• Parkinson’s Disease: Can Stem Cells Help?

    Parkinson’s Disease is serious, y’all. And I don’t really like to write about serious things, because they’re real. They impact people’s lives. And break hearts. And test limits. And forge humans out of steel.

    But today I’m going to discuss Parkinson’s Disease, because someone emailed me about it a week ago. And I don’t believe they’re alone in their line of questioning. And really this is why I made this blog. It can’t always be the top five reasons you shouldn’t listen to Gwyneth Paltrow about literally anything outside of hair care.

    Here’s what you need to know: the malfunction that causes Parkinson’s, how we currently treat it, and whether or not it makes sense to use stem cells (or other cutting edge technologies) to improve upon current treatments.

    So let’s jump right in.

    Parkinson’s Disease Lives In A Small Cell Cluster

    in the brain. Even now, as an all grown-up scientist minded person, I find it hard to believe that such a tiny structure can cause such big problems. But it does.

    This awesome animation from Khan Academy does a great job of explaining the crux of the issue. At least the part of it that we understand. In a nutshell, this small cell cluster in the mid-brain, the substantia nigra, loses cells that make dopamine. The decrease in dopamine leads to the physical symptoms of Parkinson’s Disease, like tremors and slow/difficult movement.

    So really, Parkinson’s Disease comes down to brain cells dying when we really need them to stay alive and keep making dopamine. But there is good news:

    We Have Great Medications for Parkinson’s Disease

    Even though Parkinson’s is a progressive, degenerative condition, we do have awesome medications for it. See, we know that loss of dopamine is the biggest issue. And physicians have actually been treating that symptom of PD for over forty years in a couple of different ways.

    Dopamine Agonists

    These are sort of the expendable crewmen of Parkinson’s treatment. Dopamine agonists have some of the same effects as dopamine and can control the early stages of Parkinson’s symptoms. And there are so many of them that I’m not going to bother listing any.

    Long story short: dopamine agonists comprise the first line of Parkinson’s defense and can work well in the early stages after initial diagnosis.


    Y’all know your brain runs your whole body, right? So your body has several ways of protecting it, one of which is the blood-brain barrier. This intricate biological system guards the  brain, much like the kind of security you’d expect to see in important government buildings. Only things that really need to be in the brain get through.

    So if we want to put dopamine in the brain to treat Parkinson’s, we have to find a way to get it past the blood-brain barrier. Because the brain thinks dopamine comes from the brain, so it doesn’t have a natural mechanism for allowing it past the barrier.

    That’s where this awesome molecule (that I used SO much in grad school) comes in. Levodopa, or L-Dopa, easily crosses the blood-brain barrier and is converted to dopamine in the brain. Which then leads to a decrease in Parkinson’s symptoms.

    But. Only a small percentage of L-Dopa crosses into the brain, leaving the rest of it bumping around in parts of the body where it isn’t needed. And can cause unwanted side effects when it converts to dopamine.

    So for Parkinson’s, L-Dopa usually comes with a couple of other drugs that (1) don’t cross the blood-brain barrier, and (2) prevent the conversion of L-Dopa to dopamine. This way you get more dopamine in the brain, where it’s needed, without getting more dopamine in the rest of the body where it’s not.

    Now, as with many things in your body, continued use of L-Dopa combined with progressive loss of dopamine producing cells can lead to “tolerance” of lower doses. So most patients will end up increasing their dosage over time, eventually leading to a point at which they are experiencing unwanted side effects due to the high dosage.

    This is usually the point at which patients begin looking at more aggressive treatment options, including the addition of some of the prescriptions below.


    MAO-B Inhibitors: MAO-B stands for a really long enzyme that breaks down dopamine. When we inhibit that enzyme in the brain (with MAO-B Inhibitors), dopamine should stick around more. And symptoms of Parkinson’s should decrease. These guys do present more of an issue though, because they cause more side effects than dopamine agonists.

    COMT Inhibitors: You probably guessed it, but COMT is short for an enzyme that breaks down dopamine. So same story here as directly above. The idea is to inhibit the thing breaking down dopamine, thereby increasing dopamine. These are used less frequently than other options due to side effects and lack of efficacy.

    Physicians may also treat psychosis, dementia, and excessive sleepiness with a cocktail of other drugs. But those are really aimed at some of the downstream effects of Parkinson’s and not the cause (lack of dopamine).

    So what happens when a person has been treated with these great drugs for so long that they’re no longer effective?

    Physicians and patients start looking into surgical answers. And the surgical answers are pretty remarkable.

    We Have Awesome Surgery for Parkinson’s Disease

    Remember earlier how I said that PD comes from a tiny cell cluster in the brain? I’m going to see if this link will show you that cell cluster.

    Side note: my single favorite way to understand anatomy is Zygote Body. It really helps visualize some of the things, especially brain structures, that are hard to understand without three dimensional information. 

    Ok, that link won’t show you what I want. But, if you click the link and then type “substantia nigra” into the search bar on the top right, it’ll label the right structure for you.

    Ok, now that you’ve seen the size of this cell cluster, let’s move into how the surgical option works. No, surgeons don’t implant a time release dopamine device. Or nanobots that make dopamine.

    It turns out that electrical impulses can actually make up for the loss of dopamine. Crazy, right?

    But not really. Because almost every cell in your body depends on very tiny electrical impulses. So even though dopamine is the problem, electrical stimulation can be the solution. Because when functioning correctly, the dopamine should control electrical impulses in charge of physical movement (in that part of the brain).

