To understand the ins and outs of hair loss, we're taking a deep dive into all the vital aspects of hair health. From environmental factors that contribute to thinning hair, to the hair lifecycle, and the importance of scalp health, discover expert tips on how to demystify the most common hair loss concerns on why our locks sometimes bid adieu. So join us as we take it from the top, starting with the scalp.
Aveda's principal pharmacologist and research scientist, Alison Pawlus, Ph. D., explains how thriving hair starts at the scalp.
WHAT IS THE SCALP AND WHY DOES IT MATTER?
The scalp is essential for healthy-looking hair. Scalp skin, like the rest of the skin, contributes to the barrier between the external environment and the rest of the body. Just as a plant needs healthy, well-balanced soil for optimal health, our hair also needs a nourishing environment. The scalp and hair have an interdependent relationship, with the scalp skin providing support to the hair, and the hair providing protection to the scalp.
WHAT IS THE STRUCTURE OF THE SCALP AND ROLE OF THE FOLLICLES?
The scalp supports the hair follicles that produce hair or the hair shaft. The majority of the hair follicle consists of keratin proteins along with cellular lipids that are integrated into nascent hair to give structure and elasticity. In other words, the changes that we see in our hair with age such as thinning, graying, and changes in luster, are all due to biological changes that take place in the scalp and hair follicle.
HOW DOES OXIDATION IMPACT FOLLICLES’ HEALTH?
Since our scalp is skin, it's important to protect it like we do on our face or bodies. In fact, Alison tells us since our scalp is often uncovered and exposed to the sun’s UV rays and other environmental aggressors (such as pollution and micro-dust), it’s vital to clean and protect it for overall health and hygiene.
Both intrinsic and extrinsic factors can contribute to oxidative stress, an imbalance between free radicals and antioxidants in the body, which can lead to unhealthy follicles – which can lead to premature thinning and hair loss.
HOW OXIDATION DURING SUN EXPOSURE AFFECTS HAIR LOSS
“Repeated stress can change the hair cycle dynamics, shortening the cycle. Oxidative stress has also been associated with damage to the nascent fiber as it emerges from the follicle. This can be added to by oxidized lipids and environmental aggressors.”
– Gillian Westgate, PhD, University of Bradford
“It’s very important to keep scalp skin well nourished and clean, because if you get buildup on your scalp, then that can lead to stress.”
– Professor Julie Thornton, Director of the Center for Skin Sciences at the University of Bradford
WHAT HAPPENS TO OUR STRANDS OVER TIME?
The lifecycle of hair is comprised of three phases:
1. Anagen: A highly metabolically active growth phase that typically lasts years.
2. Catagen: A transitional phase where growth stops.
3. Telogen: Once considered the resting phase, scientists are now understanding telogen to be a critical stage in the hair follicle cycle. During telogen, hair follicle cells prepare for and initiate the start of a new hair cycle.
HOW DOES FOLLICLES’ HEALTH IMPACT THE HAIR CYCLE?
When the follicle is unhealthy, the anagen (hair growth) phase can become shorter and the telogen (resting) phase can become longer. So, it is important to protect the follicles to help support a healthy hair lifecycle.
WHAT’S THE DIFFERENCE BETWEEN THIN OR FINE HAIR VS. THINNING HAIR?
Fine hair: This term defines your hair’s texture and strand diameter or thickness. Hair textures can be fine, medium, or thick.
Thin hair: Describes the density and amount of individual hair follicles you have, no matter the diameter and thickness of each strand. You can have fine hair with high density, and your hair may still lack volume simply because your hair texture is fine and delicate.
Thinning hair: Hair shedding or loss affects all genders, more than some might realize. In fact, more than 50% of women1 will experience a noticeable loss of hair versus 70% of men2 at some point in their lives.
THINNING HAIR CAN BE CAUSED BY A VARIETY OF FACTORS
Natural hair shedding: Each hair strand is in one of three growth phases at any time and eventually sheds from the follicle. Dr. Jodi LoGerfo, Doctor of Nursing Practice, Dermatology at Orentreich Medical Group, says, “It’s completely normal to lose 50-100, even 150 hairs a day, but it all depends on how much hair you have to begin with.” Hair shedding is part of the normal renewal process of the body, but excessive hair loss will result in hair thinning.
Stress: Dr. Jodi explains that many individuals face an intensified amount of hair shedding following episodes of acute stress. When we’re under stress, the levels of the stress hormone cortisol in the body increase, which can interrupt the growth of the hair follicle. Find healthy ways to deal with the stress in your life.
Nutrition: “Your hair follicles have high cell turnover and a very vigorous metabolism, so they need nutrients to sustain their growth,” says Dr. Jodi. Any excessive caloric or nutritional deficiency can cause structural defects in the hair follicle and hair loss. The key is eating a balanced, healthy diet with protein, fatty acids, vitamins, and minerals.
Illness: Those who have had a change in health status may also experience an imbalance in their hair growth cycle, resulting in increased shedding. This type of loss is called telogen effluvium and can last 4-6 months after an illness. “With this type of hair loss, it’s not permanent and never results in complete baldness,” says Dr. Jodi.
Tight hairstyles: How you style your hair can cause excess hair shedding and hair loss. Dr. Jodi points out that very tight ponytails, braids, and even hair extensions can damage the hair follicle and lead to hair thinning. This type of hair loss is called traction alopecia and results from persistent pulling and weight on the hair follicles.
Brushing and styling: Along with tight hairstyles, how you brush, style and dry hair can lead to breakage and hair shedding. “Combing wet hair can extend already thin hair to its breaking point,” says Dr. Jodi. Having a gentle approach and using products that strengthen fragile or thinning hair are key in reducing hair shedding due to styling.
WHAT IS THE HAIR LIFE CYCLE WHEN YOU ARE PREGNANT?
The hair life cycle during pregnancy is the same as before pregnancy. However, due to the extremely high levels of hormones in the bloodstream during pregnancy, the duration of the anagen growth phase is prolonged. This means that hair sheds less during pregnancy.
WHY DO WOMEN EXPERIENCE HAIR LOSS AFTER GIVING BIRTH?
Women experience hair loss after birth because hormone levels immediately plummet when the pregnancy is completed. Many of the hair follicles have been synchronized in the anagen growth phase during pregnancy due to the increased hormones and these anagen follicles are sent into the catagen transitional phase and then into the telogen resting phase all at the same time. This leads to hair loss most commonly seen 3-9 months postpartum.
1Cleveland Clinic, Hair loss in women.
2Cleveland Clinic, Why Do Men Go Bald? And Is There Anything You Can Really Do About It?
