Stupidity Gone Viral

Charlie Sheen Mosquito

If this is your reaction to seeing a mosquito at Charlie Sheen’s house, then you are unforgivably stupid.

For anybody who hasn’t heard, Charlie Sheen, the former star of Two and a Half Men who made “Winning” 2011’s most annoying catchphrase, recently announced that he is HIV-positive.  HIV stands for Human Immunodeficiency Virus, and despite denialist claims to the contrary, it is the virus that eventually causes AIDS (Acquired Immune Deficiency Syndrome).  A person with AIDS has a severely depressed immune system.  As a result, he or she might succumb to diseases that healthy people don’t normally contract, or which they are able to fight off if they do.

In the early 1980s, when HIV was first discovered in the United States, a newly-infected person might have a decade left if he was lucky.  Now, HIV isn’t necessarily the death sentence that it once was.  With treatment to suppress the growth of the virus and to quell opportunistic infections, a person infected with HIV today might reasonably expect to live long enough to die of other, non-HIV-related causes.

Still, HIV is a life-changing – if not life-ending – diagnosis, so it might be helpful to learn how HIV is transmitted, and to decide whether we really need to bathe in Off! mosquito repellent before visiting the Sheen residence.  Have a seat, kids: it’s time for the After-School HIV Special.

Generally, HIV is transmitted in bodily fluids, so the quickest way to become HIV-positive is to swap liquids with somebody else who is HIV-positive.  The most common routes of HIV transmission are through sexual contact and the sharing of injection drug paraphernalia.  An HIV-positive mother-to-be can also pass the virus to the developing fetus in her womb, or she can transmit the virus via breastfeeding.

Health care workers also assume a small risk of HIV infection due to the danger of being accidentally stuck with needles used on HIV-positive patients.  There is an even smaller risk to blood and organ transplant recipients, but advanced screening techniques have done much to minimize this threat.

And what about mosquitoes?  Surely those damned winged bloodsuckers up the HIV risk factor by a thousand, what with their indiscriminately poking their probosces into one unwitting donor after another, right?

Well, no.  Not that a mosquito particularly cares about spreading disease, but she is prevented from spreading HIV by several factors.  First, the construction of a mosquito’s blood-straw does not allow previously-sucked blood to flow downward into her most recent host.  A mosquito’s mouth parts have two tubes: one carries saliva downward and the other draws blood upward.  The saliva contains chemicals that prevent your blood from clotting, but it does not contain HIV from previously bitten humans.  And why not?

Because HIV is digested in the mosquito’s gut.  In a human host, HIV binds to T cells and begins replicating, but mosquitoes don’t have T cells.  The virus has nothing to attach to in the mosquito’s gut, so it simply gets broken down by the insect’s vile brew of digestive enzymes.  HIV never migrates from the mosquito’s belly to its salivary glands.

So, the virus cannot follow the gut-to-salivary-gland route that some other pathogens – notably malaria – follow.  But what about a more direct route of infection?  Mosquitoes are sloppy eaters, and they rarely use napkins.  When a mosquito leaves her host, she’s likely to have a bit of blood clinging to the end of her schnoz, and if that blood were HIV-positive, couldn’t she inject it into her next host, especially if she decided to feed again within a very short period of time?

Sure, that’s possible…in the same way that it’s possible to win the lottery twice and be struck by lightning five times within the same ten-minute period, and to reach the hospital just in time to see your wife giving birth to octuplets, just before she announces that she’s leaving you for Charlie Sheen.  Which is to say, it isn’t very possible at all.

Surprisingly, the virus count in an HIV-positive person’s blood is pretty low.  It’s highly unlikely that the blood stuck on the end of a messy mosquito’s maw contains even a single virus, let alone a large enough virus load to start a new infection in the mosquito’s next host.  Natalie Peretsman, writing for, reckons that if a mosquito were to drink from an HIV-positive person whose blood virus level was 1000 per milliliter, and if that mosquito were to immediately feast on a nearby healthy person, there’s still only a 1 in 10 million chance that the mosquito would transmit even a single virus to the healthy person’s blood.

So what have we learned?  Mosquitoes transmit many dangerous diseases, but HIV thankfully isn’t one of them.  You needn’t fear a mosquito at Charlie Sheen’s house, unless it turns out that Charlie Sheen has also contracted malaria, dengue fever, or chikungunya.

