From Roots to Ends: How Hair Reflects Your Internal Health

Dry, brittle, premature graying, or thinning hair is not just a cosmetic concern—it could be an alarm bell signaling that something in the body is out of balance. While we often turn to our skin, weight, or energy levels as indicators of wellness, the condition of our hair can also reflect how well our body’s internal processes are functioning. Let’s explore how your hair might be sending you signals about your health and how you can address these issues naturally.

Why Your Hair is a Reflection of Your Health

Healthy hair growth is intricately tied to many aspects of your body's wellbeing. Hair follicles are part of the integumentary system, the body’s largest organ system made up of the hair, skin, and nails, and they rely on proper nutrition, hormonal balance, and good circulation for optimal functioning [1]. If something is off within the body, it often shows up in your hair first. While we might be quick to blame hair products or genetics for issues like thinning or dryness, the root cause might be internal.

Think of your hair as a barometer for what’s happening under the surface. When your body is healthy and thriving, your hair is more likely to be full and shiny. When there are imbalances—whether hormonal, nutritional, or emotional—your hair can become dry, brittle, prematurely gray, or start falling out. While genetics do play a significant role in hair’s condition and thickness, sudden changes in hair quality are often a sign of an underlying health issue.

Internal Causes of Lackluster Hair 

Stress

Stress can lead to thinning or prematurely graying hair through multiple mechanisms. Stress can cause hair loss through a condition known as telogen effluvium, where stress pushes a significant number of hair follicles into a resting phase. Normally, about 85-90% of your hair is in the growth phase (anagen), and only a small percentage is in the resting phase (telogen). However, during periods of intense or prolonged stress, a higher proportion of hair shifts into the telogen phase prematurely. After a few months, these resting hairs shed, which is why you may notice significant hair loss 2-3 months after a stressful event. This type of hair loss is usually temporary and stops once stress is reduced.

Elevated Cortisol levels can also disrupt the production of hormones essential for hair growth, such as Estrogen and Testosterone (which we will touch more upon in the next section). This imbalance further contributes to thinning hair and increased hair shedding. In more severe cases, chronic stress can trigger an autoimmune response, leading to conditions like alopecia areata, where the immune system attacks hair follicles, resulting in patchy hair loss [2].

In addition to hair loss, stress can also lead to premature graying. Hair color is determined by melanocytes, cells in hair follicles that produce the pigment melanin. Intense stress triggers the release of norepinephrine, a neurotransmitter involved in the body's response to danger. In hair follicles, norepinephrine can cause melanocyte stem cells to activate and convert into mature melanocytes too quickly. This rapid depletion of melanocytes leaves the hair follicle unable to produce pigment, leading to gray or white hair.

Hormones

Hormonal changes or imbalances, such as those caused by pregnancy, PCOS (Polycystic Ovary Syndrome), thyroid disorders, or menopause, can significantly affect hair health. Hormones play a critical role in regulating the hair growth cycle, and disruptions in hormone levels can lead to changes in hair texture, growth, or loss.

During pregnancy, your hair gets a bit of a beauty boost, thanks to higher levels of Estrogen and Progesterone. Estrogen prolongs the hair's growth phase (anagen), reducing shedding and leading to thicker hair during pregnancy. However, after childbirth, Estrogen levels drop sharply, which often leads to postpartum hair loss. While it can be a shock to see more strands on your brush, don’t worry—this phase is usually temporary, and hair growth normalizes within a year [3].

PCOS is a hormonal disorder characterized by elevated levels of Androgens (male sex hormones like Testosterone, DHT and DHEA). High Androgen levels can affect hair growth in two significant ways:

• Androgenic Alopecia: Excess Androgens can cause thinning hair on the scalp, particularly at the crown and hairline. This pattern of hair loss, known as female-pattern baldness, is often gradual but can be distressing.

• Hirsutism: On the flip side, PCOS can cause excess hair growth in areas where women typically have less hair, such as the face, chest, or back, due to the impact of Androgens stimulating hair follicles in these regions [4].