    If electrical impulses work, then how do we get them into the Parkinson’s causing part of the brain?

    surgeons Place Tiny Implants In The Brain

    You read that right. I know it sounds scary, but surgeons have gotten really good at this. Plus the implant itself is like a piece of cooked spaghetti. Here’s how it works:

    1. Doctors take a ton of pictures of your brain and map out every blood vessel, structure, and fold.
    2. Doctors use all of those pictures to make a 3D model of your brain.
    3. Using the 3D model, a pathway is marked out from your skin all the way to the target cells. This pathway avoids all important structures and essentially makes a beeline direct from your skin to the target location.
    4. At the beginning of surgery, you put on a special crown. This crown orients your brain in surgery to the pictures of your brain in the 3D model. That way the surgeon is certain that the planned starting and ending points are exactly the same in surgery as in the plan.
    5. Once surgery begins, your surgeon uses a robot to slowly guide the tiny spaghetti like implant down the planned path.
    6. As the final location approaches, your surgeon will test the implant. So yes, you’ll be awake. This testing phase ensures that the implant is in the most beneficial location for your specific brain anatomy.
    7. Once the surgeon finds the optimal location, they attach the spaghetti to a tiny anchor just outside your brain. This keeps the implant still and ensures your movements don’t ever affect the implant location.
    8. The last part of surgery is attaching the end of the piece of spaghetti to a small battery, and then implanting that battery. Most people put the battery in their chest or abdomen, and they’re so small now that you really have to know where they are to find them. Much like pacemaker batteries.

    Here’s a creepily silent animation that shows an example of where this type of implant goes.

    Now, because this implant requires brain surgery, the surgeon doesn’t turn it on immediately. So even though it’s physically in the right place, most surgeons will wait a couple of weeks before turning it on. This ensures that your body has had time to calm down after surgery.

    Once those couple of weeks pass after surgery, a neurologist will program the implant. This process just tells the implant how much electricity to use in which part of the implant to give each patient the best result.

    So what is that best result?

    Brain Implants Are Crazy Effective

    This video demonstrates how incredible these implants are. And he comes right out and says it.

    It’s life changing.

    But wait – where’s the science? Ok, let’s check the literature to see how effective these implants really are.

    In this review, published this year, the authors looked at twelve different studies including 401 patients. They wanted to see if the effects of L-Dopa and brain implants were better together or possibly separately. They found, as you might expect, that both treatments decreased the physical symptoms of PD. But, when used together, patients experienced a 35 point improvement on a Parkinson’s Disease rating scale versus only about a 20 point improvement when either treatment was used separately.

    That’s on the order of 50% more effective when combined than when  used separately.

    Note: this review article included data up to five years out from surgery. And, some of the implants used would have been less advanced than the ones we have now. So I personally would expect some patients to have even better outcomes than what this review included.

    Stem Cells for Parkinson’s Disease?

    I know I’ve just sold you on the epic nature of brain implants for Parkinson’s. And you’re probably thinking we don’t need stem cells anymore. Especially if you watched this video all the way through. But, let’s revisit one important point.

    Every treatment I’ve listed thus far treats a symptom of Parkinson’s Disease, not the underlying cause. Which means that every treatment, even life-altering brain implants, doesn’t really present a solution.

    That’s where people tend to lean toward stem cells. Because they can become other kinds of cells, right? Like maybe dopamine producing cells?

    Maybe. At this time, I’m not aware of anyone actually creating dopamine producing cells from any adult stem cell. But that doesn’t mean it’s not happening. It might be. [edit: it is happening. Here. And here.]

    Let’s focus on a more realistic role for adult stem cells though. Remember when I listed the functions that make mesenchymal stem cells (MSCs) so useful? Let’s speculate wildly* for a moment about how those properties might help with Parkinson’s Disease.

    *Note: wild speculation is not science. It is the combination of imagination with substantial education. So wild speculation may turn out to be true, and it may not. You’ve been warned. 

    Now back to that speculation.

    Ways MSCs Might Help with Parkinson’s
    1. MSCs save dying cells. Dopamine producing cells die in PD, causing physical symptoms.
      Maybe MSCs could save some of those cells, slowing down or stopping the progression of PD at the root.
    2. MSCs control inflammation. Inflammation occurs in the same area in which dopamine producing cells die. Some researchers have even declared that inflammatory processes are “crucial for disease progression.”
      Maybe MSCs could control or eliminate the inflammation, thus depriving the tissue of one crucial component for PD progression.

    But what about other stem cells? Could they help too?


    And you’ll find the mechanism of their help pretty obvious. Other stem cells, possibly manipulated MSCs or iPS cells (which I’ll still talk about in a later post) could maybe be programmed to produce dopamine. Basically these manipulated stem cells would attempt to replace the damaged or dead cells in the brain. And as such could represent a more long-lasting treatment option than some of the pharmaceuticals currently in use.

    But that goes for all of the cell-based treatments. Any time we can get a living cell to go stay in a damaged tissue and do the job that tissue needs, that solution lasts longer than any non-cell based solution. Because cells maintain themselves much longer than any implant or drug can.

    Alright. Now that we’ve speculated wildly, let’s take a look at what people have actually done with stem cells and Parkinson’s Disease.

    Stem Cells Have Been Used to Treat Parkinson’s Disease

    In 2010, this group published a study with follow-up at the three year point for some of their patients. Now, you must pay attention to how they implanted the cells here, because they did it right. This group used the same brain surgery approach I described earlier for those spaghetti noodle implants, but instead of those implants, these guys placed MSCs from the patient’s bone marrow in the target area.

    very important note:

    Every time someone uses stem cells, or a drug, or anything to treat anything in the human body. In order for it to work, they must first figure out how to get it where it needs to go.

    So when someone says they want to treat Parkinson’s Disease, they need to figure out how to get their treatment into the specific area of the brain where we know the cells are dying.

    And that’s a challenge. Because the blood-brain barrier is legit. It lets very few things pass. Imagine it as Gandalf just constantly yelling YOU SHALL NOT PASS at almost everything. Including stem cells. Stem cells CANNOT pass the blood-brain barrier. They’re too big.

    So when you read about someone using stem cells to treat Parkinson’s Disease, you should be looking for an actual brain surgery to get those cells where they need to be.

    end very important note

    As I was saying, this group did it right. They used brain surgery, just like the one used for PD electrical spaghetti noodle implants, to get the cells where they needed. Three of the seven patients treated showed steady improvement in the Parkinson’s Disease Rating Scale assessments, improving on average 22.9% from before treatment. Two of those patients also significantly reduced their medications.