On a personal note, the vectors of HIV have been known for decades, and it’s well established that mosquitoes are not among them.  To make a joke like this either (A) portrays devastating ignorance of (and indifference towards) a very real public health issue, or (B) says that you’re the kind of person who thinks it’s hilarious to paint yourself and your supporters as blithering idiots.  In either case, shame on the person who made this macro, and shame on anybody who shares it.  Abysmal ignorance isn’t funny.  Stop glorifying it.


If It’s On The Internet…

Total BS

If you’ve spent any time around humans, you’ve probably noticed that we’re not a rational bunch. We tend to draw conclusions based on our personal prejudices rather than empirical evidence. When confronted with conflicting evidence, we often reject it out of hand. I’m as guilty of this as everybody else; I think it’s a defense mechanism meant to keep our minds from having to reconstruct our worldviews on a daily basis. Evolutionarily speaking, it’s good for us to have a consistent image of how the world works.

Fortunately, we’ve recognized this shortcoming and invented science as a means of by-passing it. We humans use science to know about the natural world, but also to improve the quality of our lives. One of the greatest practical achievements of science is medicine, that vast branch that helps determine what’s good and bad for us.

Of course, not everybody accepts the findings of science/medicine, because – as I pointed out – it’s a lot more comfortable to stick to your ideological guns. Every now and then you’ll come across a meme like this one, which seems to fly in the face of established science. It’s tempting to dismiss this meme as so much bollocks, but let’s take the time to see what evidence is available to confirm or refute each of the author’s claims.

Exposure to the sun generates vitamin D which will protect you from cancer.

If you want to stir up a poop-storm of controversy, nothing stirs faster than the topic of cancer (not the Tropic of Cancer, which to the best of my knowledge is not controversial at all). Claim that something causes or prevents cancer, and soon you’ll have a multitude of angry self-proclaimed medical experts beating down your door to tell you why you’re wrong. Unfortunately these armchair physicians seldom come armed with peer-reviewed studies. What do the real experts have to say about the Sun, vitamin D, and cancer?

According to the National Cancer Institute, an arm of the National Institute of Health, the link between vitamin D and cancer is not well-understood. Here’s what we do know:

Vitamin D helps the human body process calcium and phosphorus, which are essential for healthy teeth and bones. Your skin does indeed produce vitamin D when exposed to sunlight, but you also get vitamin D in your food. What’s the connection between vitamin D and cancer? Early studies indicated that certain types of cancer were less common – and less often fatal – in people living close to the equator than in people living at higher latitudes. One proposed hypothesis was that since equatorial inhabitants receive more direct sunlight, their bodies produce more vitamin D. Vitamin D does seem to inhibit cancer growth in mice; perhaps something similar is happening in people? Sadly, further studies have been inconclusive. At present, there is little data to indicate what benefit, if any, vitamin D has in keeping people cancer-free.

Furthermore, there are many types of cancer: the NCI never mentions a specific link between vitamin D and skin cancer, which is the kind of cancer most often associated with excessive exposure to sunlight. So, even if vitamin D does protect you from some types of cancer, it might not protect you from skin cancer; ergo, you should probably stock up on sunscreen if you’re going to be outdoors a lot, right? Right?

Sunscreen contains chemicals that actually give you skin cancer.

Ah, so this is the author’s angle. Silly people: the Sun doesn’t cause cancer – the cream you rub on your skin to protect yourself from cancer causes cancer! What cruel irony!

Well, not so fast. Dr Ronald Siegle, writing for the Skin Cancer Foundation, debunks rumors regarding the potential carcinogenic properties of sunscreen. According to Dr Siegle, there is no compelling evidence that the ingredients in sunscreen present a cancer risk to humans. So why do some folks think otherwise?

Probably because some sunscreens contain titanium dioxide nanoparticles. Titanium dioxide in powder form is highly toxic when inhaled, and a possible carcinogen to humans. Some people are concerned that the tiny titanium dioxide particles in commercial sunscreens could penetrate through the skin and enter the bloodstream. Dr Kenneth Portier, writing for the American Cancer Society, says that scientists have been unable to determine what amount of TiO2 actually makes it through the outer layer of skin cells, and to what depth. Dr Portier also points out that not every brand of sunscreen contains titanium dioxide, and echoes Dr Siegle in saying that overall, applying sunscreen is still a smart idea if you’re going to be outdoors. Despite what some people say, sunscreen helps reduce the risk of skin cancer, so slather up.

Al Qaeda is the CIA and your government is the major threat.