For a deeper dive into how hormonal conditions, especially PCOS, can impact hair growth, check out PCOS: Beyond The Diagnosis.

Thyroid imbalances are another common cause of dry or thinning hair. The thyroid gland produces hormones that regulate metabolism, energy production, and overall body function. Imbalances in thyroid hormone levels—either too much (hyperthyroidism) or too little (hypothyroidism)—can affect both hair and nail growth and lead to hair changes.

• Hypothyroidism: Low thyroid hormone levels slow down metabolic processes, including hair follicle activity. This can result in diffuse hair thinning all over the scalp, as hair follicles enter the resting phase prematurely. Hair may also become dry, brittle, and thin. In addition to scalp hair loss, hypothyroidism can also cause loss of hair in the outer edges of the eyebrows.

• Hyperthyroidism: In hyperthyroidism, excess thyroid hormones can also lead to hair thinning or shedding. The hair might become fine and fragile, breaking easily [5].

Finally, during menopause, many women experience some noticeable changes in their hair's thickness, color, or texture, thanks to a drop in Estrogen and Progesterone. As these hormones dip, hair tends to take a little snooze, entering the resting phase (telogen) sooner, which means thinning strands and slower growth. Plus, with fewer hormones around to keep the scalp's oil glands in action, things can get a bit dry and coarse up top. Without that extra boost of Estrogen, the scalp produces less oil (sebum), making hair feel less silky and more straw-like.

Diet 

Proper nutrition and adequate caloric intake are crucial for maintaining healthy hair and preventing premature graying. Hair is a rapidly growing tissue, and like any other part of the body, it requires sufficient nutrients to support growth and maintain its structure. Inadequate nutrition or low-calorie intake can weaken hair, slow growth, and accelerate hair loss or graying [6].

Dietary Must-Haves for Healthy Hair

• Adequate Caloric Intake: Hair growth demands a lot of energy, so if your body isn't getting enough calories—perhaps from prolonged dieting or fasting—it will prioritize essential functions like organ repair over hair growth. This can result in thinning, shedding, changes in texture, or slower growth. If you've struggled with extreme yo-yo dieting and noticed your hair looking less vibrant, it might be time to rethink those restrictive habits and give your body the nourishment it needs!

• Protein: Hair is primarily made of a protein called keratin, so an adequate protein intake is essential for maintaining hair strength and growth. Low protein levels can weaken hair, making it more prone to breakage, and may slow the rate of hair growth. Healthy protein choices include pasture-raised meats + eggs, wild-caught seafood, and organic beans + legumes [6].

• Iron: Iron deficiency is one of the most common causes of hair loss, particularly in women. This mighty mineral is your hair’s best friend, as it helps deliver oxygen to those precious hair follicles, sparking healthy growth. Top sources of Iron include grass-fed beef, spinach, oysters, and eggs.

• Biotin: Biotin (Vitamin B7) helps produce keratin, which strengthens hair and promotes growth. A deficiency can cause hair thinning, breakage, and slow growth. Healthy sources include salmon, eggs, sweet potatoes, and avocados.

• Vitamin B12 + Folate (B9): Think of these dynamic duo B-vitamins as your hair's best friends! B12 + Folate support the production of red blood cells, which carry oxygen and nutrients to the scalp and hair follicles. They are also necessary for the production of melanin, which helps keep hair color in tact. Insufficient levels can lead to hair loss, slow regrowth, and premature graying. Choose options such as pasture-raised animal products, organ meats, and leafy greens (like spinach + kale) to up your intake of B12 + Folate.

• Zinc: Zinc supports hair growth and repair by maintaining the function of oil glands around the hair follicles. Without enough zinc, you might find yourself facing hair loss and a dry, flaky scalp—yikes! Load up on tasty sources like oysters, pumpkin seeds, grass-fed beef, and beans to avoid a deficiency.

