Why is my hair thinning?
Hair loss is an extremely common concern I see in clinic and can be very distressing for those experiencing it. If this is you, please know you are not alone and there is usually a lot that can be done to address it.
Whilst it’s perfectly normal to lose several strands of hair from your scalp daily, which you may notice when in the shower or when brushing, if you are losing a substantial amount of hair, you may well want to do something about it.
For women, hair loss can carry a unique emotional weight and feel incredibly upsetting. Hair forms a unique part of a person’s identity, but for women, emotions can be intensified due to social expectations surrounding hair and femininity. Having experienced a significant degree of hair thinning in my twenties following a period of emotional, physical and nutritional stress, I really understand how powerless and out of control hair loss can make you feel.
This article addresses some of the most common causes of hair loss and what can be done to address it when the cause has a nutritional or hormonal component, as it frequently can.
Introduction
Hair loss, or alopecia, affects one-third of women at some point in their lives and as many as two-thirds of women post menopause (1). Hair growth occurs in a cycle of four stages: the anagen (growth) stage, catagen (transition) phase, telogen (resting) phase and exogen (shedding) phase. Not all hair is in the same stage of the cycle at any one point. Understanding these stages can help identify the type of hair loss, which can inform the approach to treatment.
What are some of the most common types of hair loss?
Androgenetic alopecia is a genetic disorder characterised by a progressive loss of hair from the scalp any time after puberty. Commonly referred to as male or female pattern hair loss, hair thins dramatically around the parting line, at the front and/or top of the scalp. Although there is currently no known cure for this, there are ways to slow and mildly reverse this loss.
Telogen effluvium occurs when hair prematurely bypasses the anagen (growth) phase into the telogen (resting) stage leading to excessive shedding of the hair as the hair growth cycle progresses. There is diffuse shedding (from all over the head) with no specific pattern. This is the most common cause of hair loss I see in clinic. It is typically caused by stress, nutrition, hormones or other biochemical changes within the body.
Alopecia Areata is an autoimmune condition that causes damage to hair follicles preventing new hair from growing. It causes hair to fall out from all parts of the body, often including eyebrows and eyelashes. It can come and go, and the extent of hair loss differs between individuals (2).
Trichotillomania is a hair pulling disorder and mental health condition. It involves frequent, repeated urges to pull hair out of the scalp.
What are the main causes of female hair loss?
Hair loss can have multiple underlying causes, with age and genetics being primary factors. Infections, certain medical treatments and medications can also play a role. There are also several factors over which we may have more influence. Of these, the three most common causes in women are stress, hormones and diet.
Stress
Hair follicles are the body’s second-fastest dividing cells. This makes them especially vulnerable to stress and lifestyle changes that can disrupt their natural growth cycle. The stress associated with severe illness, surgery or infection causes the body to prioritise its energy for major organs or repair. This causes hair follicles to enter the resting phase prematurely, and new hair temporarily ceases to grow.
Similarly, sleep deprivation, chronic psychological stress or physiological events such as pregnancy can also trigger hair in the anagen (growth) phase to transition to an extended telogen (resting) phase, halting or interrupting the hair growth cycle. High cortisol (our main stress hormone) can also trigger an excess of pro-inflammatory cytokines, which can prevent hair growth.
In telogen effluvium, addressing the source of stress by (for example) improving sleep, reducing emotional stress or recovering from illness usually allows normal hair growth to resume within 6-9 months.
Hormonal Changes
Hormonal changes within the body also contribute to hair loss. A decline in oestrogen post-partum, around the menopause, due to functional hypothalamic amenorrhoea (FHA) or the discontinuation of oestrogen-containing medication, can all temporarily disrupt the hair growth cycle leading to more hair entering the exogen (shedding) phase and less hair growth (3).
It is worth nothing that the cause of hair loss in those with functional hypothalamic amenorrhoea is usually multifactorial, resulting from a combination of reduced growth factors, reproductive and other hormones, high stress hormones, as well as energy and nutritional deficiencies (see below).
Around 20% to 30% of females with polycystic ovary syndrome (PCOS) also experience some form of hair loss, potentially due to an excess of male sex hormones, such as testosterone, coupled with increased 5-alpha reductase activity (4). Since thyroid hormones control the growth, differentiation, metabolism and thermogenesis of body cells, both hyperthyroidism and hypothyroidism can also induce widespread hair shedding (5).
Understanding your unique hormonal situation, alongside the potential drivers of that condition, can go a long way to helping us ascertain the best approach to help you recover your hair health.
If you’d like information on how I can help you with the above, please get in touch or feel free to book a call with me.
