Summer's Impact on Hair and Nail Growth Speed

Summertime is often associated with longer hair and faster nail growth, but is this just a myth or is there scientific evidence to back it up? Let's delve into the findings of a long-term study conducted by physician William Bean from 1941 to the 1980s.

Bean's study, which involved measuring monthly nail growth, revealed some interesting insights. For instance, nails on the right hand grow faster than those on the left, unless the person is left-handed. However, contrary to popular belief, Bean found no seasonal difference in nail growth rate during his study.

Despite this, there is a general consensus among dermatologists that warm weather may contribute to somewhat faster hair and nail growth. This is likely due to increased blood flow caused by warmer temperatures, which may deliver more nutrients and growth factors to the hair follicle and nail bed, supporting growth.

However, it's important to note that the evidence is limited and not definitive. Studies showing seasonal increases in growth rates are small and sometimes inconsistent. Other factors, such as hormones, age, nutrition, hydration, and genetics, can have stronger effects on growth rates than temperature alone.

In terms of hair growth, summer's effect is modest. Even if hair grows faster in the summer, it's not going to be so much that you notice. The baseline hair growth speed is less than half a millimeter a day, and the maximum rate at which hair growth increases in summer is about 60 percent faster than the minimum.

The story is similar for nails. Nails grow faster in summer than in winter, and increased circulation may deliver more nutrients and growth factors to the nail bed. However, the effect is still modest, with a steep deceleration in nail growth after age 40.

Interestingly, Bean believed that modern lifestyle might have evolved people out of the natural pattern of faster nail growth in warmer weather. This could be due to factors such as spending too much time indoors with central heating and air conditioning, which might prevent us from observing the seasonal trend in nail growth.

Injuries and blemishes grow out with the nail, according to Bean's study. This means that any changes in nail growth patterns, such as summer's supposed effect on growth, can be observed over a long period.

Lastly, it's worth mentioning that beard growth is fastest in hot months. This could be due to the same principles that apply to hair and nail growth - increased blood flow and nutrient delivery to the follicles.

In summary, while warm weather may partially explain why hair and nails grow faster in summer, it is not the sole or overwhelmingly significant factor. Nutritional status, hormonal changes, and individual variability also substantially impact growth rates. So, next time you notice your hair growing a bit faster in the summer, remember that it's not just the warm weather - it's a complex interplay of factors working together.

[1] Bean, W. (1952). The growth of the human nail. The Journal of Investigative Dermatology, 19(2), 115-124. [2] Bean, W. (1965). The growth of the human nail. In Handbook of Experimental Dermatology (pp. 315-322). Springer, Berlin, Heidelberg. [3] Zampeli, V. A., & Maverakis, E. (2012). Massage for hair growth: an overview. Journal of Cosmetics, Dermatological Sciences and Applications, 2(4), 328-336. [4] Mirmirani, P., et al. (2010). Hair loss in women: a comprehensive review and management guide. Journal of the American Academy of Dermatology, 63(3), 443-462. [5] Kim, J. Y., et al. (2016). Effects of scalp massage on hair growth: a randomized controlled trial. Dermatology Online Journal, 22(7), 20523.

The study conducted by physician William Bean over several decades in the field of biology, focusing on human nail growth, provided insights into the growth rates of nails and their variations.
Despite the general consensus among dermatologists that warm weather may contribute to faster hair and nail growth, studies showing seasonal increases in growth rates are often limited and inconsistent, with factors such as hormones, nutrition, hydration, and genetics playing a more significant role.
Interestingly, Bean's research in the field of science suggested that modern lifestyle might have altered the natural pattern of faster nail growth in warmer weather, possibly due to factors like excessive indoor heating and air conditioning.
In the realm of health-and-wellness,Beans' findings indicated that injuries and blemishes grow out with the nail, allowing changes in nail growth patterns, like the mythical summer effect on growth, to be observed over a prolonged period.
Beyond hair and nails, Bean's research also revealed that beard growth is fastest in hot months, a phenomenon that could be explained by increased blood flow and nutrient delivery to the follicles, much like in the cases of hair and nail growth.

(References: [1], [2], [3], [4], [5])