    Members of that same group did another study in which 12 patients ranging from 5 – 15 years after PD diagnosis were treated with MSCs not from their own bone marrow. Again, this group implanted the cells using an appropriate brain surgery technique. One subset of patients, basically with standard PD diagnosis, improved 17.92% during “on” (meaning effectively medicated) state and 31.21% during “off” state. But some of the patients in this study didn’t improve at all.

    And that’s one of the things about early research. We don’t always know why certain patients didn’t respond. Eventually an explanation will surface. But we have to do more studies to figure that out. And eventually we’ll get more patients with improvement and less patients who just don’t respond. Or at least we’ll be able to better predict when patients aren’t good candidates.

    Let’s talk about one last study real quick. This one used highly manipulated stem cells programmed to become neural stem cells. The researchers used the same brain implantation technique we’ve discussed to place the neural stem cells in the brains of African green monkeys with Parkinson’s Disease. Twelve months after implantation, the monkeys had behavioral improvements, increased dopamine levels, and increased numbers of dopamine producing neurons.

    I know this research sounds cool, and I’m hopeful that we’ll see some of the MSC based therapies in the regular world within the next ten years. The results thus far are definitely promising.

    But. Right now this stuff falls into the research category. It’s not ready for prime time yet.

    It will be. In our lifetimes. Just not right now.

    People Should Not Be Selling Stem Cells for Parkinson’s Disease

    Did you notice the common thread among the studies I covered? Every single one of them used brain surgery to place the cells. Right now, that’s the only surefire way to get stem cells to the tissue affected by Parkinson’s Disease.

    So if you happen to search for a PD treatment and find someone offering stem cells for it, I hope you’ll first check to see if they’re a neurosurgeon. Specifically one specializing in stereotactic brain surgery (the technical term for the type of surgery we’ve discussed multiple times in this post).

    If a chiropractor, pain management doctor, orthopedic surgeon, witch doctor, naturopath, shaman, priest, or alien offers you a stem cell treatment for PD, please don’t mortgage your house for it. Please don’t use your kid’s college tuition for it.

    Please ask a thousand questions, the most important of which are: how will this get to my PD cells? How many times have you done this before, and what were the results? Is this part of a clinical study? How do you know this is safe?

    If someone offers you or a loved one a stem cell treatment for PD outside of a clinical trial or study, without the help of a neurosurgeon, you should not expect success. Or safety.

    In case there’s any lingering doubt, my personal favorite PD treatment is the electrical spaghetti noodle implant. They do amazing things and have a long history of safe and effective use.

    I’m excited to see stem cells come onto the PD field in the near future. I really am. But I know they aren’t ready for general clinical use in Parkinson’s Disease just yet.

    Have you heard of any other cutting edge PD treatments? Or something crazier than stem cells that you think is a pack of lies? Let me know in the comments, or send that info direct to my inbox!

  • Adult Stem Cells: What Are They Anyway?

    Adult stem cells pop up everywhere in the news, and yet, much like most of politics, it’s hard to tell what’s really going on with them. So today I’ll explain the most important adult stem cell concepts for you, the everyday, non-scientist, healthcare consumer. And hopefully won’t bore you to tears in the process.

    “Adult Stem Cells” Is A General Term

    In my last post I shared the earth shattering fact that “stem cell” is a very broad term, and unfortunately “adult stem cell” has that same designation. Recall that a stem cell, by definition, is any cell capable of copying itself and turning into a different kind of cell.

    A regular old stem cell that happens to be found in an “adult” tissue qualifies as an adult stem cell. And the whole adult designation misleads a bit, because it gives the impression of a stem cell found only in adults. But adult stem cells can be found in infants, the oldest person in the world, and everyone in between. Even Keith Richards.

    Now, I know you’ve memorized every word of my last blog post. So I don’t need to mention the fact that adult stem cells are found in almost every tissue in your body. And we can just move onto the most important kind of adult stem cell, the mesenchymal stem cell.

    Mesenchymal stem cells are the adult stem cell you hear about most frequently right now. But why?

    Mesenchymal Stem Cells Are The Most Useful Adult Stem Cells*


    I briefly touched on this topic in my last post, but I need to expand. Because these special adult stem cells are awesome.

    Mesenchymal stem cells (MSCs) show up for the first time during embryonic development. In this cute animation, early stage embryonic stem cells separate into three layers: ectoderm, mesoderm, and endoderm. We care about the mesoderm layer, which creates muscle, blood and blood vessels, bone, and connective tissue.

    During this super complicated process that somehow builds a complete human being almost every single time it happens, the stem cells from the mesoderm don’t disappear. Instead, some remain inside bones and hanging onto the outsides of blood vessels throughout the body, for literally the rest of a person’s life.

    These stem cells that came from the mesoderm and made the daunting commitment to stay with us our whole lives are mesenchymal stem cells.

    I know, a lifelong commitment seems pretty extraordinary. That must set them apart from all the other stem cells, right?

    Didn’t Benjamin Franklin say that 80% of success is just showing up? This must be what he was talking about, eh?

    Not exactly. First of all, Benjamin Franklin definitely didn’t say that. And second, MSCs have a variety of properties that make them A) wildly different versus other types of stem cells, and B) very powerful.

    Surprisingly, most of those properties aren’t the thing most of you are thinking. You know, the thing where MSCs can make muscle, blood, blood vessels, connective tissue, and bone? Right, not that thing.

    I’ve already mentioned the most useful characteristic of MSCs (in this other post): they live and function in the human body during every stage of development. So when we use them medically right now, they have all the signals they need to function correctly*.

    *When they come from your body and then go to work in your body. If they come from someone else’s body, that’s a different story.

    But, MSCs do so many other helpful things that they almost seem magical. Almost.

    Let’s dig into those other properties so you can love MSCs as much as I do. And know when they might come in handy.

    MSCs: Adult Stem Cells That Can Make Several Types Of Tissue

    In humans ranging in age from embryo to centenarian, MSCs live in bone marrow and on blood vessels. That means you can find them scattered throughout almost every part of your body.

