Marijuana and cancer – Sanjay Gupta’s anecdotes are not science

Editor’s note–this article has been updated and included into a multi-part series on marijuana and medicine. Check it out there. 

Unless you were hiking in the Amazon River jungles, with no access to the internet or American TV, you probably have heard that CNN’s chief medical correspondent, Dr. Sanjay Gupta, changed his mind about marijuana (or “weed” as he keeps saying). Of course, this has become big news, because he’s such a “respected doctor” (why is that? Because he’s on TV?), and because a few years ago he was vociferously anti-cannabis.

I have no doubt that Dr. Gupta’s “conversion” to being pro-weed is genuine (and that his previous stance of anti-weed was similarly authentic), but we need to weed out what is real and what’s just smoke about his comments. His first major point about cannabis* was that the United States Drug Enforcement Agency (DEA) considers marijuana to be a Schedule 1 drug, which is defined as “drugs with no currently accepted medical use and a high potential for abuse.”

Dr. Gupta thinks this classification is ridiculous, and on the surface, many people, even those who are not devoted pot smokers, would probably agree. However, this is a political discussion, at least in the USA, and it is hardly a medical/scientific one. The chances of any political party having the fortitude to correct this classification is about as close to 0 as you can get, without actually stating that there is a 0 chance. But if Gupta wants to make a big deal of this, or that he’s so self-centered that he thinks he’ll change the mind of politicians, more power to him. But for me as a skeptic, it is not the most important thing he says.

In his article, he mentions a young girl who “started having seizures soon after birth. By age 3, she was having 300 a week, despite being on seven different medications. Medical marijuana has calmed her brain, limiting her seizures to 2 or 3 per month.” This is simply an anecdote of no quality whatsoever. Did he thoroughly investigate her case to determine if the number of seizures actually went down? Do we know that cannabis has anything to do with the change? Is this nothing more than a Post hoc ergo propter hoc fallacy, that just because she consumed cannabis and the seizures decreased does not mean anything about cannabis’ causative properties with regards to this type of seizure. And then, Dr. Gupta continues with the anecdotes by stating, “I have seen more patients like Charlotte first hand, spent time with them and come to the realization that it is irresponsible not to provide the best care we can as a medical community, care that could involve marijuana.” Why do these TV doctors (like Dr. Oz) think that their anecdotes are better than anyone else’s.

Anecdotes are useless because they aren’t controlled, because they are subject to all levels of bias, and because these stories aren’t peer-reviewed. In other words, anecdotes have no value in science-based medicine. Anecdotes do have value in formulating testable scientific hypotheses, but assuming that anecdote=data, and more anecdotes=more data is simply pseudoscientific. I don’t care what Sanjay Gupta writes or says publicly, but providing these stories as “evidence” that marijuana has a medical benefit is essential like telling me that he observed homeopathy (which is just water) working. It’s laughable.

Continue reading “Marijuana and cancer – Sanjay Gupta’s anecdotes are not science”

More evidence Vitamin D supplementation does not reduce breast cancer risk

vitamin-DPotential causes for cancer are numerous. InfectionsRadon gasCigarette smokingSun exposure. Obesity. With over 200 types of cancer, each with a different pathophysiology, there may be an equal (and probably greater) number of causes.

Although some cancers can be easily prevented, such as never smoking, which reduces your risk of lung cancer, one of the most prevalent cancers in the USA, by over 85%. Or getting the HPV vaccine (Gardasil or Silgard) which blocks HPV infections that are associated with several types of cancer, including cervical, anal, and penile cancers. Unfortunately, the sheer complexity and number of types of cancer means that there is probably not going to be any simple panacea to preventing (or even curing) cancer. In fact, some hereditary cancers, such as those individuals who carry genes that are implicated in breast and ovarian cancers, may not be preventable at all. 

Other than eliminating direct risks, are there things that can be done to actually prevent “cancer”? Once again, with over 200 types of cancer, this may be an impossibility, but the three most popular cancer prevention ideas are diet, vitamins and other types of nutritional supplements. Vitamins and other supplements are a $61 billion industry in the US. They generate these sales with minimal regulation, minimal quality control over the quality and dosage, and no requirement to actually provide evidence that the supplements do what is claimed by the supplement industry, aka Big Herbal. The FDA only gets involved with the industry if there’s some dangerous side effect, or when the claims of the industry are so outrageous that the FDA has no choice but to get involved.

Not too astonishingly, there just hasn’t been much evidence that cancer can prevented with supplements. Prostate cancer and fish oil? May actually increase risk, but generally no effect. Prostate cancer and soy? Nothing there either. Folic acid and cancer? May actually increase risk.  Continue reading “More evidence Vitamin D supplementation does not reduce breast cancer risk”

HPV vaccinations lagging despite strong safety and effectiveness

hpvThe CDC recently reported that only about half of US teenager girls have received the safe and effective quadrivalent HPV vaccine (HPV4), a disappointing level of vaccine uptake. Moreover, this rate hasn’t changed over the past three years, despite significant efforts to increase the awareness and effectiveness of the vaccine amongst teenagers. Even worse news in this report is that only about one-third of teenage girls have been fully immunized with all three doses.

