Sonia M. Rompoti, MSc, Bsc

Fasting, the voluntary abstinence from food or drink for a defined period, has been practiced for millennia for religious, health, and spiritual reasons. However, its effects on the female menstrual cycle remain a topic of discussion.

Intermittent fasting (IF) has gained significant attention in recent years due to its array of potential health benefits. Numerous studies have shown that IF can lead to weight loss by optimizing metabolism and promoting the burning of stored fats. Additionally, IF may improve insulin sensitivity, reducing the risk of type 2 diabetes. It’s also believed to enhance brain health by promoting the release of the neurotrophic factor BDNF and facilitating the cellular repair process through autophagy. Furthermore, some research suggests that IF might support heart health by improving blood pressure, cholesterol levels, triglycerides, and inflammatory markers. Beyond these physiological advantages, many practitioners find that IF simplifies their eating patterns and can lead to a more mindful relationship with food.

This article will explore the relationship between fasting and menstrual health, shedding light on the potential impacts and considerations for women while offering scientific research you can follow for a deeper understanding of the topic.

1. Hormonal Fluctuations and Energy Intake

The menstrual cycle is orchestrated by a delicate balance of hormones. The primary hormones include estrogen, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Disruption in their balance can lead to menstrual irregularities.

Reference: Schmidt, J., Brännström, M., Landin-Wilhelmsen, K., & Dahlgren, E. (2011). Reproductive hormone levels and anthropometry in postmenopausal women with polycystic ovary syndrome (PCOS): A 21-year follow-up study of women diagnosed with PCOS around 50 years ago and their age-matched controls. The Journal of Clinical Endocrinology & Metabolism, 96(7), 2178-2185.

During fasting, the body perceives a lack of energy intake. This energy deficit can potentially impact the production and release of these reproductive hormones. In its wisdom, the body might prioritize survival over reproduction during times of perceived scarcity, so fasting -depending on your lifestyle and general calory intake- might not offer you the benefits a male organism will reap from the exact same experience.

2. Fasting and Menstrual Irregularities during extended fasting periods

Prolonged fasting or extreme caloric restriction has been linked with menstrual irregularities. These can manifest as:

• Amenorrhea (absence of menstruation)
• Oligomenorrhea (infrequent menstrual periods)
• Anovulation (lack of ovulation)

Reference: Loucks, A. B., & Thuma, J. R. (2003). Luteinizing hormone pulsatility is disrupted at a threshold of energy availability in regularly menstruating women. The Journal of Clinical Endocrinology & Metabolism, 88(1), 297-311.

3. Intermittent Fasting and the Menstrual Cycle

Intermittent fasting (IF), a pattern of eating that alternates between periods of eating and fasting, has gained popularity for its potential health benefits. While short-term, intermittent fasting might not pose significant risks for many women, prolonged or extreme IF regimens might still disrupt the menstrual cycle.

Reference: Tinsley, G. M., & La Bounty, P. M. (2015). Effects of intermittent fasting on body composition and clinical health markers in humans. Nutrition reviews, 73(10), 661-674.

4. Importance of Nutritional Intake

Quality of diet also plays a role. Even if a woman is not strictly fasting, a diet deficient in essential nutrients, like iron or vitamin B12, can affect menstrual health. Ensuring a nutrient-rich diet during non-fasting periods is crucial.

Reference: Gaskins, A. J., & Chavarro, J. E. (2018). Diet and fertility: a review. American journal of obstetrics and gynecology, 218(4), 379-389.

5. Individual Variation

Each woman’s body responds differently to fasting. Some might experience disruptions in their cycle, even with short fasting periods, while others remain unaffected even with prolonged fasting. So it is best to always start with short bouts of fasting and see how your body reacts to it.

6. Recommendations

For women considering fasting:

• Monitor menstrual cycles regularly.
• Ensure adequate nutrient intake during non-fasting periods.
• Consult a healthcare provider or a nutritionist about potential risks and individual considerations.
• Start with short periods of fasting, and increase it with increments of 30 minutes, to see how your body reacts.

Conclusion

Fasting can offer numerous health benefits, but its impact on the menstrual cycle should not be overlooked. As with all health practices, an individualized approach, combined with careful monitoring and professional advice, can help strike the right balance.