• Vitamin D: Vitamin D is necessary for the creation of new hair follicles and helps activate hair growth. A deficiency can result in hair thinning or a condition known as alopecia. To optimize Vitamin D status, soak up some sun or increase your intake of wild-caught salmon or egg yolks.

• Vitamin A: Vitamin A supports cell growth, including hair cells, and helps the scalp produce sebum, keeping hair healthy and moisturized. Healthy sources include beef liver, cod liver oil, salmon, sweet potatoes, and carrots.

• Omega-3 Fatty Acids: These essential fats help nourish hair and support scalp health, preventing dry, brittle hair. They also reduce inflammation, which can promote healthier hair follicles. Up your Omega-3 intake with wild-caught fish (think salmon, mackerel, and sardines), or snack on crunchy walnuts and flax seeds.

• Copper: Copper is a mineral essential for melanin production. If you’re running low on copper, you might notice some unwelcome silver strands creeping in early. You can find this under-appreciated mineral in sources including shellfish, liver, and dark chocolate [7].

• Antioxidants (Vitamin C, Vitamin E, Selenium): These nutrients protect hair follicles from oxidative damage, which can deplete melanocytes (the cells responsible for pigment) and lead to graying. To power up your antioxidant arsenal, load up on a rainbow of vegetables, fruits, herbs, and spices.

External Causes of Lackluster Hair 

External factors can also play a significant role in dry, brittle, or thinning hair, often through daily grooming practices and environmental exposures. Some of the most common external causes of lackluster hair include:

• Frequent use of heat styling tools like flat irons, curling wands, and blow dryers can strip hair of its natural moisture, leading to damage and breakage.

• Harsh and / or toxic haircare products containing sulfates, parabens, formaldehyde, phthalates, or alcohols can further dehydrate the hair, weakening the hair shaft over time [8].

• Minerals in hard water, such as calcium and magnesium, can build up on the hair, making it difficult for moisture to penetrate and leaving hair feeling rough and dry.

• Frequent bleaching or dyeing exposes hair to harsh chemicals that strip away its protective outer layer, resulting in weakened strands and increased shedding.

• Overwashing can disrupt the scalp’s natural oil balance, leading to dryness and making the hair more prone to breakage.

How to Identify Health-Related Hair Issues

Identifying health-related hair issues involves looking beyond the symptoms to uncover potential underlying causes. Start by tracking the timeline of when changes in your hair occurred, such as increased shedding, dryness, or thinning, and any lifestyle changes or stressors that might coincide. Evaluate your diet to ensure you're consuming enough calories and essential nutrients, including protein, Iron, Biotin, Omega-3s, and the other aforementioned nutrients that affect hair health. Don’t forget to check in on your scalp—dandruff or seborrheic dermatitis could be clues pointing to inflammation, poor immune function, or a weakened skin barrier. For a more in-depth assessment, consider working with a naturopathic or holistic healthcare provider to test for nutrient levels, thyroid function, Cortisol, and sex hormones (Estrogen, Progesterone, Testosterone, DHEA, and DHT). By addressing these factors, you'll unlock the secrets to your hair health and discover the ideal solutions for restoring your luscious locks to their full glory!

Natural Ways to Improve Hair Health

1. Diet: Focus on a whole-foods based diet rich in protein, Iron, B-Vitamins, and antioxidants. If you restrict any food groups from your diet, be mindful of certain nutrients which you may be more susceptible to lack in. For example, vegans and vegetarians should be mindful of their B12, Iron, protein, Zinc, Vitamin D, and Omega-3 intake. 

2. Supplements: Key supplements like Biotin,Collagen, Vitamin D, Zinc, and Omega-3 Fatty Acids can support hair growth and strength from within. Always speak to a healthcare professional before starting any new supplements, and consider testing nutrient status prior to supplementing.

3. Stress Management: Chronic stress can contribute to hair loss by disrupting hormone balance and pushing hair follicles into a resting phase. Practices like meditation, acupuncture, gentle yoga, grounding, regular exercise, spending time in nature, and prioritizing quality sleep can help reduce stress levels and support hair growth.

