science on hair grwoth rates in warm season

[my2cats1]

Happy Spring, fellow LHCers!

I posted a question on the Beauty Brains forum about hair growth rates in summer, and a couple of people have posted some interesting research articles. If you want to take a look, the links are here (http://www.thebeautybrains.com/vanilla/comments.php?DiscussionID=1363) or just look under Hair Biology in the Ask the Beauty Brains section.

Happy growing!
:cheese:

[pinchbeck]

Back in the cavemen days you would think that hair would grow faster in colder climates to help insulate the body from the harsh elements. I wonder what the benefits of faster hair growth during the warmer months would be?

[walterSCAN]

Back in the cavemen days you would think that hair would grow faster in colder climates to help insulate the body from the harsh elements. I wonder what the benefits of faster hair growth during the warmer months would be?

You know, I've wondered that too...

[Ravenne]

Maybe it's because growing hair takes vital nutrients that the body could otherwise use and store during cold weather. I think hair's one of the last things that the body takes care of... correct me if I'm wrong. So it's one of the first things that it takes from when the environment is less than forgiving. Just my theory.

[frizzalot]

Back in the cavemen days you would think that hair would grow faster in colder climates to help insulate the body from the harsh elements. I wonder what the benefits of faster hair growth during the warmer months would be?

Just a guess, there's no science behind this but....

Hair is supposed to reflect the overall health of a person (diet and excercise), and spring is the 'mating season'....:p

[jackiesjottings]

I buck the trend here as for some reason my hair grows faster in winter, then stalls a bit in summer.

[Snowcold]

Well, if hair would be starting to grow faster in winter it would probably be too late! I can see why mother nature would let it grow faster in summer, so you're all covered up for the winter. ;)

Not sure if it's true, but it makes sense. :p

[FrannyG]

I've never experienced a summer growth spurt. I maintain a pretty steady 3/4 inch per month, whether in December or July. :shrug:

[wendyg]

pinchbeck: shed in spring, grow in summer/fall to be warm in winter would seem logical to me.

wg

[LunarAurora]

But summer growth often leads to autumn shed :?:
Personnaly my hair grows faster in summer but in winter, it is quite thin...

[Masara]

My hair grows fastest in spring and autumn. Autumn seems logical if we're going with the "warmth for winter" theory. But I've never really worked out the spring growth.
It usually slows right down in summer.

[hmmm]

My hair grows faster the hotter it is. See my albums for proof :D.

[Arniky]

its difficult to find out the exact reson for hair growth speed. good diet etc is okay but its more of body chemistry along with care that determines growth

[Jenn of Pence]

I always thought it had something to do with the sun...vitamin D they say. I've never researched it, though.

[spidermom]

I'm pretty sure it's that more hours of daylight = faster growth. The last year I kept measurements, my hair grew fastest May -- October.

[Jenn of Pence]

So does that mean you have to shave your legs more in the summer? ;)

[harpgal]

I'm pretty sure it's that more hours of daylight = faster growth.Bingo!

This has been proven:

http://sbrjournal.net/currentissue/articles/Hair/Hairgrowth.htm

How do I know? I was the lab rat. :D

[pinchbeck]

pinchbeck: shed in spring, grow in summer/fall to be warm in winter would seem logical to me.

wgYes...that does make sense!

[pinchbeck]

Well, if hair would be starting to grow faster in winter it would probably be too late! I can see why mother nature would let it grow faster in summer, so you're all covered up for the winter. ;)

Not sure if it's true, but it makes sense. :pBoth you and wendyg share the same idea and I think you've both got me convinced.:D

[Idun]

Bingo!

This has been proven:

http://sbrjournal.net/currentissue/articles/Hair/Hairgrowth.htm

How do I know? I was the lab rat. :D

I don´t dispute that the results are accurate for you harpgal. Still I wouldn´t exactly call the study of one persons hairgrowth proof though! :hmm:

[Burgundyhair]

I don´t dispute that the results are accurate for you harpgal. Still I wouldn´t exactly call the study of one persons hairgrowth proof though! :hmm:

Idun, scroll down to the references and you'll find other studies done on seasonal hair growth on humans.

[lastnite]

I always thought it had something to do with the sun...vitamin D they say. I've never researched it, though.


I've been recently thinking this too. I've started being more of aware of taking vitamin D and my hair seems to be shedding alot less I also heard somewhere it's because people are more active and more outdoors, moving and getting exercise, getting the blood flowing. In the winter we tend to stay in doors more, less active staying warm, etc...

[natorade]

Back in the cavemen days you would think that hair would grow faster in colder climates to help insulate the body from the harsh elements. I wonder what the benefits of faster hair growth during the warmer months would be?
What happened in cave man days does not necessarily reflect on us now, seeing how we have evolved so much since then. In cave man days hair was probably used for warmth, but now a days we don't need to rely on our hair as a main source for warmth. Just like in cave man days wisdom teeth were important for chewing hard items. One of my teachers told me that soon there will be a day when people won't even be born with wisdom teeth, because humans no longer need them, so as we evolve more and do not use them, we will no longer be born with them.