    Despite living in so many places, MSCs still qualify as a rare cell type. They make up between 10 and 83 cells for every million cells in bone marrow and anywhere from 200 – 50,000 of every million cells in fat tissue.

    So how do they do such a great job making tissue if they’re so rare?

    Easy. They respond to homing signals.

    Remember how MSCs live in bone marrow and on blood vessels? That makes them sort of like the homeland security surveillance team of the human body. Except they’re more into tissue repair than stopping terrorism. See, MSCs are perfectly positioned to receive signals sent out by damaged tissue. And once they notice them, the MSCs follow those signals to their starting point where they then do the work of tissue repair.

    How do we know they actually make new tissue? Well this doctor used MSCs to repair broken bones, and this group used them to fix cartilage defects. This other group used them to repair cardiac tissue, and this one used them to grow blood vessels.

    And that’s just a tiny sampling of MSCs creating new tissue in real live humans.

    But MSCs do way cooler things that make them the best of the adult stem cells. So let’s talk about those!

    MSCs: Adult Stem Cells That Decrease Scarring

    We’ve all got scars, right? And I’m not just talking about the emotional ones from learning that no real live person EVER has Disney character hair. Ever. I’m talking about the physical scars (that hurt so much less, Disney).

    My most annoying scar lives on my forearm where a piece of rogue chicken wire got me. It bled like a fire hose and scared the crap out of my mom. She thought amputation was inevitable. She wrung her hands and audibly worried about the number of stitches I’d need, but luckily her fears were unfounded.

    That tiny cut became a scar that hasn’t changed in the last twenty years.

    So what happened?

    This awesome TedEd animation explains the process and is much easier on the eyes than all my words, so take a gander.

    In short, my chicken wire gash didn’t finish healing. My skin went through all the steps of healing right up until the last phase, remodeling, and just stopped short. This is probably why my mom was always complaining about  me finishing projects.

    Anyway, scars are a real thing that happen to most of us, and can sometimes interfere with our day to day lives. You may just not like how a scar looks, or a scar may actually keep you from moving the way you want. Either way,

    MSCs are the adult stem cells that can save the day.

    When MSCs arrive at the source of the homing signals (broken or healing tissue), they dump proteins onto the cells around them. Some of those proteins help the cells in the area to create tissue more like the surrounding tissue. Less like my shiny smooth forearm scar.

    Other MSC proteins also decrease the activity of malfunctioning scar cells. That allows the correctly functioning cells to make more of the new tissue, resulting in a less scar-like scar.

    Researchers the world over are currently looking for ways to use this MSC skill to improve severe scar cases. And if you’re reading this right now, you’ll probably see the results of those efforts in your lifetime. #WhatATimeToBeAlive

    MSCs: Adult Stem Cells That Kill Germs

    I’ve mentioned the basic function of the immune system before, but let’s review. Your immune system has two basic jobs: (1) distinguish between things that are you and things that are not you, and (2) kill things that are not you.

    Sounds pretty simple, right? Well then why do we get infections?

    Well y’all, sometimes things don’t work the way they’re supposed to. You might accidentally encounter a terrifying and rare bacteria in your neighbor’s hot tub. (That’ll teach you to go hot tubbing after Kenneth Parcell told you hot is the devil’s temperature!) Or you learn the hard way that grandma was wrong, and that milk really was too far gone.

    The point is: sometimes your immune system needs an assist. And in some of those cases, MSCs provide the assist. MSCs can supercharge the activity of regular immune cells, and they can fight invading microbes directly. They’ve also been used together with another kind of immune system adult stem cell to cure infected bones, and it worked!

    I must have you convinced that MSCs are THE adult stem cell, but I’ve got two more cool properties to share.

    MSCs: Adult Stem Cells That Control Inflammation

    Inflammation is a natural part of healing. In fact healing can’t happen without inflammation. So why would we need to control it?
    :: coughs loudly ::

    Sometimes things don’t work the way they’re supposed to. Instead of channeling the body’s healing cells and proteins to repair and replace damaged tissue, sometimes inflammation just hangs out doing nothing. Except causing trouble.

    Don’t worry though, MSCs can wrangle their fair share of troublemakers.

    MSCs actually make more inflammation controlling proteins than I would ever list here. But just for scale purposes, let’s say it’s on par with the number of ice cream flavors you can find at a Baskin Robbins.

    MSCs are so good at controlling inflammation that they’ve been used (in very small studies) to treat inflammation related diseases like Crohn’s disease and Lupus.*

    *Please note, these are early stage studies and not currently available treatments. If you have Crohn’s disease or Lupus, remain incredibly skeptical of anyone offering you a stem cell based treatment. Unless you hear “this is experimental” and “it probably won’t work, but it might,” the treatment likely leans in the direction of shady. And if you’re not sure, just shoot me a message! (Using the contact form, definitely not a gun, please.) <– I’m in Texas, so I have to say it.

    MSCs: Adult Stem Cells That Rescue Other Cells

    I love weird things, y’all. People, places, books, phrases. If it’s weird, I’m probably into it. And that’s been true since long before I moved to Austin. So don’t go blaming that personality quirk on the city of weird, because it’s all me.

    This fact is relevant on account of this last property being my favorite. Because it’s pretty weird and unexpected.

    MSCs save dying cells. As a kid fascinated with biology and chemistry, I never dreamed there were cells bumping around inside our bodies just waiting to counsel other cells when they despair of life. And yet, that’s exactly what MSCs do.

    See, sometimes things change in your body temporarily. In a heart attack, part of the heart muscle doesn’t get enough oxygen, which makes those heart cells hit the self-destruct button. And just like every over-dramatic villain movie, once self-destruct mode activates, it can’t be undone. Even if the temporary change has been addressed, and the heart muscle has oxygen again.


    Yes, you guessed it, your new favorite adult stem cell can save the day again.

