From straight to curly, thick to thin: here’s how hormones and chemotherapy can change your hair
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Head hair comes in many colours, shapes and sizes, and hairstyles are often an expression of personal style or cultural identity.
Many different genes determine our hair texture, thickness and colour. But some people’s hair changes around the time of puberty, pregnancy or after chemotherapy.
So, what can cause hair to become curlier, thicker, thinner or grey?
Curly or straight? How hair follicle shape plays a role
Hair is made of keratin, a strong and insoluble protein. Each hair strand grows from its own hair follicle that extends deep into the skin.
Curly hair forms due to asymmetry of both the hair follicle and the keratin in the hair.
Follicles that produce curly hair are asymmetrical and curved and lie at an angle to the surface of the skin. This kinks the hair as it first grows.
The asymmetry of the hair follicle also causes the keratin to bunch up on one side of the hair strand. This pulls parts of the hair strand closer together into a curl, which maintains the curl as the hair continues to grow.
Follicles that are symmetrical, round and perpendicular to the skin surface produce straight hair.
Life changes, hair changes
Our hair undergoes repeated cycles throughout life, with different stages of growth and loss.
Each hair follicle contains stem cells, which multiply and grow into a hair strand.
Head hairs spend most of their time in the growth phase, which can last for several years. This is why head hair can grow so long.
Let’s look at the life of a single hair strand. After the growth phase is a transitional phase of about two weeks, where the hair strand stops growing. This is followed by a resting phase where the hair remains in the follicle for a few months before it naturally falls out.
The hair follicle remains in the skin and the stems cells grow a new hair to repeat the cycle.
Each hair on the scalp is replaced every three to five years.
Hormone changes during and after pregnancy alter the usual hair cycle
Many women notice their hair is thicker during pregnancy.
During pregnancy, high levels of oestrogen, progesterone and prolactin prolong the resting phase of the hair cycle. This means the hair stays in the hair follicle for longer, with less hair loss.
A drop in hormones a few months after delivery causes increased hair loss. This is due to all the hairs that remained in the resting phase during pregnancy falling out in a fairly synchronised way.
Hair can change around puberty, pregnancy or after chemotherapy
This is related to the genetics of hair shape, which is an example of incomplete dominance.
Incomplete dominance is when there is a middle version of a trait. For hair, we have curly hair and straight hair genes. But when someone has one curly hair gene and one straight hair gene, they can have wavy hair.
Hormonal changes that occur around puberty and pregnancy can affect the function of genes. This can cause the curly hair gene of someone with wavy hair to become more active. This can change their hair from wavy to curly.
Researchers have identified that activating specific genes can change hair in pigs from straight to curly.
Chemotherapy has very visible effects on hair. Chemotherapy kills rapidly dividing cells, including hair follicles, which causes hair loss. Chemotherapy can also have genetic effects that influence hair follicle shape. This can cause hair to regrow with a different shape for the first few cycles of hair regrowth.
Hormonal changes as we age also affect our hair
Throughout life, thyroid hormones are essential for production of keratin. Low levels of thyroid hormones can cause dry and brittle hair.
Oestrogen and androgens also regulate hair growth and loss, particularly as we age.
Balding in males is due to higher levels of androgens. In particular, high dihydrotestosterone (sometimes shortened to DHT), which is produced in the body from testosterone, has a role in male pattern baldness.
Some women experience female pattern hair loss. This is caused by a combination of genetic factors plus lower levels of oestrogen and higher androgens after menopause. The hair follicles become smaller and smaller until they no longer produce hairs.
Reduced function of the cells that produce melanin (the pigment that gives our hair colour) is what causes greying.
Theresa Larkin, Associate professor of Medical Sciences, University of Wollongong
This article is republished from The Conversation under a Creative Commons license. Read the original article.
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Women’s Strength Training Anatomy – by Frédéric Delavier
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Fitness guides for women tend to differ from fitness guides for men, in the wrong ways:
“Do some squats and jumping jacks, and here’s a exercise for your abs; you too can look like our model here”
In those other books we are left wonder: where’s the underlying information? Where are the explanations that aren’t condescending? Where, dare we ask, is the understanding that a woman might ever lift something heavier than a baby?
Delavier, in contrast, delivers. With 130 pages of detailed anatomical diagrams for all kinds of exercises to genuinely craft your body the way you want it for you. Bigger here, smaller there, functional strength, you decide.
And rest assured: no, you won’t end up looking like Arnold Schwarzenegger unless you not only eat like him, but also have his genes (and possibly his, uh, “supplement” regime).
What you will get though, is a deep understanding of how to tailor your exercise routine to actually deliver the personalized and specific results that you want.
Pick Up Today’s Book on Amazon!