[Idun]

Idun, scroll down to the references and you'll find other studies done on seasonal hair growth on humans.

I have now gone through the references at the bottom of the page. Although several are very interesting, only two of them says anything about sun or seasonal changes in hair growth (as far as I can see). The first one is a study of sheep. The second, which probably is the only relevant one in this context, we can´t read since there is no link:

*Craven, A. J., et. al., The Effect of Long-day Photoperiod Treatments on Plasma Prolactin and Wool Follicle Activity in New Zealand Wiltshire Sheep, Proceedings of the New Zealand Society of Animal
Production,1994, (54) 135-138. http://nzsap.org.nz/proc/1994/ab94035.txt (http://nzsap.org.nz/proc/1994/ab94035.txt)

* Randall V. A., Ebling, F. J., Seasonal changes in human hair growth, British Journal of Dermatology, 1991, Vol. 124, (2) 146-151.

If you read the conclusion of the paper you will find that the author himself says:
Further study is warranted in two areas.
Firstly, this same subject should reside at a lower latitude (where the photo period is more nearly constant) for a period of time and the hair growth measured to discern whether the seasonal growth rate can be influenced simply by manipulating the photo period. Secondly, this same study should be repeated using a large number of individuals, allowing matching of such factors as hair type, fitness level, diet, age, sex, etc.

To me this paper does not give proof, even if it is interesting. :)

[Anlbe]

What happened in cave man days does not necessarily reflect on us now, seeing how we have evolved so much since then. In cave man days hair was probably used for warmth, but now a days we don't need to rely on our hair as a main source for warmth. Just like in cave man days wisdom teeth were important for chewing hard items. One of my teachers told me that soon there will be a day when people won't even be born with wisdom teeth, because humans no longer need them, so as we evolve more and do not use them, we will no longer be born with them.

We won't loose our wisdom teeth unless there's a reproductive advantage to not having them. At the moment you'd be hard pushed to find any genetic variable which gives a person a better chance of surviving and reproducing in our 'civilised' environment.

The point of hair on our the top of our head is to stop the part of our body that gets the most exposure to the sun from burning and to keep it cool. Due to the size of our brains and our posture our heads are at high risk of overheating which can lead to serious malfunctions. Ask anyone whose bald, overheating is a serious issue.

The thing I find surprising with hair isn't that we've kept it where we have, but that most of us got rid of it everywhere else.

p.s. I don't get a summer spurt which I always assumed was because I wear hats the whole time. I also think this is partially responsible for my slow growth rate.

[julliams]

We are probably talking about a very minimal difference per month here. If hair grew more in warmer months it would stand to reason that people who lived in warmer climates' hair would grow more per year. Since hair is reported to be 1/2 an inch per month internationally, I would think that climate plays little part in it. Having said that, my growth rate has only been measured since November which is summer here so I'll see how I go in the winter and see if that makes any difference.

[julliams]

Could it simply be related to exercise??? If we are more active during the summer, perhaps that leads to better circulation and thus slightly faster hair growth. In the winter we are more likely to snuggle up indoors (which incidently would be heated anyway).

For those who visit gyms year round, an increase in hair growth in either summer or winter may not be noticeable because their activity is the same.

What do you think?

[Idun]

Could it simply be related to exercise??? If we are more active during the summer, perhaps that leads to better circulation and thus slightly faster hair growth. In the winter we are more likely to snuggle up indoors (which incidently would be heated anyway).

For those who visit gyms year round, an increase in hair growth in either summer or winter may not be noticeable because their activity is the same.

What do you think?

I imagine exercise have a positive effect on the health of your hair in the same way it has on your general health. - In the respect that you with exercise optimize your bodily functions (heart rate, bloodflow, colesterol levels, hormone levels, oxygenlevels in blood, etc.), and therefore also optimize the basis for great hair growth. Personally I think the effect will be seen best by long term healthy living and not so much by seasonal efforts.

[Toadstool]

My hair and nails have always grown faster in the Summer. I always thought it was Vitamin D in sunlight.

[my2cats1]

I have assumed faster growth in summer was the result of more exercise and humidity increasing cirrculation to the scalp, and also more seasonal fruits and veggies in our diets resulting in better overall nutrution. Perhaps the Vitamin D effect, too.

I've been eager to see some research on it, but apparently the lack of studies suggests that the Scientific Community does not regard this as a priority. Imagine that! :p

I was really hoping The Beauty Brains would be interested in the question, but they just didn't bite. :confused:

[ccmuffingirl]

These are some very valid points, ladies. I've always heard rumors that hair grows faster in hotter months than in colder months. But the question I pose is: What about those who live in or move to tropical climates? I live in south florida, and on average the temperature variation is 70-90 degrees, with a lot of humidity (We do get intermittent cold fronts in winter, but no true winters). Most of time the temp is in the late 70's to mid 80's realm. Does this mean that the growth rate will become similar to that of summer, or does something in us "know" when winter is technically supposed to be, regardless of the actual temperature. And I guess a similar question could be posed for those who live in colder climates.

Long story short, my question is: "Is it the actual temperature that affects hair growth or the season? Or is it both?"