical interventions. These tools have their place. But they don’t address why the body stopped doing what it was designed to do.

Functional medicine asks the harder question. Why isn’t ovulation happening? Why is the cycle irregular? Why are hormones dysregulated? The answer is usually upstream.

Blood sugar. Thyroid function. Gut health. Adrenal stress. Nutrient status. Toxic burden. Inflammation. Each of these is testable, addressable, and reversible.

Addressing lifestyle factors, identifying the underlying physiological dysfunction, and restoring the systems on which fertility depends are best addressed well before a couple wants to conceive.

And you might be wondering how this affects the health of the offspring. The same factors that promote infertility can also promote childhood developmental disorders such as autism, ADHD, learning disabilities, behavioral and mood disorders, sensory processing disorders, and a higher risk for anxiety, depression, and chronic illness.

The body wants to reproduce and create healthy offspring. Sometimes it just needs the right conditions to remember how.

Source: Jeon B, Kang T, Choi SW. Lifestyle factors and health outcomes associated with infertility in women: A case-control study using National Health Insurance Database. Reprod Health. 2025 May 21;22(1):88. doi: 10.1186/s12978-025-02030-0. PMID: 40394661; PMCID: PMC12093646.

Learn more about a functional medicine approach for fertility health at RedRiver Health and Wellness.