HPV quadrivalent vaccine, also known as Gardasil (or Silgard in Europe), is marketed by Merck & Co., usually for vaccination of teenage girls (with an increasing number of boys). The vaccine prevents the transmission of certain types (pdf) of human papillomavirus (HPV), specifically types 6, 11, 16 and 18. 

HPV types 16 and 18 cause approximately 70% of cervical cancers, and caused most HPV-induced anal (95% linked to HPV), vulvar (50% linked), vaginal (65% linked), oropharyngeal (60% linked) and penile (35% linked) cancers. These cancers, mostly related to HPV, can be prevented as long as you can prevent the HPV infection from ever happening, which usually happens through genital contact, most often during vaginal and anal sex.

HPV may also be passed on during oral sex and genital-to-genital contact. HPV can be passed on between straight and same-sex partners—even when the infected partner has no signs or symptoms. Approximately 79 million Americans, most in their late teens and early 20′s, are infected with HPV, and about 14 million people become infected each year in the USA. Continue reading “HPV vaccinations lagging despite strong safety and effectiveness”

Soy supplements and prostate cancer–no effect

Tofu is displayed in a supermarket in Santa MonicaOver the past few years, some research has suggested that there might be a correlation between high soy consumption and lowered prostate cancer risk. Most of the research suggesting the link was observational or based on animal studies on the role of soy supplements on the risk of prostate cancer, or on the risk of recurrence of the cancer after treatment.

According to the American Cancer Society, there is some logic to a potential causal relationship between soy consumption and risk of prostate cancer:

Plant estrogens (phytoestrogens) were first identified in the early 1930s. At that time it was discovered that soybeans, willows, dates, and pomegranates contained compounds that were much like estrogens. Scientists began studying the role isoflavones play in reducing breast cancer risk in the 1960s. In a 1981 prospective study in Japan, researchers found that daily intake of miso, a soybean paste, was linked to lower death rates from stomach cancer in more than 260,000 men and women. Around that time, other studies on soy began to be published in the United States. In October 1999, the U.S. Food and Drug Administration (FDA) agreed to allow health claims about soy’s role in reducing heart disease on food products containing soy protein. Continue reading “Soy supplements and prostate cancer–no effect”

Study shows HPV vaccine lowers HPV infection risk in teen girls

conservative-HPV-vaccineHPV quadrivalent vaccine, also known as Gardasil (or Silgard in Europe), is marketed by Merck, usually for vaccination of teenage girls (with an increasing number of boys). The vaccine prevents the transmission of certain types (pdf) of human papillomavirus (HPV), specifically types 6, 11, 16 and 18. HPV types 16 and 18 cause approximately 70% of cervical cancers, and caused most HPV-induced anal (95% linked to HPV), vulvar (50% linked), vaginal (65% linked), oropharyngeal (60% linked) and penile (35% linked) cancers. These cancers, mostly related to HPV, can be prevented as long as you can prevent the HPV infection from ever happening, which usually happens through genital contact, most often during vaginal and anal sex. HPV may also be passed on during oral sex and genital-to-genital contact. HPV can be passed on between straight and same-sex partners—even when the infected partner has no signs or symptoms. Approximately 79 million Americans, most in their late teens and early 20’s, are infected with HPV, and about 14 million people become infected each year in the USA. Continue reading “Study shows HPV vaccine lowers HPV infection risk in teen girls”

Japan Health Ministry pulls recommendation for HPV vaccination

The comments have been closed for this article. Please comment at the revised article.

I was going to put some snarky comment in the title like, “but wait, what about the statistics.” Because we know that this isn’t a good decision, and that the vaccine deniers will be all over it like MrAndy Wakefield’s fraudulent and retracted study claiming that vaccines cause autism. But let’s move on to what happened.

According to a English newspaper in Japan,

The health ministry decided June 14 to withdraw its recommendation for a vaccination to protect girls against cervical cancer after hundreds complained about possible side effects, including long-term pain and numbness.

The Ministry of Health, Labor and Welfare is not suspending the use of the vaccination, but it has instructed local governments not to promote the use of the medicine while studies are conducted on the matter.

So far, an estimated 3.28 million people have received the vaccination. However, 1,968 cases of possible side effects, including body pain, have been reported.

The ministry’s task force discussed 43 of those cases. However, a cause-and-effect relationship between the vaccination and the pain and numbness could not be established, so the task force members called for further studies by the ministry.

The ministry’s investigation is expected to take several months. It will then decide whether to reinstate or continue to withhold its recommendation for the vaccination.