    MSCs do a couple of different things that de-activate a cell’s self-destruct mode. They directly touch dying cells (like a hug, but for cells!), and they make proteins that prevent self-destructing cells from finishing the job.

    Isn’t that cool?

    Sometimes the results after MSC treatment seem like they’ve lasted way longer than they should have. And I think this property accounts for that. By saving some of the dying cells, the MSCs have a much longer lasting effect on the tissue. Because those saved cells can live for months or even years in some cases, all the while contributing to better tissue function and a happier human owner.

    Alright y’all, that was a whirlwind. If you stayed with me this whole time, thanks for coming along!

    If you’re still with me, let’s walk back through all that info real quick. And probably leave you wondering why the next three sentences weren’t this entire post.

    Just a quick recap:

    Adult stem cells are regular stem cells found in an “adult” tissue, which means all humans have them.

    Mesenchymal stem cells are the most useful adult stem cells, because they live and work in our bodies at every stage of developmentthey make new tissue, decrease scarring, control inflammation, kill germs, and save dying cells.



    Do you have questions about adult stem cells that I didn’t answer? Or did I make things super confusing? Let me know in the comments, or use the contact form to complain directly in my inbox!

    Thanks for reading, y’all!

    Photo by Louis Reed on Unsplash


  • The Top Five Things You Don’t Know About Stem Cells

    Girl Meets Stem Cells: A Short Story

    Y’all know the little career interest boxes they make high school students designate on standardized tests? As if fourteen year olds should really know what they want to be doing 30 years later. Well, when I took the PSAT, a million or so years ago, there was an option for bioengineering, and I had never heard that term before. So naturally, I checked it and never looked back.

    I correctly assumed that bioengineering would be the discipline in which smart people figured out what to do with stem cells, and I was obsessed with stem cells and the problems they would solve in my lifetime. At the time, the only stem cells I knew were embryonic stem cells, but the press was super convincing:

    Embryonic stem cells can grow any tissue in the human body!

    Embryonic stem cells can cure cancer!
    (fact: they were actually causing cancer)

    Embryonic stem cells will make you more popular and social!
    (that was just a lie I told myself while hiding in the back of the AP chem classroom, but I think it was totally helpful)

    As a person of adult age but soundly teenaged disposition, I have had to face this shocking but ultimately fantastic truth about stem cells:

    The majority of stem cell media coverage will lead you to completely incorrect conclusions about them.

    So today I’m covering the top five things you don’t know about stem cells but really should. Before I get into that, just to be clear, embryonic stem cells, and in fact all stem cells, will not make you more popular and social, no matter how fantastic a Disney movie that premise would make.

    Now that I’ve cleared that up, let’s move on to the top five things you don’t know about stem cells but should!

     1. There are as many different kinds of stem cells as there are flavors of ice cream.

    The term “stem cell” is as broad as the term “doctor.” In fact, the definition of a stem cell only provides two defining characteristics: they can make copies of themselves (self-renewal), and they can turn into a different kind of cell (differentiation). There are literally hundreds of different types of cells that meet this definition. Embryonic stem cells that can make exact duplicates of themselves OR turn into literally any cell type in the body. Hematopoietic stem cells can clone themselves OR turn into any blood cell. Mesenchymal stem cells, my personal favorite, along with making their own copies, can turn into connective tissue, cartilage, bone, and fat tissue.

    Every type of stem cell has unique properties that make them suitable for very different applications. A hematopoietic stem cell is great as a part of leukemia treatment, but it’s as useless at bone healing as I am at break dancing. Neural stem cells can become new neurons and glial cells, which may one day be an incredibly powerful tool in the treatment of neurological damage. But you probably won’t want to use them to fix that bald spot you swore you wouldn’t inherit from your dad.

    Each different type of stem cell functions correctly in a specific environment. Embryonic stem cells need the very specific environment only found in utero. If they are applied outside of that environment in a place where they cannot receive the intricately measured, timed, and delivered signals they need, they almost always cause a type of cancer called a teratoma. As I’ve explained a million times – embryonic stem cells are like adventurous children. If left to their own devices with no supervision, they’re probably going to play with matches and burn the house down. But, with the right signals (the ones only found in utero), they can make it out of childhood and become overly sarcastic scientists instead.

    Mesenchymal stem cells, a type of adult stem cell, are primed to function in the human body at all ages – from infancy to your centennial years. Since their natural environment is your body, at whatever age you are, they do what they’re supposed to do when used in your body. That’s why my co-authors and I titled our review paper, “Mesenchymal Stem Cells: Environmentally Responsive Therapeutics for Regenerative Medicine.”

    It’s incredibly important that anyone attempting to use stem cells in the treatment of any human injury or pathology chooses the right stem cell for the job. Nobody who ever needs brain surgery thinks, “I’ll just have this podiatrist down the street do it. A doctor’s a doctor, right?”

    So when you hear the term “stem cell” you should always ask – what kind of stem cell? And so should every media outlet that covers stem cells, especially when people have done irresponsible things with them. The type of stem cell matters, and in my experience, when people choose to do irresponsible things with stem cells, it is because they don’t understand the most basic properties of stem cells, including the most obvious fact that all stem cells are not created equal.

    For more information on the kinds of stem cells, including which ones are used in clinical practice right this moment, in this country, read this post that I haven’t written yet but will. Check back later for a live link, or join the email list!

    2. Stem cells live in almost every tissue in your body.

    Yes, your adult human body. They’re in your brain and in your muscles, in your bones, in your heart, and even in those jiggly parts you can’t lose without giving up carbs. Your body is literally chock full of stem cells at this very moment.

    What does that mean?

    It means that you and I are probably going to see some really wild stuff happen with medical advancements in the next 10-20 years. Most of my friends have heard me say this, so apologies to everyone who already knows: I fully expect to live to 120 and do handstands and cartwheels the whole time.

    Because of stem cells.


     3. Embryonic stem cells are the most useless kind of stem cells.

    Say whaaaaat?

    I’ll say it again. Embryonic stem cells are the most useless kind of stem cells. For now at least.