This statement opens many cans of worms.

It has certainly been rumored that the United States armed and supported Al Qaeda during the latter operation’s formative years. Is there any truth to these rumors? Predictably, that depends on who you ask. The supposed link between the CIA and Al Qaeda goes back to the Soviet invasion of Afghanistan. The United States, in an effort to stymie the Soviets, provided support to the local Afghan mujahideen (Islamic guerilla fighters), but denies ever having been intimately connected with so-called foreign, or Arab, mujahideen who laid the foundation of Al Qaeda. United States government officials argue that there were plenty of indigenous mujahideen invested in repelling the Soviet invasion force; ergo it was unnecessary to bring in foreign fighters, particularly those who were already well-funded by Muslim sources and openly hostile to Americans.

Remarkably, Osama bin Laden, a co-founder of Al Qaeda, agreed with the United States government’s portrayal of the U.S./Al Qaeda relationship in those early years; i.e. that there was none. And yet…

Other sources, notably Saudi Prince Bandar bin Sultan, have claimed that Osama bin Laden expressed gratitude toward the United States of America for its role in helping the Afghan mujahideen. This seems to contradict most other depictions of Osama bin Laden, who was never portrayed as being a fan of the United States.

Flash forward to September 11, 2001, when terrorists linked to Al Qaeda hijacked four airplanes and intentionally crashed three of them into the World Trade Center and the Pentagon. Despite an extensive investigation showing that the 9/11 attacks were in fact the act of a radical Islamic terrorist organization, many conspiracy theorists leapt headfirst into the conclusion that the United States government either orchestrated the attacks themselves, or knew about them beforehand and was complicit in allowing them to happen.

The conspiracy theorists point to what they perceive as inconsistencies and physical impossibilities in the events leading up to the attacks. I don’t have the time or energy to review and debunk every conspiracy theory that has popped up in the wake of 9/11 (nor do I need to, as many sources, Popular Mechanics, e.g., have already done so). I don’t expect the diehards to be convinced; conspiracy theories are born of a need to have an explanation that fits one’s prejudices, regardless of whether the explanation is true or even plausible.

So where does that leave us? Is Al Qaeda the CIA? Is our government a major threat? There’s no evidence to support a positive answer to the first question, and I don’t think the second question even has a defensible answer. Sure, the government has done some shady stuff; in fact, it continues to do so. But just because our government has done some bad things doesn’t mean it has done every bad thing. We must be careful when leveling such accusations.

Diet products contain aspartame and aspartame causes brain cancer.

Some diet products contain aspartame, but aspartame has never been scientifically linked to an increased risk of brain cancer in humans. Many of the misconceptions about aspartame are probably connected to a hoax email that has been circulating since at least 1998. The Food & Drug Administration has responded to the email, saying that it is full of pseudoscientific nonsense. Both the National Cancer Institute and the American Cancer Society attest to the safety of aspartame and other artificial sweeteners.

“But wait a minute,” you might say, “What about that study showing that aspartame increased cancer risks in men who drink diet sodas?” People who already wanted backing for their pre-formed conclusions that aspartame was dangerous leapt on the report like a lion on a gazelle. They seemingly had their smoking gun. Nevermind that the report’s authors – who pre-maturely promoted it – recanted their support almost immediately when the report was finally released. They called their own findings weak and untenable; in other words, they no longer felt comfortable hanging their confidence on it. Similar studies purporting to show hidden dangers in aspartame have likewise been called methodologically unsound by the international scientific community. Aspartame is one of the best-tested food additives in existence, and the available evidence – from laboratories all over the world – shows that it is safe.

Mammograms expose you to ionizing radiation which will give you cancer.

Life exposes you to ionizing radiation. Every day, every second, your body is being bombarded by charged particles and high-energy photons moving at fantastic speeds. Although these particles are sub-microscopic, they pack quite a wallop on the molecular scale; in fact, they can damage your sensitive genetic code.

In many cases your cells are able to catch the damage and repair it before it can spread. In other cases the cell is sacrificed to save its host: you. Your body has myriad ways to protect itself from the effects of ionizing radiation.

In very rare situations, a cell suffers a mutation that shuts off the mechanism that tells it when to stop growing. If your body’s defense system fails to identify and destroy the cancerous cell, it will grow and divide out of control, threatening the survival of tissues, organ systems, and eventually its own host. It’s a testament to the power of our immune systems that these aggressive cancers seldom get beyond the single-stage cell, but when they do, the results can be devastating.