So, the health ministry is going to withhold recommendation of the HPV vaccination because they notice 43 cases for which they couldn’t establish a causal relationship to the vaccine. In other words, 0.0013% of cases, a number so small that it’s pretty close to impossible to affix any statistical significance to it. In fact, random background “noise” (that is that some whole body pain could be expected in any random sampling of vaccinated or unvaccinated individuals) of this type of observation is as plausible as correlation (let alone causation) to the vaccine. In fact, the Health Ministry failed to provide us with data concerning the level of these side effects in the general population. Nor how soon after vaccination. Nor anything potentially useful in a scientific analysis.

What’s worse is that, according to the same article, about 2700 women in Japan die every year from HPV related cancers. So, because of complaints from the antivaccination lunatics in Japan (didn’t know they had any, but I shouldn’t be surprised), and bad statistics (43 potential cases of “body pain” out of 3,280,000 vaccinations), the Health Ministry stops recommending the vaccine. Exactly what were these people thinking?

Finally, let’s be clear here. The vaccine hasn’t been pulled from the market nor has it been outlawed; teenagers can still get the vaccine. And this was a very unusual move, since only 3 years ago, Japan’s parliament added the HPV vaccine to the mandatory schedule. Hopefully, this committee will look at the numbers from a statistical and scientific point of view and fix this stupidity.

By the way, the World Health Organization still recommends the HPV vaccine.  Because the HPV vaccine saves lives by preventing future cervical cancers.

 

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Do GMO crops have a higher yield? It depends on the answer.

gmo-corn-rxThe Union of Concerned Scientists (UCS) is an American environmental organization founded in 1969 at the Massachusetts Institute of Technology, which claims 400,000 members. They focus, generally, on environmental issues like nuclear power, global warming and a few other issues. Many of these issues are critically important, and a science advocacy group like UCS helps keep the scientific facts about global warming and other environmental issues at the forefront of the discussion.

But one area where UCS has gone off the rails of scientific evidence and embraces generally left wing science denialism is agriculture, more specifically GMO, or genetically modified organisms (or in this case crops). They are generally supportive of organic farming (which has little or no health benefit at a high cost to consumers) and vehemently opposed to GMO crops, based on what appears to be the same bad scientific critical skills that we observe in global warming deniers. There is nothing more frustrating than dogmatic science that stands against evidence.  Continue reading “Do GMO crops have a higher yield? It depends on the answer.”

Folic acid supplements and cancer–myth vs. science

supplement-burgerPotential causes for cancer are numerous. InfectionsRadon gasCigarette smokingSun exposure. Obesity. With over 200 types of cancer, each with a different pathophysiology, there may be an equal (and probably greater) number of causes. Although many causes can be easily eliminated, such as stopping smoking, testing your house for radon, getting an HPV vaccine to prevent human papillomavirus infections, and wearing sunblock to reduce the risk of melanomas, the sheer complexity and number of types of cancer means that there is probably not going to be any simple panacea to preventing (or even curing) cancer. In fact, some hereditary cancers, such as those individuals who carry genes that are implicated in breast and ovarian cancers, may not be preventable at all.

Other than eliminating direct risks, are there things that can be done to actually prevent “cancer”? Once again, with over 200 types of cancer, this may be an impossibility, but the two most popular cancer prevention ideas are supplements and nutrition. Vitamins and other supplements are a $61 billion industry in the US. They generate these sales with minimal regulation, minimal quality control over the quality and dosage, and no requirement to actually provide evidence that the supplements do what is claimed by the supplement industry, aka Big Herbal. The FDA only gets involved with the industry if there’s some dangerous side effect, or when the claims of the industry are so outrageous that the FDA has no choice but to get involved. Continue reading “Folic acid supplements and cancer–myth vs. science”

Survey identifies reasons for not vaccinating teens

vacs-save-lives-003Vaccines are one of the most important and crucial aspects for the long-term health of babies and young children. Except for a tiny, and irresponsible, minority of individuals who are opposed to vaccinations, greater than 95% of children are fully vaccinated for most vaccine preventable diseases by kindergarten. Unfortunately, a recently published article in Pediatrics provided evidence that teens are not keeping up with vaccinations that are critical to avoid infections from serious, and deadly, diseases. The study examines how vaccination rates have changed over the three year study period, and some of the reasons why they are not getting vaccinated. Continue reading “Survey identifies reasons for not vaccinating teens”

I get an email about Gardasil

hpv posterI get lots of email about my articles that are published here. Sometimes, it’s about grammar or spelling (and the grammar KGB can be uncivil at times). Sometimes, it’s compliments or questions about what I’ve written. Rarely, they’re rude and usually include quite immature comments about the location of my head. However, I recently received an email that is more or less polite, but is filled with so many errors and logical fallacies, that I thought it should be critiqued publicly.

Here are my point-by-point comments about the email:

I stumbled across your blog and could not believe what I was reading about the safety of Gardasil.  As a mother of a Gardasil injured daughter, your profuse endorsement made me skeptical.  I want to begin by saying I am not anti-vaccine;  I am anti-Gardasil.  Continue reading “I get an email about Gardasil”