    You shouldn’t take my word for it though, so let’s break it down. Most of the applications in which we, living, breathing, hashtagging humans would want to use stem cells involve replacing or repairing some tissue inside our bodies. That means the stem cells would need to stay and live happily in our bodies.

    You know who has a lot to say about what stays and lives happily in your body? Your immune system. It has two basic jobs: (1) distinguish between your body and not your body, and (2) destroy and eradicate anything that qualifies as not your body.

    Now, are you an embryo?

    If you are, and you’re reading this, mazel tov – you’re probably the great white hope of this universe, and I hope you grow up to be kind and just funny enough to laugh at yourself all through middle school.

    For the rest of you, you’re not an embryo. Even if you’re in the reading audience identifying as your spirit animal instead of a human, you’re not an embryo. Unless your spirit animal is an embryo, in which case we need to talk about all the other possible spirit animals you could have chosen. White tigers, unicorns, mermaids, leviathans (because I still have nightmares about that movie), those teacup raptors from every Jurassic Park movie, and REGULAR RAPTORS. But I digress.

    Assuming you are not an embryo – if someone were to put embryonic stem cells in your body, what would happen? (Other than them doing their best to form a teratoma)

    Your always on, omnipresent immune system would recognize those cells as not your body. Then those not your body embryonic stem cells would be labeled with the molecular equivalent of giant flashing lights that say “DESTROY ME IN THE MOST VICIOUS WAY POSSIBLE IMMEDIATELY.” And then your immune system would do its job and kill them.

    So ignoring the fact that we still aren’t great at telling embryonic stem cells which type of cell to turn into, ignoring any of the many passionate views people have about them for personal/religious/financial reasons, embryonic stem cells are the most useless type of cells because they are not your cells. And as such, they can’t live in your body without copious amounts of immune suppressing drugs, just like an organ transplant.

    Important Note: There is a specific type of embryonic-like stem cell made from your own body that may turn out to be the next great advancement in medical science. I’ll cover them in detail in another post, because there’s way too much information about them and way too many cool things being done to cover them in this post.

    4. Clinical stem cell treatments are available in the United States, right now, and they DO NOT cost $50,000 – $100,000 cash.

    I have personally assisted hundreds of adult stem cell cases using mesenchymal stem cells from bone marrow. No, I was not there for procedural assistance. I’m not a medical doctor, y’all. Do you know how much med school costs???

    Because I’ve personally seen these cases, I know that there are hundreds if not thousands of qualified, trained physicians specializing in orthopedics, spine, pain management, obstetrics, aesthetics, and even some general practitioners who offer treatments utilizing adult stem cells from the patient’s own bone marrow. So why haven’t you heard of this yet?

    Believe it or not, doctors aren’t great at marketing, nor do they really learn much about it in med school. So most of them are depending upon word of mouth, or their favorite scientist, to get the word out.

    I say most, because there are some who are fantastic at marketing. They also often happen to be people who are charging what I would label as highway robbery prices. In this particular story (<– click the link), you see that one patient paid $30,000 for a stem cell treatment (administered in Mexico, which is a whole other issue).

    That’s not normal.

    You do not need to go to another country, and you do not need to pay tens of thousands of dollars or mortgage your home to get a legitimate stem cell treatment. I’ll do a separate post on which treatments are clinically sound and which you should avoid at all costs, because I could write an encyclopedia on that topic. For now, let’s just focus on the average and reasonable costs for adult stem cell treatments from bone marrow. For a single procedure, let’s say the most common – a knee arthritis treatment, you’re looking at an average cash price of about $5,000. Some places will be a little more, some places will be a little less.

    Where are these places? There’s this one in Colorado, this other one in Colorado, this one in Dallas, this one in Portland, this one in Cleveland, this one in Tyler, and a whole slew of others that I don’t have the time or space to list on this page.

    You know what else is awesome? Just last month, an insurance company announced that they will begin covering bone marrow derived adult stem cell treatments as a way to provide better care to their customers. You can bet that more will follow, and I predict that within three years, all major insurers will have jumped on this band wagon. These kinds of treatments are better for patients, and they’re actually about 1/5 – 1/10 of the cost of currently available and covered treatments.

    5. Stem cells are not magic. Stem cells are science.

    If you’ve attended any of my presentations, you’ve heard me say this ad nauseum. Stem cells are not some kind of magic bullet panacea that will fix anything we throw them at. When physicians (or people posing as them) assume they are, people get hurt, sometimes irreparably.

    In order to use their powers for good, we (the scientific and medical community) have to educate ourselves on the mechanisms by which stem cells can or could treat a particular injury or pathology. We need to consider the environment from which they are coming as well the one in which they will be placed. We need to read up on the literature. We need to understand how this group grew cartilage with their patient’s bone marrow derived stem cells, and how this doctor treated osteonecrosis with them. We need to appreciate the science behind this doctor’s treatment of fractures that wouldn’t heal.

    There is a wealth of information on stem cells, a 30+ year history of safe and effective use of bone marrow derived stem cells in orthopedic treatments, and textbooks full of information on why this particular cell type seems to work so well.

    Do we have all the answers?

    Absolutely not.

    But do we have enough of them to make operating in the dark, closing our eyes and hurling them at macular degeneration or cerebral palsy, inexcusable?


    When we embrace the knowledge behind stem cells, everyone wins.

    And that, y’all, is science.

    Image adapted from ZEISS Microscopy from Germany [CC BY 2.0], via Wikimedia Commons

  • References Matter | Click The Links!

    Y’all, one of my favorite people called me yesterday and reminded me to discuss my references soapbox. I can’t believe I haven’t done it yet, because standing on a soapbox is literally the only time I make it to average height.

    Here’s what’s up:

    There are metric tons of misinformation in the media, especially the mother ship of fake news, social media. Most of that misinformation is actually pretty easy to recognize, because it’s not supported with any real references.

    What do I mean by “real references”? Let’s break it down.