Not looking for a feminine figure? You may like the same author’s book for men:
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Treat Your Own Knee – by Robin McKenzie
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First, a note about the author: he’s a physiotherapist and not a doctor, but with 40 years of practice to his name and 33 letters after his name (CNZM OBE FCSP (Hon) FNZSP (Hon) Dip MDT Dip MT), he seems to know his stuff.
The book covers recognizing the difference between arthritis, degeneration, or normal wear and tear, before narrowing down what your actual problem is and what can be done about it.
While there are many possible causes of knee pain (and by causes, we mean the first-level cause, such as “bad posture” or “old sports injury” or “inflammatory diet” or “repetitive strain” etc, not second-level causes that are also symptoms, like inflammation), McKenzie’s approach involves customizing his system to your body’s specific problems and needs. That’s what most of the book is about.
The style is direct and to-the-point; there’s no sensationalization here nor a feel of being sold anything. There’s lots of science scattered throughout, but all with the intent of enabling the reader to understand what’s going on with the problems, processes, and solutions, and why/how the things that work, work. Where there are exercises offered they are clearly-described and well-illustrated.
Bottom line: this is not a fancy book but it is an effective one. If you have knee pain, this is a very worthwhile one to read.
Click here to check out Treat Your Own Knee, and treat your own knee!
PS: if you have musculoskeletal problems elsewhere in your body, you might want to check out the rest of his body parts series (back, hip, neck, wrist, ankle, etc) for the one that’s tailored to your specific problem.
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Algorithms to Live By – by Brian Christian and Tom Griffiths
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As humans, we subconsciously use heuristics a lot to make many complex decisions based on “fuzzy logic”. For example:
Do we buy the cheap shoes that may last us a season, or the much more expensive ones that will last us for years? We’ll—without necessarily giving it much conscious thought—quickly weigh up:
- How much do we like each prospective pair of shoes?
- What else might we need to spend money on now/soon?
- How much money do we have right now?
- How much money do we expect to have in the future?
- Considering our lifestyle, how important is it to have good quality shoes?
How well we perform this rapid calculation may vary wildly, depending on many factors ranging from the quality of the advertising to how long ago we last ate.
And if we make the wrong decision, later we may have buyer’s (or non-buyer’s!) remorse. So, how can we do better?
Authors Brain Christian and Tom Griffiths have a manual for us!
This book covers many “kinds” of decision we often have to make in life, and how to optimize those decisions with the power of mathematics and computer science.
The problems (and solutions) run the gamut of…
- Optimal stopping (when to say “alright, that’s good enough”)
- Overcoming cognitive biases
- Scheduling quandaries
- Bayes’ Theorem
- Game Theory
- And when it’s more efficient to just leave things to chance!
…and many more (12 main areas of decision-making are covered).
For all it draws heavily from mathematics and computer science, the writing style is very easy-reading. It’s a “curl up in the armchair and read for pleasure” book, no matter how weighty and practical its content.
Bottom line: if you improve your ability to make the right decisions even marginally, this book will have been worth your while in the long run!
Order your copy of “Algorithms To Live By” from Amazon today!
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Asparagus vs Eggplant – Which is Healthier?
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Our Verdict
When comparing asparagus to eggplant, we picked the asparagus.
Why?
In terms of macros, they’re very similar. Technically asparagus has twice the protein, but it’s at 2.2g/100g compared to eggplant’s 0.98g/100g, so it’s not too meaningful. They’re both mostly water, low in carbs, with a little fiber, and negligible fat (though eggplant technically has more fat, but again, these numbers are miniscule). For practical purposes, the two vegetables are even in this category, or if you really want decisive answers, a tiny margin of a win for asparagus.
In the category of vitamins, asparagus is much higher in vitamins A, B1, B2, B3, B5, B6, B9, E, & K, as well as choline. Eggplant is not higher in any vitamins. A clear win for asparagus.
When it comes to minerals, asparagus is much higher in calcium, copper, iron, phosphorus, selenium, and zinc, while eggplant is a little higher in manganese. Another easy win for asparagus.
Lastly, asparagus wins on polyphenols too, with its high quercetin content. Eggplant does contain some polyphenols, but in such tiny amounts that even added up they’re less than 7% of what asparagus has to offer in quercetin alone.
Obviously, enjoy both, though! Diversity is healthy.
Want to learn more?
You might like to read:
Fight Inflammation & Protect Your Brain, With Quercetin
Take care!
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Do You Have A Personalized Health Plan? (Here’s How)
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“Good health” is quite a broad umbrella, and while we all have a general idea of what “healthy” looks like, it’s easy to focus on some areas and overlook others.
