Cochrane Collaboration

Scientific consensus – collective opinion on vaccines, evolution, climate change

In the hierarchy of scientific principles, the scientific consensus – that is, the collective opinion and judgment of scientific experts in a particular field – is an important method to separate real scientific ideas and conclusions from pseudoscience, cargo cult science, and other beliefs.

I often discuss scientific theories which “are large bodies of work that are a culmination or a composite of the products of many contributors over time and are substantiated by vast bodies of converging evidence. They unify and synchronize the scientific community’s view and approach to a particular scientific field.”

A scientific theory is not a wild and arbitrary guess, but it is built upon a foundation of scientific knowledge that itself is based on evidence accumulated from data that resulted from scientific experimentation. A scientific theory is considered to be the highest scientific principle, something that is missed by many science deniers. In addition, a scientific consensus is formed by a similar method – the accumulation of evidence.

I have written frequently about the scientific consensus because it is one of the most powerful pieces of evidence in a discussion about critical scientific issues of our day – evolution, climate change, vaccines, GMOs, and many other areas of science.

This tome has one goal – to clarify our understanding of the scientific consensus, and how we arrive at it. Through this information, maybe we all can see the power of it in determining what is real science and what are policy and cultural debates.

But the most important thing is that the scientific consensus (and theories, for that matter) are not opinions. They aren’t random thoughts pulled out of the ether. Scientific consensus is based on overwhelming scientific evidence published in respected journals.

Scientific consensus – collective opinion on vaccines, climate change, evolution

HPV vaccine systematic review – anti-vaxxers and Cochrane

Back in May 2018, I wrote an analysis of a new HPV vaccine systematic review that clearly showed that not only was the HPV vaccine very safe, but it was also effective in significantly reducing the risks of cervical cancer. This was powerful and robust evidence that the HPV vaccine is one of the best tools in reducing HPV-related cancers. And that the vaccine is extremely safe, possibly the safest of all the very safe vaccines on the market.

For those who aren’t science nerds like me, you should know systematic reviews are at the pinnacle of the hierarchy of biomedical research. These type of reviews are one of the foundations of science-based medicine (SBM).

The idea of SBM is …to answer the question “what works?” we must give more importance to our cumulative scientific knowledge from all relevant disciplines.

Now I’ve said that systematic reviews are not perfect. For example, the Cochrane Database is considered one of the premier organizations that perform systematic and meta-reviews in the biomedical sciences. If I am looking to determine if there is evidence supporting a medical claim, I look there first. As a scientist, I don’t take their conclusions at face value – for example, they have made egregious errors in systematic reviews of acupuncture quackery in the past. Like all scientific literature, one must examine a systematic review (whether published in Cochrane or any other journal) with a critical eye. Is there bias in including or excluding data? Do they overstate the conclusion? Do they rely upon unusual or bad statistical analyses?

Recently, one Cochrane group has attacked the aforementioned HPV vaccine systematic review, written by another Cochrane group. Time to take a look at that.Read More »HPV vaccine systematic review – anti-vaxxers and Cochrane

Monsanto glyphosate causes cancer – so do apples

Monsanto glyphosate (Roundup) is a broad-spectrum systemic herbicide used to kill weeds, especially annual broadleaf weeds and grasses that are known to compete with commercial crops grown around the world. It has several advantages over many herbicides in that it breaks down in the soil into non-toxic organic molecules, reducing or eliminating contamination of groundwater and lower soils.

Monsanto has developed genetically modified (GMO) grains that are resistant to glyphosate, so that agriculture can apply the herbicide to kill the competitive weeds while not harming the crop. This allows farmers to suppress the weeds while allowing better production out of the grain crop.

Whatever the benefits of Monsanto glyphosate, GMOs and the herbicide are tied together in many minds. And there has been an ongoing effort by many people to claim that glyphosate causes cancer. But let’s look at the science, because maybe we’ll get some information.

Developing and supporting a scientific consensus

by Michael Simpson
2017-02-13
41 Comments
Biotechnology, Cancer, Climate change, Evidence based medicine, Evolution, Food, Pharmaceutical, Pseudoscience, Science journalism, Skepticism, Vaccines

In my writing, I often refer to the scientific consensus, which is the collective opinion and judgement of scientists in a particular field of study. This consensus implies general agreement, though disagreement is limited and generally insignificant.