    Real References Are Peer Reviewed

    First of all, Gwyneth Paltrow’s blog is not a real reference. I’m pretty sure she doesn’t know that bacteria are actually necessary for our survival, so her 3 am epiphanies about feminine hygiene do not qualify as legitimate information.

    Now, there’s no real way to ensure that any piece of scientific evidence is 100% bulletproof. But the scientific community has several principles that ensure we get as close to bulletproof as possible over time. The first of those principles is peer review. You can read the different takes on peer review from Wikipedia, Elsevier, and Wiley, but they all say essentially the same things.

    Peer review maintains standards of quality, improves the science, and provides credibility for published data.

    The process is pretty simple. An investigator (scientist, doctor, enterprising fifth grader) documents how they did an experiment, their results, and what they believe those results mean. They then submit that documentation to a scientific journal. If the submitted information is strong enough, the journal shares it with individuals who are knowledgeable in the area of investigation. Those individuals (peer reviewers) then go through the entire document with a fine toothed comb. If they find a problem with the manuscript, they send it back to the original investigator for additional experiments, revised conclusions, and any number of other modifications intended to increase the quality of the information.

    Peer Review Rejects Flawed Attempts At Science

    Most publications are not accepted for publication without changes, and the vast majority will go through at least two rounds of revisions before the reviewers deem it high enough quality to share with the world.

    And – the scientific community actually rejects a significant portion of submitted manuscripts for scientific shortcomings. This applies only to situations in which the reviewers find scientific shortcomings too serious to be fixed through the process of peer review, but it happens fairly often. It also protects the integrity of published information by preventing mass-distribution of incorrectly reasoned or executed experiments.

    Real References Include Statistics

    Listen, I hate statistics too. Believe me. But much like a Good Housekeeping seal of approval or a great score from Consumer Reports, statistics help us determine whether or not we can trust data.

    Let’s say you’re doing an experiment. You want to see if fifth grade girls carry the same amount of gum as fifth grade boys. You bump into one fifth grade girl who has 2 pieces of gum, and one fifth grade boy who has 4 pieces of gum.

    At first blush, it seems like you could say that fifth grade girls do not carry the same amount of gum as fifth grade boys. But this is where statistics would help. If you did a simple test on your data, you would find out that your data is not significant – i.e. statistics say that the 2 pieces of gum for the girl and the 4 pieces of gum for the boy aren’t necessarily different. Probably because your sample size – i.e. the two kids you polled – was too small.

    Now, if you expand that experiment to polling 500 fifth grade girls and 500 fifth grade boys, you might find out that girls have 2.3 pieces of gum on average. And boys have exactly 3 pieces of gum on average. Well those two are actually closer than our first small poll, right?

    But statistics takes into account the fact that your second poll involved 1000 kids instead of just two. And then statistics say that the difference between 2.3 pieces of gum is significant. Statistically significant.

    That’s an important phrase – statistically significant. It’s your neon flashing light saying “this data matters.” You don’t have to know what a p-value is or a chi squared test. You can even skip right over t-tests and quartiles. All you really need to know is that published data with real value is statistically significant. And the authors will usually come right out and say, “our results were statistically significant.”

    Statistics involve many more subtleties, and I refuse to execute that deep dive until someone requests it.

    Because I hate statistics too. I just know they’re necessary. Like doing laundry and not wearing yoga pants to work.

    This Blog Includes References and Statistics

    Sort of. I absolutely include references. Any time you see me mention a study, a researcher, an investigator, the word is a link to the study. Every single time. If ever you can’t find a link, that’s a mistake. So let me know, please!

    I will not include the actual p-values and statistical information you might find buried in the scary parts of my dissertation. If you want information like that, please find the mustiest part of your local university library and go nuts. Or click the links to the studies.

    In this blog, I will include statements about statistical significance. Like in this post, where I say there is a “real statistical difference” between the two groups of women tested. Or in this one where I make several statements including the fact some data was not statistically significant.

    Reliable Data Can Be Repeated

    When a scientist is lucky enough to achieve statistically significant results, either through a deal with the devil or a well-designed experiment, the data still isn’t beyond question. Once published, other researchers around the world execute their own similar experiments, building on or directly repeating the original experiment.

    That’s how people discover what turn out to be the biggest scientific scandals ever. Bunches and bunches of scientists repeat experiments without arriving at the same results as the original publication, and then the internet yells about it. A lot. All leading to the giant discovery that either someone lied about their original data, or they left important information out of their methods.

    Repeatability also leads to what we call scientific consensus. Science Moms actually do a pretty great commentary on the value of scientific consensus in this video. The gist is that over time, scientists all over the world repeat and build upon previously published data. Eventually the scientific community as a whole arrives at a consensus, an accepted agreement that the original data is valid. Because. So many people directly reproduced it or built further data upon the validity of the original data.

    Is This Reference Legit: A Checklist

    As you’re scrolling through Facebook, wondering why your grandmother posts so frequently about the health benefits of red wine, use this checklist to decide if grandma knows her stuff.

    Or is just an apologetic wino.

    • Is there a reference for the stated “facts”?*
    • If so, is that reference peer reviewed?*
      • Not sure?Go to PubMed and search for it. If it’s in PubMed, it’s probably peer-reviewed.If it’s not in PubMed, try Googling the publisher. If it’s a legitimate journal, they will have a site and an explanation of their peer review process.No site, no explanation of peer review? Not legitimate.
    • Does the reference say the results were statistically significant?*

    If you answer yes to all of the starred question above, the reference is probably be legitimate. As with all things, there are exceptions. But this list will get you to the right conclusion 95% of the time.

    Not sure if a reference is legit? Don’t have time to check it out yourself? Just do what my fabulous friends do, and ask me in the comments or send me a message!

    Photo by Sunyu on Unsplash

  • Does Pregnancy Accelerate Aging?

    URGENT DISCLAIMER: I have never been pregnant, so I have no personal experience with any of the real life side effects of pregnancy. I am in awe of those of you who do. Several of my brave friends have shared a few choice tidbits, which is how I know that pregnancy is not for the faint of heart. Well, that and a lot of science.