Diet and Nutrition
Several diet-related or nutritional imbalances can also lead to hair loss. Below, I’ve outlined some of the most common nutritional culprits.
Total Energy Intake: Hair cells are very energy demanding. This means they require a lot of energy to go through their normal growth cycle. When the energy (calories) we consume from food and drink is not enough to match the demands of our life, especially over a substantial amount of time, the body will prioritise essential functions, causing hair growth to pause. Avoiding crash diets and simply allowing sufficient energy intake daily to support your body, can go a long way to helping you recover your locks.
Protein Intake: Hair is primarily composed of a strong, fibrous protein called keratin. Adequate protein intake in the diet is therefore crucial for hair structure and growth, preventing fine and brittle hair (6). Whilst most people in the UK get enough protein, this is not always the case for my clients. The official RNI for protein is 0.75g per kilogram of body weight per day for adults, or an average of 45g for women. However, this value can increase to 1.2-1.6g per kg for those with higher activity levels, potentially higher still for athletes or elderly individuals. Protein is best split up across multiple meals during the day. For optimal hair health, try to include plenty of good-quality proteins, particularly those containing methionine, found in eggs, meat, fish, Greek yoghurt, tofu, hemp and pumpkin seeds.
Iron: Iron is crucial for cell division and hair growth, whilst deficiency has been linked to telogen effluvium (7). Good sources of iron include liver, beef, lamb, mussels, spinach, soya beans, lentils and fortified grain products. Consuming plant sources of iron with foods rich in vitamin C, such as citrus fruits, blackcurrants, strawberries, kiwis, bell peppers, fresh tomatoes and broccoli can increase iron absorption from these foods.
Zinc: Zinc also plays a role in the hair growth cycle. Low levels can increase hair loss by influencing the shedding (catagen) phase (7, 8). Zinc is found in a huge variety of animal and plant foods, although tends to be better absorbed from animal or fish sources. The foods highest in zinc include oysters, beef, crab, lobster, pumpkin seeds, legumes, and other nuts and seeds.
Selenium: Another trace mineral important for hair health is selenium with deficiencies linked to hair loss (8). Selenium is most concentrated in seafood, organ meats and Brazil nuts. It is best to limit intake of Brazil nuts to no more than 3 per day to prevent potential selenium toxicity.
Vitamin D: Vitamin D supports cell division and helps to regulate hormones related to hair growth. Deficiencies may shorten the growth (anagen) phase, affecting hair thickness and resilience. Between October and March in the UK, a supplement of 400IU per day of Vitamin D is recommended to prevent deficiency. Your exact dosage will depend on factors including your current blood level, age, skin colour and body weight. Many of the women I see in clinic require more than 400IU per day.
Biotin: anecdotally known as the hair and nail supplement, there is currently limited scientific evidence supporting the efficacy of biotin for hair loss in healthy individuals, although correcting a biotin deficiency may help restore hair growth in some people (6).
Other micronutrients can also play a role in hair health and loss. For example, every single cell in the body requires vitamin A for growth, including hair cells. However, excessive intake of vitamin A, along with selenium, can lead to hair loss, so it's important to maintain a balanced diet and avoid over-supplementing.
If you are worried about your hair and think your diet could play a role, I do recommend seeking professional support, alongside appropriate laboratory testing, to help identify any overt micronutrient deficiencies. This is particularly important before commencing iron supplements.
If you’d like information on how I can help you with the above, please get in touch or feel free to book a call with me. I’d love to help you.
Management of hair loss – where do I start?
Hopefully, this article has already provided some insights to help you on your way to better hair health. The following section provides a quick summary plus some additional lifestyle and supplement considerations.
Medical management of hair loss often includes pharmacological options like antiandrogens and minoxidil, which can slow or reverse certain types of hair loss.
For conditions like telogen effluvium, which is typically self-limiting, hair growth often resumes naturally once the underlying cause is addressed and treated. If the cause of your hair loss is likely to be stress and/or hormone-related, it’s worthwhile considering the factors at play here. If you’re feeling a little lost in this respect, feel free to get in touch to see how I might be able to help.
When it comes to your diet, ensuring adequate energy and protein intake are key. Consuming an energy replete, balanced and varied diet can go a long way to addressing deficiencies in specific nutrients. However, if you have an overt micronutrient deficiency you may need to supplement temporarily to address this. Speak to your GP or get in touch if you need more support.
Additional lifestyle considerations
· Use gentle hair products and avoid overtreating your hair with harsh chemicals (e.g. sulfates, parabens) and heating tools.
· Focus on stress reduction through mindfulness, journaling or breathwork.
