Eggs: Healthy Protein or Hen’s Menstrual Waste? What Does Science Say?

Eggs have long been a staple in many diets worldwide — hailed as a complete protein, easy to cook, affordable, and packed with essential nutrients. But in recent years, a rather provocative claim has been circulating: that eggs are nothing more than “hen’s menstrual waste.”

So what’s the truth? Are eggs a nutritional powerhouse or something to avoid? Let’s break it down based on science — and a little common sense.

🔹 First, What Is an Egg?

A chicken egg is an unfertilized reproductive cell (ovum) produced by a hen. It contains everything required to nourish a developing chick if fertilized. However, in commercial and backyard poultry farms, hens lay eggs regularly without mating, meaning no embryo or chick is ever formed in most eggs sold for consumption.

• So, is it menstruation? No. Chickens don’t menstruate. Menstruation, as seen in humans and some mammals, involves the shedding of the uterine lining. Hens don’t have a uterus, nor do they shed a uterine lining. The comparison is biologically incorrect.

🔍 Scientific consensus: Eggs are ovulated reproductive cells, not waste products.

🌿 Nutritional Powerhouse: What Does an Egg Contain?

One large egg (~50g) contains:

• 6–7g high-quality protein with all 9 essential amino acids
• 70–80 kcal
• Vitamins: B2, B12, D, A, and choline
• Minerals: iron, phosphorus, selenium
• Healthy fats and antioxidants like lutein and zeaxanthin (good for eyes)

Eggs are often referred to as the gold standard for protein because of their high bioavailability and amino acid profile.

💪 Health Benefits of Eating Eggs

Eggs are more than just a source of protein — they offer several science-backed health benefits that make them a valuable part of a balanced diet.

✅ Key Benefits:

• Muscle Repair & Growth: Thanks to their complete amino acid profile, eggs are ideal for rebuilding muscle tissue — especially after workouts.
• Brain Support: Rich in choline, which is essential for brain development, memory, and mood regulation. Recent reserach suggests that frequent egg consumption is associated with a lower risk of Alzheimer’s dementia and AD pathology.
• Eye Health: Contain lutein and zeaxanthin, two antioxidants that help reduce the risk of macular degeneration and cataracts.
• Weight Management: High satiety value means eggs help you feel fuller longer, reducing the urge to snack.
• Bone Strength: Contain vitamin D, which supports calcium absorption and bone health.
• Heart Health: Despite past cholesterol concerns, eggs (especially omega-3 enriched varieties) may help improve good HDL cholesterol in many people.
• Anti-cancer properties: Research suggests that lysozyme from egg white exerts anti-cancer activity in both in vitro and in vivo conditions

🔍 Studies show that including eggs as part of a healthy diet can support weight loss and metabolic health.

🚨 The Cholesterol Concern: Still Valid?

Eggs are high in dietary cholesterol (~186 mg per egg), which once raised concerns about heart health. But recent research suggests dietary cholesterol doesn’t significantly raise blood cholesterol in most people. The American Heart Association’s latest nutrition recommendations do not limit the number of eggs that can be eaten, as long as one’s total cholesterol is limited to no more than 300 milligrams per day.

Still, moderation is key — those with genetic cholesterol issues or existing heart conditions should consult a physician.

🚫 Are There People Who May Avoid Eggs?

Yes:

• Individuals with egg allergies (especially children)
• Vegans for ethical reasons
• People with certain gut sensitivities or autoimmune conditions

But for most healthy individuals, eggs can be safely included as part of a balanced diet. Introducing eggs early, around 6 months, may actually help prevent egg allergies. 

🥚 Types of Eggs: What Do Labels Really Mean?

Not all eggs are created equal, and labels like “free-range” or “organic” can be confusing. Here’s what they generally mean:

• Conventional (Caged): Hens are kept in small cages with limited mobility. These eggs are cheapest but raise ethical concerns.
• Cage-Free: Hens are not kept in cages but usually live in indoor barns. Better than caged, but still limited movement.
• Free-Range: Hens have some access to the outdoors. They can roam and often eat a more varied diet.
• Pasture-Raised: These hens live primarily outdoors and can forage naturally. Often considered the most ethical and nutrient-rich option.
• Organic: Hens are fed organic feed, not treated with antibiotics or hormones, and typically have access to the outdoors.

🧐 Note: Nutritional differences between types of eggs are small, but pasture-raised and organic eggs may contain slightly more omega-3 fats and vitamins due to a better diet and living conditions.

🥴 The Verdict: Protein Power, Not Waste

Calling eggs “menstrual waste” is scientifically inaccurate and misleading. While eggs are a product of the hen’s reproductive cycle, they are not harmful waste but rather nutrient-rich biological offerings designed to support life.

Whether you eat them or not is your choice — but if you do, rest assured you’re getting one of nature’s most complete, affordable, and accessible protein sources.

📖 References:

1. Puglisi MJ, Fernandez ML. The Health Benefits of Egg Protein. Nutrients. 2022 Jul 15;14(14):2904. doi: 10.3390/nu14142904. PMID: 35889862; PMCID: PMC9316657.
2. Li LH, Lee JC, Leung HH, Lam WC, Fu Z, Lo ACY. Lutein Supplementation for Eye Diseases. Nutrients. 2020 Jun 9;12(6):1721. doi: 10.3390/nu12061721. PMID: 32526861; PMCID: PMC7352796.
3. Pan Y, Wallace TC, Karosas T, Bennett DA, Agarwal P, Chung M. Association of Egg Intake With Alzheimer’s Dementia Risk in Older Adults: The Rush Memory and Aging Project. J Nutr. 2024 Jul;154(7):2236-2243. doi: 10.1016/j.tjnut.2024.05.012. Epub 2024 May 22. PMID: 38782209; PMCID: PMC11347793.
4. Kritchevsky SB. A review of scientific research and recommendations regarding eggs. J Am Coll Nutr. 2004 Dec;23(6 Suppl):596S-600S. doi: 10.1080/07315724.2004.10719429. PMID: 15640512.
5. Venter C, Smith PK, Fleischer DM. Food allergy prevention: Where are we in 2023? Asia Pac Allergy. 2023 Mar;13(1):15-27. doi: 10.5415/apallergy.0000000000000001. Epub 2023 Apr 28. PMID: 37389093; PMCID: PMC10166243.

Akanksha Sharma

Dr. Akanksha Sharma, Head Writer and creator of AtoZ of Pregnancy, is dedicated to empowering women, parents, and families through 360-degree knowledge. She and her team provide evidence-based advice to guide families through pregnancy, parenting and beyond.