If we increase our exposure to ionizing radiation, we increase the likelihood of developing cancer. Scientists have made careful measurements and estimates of the amount of radiation received in various situations, and these measurements inform dosage recommendations. Check out this website to learn about how much radiation is too much. While you’re there, be sure to click on the diagram for a closer look; it’s really informative.

As you can see, the average radiation dose from a mammogram is 3 milliSieverts. The maximum yearly dose permitted for U.S. radiation workers is 50 milliSieverts, so you could have sixteen mammograms in a one-year period without exceeding the recommended maximum dose for people who routinely work in high-radiation environments.

You would have to receive a yearly dose of 100 milliSieverts (about 33 mammograms) before you had an increased risk of cancer. I don’t think too many people will receive 33 mammograms in a year. Bottom line: the radiation you receive during a typical mammogram is far below the level needed to increase your risk for developing cancer.

To be fair, it takes only one radiation particle to get the cancer ball rolling. The longer you live, the more likely you are to take a critical hit in your DNA. Ironically, that makes it more important that women over 50 get regular mammograms. It’s a measured risk: the microscopic impact in your yearly radiation budget is more than countered by the likelihood that you’ll detect breast cancer in its early stages.

Most vaccines contain thimerosal (mercury) that will kill you.

In a word, no. Thimerosal is not mercury; it is an organic compound that contains mercury. That’s an important distinction, because it changes how the chemical is absorbed and processed inside the body. Many vaccines used to contain thimerosal as a preservative because it would prevent the growth of harmful bacteria in the vaccine medium. According to the USFDA, thimerosal was eliminated or reduced to trace amounts in most vaccines in response to growing concerns about its safety. Today, most of the vaccines recommended for children under 6 are thimerosal-free, with the exception of flu vaccines (and you can even request a thimerosal-free flu vaccine). Contrary to this meme’s assertion, most vaccines do not contain thimerosal.

Now let’s address the second part of the statement: can thimerosal kill you? Well, it’s no secret that mercury is exceedingly bad for you, but different compounds of mercury behave in different ways. Thimerosal is a derivative of a compound called ethylmercury. The Center for Disease Control explains that ethylmercury, unlike elemental mercury and methylmercury, is broken down and eliminated by the body. It doesn’t slowly accumulate to dangerous levels; furthermore, the few vaccines that still contain thimerosal have it in exceedingly low concentrations.

You’ve no doubt heard stories of people who claim that they or their children were made ill by a vaccine. There will always be people who react badly to certain vaccines, but it almost certainly has nothing to do with mercury. As with mammograms, vaccines represent a miniscule risk, and the benefits far outweigh it.

One more question needs answering: if thimerosal is so harmless, why did the FDA request that vaccine manufacturers remove it from most of their products? The FDA and its European cousin, the AAP, followed a better-safe-than-sorry approach. They opted out of thimerosal in the remote chance that it was harmful, reasoning that there was little harm in being overly cautious. Unfortunately, the destructive and now discredited ex-Dr Andrew Wakefield confused the issue by releasing a study supposedly establishing a link between the measles-mumps-rubella (MMR) vaccine and autism. To the conspiracy-minded, the timing was too good to ignore: of course the FDA knew that vaccines cause autism; that’s why they rushed to eliminate thimerosal. By the time the dust settled on the Wakefield scandal, the damage was done. Too many parents still refuse important vaccines for their children in the mistaken belief that they pose a health risk. Subsequently, dangerous diseases that were once under control are making a roaring comeback.

Fluoride is poison and it will give you cancer and kill you and cause dental fluorosis.

It tickles me that dental fluorosis is thrown in almost as an afterthought. Fluoride will kill you…and your teeth will be ugly at your funeral!

At any rate, I’ve written about the “dangers” of fluoride before. To summarize: the fluoride levels in toothpaste and drinking water are far below dangerous levels. You would have to gobble down many tubes of toothpaste (at once) before you stood a better-than-average chance of being harmed by fluoride. There is no credible evidence to suggest that our health is being jeopardized by the fluoride we regularly consume. Warnings on toothpaste tubes are put there to protect the companies, not because their product is actually dangerous.

So that’s it. This meme was a whole lot of nonsense, but I think we’ve gained a valuable insight into the mind of its author. The author hates and distrusts the medical establishment and the government, and is willing to accept anything as long as it confirms his beliefs. Let’s consider this a cautionary tale…not of the evils of Big Government, but of the evils of uncritical thinking.