· Improve your sleep quality - see our blog on sleep for more insights
· If you have (or suspect you have) functional hypothalamic amenorrhea, consider getting in touch if you need more support
· Avoid smoking and excessive alcohol
What about herbal supplements? Do they work?
Ginseng – is an ancient herbal medicine suggested to support hair growth. Whilst there is currently no substantiated evidence supporting claims, preliminary research suggests an improvement in hair density and thickness in patients with alopecia (9).
Saw Palmetto – similarly, this botanical extract is thought to possess antiandrogenic properties. Although higher quality studies are needed to assess its effectiveness, a systematic review found improvement in hair quality, total hair count and increased hair density in those with telogen effluvium and androgenic alopecia (10).
What about hair tissue mineral analysis (HTMA)?
Hair Tissue Mineral Analysis (HTMA) is a non-invasive test that measures nutrient and toxin levels in hair. Its reliability is questionable due to variations in laboratory standards, hair growth cycles, and potential interference from hair treatments. It is also worth bearing in mind that hair mineral levels might not accurately reflect mineral levels in other body tissues or organs. Given these limitations, it may not be a worthwhile investment. However, there are certainly other laboratory tests that may be useful to you when seeking to address the cause of your hair loss.
Conclusion
Ultimately, while hair loss is common, it is often treatable depending on the underlying cause. Understanding the root cause of your hair loss (no pun intended) is key to selecting the right treatment and fostering healthy hair growth.
REFERENCES
1. Fabbrocini G, Cantelli M, Masarà A, Annunziata MC, Marasca C, Cacciapuoti S. Female pattern hair loss: A clinical, pathophysiologic, and therapeutic review. Int J Women’s Dermatol. 2018; 4(4):203-211. Available from: https://pubmed.ncbi.nlm.nih.gov/30627618/ doi: 10.1016/j.ijwd.2018.05.001
2. Lepe K, Syed HA, Zito PM. Alopecia Areata. In: StatPearls. Treasure Island (FL): StatPearls Publishing; February 8, 2024. Available from: https://pubmed.ncbi.nlm.nih.gov/30725685/
3. Grymowicz M, Rudnicka E, Podfigurna A, et al. Hormonal Effects on Hair Follicles. Int J Mol Sci. 2020;21(15):5342. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7432488/ doi:10.3390/ijms21155342
4. Carmina E, Azziz R, Bergfeld W, et al. Female Pattern Hair Loss and Androgen Excess: A Report From The Multidisciplinary Androgen Excess and PCOS Committee. J Clin Endocrinol Metab. 2019;104(7):2875-2891. Available from: https://pubmed.ncbi.nlm.nih.gov/30785992/ doi:10.1210/jc.2018-02548
5. Hussein RS, Atia T, Bin Dayel S. Impact of Thyroid Dysfunction on Hair Disorders. Cureus. 2023;15(8):e43266. Available from https://pmc.ncbi.nlm.nih.gov/articles/PMC10492440/ doi:10.7759/cureus.43266
6. O'Connor K, Goldberg LJ. Nutrition and hair. Clin Dermatol. 2021;39(5):809-818. Available from: https://pubmed.ncbi.nlm.nih.gov/34785008/ doi:10.1016/j.clindermatol.2021.05.008
7. Hodeib AAH, El-Hamd N, Yomna MM, Ahmed MH, Sabry DRA. Role of iron in telogen effluvium among premenopausal women. Egyptian Journal of Dermatology and Venereology. 37(2):56-61. Available from: doi: 10.4103/ejdv.ejdv_64_16
8. Kil MS, Kim CW, Kim SS. Analysis of serum zinc and copper concentrations in hair loss. Ann Dermatol. 2013;25(4):405-409. Available from: https://pubmed.ncbi.nlm.nih.gov/24371385/ doi:10.5021/ad.2013.25.4.405
9. Choi BY. Hair-Growth Potential of Ginseng and Its Major Metabolites: A Review on Its Molecular Mechanisms. Int J Mol Sci. 2018;19(9):2703. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC6163201/ doi:10.3390/ijms19092703
10. Evron E, Juhasz M, Babadjouni A, Mesinkovska NA. Natural Hair Supplement: Friend or Foe? Saw Palmetto, a Systematic Review in Alopecia. Skin Appendage Disord. 2020;6(6):329-337. Available from: https://pmc.ncbi.nlm.nih.gov/articles/PMC7706486/ doi:10.1159/000509905
This article was researched with the help of Noor Wadi, MSc GHP & HCPC Registered Diabetes Dietitian, and wonderful intern at Holly Dunn Nutrition.
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