Of course, how much one does this will still depend on one’s level of interest in health, which can change over the course of life, and (barring serious midlife health-related curveballs such as a cancer diagnosis or something) often looks like an inverse bell curve:
- As small kids, we probably barely thought about health
- As teenagers, we probably had a narrow view of health (often related to whatever is considered sexually attractive at the time)
- In our 20s, may have a bit of a health kick in which we learn and apply a lot… Which often then gets to later take a bit of a back seat to work responsibilities and so forth
- This is commonly followed by a few decades of just trying to make it to Friday by any means necessary (definite risk factor for substance abuse of various kinds), double if we have kids, triple if we have work, kids, and are also solely responsible for managing the household.
- Then just as suddenly as it is predictably, we are ambushed when approaching retirement age by a cluster of age-related increased health risks that we now get to do our best to mitigate—the focus here is “not dying early”. A lot of health education occurs at this time.
- Finally, upon retirement, we actually get the time to truly focus on our health again, and now it’s easier to learn about all aspects of health, even if now there’s a need to juggle many health issues all at once, most of which affect the others.
See also: How Likely Are You To Live To 100? ← in which we can also see a graph of 10almonds subscribers’ ages, consistent with the above
So, let’s recap, and personalize our health plan
There are often things we wish we could have focused on sooner, so now’s the time to figure out what future-you in your next decade (or later!) is going to thank you for having done now.
So, while 20-year-old us might have been focusing on fat levels or athletic performance, how much does that really help us now? (With apologies to any readers in their 20s, but also, with the bonus for you: now’s the perfect time to plan ahead!)
At 10almonds, while we cover very many health topics, we often especially focus on:
- Brain health
- Heart health
- Gut health
…because they affect everything else so much. We’ve listed them there in the order they appear in the body, but in fact it can be useful to view them upside down, because:
- Gut health is critical for good metabolic health (a happy efficient gut allows us to process nutrients, including energy, efficiently)
- Metabolic health is critical for good heart health (a nicely ticking metabolism will not strain our heart)
- Heart health is critical for good brain health (a strong heart will nourish the brain with well-oxygenated blood and the nutrients it also carries)
So, this isn’t a catch-22 at all! There is a clear starting point:
“How do I do the other bits, though?”
We have you covered here: Your Health Audit, From Head To Toe
“Wait, where’s the personalization?”
This comes once you’ve got those above things in order.
Hopefully you know what particular health risks you have—as in, particular to you.
First, you will have any current diagnoses, and a plan for treating those. Many chronic illnesses can be reversed or at least lessened with lifestyle changes, in particular, if we reduce chronic inflammation, which is implicated in countless chronic illnesses, and exacerbates most of the rest.
So: How to Prevent (or Reduce) Inflammation
The same goes for any heightened risks you have as a result of those current diagnoses.
Next, you will have any genetic health risks—so here’s where genetic testing is a good one-shot tool, to get a lot of information all in one go.
Learn more: The Real Benefit Of Genetic Testing
…and then, of course, take appropriate steps to avoid suffering the things of which you are at increased genetic risk.
Finally, you will have any personal concerns or goals—in other words, what do you want to still be able to do, later in life? It’s easy to say “everything”, but what’s most important?
This writer’s example: I want to remain mobile, free from pain, and sharp of mind.
That doesn’t mean I’ll neglect the rest of my health, but it does mean that I will regularly weigh my choices against whether they are consistent with those three things.
As for how to plan for that?
Check out: Train For The Event Of Your Life! ← this one is mostly about the mobility aspect; staying free from pain is in large part a matter of avoiding inflammation which we already discussed, and staying sharp of mind relies on the gut-heart-brain pipeline we also covered.
You can also, of course, personalize your diet per which areas of health are the most important for you:
Four Ways To Upgrade The Mediterranean (most anti-inflammatory, gut-healthiest, heart-healthiest, brain-healthiest)
Take care!
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Nature Valley Protein Granola vs Kellog’s All-Bran – Which is Healthier?
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Our Verdict
When comparing Nature Valley Protein Granola to Kellog’s All-Bran, we picked the All-Bran.
Why?
While the Protein Granola indeed contains more protein (13g/cup, compared to 5g/cup), it also contains three times as much sugar (18g/cup, compared to 9g/cup) and only ⅓ as much fiber (4g/cup, compared to 12g/cup)
Given that fiber is what helps our bodies to absorb sugar more gently (resulting in fewer spikes), this is extremely important, especially since 18g of sugar in one cup of Protein Granola is already most of the recommended daily allowance, all at once!
For reference: the AHA recommends no more than 25g added sugar for women, or 32g for men
Hence, we went for the option with 3x as much fiber and ⅓ of the sugar, the All-Bran.
For more about keeping blood sugars stable, see:
10 Ways To Balance Blood Sugars
Enjoy!
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