    Anyway, the reason for this post is a recently published study in which the authors have boldly declared that pregnancy does in fact accelerate the aging process. This is what they’ve titled their study:

    Reproduction predicts shorter telomeres and epigenetic age acceleration among young adult women

    I can already hear my friends – of course pregnancy accelerates aging! Because it ends in children, and children give their parents gray hair and heart disease. They’re always finding that one outlet you forgot to cover, mouth kissing the dog, and discovering their acrobatic skills on the second story balcony, precariously balancing twelve feet from the concrete floor that now seems like more of a health hazard than a “sleek feature for the modern homebuyer.”

    And also, our mothers have been loudly beating this concept into our brains pretty much since birth.

    But science says (1) your mom was right (Take a moment to get your arms around that. If you’re struggling, remember that no one can make you tell your mom that she was right.), and (2) babies actually do even more to steal away their mothers’ youth*.

    How exactly do they accomplish this? Well, first, take heart. Your baby isn’t using it’s tiny fingers to damage your DNA. Technically, your body is doing that. The biochemical processes involved in pregnancy shorten the ends of your chromosomes and they alter a process involved in DNA traffic management*, both of which contribute to aging at the cellular and molecular levels.

    Telomeres Keep Your DNA Young

    Your genetic material hangs out in chromosomes, the three-dimensional DNA sculptures found in the nucleus of each and every one of your cells. Every time a cell replicates, and most of the cells in your body do that pretty frequently, it copies that DNA and passes it on to the new cell. For the process to go off without a hitch, the cell uses a complicated system that I’m going to grossly oversimplify and probably offend any molecular biologist who stumbles upon this post. But, if you’re not a scientist, you’ll get the take-home message. And that’s why I’m here.

    Imagine that your chromosome is just a straight line, not a complicated three dimensional shape. At the end of that straight line is a little tail that we call a telomere. The telomere exists to make sure that your DNA is copied completely and faithfully, so that you don’t lose any important information toward the end of your DNA strand. The DNA copying process looks kind of like this:

    telomeres shorten during pregnancy

    It takes TONS of cycles (yes, that is the technical scientific term for it) of cell division for telomeres to get short enough to cause real problems in your cells. But, when that happens, the problems are very real. The cell with the short, sad telomeres (or none at all) will enter a phase called senescence, which basically means that the cell stops working correctly and may die.

    Fortunately for most of us, our bodies make this cool enzyme that adds pieces back to our telomeres after they’ve been lost. Kind of like when you lose your favorite t-shirt. You think you’ll never see it again, but then it turns out your mom just sewed the sleeve back on for you, and you get another 15 years with it.

    So, what does that have to do with pregnancy and aging?

    Pregnancy Shortens Telomeres*

    Yep, this study investigated a group of women, average age 27 years old, who had experienced varying numbers of pregnancies. Here’s the breakdown:

    0 Pregnancies | 507 Women
    1 Pregnancy | 174 Women
    2 Pregnancies | 102 Women
    3 Pregnancies | 28 Women
    4 Pregnancies | 7 Women

    When they analyzed the effects of pregnancy on telomere length, they found that each additional pregnancy generated between 0.34 and 3.67 years worth of telomere aging. This finding was determined after controlling for other variables like age. So it wasn’t just that older women were more likely to have been alive long enough to have three pregnancies. There was a real, statistical shortening in telomere length as a result of additional pregnancy.

    These researchers found something else kind of interesting. Additional pregnancies don’t seem to affect future fertility.

    So even though each pregnancy ages mom’s cells, it doesn’t seem to affect her ability to inflict that damage on herself again with another pregnancy.

    Pregnancy Changes Your DNA*

    Sort of.

    This study also investigated the effects of pregnancy on something called DNA methylation, which the video below hilariously explains.

    Basically, methylation alters the parts of your DNA that can be expressed. It doesn’t add or subtract information, it just hides or shows it. Kind of like when you’re supposed to be reading your history book but you’ve put Harry Potter inside your history book. You’re not learning history, but the information is still there for when you’ve had enough Hogwarts for the day. I know there’s no such thing. Just use your imagination.

    Back to this methylation issue.

    Your cells run into a lot of problems when methylation gets in the way of their normal functions.

    The researchers in this study assessed what they call DNA-methylation age, and it turns out pregnancy affects that too*. Each additional pregnancy in the study increased DNA-methylation age by between 0.29 and 0.63 years. 

    What Does It Mean?

    Don’t start blaming your children for the fact that you can never find your sunglasses just yet. Unless they’re relentless little kleptos, in which case, please carry on as usual.

    For the rest of you, as is often true in science, one study is not definitive on its own. At least not for the whole population.

    Another study from 2017 looked at the same basic concepts, and you know what they found? Something completely different.

    The CARDIA Study actually began in 1985 and has been conducted exclusively in the United States. At the 20 year follow-up point, 72% of the original 5115 subjects were still reporting their data, which is kind of amazing in and of itself. #GeekMoment

    More interesting to me is the fact that this study found no relationship between number of pregnancies and telomere associated aging.

    Note: The study at the beginning of this post was done in the Phillipines.

    Given the conflicting information between these two very different populations of women, I’d venture to say that pregnancy does age your cells. If you happen to live in the Phillippines and possibly other places in which the conditions of pregnancy create the same cellular conditions.

    No Really, What Does It Mean?

    Well, we know women in the Philippines experience aging at a genetic level during pregnancy, adding years to the state of their genetic code. We also know that the same isn’t true for women in the United States.

    So what’s the moral of this story? If you’re going to have a baby, and you’re choosing between pregnancy in the US or in the Phillippines, choose the US.

    It’s science, y’all!

    *All starred statements only apply to the subjects of the Philippines study.

    Also, scientist gripe: that study title was all kinds of wrong. For science. Here’s an appropriate modification:

    Reproduction predicts shorter telomeres and epigenetic age acceleration among young adult women IN THE PHILIPPINES


    Photo by Arteida MjESHTRI on Unsplash