Good Health By The Cup?

In Tuesday’s newsletter, we asked you for your opinion of cupping (the medical practice), and got the above-depicted, below-described, set of responses:

• About 40% said “It may help by improving circulation and stimulating the immune system”
• About 26% said “I have never heard of the medical practice of cupping before this”
• About 19% said “It is pseudoscience and/or placebo at best, but probably not harmful
• About 9% said “It is a good, evidence-based practice that removes toxins and stimulates health”
• About 6% said “It is a dangerous practice that often causes harm to people who need medical help”

So what does the science say?

First, a quick note for those unfamiliar with cupping: it is the practice of placing a warmed cup on the skin (open side of the cup against the skin). As the warm air inside cools, it reduces the interior air pressure, which means the cup is now (quite literally) a suction cup. This pulls the skin up into the cup a little. The end result is visually, and physiologically, the same process as what happens if someone places the nozzle of a vacuum cleaner against their skin. For that matter, there are alternative versions that simply use a pump-based suction system, instead of heated cups—but the heated cups are most traditional and seem to be most popular. See also:

National Center for Complementary and Integrative Health | Cupping

It is a dangerous practice that often causes harm to people who need medical help: True or False?

False, for any practical purposes.

• Directly, it can (and usually does) cause minor superficial harm, much like many medical treatments, wherein the benefits are considered to outweigh the harm, justifying the treatment. In the case of cupping, the minor harm is usually a little bruising, but there are other risks; see the link we gave just above.
• Indirectly, it could cause harm by emboldening a person to neglect a more impactful treatment for their ailment.

But, there’s nothing for cupping akin to the “the most common cause of death is when someone gets a vertebral artery fatally severed” of chiropractic, for example.

It is a good, evidence-based practice that removes toxins and stimulates health: True or False?

True and False in different parts. This one’s on us; we included four claims in one short line. But let’s look at them individually:

• Is it good? Well, those who like it, like it. It legitimately has some mild health benefits, and its potential for harm is quite small. We’d call this a modest good, but good nonetheless.
• Is it evidence-based? Somewhat, albeit weakly; there are some papers supporting its modest health claims, although the research is mostly only published in journals of alternative medicine, and any we found were in journals that have been described by scientists as pseudoscientific.
• Does it remove toxins? Not directly, at least. There is also a version that involves making a small hole in the skin before applying the cup, the better to draw out the toxins (called “wet cupping”). This might seem a little medieval, but this is because it is from early medieval times (wet cupping’s first recorded use being in the early 7th century). However, the body’s response to being poked, pierced, sucked, etc is to produce antibodies, and they will do their best to remove toxins. So, indirectly, there’s an argument.
• Does it stimulate health? Yes! We’ll come to that shortly. But first…

It is pseudoscience and/or placebo at best, but probably not harmful: True or False?

True in that its traditionally-proposed mechanism of action is a pseudoscience and placebo almost certainly plays a strong part, and also in that it’s generally not harmful.

On it being a pseudoscience: we’ve talked about this before, but it bears repeating; just because something’s proposed mechanism of action is pseudoscience, doesn’t necessarily mean it doesn’t work by some other mechanism of action. If you tell a small child that “eating the rainbow” will improve their health, and they believe this is some sort of magical rainbow power imbuing them with health, then the mechanism of action that they believe in is a pseudoscience, but eating a variety of colorful fruit and vegetables will still be healthy.

In the case of cupping, its proposed mechanism of action has to do withbalancing qi, yin and yang, etc (for which scientific evidence does not exist), in combination with acupuncture lore (for which some limited weak scientific evidence exists). On balancing qi, yin and yang etc, this is a lot like Europe’s historically popular humorism, which was based on the idea of balancing the four humors (blood, yellow bile, black bile, phlegm). Needless to say, humorism was not only a pseudoscience, but also eventually actively disproved with the advent of germ theory and modern medicine. Cupping therapy is not more scientifically based than humorism.

On the placebo side of things, there probably is a little more to it than that; much like with acupuncture, a lot of it may be a combination of placebo and using counter-irritation, a nerve-tricking method to use pain to reduce pain (much like pressing with one’s nail next to an insect bite).

Here’s one of the few studies we found that’s in what looks, at a glance, to be a reputable journal:

Cupping therapy and chronic back pain: systematic review and meta-analysis

It may help by improving circulation and stimulating the immune system: True or False?

True! It will improve local circulation by forcing blood into the area, and stimulate the immune system by giving it a perceived threat to fight.

Again, this can be achieved by many other means; acupuncture (or just “dry needling”, which is similar but without the traditional lore), a cold shower, and/or exercise (and for that matter, sex—which combines exercise, physiological arousal, and usually also foreign bodies to respond to) are all options that can improve circulation and stimulate the immune system.

You can read more about using some of these sorts of tricks for improving health in very well-evidenced, robustly scientific ways here:

The Stress Prescription (Against Aging!)

Take care!

And The Brain Goes Marching On!