4. Use Gentle, Natural Products: Choose hair products that are free from harsh chemicals like sulfates, parabens, phthalates, and synthetic fragrances. Look for natural, plant-based ingredients like aloe vera, coconut oil, and essential oils that nourish and hydrate without stripping away natural oils. Limiting heat styling and chemical treatments can also prevent damage and promote healthier hair over time. Our favorite non-toxic hair care brands are Vegamour + Prose. Rosemary oil, castor oil, and fermented rice water are other natural products that have been shown to stimulate hair growth, add shine, or calm the scalp.

5. Consider a Shower Filter: A shower filter can be highly beneficial for hair health by removing impurities and harsh minerals from the water. Our favorite shower filter is Vitaclean because in addition to removing the bad stuff (chlorine, sediment + heavy metals) it also infuses the good stuff (essential oils + antioxidants) into your water (use code DRLANAWELLNESS for 10% off)

To shop Dr. Lana’s favorite non-toxic haircare must-haves, click here

Final Thoughts

It’s critical to remember your hair is more than just a cosmetic feature; it’s a reflection of your internal health. Whether it's stress, hormonal imbalances, dietary deficiencies, or external factors like harsh products or heat styling, the condition of your hair can reveal important clues about what's happening inside your body. Understanding the root causes behind changes in hair texture, color, or growth can help you take proactive steps to restore balance naturally. By nourishing your body with a healthy diet, managing stress, choosing gentle hair care products, and addressing underlying health concerns, you can support your hair from the inside out and enjoy healthier, stronger, and more vibrant locks. To work with a member of the Dr. Lana Wellness team to uncover the root cause(s) of your hair concerns, visit our website here. Remember, the path to beautiful hair starts with a healthy body!

Want to talk about hair loss or other health concerns?

References

1. Murphrey MB, Agarwal S, Zito PM. Anatomy, Hair. [Updated 2023 Aug 14]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513312/

2. O'Sullivan JDB, Peters EMJ, Amer Y, Atuluru P, Chéret J, Rosenberg AM, Picard M, Paus R. The impact of perceived stress on the hair follicle: Towards solving a psychoneuroendocrine and neuroimmunological puzzle. Front Neuroendocrinol. 2022 Jul;66:101008. doi: 10.1016/j.yfrne.2022.101008. Epub 2022 Jun 2. PMID: 35660551.

3. Hasan, R., Juma, H., Eid, F. A., Alaswad, H. A., Ali, W. M., & Aladraj, F. J. (2022). Effects of Hormones and Endocrine Disorders on Hair Growth. Cureus, 14(12), e32726. https://doi.org/10.7759/cureus.32726

4. Jiang, V. S., Hawkins, S. D., & McMichael, A. (2022). Female pattern hair loss and polycystic ovarian syndrome: more than just hirsutism. Current opinion in endocrinology, diabetes, and obesity, 29(6), 535–540. https://doi.org/10.1097/MED.0000000000000777

5. Hussein, R. S., Atia, T., & Bin Dayel, S. (2023). Impact of Thyroid Dysfunction on Hair Disorders. Cureus, 15(8), e43266. https://doi.org/10.7759/cureus.43266

6. Guo, E. L., & Katta, R. (2017). Diet and hair loss: effects of nutrient deficiency and supplement use. Dermatology practical & conceptual, 7(1), 1–10. https://doi.org/10.5826/dpc.0701a01

7. El-Sheikh, A. M., Elfar, N. N., Mourad, H. A., & Hewedy, E. S. (2018). Relationship between Trace Elements and Premature Hair Graying. International journal of trichology, 10(6), 278–283. https://doi.org/10.4103/ijt.ijt_8_18

8. Chiu, C. H., Huang, S. H., & Wang, H. M. (2015). A Review: Hair Health, Concerns of Shampoo Ingredients and Scalp Nourishing Treatments. Current pharmaceutical biotechnology, 16(12), 1045–1052. https://doi.org/10.2174/1389201016666150817094447