Sweet Suffering

Aspartame Poisoning

Nobody needs soda. Tell the truth, we’d be better off if they’d never been invented. There’s not a lot of clear evidence to show that diet sodas are any healthier (or unhealthier) than regular sodas. If somebody wants to swear off all sodas, that’s probably a wise decision.

So I’m not here to defend diet sodas. I just want people to make decisions based on reality, not alarmism.

You would be hard pressed to find any topic about which more people are self-proclaimed experts than the relative safety of the things we put into our bodies. From vaccines to vitamins, from aspartame to gluten, if it has the potential to enter your body orally, anally, or hypodermically, everybody’s got an opinion they are not interested in changing.

Some of these opinions are based on solid scientific evidence, but many are not. A lot of opinions are based on anecdotal evidence. Anecdotal evidence comes from a small number of personal observations. It doesn’t bear the weight of repeated scientific observations and analysis; in fact, it may be cherry-picked to fit a pre-formed conclusion.

Here’s an example of anecdotal evidence: If you suspect that aspartame is toxic, and a friend (who loves Diet Coke) suddenly develops anxiety issues, then bingo: that’s all the confirmation you need. Aspartame is bad. Aspartame is evil. Aspertame caused your friend’s health problems.

Right? Well, not necessarily.

There are hundreds of reasons a person might suffer from sudden anxiety. It takes a thorough examination (sometimes lasting weeks or months) to pin down a cause. You cannot make a snap diagnosis. Furthermore, you’re conveniently ignoring all the people who drink Diet Coke on a regular basis and never develop anxiety-related disorders. If you claim that you know aspartame caused your friend’s anxiety attacks before a medical professional has examined him…well, that’s irresponsible, arrogant, and naive.

Scientific studies – conducted by real scientists who understand the value of repeatable experiments – have shown that aspartame is safe. And we’re not just talking about a few studies done 30 years ago, when aspartame was first used as an artificial sweetener. Hundreds of studies spread over three decades have amassed evidence pointing to the same conclusion. There is no reason to believe that aspartame causes lupus, multiple sclerosis, anxiety, fibromyalgia, slurred speech, blurred vision, zombiism, rockin’ pneumonia, boogie woogie flu, or any of the other illnesses often attributed to it.

Cue the conspiracy theorists:

The FDA and diet soda producers know that aspartame is harmful, but they won’t acknowledge the truth because it would mean a huge cut to their profits.

Ah, the final line of defense for somebody who doesn’t have a scientific leg to stand on: paint a picture of corporate greed so vile that the corporate masters would rather see people suffer and die than spend the money necessary to re-engineer their product. Who doesn’t hate that? Oooh, scary.

Yeah, sure, some corporations do shady things. I mean some really shady things. I wouldn’t put it past a corrupt CEO to sweep damaging evidence under the rug. But the level of conspiracy needed to hide the supposed toxicity of aspartame from the world would be truly staggering. Remember those studies I mentioned showing that aspartame was safe? Many of them were conducted in other countries, far from the controlling arms of the FDA and its corporate sugar daddies (or NutraSweet daddies, I guess). Who bribed, cajoled, or threatened those scientists to suppress the heinous truth about aspartame?

Once again, diet sodas may not be a healthier choice than regular sodas. If you don’t want to drink them (or any other sodas), good for you, but please be rational about your reasons for abstaining. Leaving aspartame out of your diet won’t hurt you, but neither will consuming it.

You might be asking: “If you’re going to imply that we shouldn’t drink sodas at all, then why does it matter what people think about aspartame?” I’m glad you hypothetically asked. I have two reasons for deconstructing this meme.

  1. Aspartame is used in other products besides diet sodas, not of all of which are as unhealthy as sodas in general. Unfairly maligning aspartame will hurt the business of companies that really aren’t pedalling dangerous products.
  2. The anti-aspartame argument smacks of the anti-vaccination argument. It doesn’t matter if you avoid aspartame, but it definitely matters if you avoid vaccinations for yourself or for your children. If you fall prey to uncritical thinking in one situation, what’s to prevent you from doing so in the other?

In the interest of full disclosure, I do drink sodas. I drink the high-octane, high-fructose regular sodas, not the diet kind. I know it’s not a healthy decision, but I enjoy them. I’m not wagging my finger at you if you drink sodas. I’m wagging my finger at you if you cite a false reason for not drinking diet sodas.