The foods you eat influence everything from hormone balance and ovulation to egg and sperm quality. Research—such as the comprehensive Harvard Nurses’ Health Study (PMC, 2018)—has shown that certain dietary patterns are linked with improved fertility, while others can make conception harder. This applies both for those trying to conceive naturally and for those undergoing fertility treatments.
What you avoid is just as important as what you add: certain foods can trigger inflammation, disrupt hormone balance, or add toxic burdens the body must work extra hard to eliminate. The goal isn’t perfection—it’s about awareness, so you can make compassionate choices that serve your unique body.
Let’s zoom in on the main food categories that have been shown to play a negative role in fertility, and the science behind each.
Trans fats—commonly found in packaged snacks, fried foods, margarine, and fast food—are known to increase inflammation in the body. Multiple studies highlight a clear association between trans fat intake and reduced fertility, particularly in women experiencing ovulatory disruption (BMJ, 2007). In the Harvard cohort, women who consumed the most trans fats had twice the risk of ovulatory infertility.
Highly processed foods—think white bread, cereals, candy, and sugary drinks—are absorbed rapidly, sending blood sugar soaring. Chronic spikes and drops in blood sugar don’t just impact energy and mood; they lead to insulin resistance and inflammation, which have been linked to higher rates of miscarriage and polycystic ovary syndrome (PCOS)—a major cause of fertility struggles (Frontiers in Endocrinology, 2019).
Regular consumption of processed meats—like bacon, sausages, hot dogs, and deli meats—has been associated with lower sperm quality and DNA fragmentation, as shown in research from the American Society for Reproductive Medicine (ASRM Annual Meeting, 2014). For women, processed meats may also contribute to inflammation, which can create a less hospitable environment for conception.
Caffeine is a part of many daily routines, but high intake—over 300-400mg a day, or roughly more than two large cups of brewed coffee—has been implicated in delayed conception and (in some studies) higher miscarriage risk (CDC, 2022). For those particularly sensitive, even moderate amounts can disrupt sleep and stress hormones, both crucial for fertility.
While an occasional glass is often part of social life, research suggests that regular or high alcohol intake can decrease fertility in both women and men. Even moderate drinking (7 or more drinks per week) may extend the time to conception and increase risks during IVF (Reprod Biol Endocrinol, 2014). Alcohol disrupts estrogen and testosterone balance, can harm egg and sperm quality, and impairs nutrient absorption.
Although the research here is developing, some studies suggest that artificial sweeteners—especially aspartame and saccharin—may negatively affect gut microbiome and hormone function. Data from animal studies (Frontiers in Nutrition, 2021) indicate possible changes in fertility markers with heavy use, though conclusive human data is still pending. For those on a fertility journey, erring on the side of less may be wise.
Seafood is often praised for its omega-3s, but certain large predatory fish accumulate high levels of mercury—a toxin shown to harm reproductive health and later, fetal brain development (US FDA Fish Advisory). Mercury exposure can reduce fertility in both men and women, and is linked with longer times to conception.
It’s easy to get lost in a list of foods to avoid, but real results come from the overall dietary pattern. Diets centered on whole, unprocessed foods—like the Mediterranean diet—are consistently linked to better fertility outcomes (JAMA, 2010). Prioritizing vegetables, fruits, whole grains, healthy fats, and lean protein gently crowds out less supportive foods, making the process less about restriction, and more about nourishment.
No single food sabotages or saves your fertility—but eating patterns over weeks and months compound, for better or worse. Stress, sleep, gentle movement, and emotional well-being are all intimately linked with reproductive hormones. If changing food habits feels overwhelming, begin with one swap or gentle reduction at a time. Notice how your energy, cycles, or mood respond—the body is wise, and subtle improvements matter.
Choosing to avoid certain foods for fertility isn’t about striving for some mythical perfection. It’s about creating the most nurturing environment for your body, mind, and future family—whatever that looks like for you. Small changes, made with kindness, can ripple outward: less stress on the body, steadier moods, more resilience. In focusing on what truly supports your whole self, you open doors to hope, not just for conception, but for lifelong well-being.
If you’re looking for personalized help or have a complex health history, consulting a registered dietitian or naturopath knowledgeable in fertility can help shape the right approach for you. Whatever your path, know that every step you take towards gentle, conscious eating honors both your body and your dreams.