In Tuesday’s newsletter, we asked you “when does the human brain stop developing?” and got the above-depicted, below-described, set of responses:

• About 64% of people said “Never”
• About 16% of people said “25 years”
• About 9% of people said “65 years”
• About 5% of people said “13 years”
• About 3% of people said “18 years”
• About 3% of people said “45 years”

Some thoughts, before we get into the science:

An alternative wording for the original question was “when does the human brain finish developing”; the meaning is the same but the feeling is slightly different:

• “When does the human brain stop developing?” focuses attention on the idea of cessation, and will skew responses to later ages
• When does the human brain finish developing?” focuses on attention on a kind of “is it done yet?” and will skew responses to earlier ages

Ultimately, since we had to chose one word or another, we picked the shortest one, but it would have been interesting if we could have done an A/B test, and asked half one way, and half the other way!

Why we picked those ages

We picked those ages as poll options for reasons people might be drawn to them:

• 13 years: in English-speaking cultures, an important milestone of entering adolescence (note that the concept of a “teenager” is not precisely universal as most languages do not have “-teen” numbers in the same way; the concept of “adolescent” may thus be tied to other milestones)
• 18 years: age of legal majority in N. America and many other places
• 25 years: age popularly believed to be when the brain is finished developing, due to a study that we’ll talk about shortly (we guess that’s why there’s a spike in our results for this, too!)
• 45 years: age where many midlife hormonal changes occur, and many professionals are considered to have peaked in competence and start looking towards retirement
• 65 years: age considered “senior” in much of N. America and many other places, as well as the cut-off and/or starting point for a lot of medical research

Notice, therefore, how a lot of things are coming from places they really shouldn’t. For example, because there are many studies saying “n% of people over 65 get Alzheimer’s” or “n% of people over 65 get age-related cognitive decline”, etc, 65 becomes the age where we start expecting this—because of an arbitrary human choice of where to draw the cut-off for the study enrollment!

Similarly, we may look at common ages of legal majority, or retirement pensions, and assume “well it must be for a good reason”, and dear reader, those reasons are more often economically motivated than they are biologically reasoned.

So, what does the science say?

Our brains are never finished developing: True or False?

True! If we define “finished developing” as “we cease doing neurogenesis and neuroplasticity is no longer in effect”.

Glossary:

• Neurogenesis: the process of creating new brain cells
• Neuroplasticity: the process of the brain adapting to changes by essentially rebuilding itself to suit our perceived current needs

We say “perceived” because sometimes neuroplasticity can do very unhelpful things to us (e.g: psychological trauma, or even just bad habits), but on a biological level, it is always doing its best to serve our overall success as an organism.

For a long time it was thought that we don’t do neurogenesis at all as adults, but this was found to be untrue:

How To Grow New Brain Cells (At Any Age)

Summary of conclusions of the above: we’re all growing new brain cells at every age, even if we be in our 80s and with Alzheimer’s disease, but there are things we can do to enhance our neurogenic potential along the way.

Neuroplasticity will always be somewhat enhanced by neurogenesis (after all, new neurons get given jobs to do), and we reviewed a great book about the marvels of neuroplasticity including in older age:

The Brain’s Way of Healing: Remarkable Discoveries and Recoveries from the Frontiers of Neuroplasticity – by Dr. Norman Doidge

Our brains are still developing up to the age of 25: True or False?

True! And then it keeps on developing after that, too. Now this is abundantly obvious considering what we just talked about, but see what a difference the phrasing makes? Now it makes it sound like it stops at 25, which this statement doesn’t claim at all—it only speaks for the time up to that age.

A lot of the popular press about “the brain isn’t fully mature until the age of 25” stems from a 2006 study that found:

❝For instance, frontal gray matter volume peaks at about age 11.0 years in girls and 12.1 years in boys, whereas temporal gray matter volume peaks at about age at 16.7 years in girls and 16.2 years in boys. The dorsal lateral prefrontal cortex, important for controlling impulses, is among the latest brain regions to mature without reaching adult dimensions until the early 20s.❞

~ Dr. Jay Giedd

Source: Structural Magnetic Resonance Imaging of the Adolescent Brain

There are several things to note here:

• The above statement is talking about the physical size of the brain growing
• Nowhere does he say “and stops developing at 25”

However… The study only looked at brains up to the age of 25. After that, they stopped looking, because the study was about “the adolescent brain” so there has to be a cut-off somewhere, and that was the cut-off they chose.

This is the equivalent of saying “it didn’t stop raining until four o’clock” when the reality is that four o’clock is simply when you gave up on checking.

The study didn’t misrepresent this, by the way, but the popular press did!

Another 2012 study looked at various metrics of brain development, and found:

• Synapse overproduction into the teens
• Cortex pruning into the late 20s
• Prefrontal pruning into middle age at least (they stopped looking)
• Myelination beyond middle age (they stopped looking)

Source: Experience and the developing prefrontal cortex ← _{^{check out figure 1, and make sure you’re looking at the human data not the rat data}}

So how’s the most recent research looking?

Here’s a 2022 study that looked at 123,984 brain scans spanning the age range from mid-gestation to 100 postnatal years, and as you can see from its own figure 1… Most (if not all) brain-things keep growing for life, even though most slow down at some point, they don’t stop:

Brain charts for the human lifespan ← _{^{check out figure 1; don’t get too excited about the ventricular volume column as that is basically “brain that isn’t being a brain”. Do get excited about the rest, though!}}

Want to know how not to get caught out by science being misrepresented by the popular press? Check out:

How Science News Outlets Can Lie To You (Yes, Even If They Cite Studies!)

Take care!