The major difference between a scientific theory and a scientific consensus is that the theory is essentially fact. It is so predictive, it is supported by so much evidence, and it is so well accepted, it takes an almost ridiculous amount of data to refute it, though it is possible.

In the hierarchy of scientific principles, we often mention scientific theories which “are large bodies of work that are a culmination or a composite of the products of many contributors over time and are substantiated by vast bodies of converging evidence. They unify and synchronize the scientific community’s view and approach to a particular scientific field.” A scientific theory is not a wild and arbitrary guess, but it is built upon a foundation of scientific knowledge that itself is based on evidence accumulated from data that resulted from scientific experimentation.

We want to focus on the scientific consensus, describing what it is. Take a deep breath, because this is a complicated one.

It’s difficult to be a real scientific skeptic – let’s make it easier

by Michael Simpson
2017-02-13
14 Comments
Acupuncture, Evidence based medicine, Logical fallacy, Pseudoscience, Scientific method, Skepticism

Since I started this website, nearly four years ago (that’s 50 internet years), I’ve noticed a serious problem – some skeptics, even scientific skeptics, are lazy, trying to take the easiest way to accept or refute a claim. It is difficult to be a real scientific skeptic (see Note 1). It’s not impossible, but it takes more than using some intentional or unintentional bias or fallacy.

This lack of real skepticism has manifested itself in some incredible meta memes: “vaccines are dangerous,” “gluten is dangerous,” and “GMOs are dangerous,” even in groups who are ostensibly “pro-science.” However, if I replied to them, “wow, you must be a creationist too,” generally, their indignant reply would make a sailor blush.

Scientific skepticism is hard, not because of the complex science (even though, that is part of the issue), it’s because searching for the evidence that supports or refutes some claim is often nuanced, and contradictory. And researching it isn’t easy.

Thus, as a self-proclaimed scientific skeptic, I thought I’d write an article to help anyone learn more about what interests them, how to discriminate between bad and good research, and where to find good information. Sit down with your favorite internet consuming device, grab your favorite snack and drink, and enjoy.

“Homeopaths without Borders” are not humanitarians

by Michael Simpson
2019-08-24
38 Comments
Evidence based medicine, Homeopathy, Pseudoscience, Skepticism

There is an American group called Homeopaths without Borders (HWB), who claims that it provides humanitarian aid, in the form of homeopathic “medicine” or just plain water, to devastated areas of the world. The more famous group that does real lifesaving work across the world, Doctors without Borders, are probably too busy, utilizing real evidence-based medicine with real medications, risking their own lives, and performing great service humanity, to be worried that a bunch of pseudoscientific homeopaths stole their noble trademark to push quackery.

HWB is sending their water magicians to Haiti, Guatemala, Dominican Republic, Sri Lanka, and El Salvador, all countries that have suffered so much during the past few years. During their time in Haiti, “the team will be in Port-au-Prince to complete the final session of the Fundamentals Program—a foundational curriculum in homeopathic therapeutics incorporating theoretical and clinical training.” So not only are they providing nonsense, useless, unscientific healthcare to Haiti, they are training new homeopaths there. Haiti needs to train real doctors who use science based medicine, not quack medicine.

Opinion – vaccine deniers annoy the shit out of me

by Michael Simpson
2015-09-16
68 Comments
Andrew Wakefield, Anti-vaccines, Autism, Logical fallacy, Opinion, Vaccines

This is part of my series of opinion pieces. As I’ve written, it is not meant to be supported by evidence or data – unless I link to evidence. Then it is.

Vaccine deniers, or anyone who is antivaccine for any reason, are a difficult group. They have ideas that are just unsupported by any factual evidence. They have an opinion that they’ll hold on to as if it were a commandment from Thor.

Again, as I’ve written before,

[infobox icon=”quote-left”]Even if you believe that your opinion is right, does not make it so. It’s still wrong. And just because you can troll the internet finding others who share that misconception, again does not move it into the realm of fact, it merely means you’ve found like-minded people who are also wrong. Your wrong opinion is still wrong, and it has no validity. None.[/infobox]

The opinion that vaccines are neither safe nor effective is simply wrong. The vaccine deniers want to claim there is a scientific debate. No there’s not. The vaccine deniers want to claim that their opinion is more valid than the mountains of evidence. It isn’t.

Let’s make this clear – the antivaccination cult is wrong. We’re going with that assumption, because it is valid, and it is supported by mountains of evidence. And just because they whine loudly, they’re still wrong.

So how do they get there? Here are some of my “opinions” of what led them to being so wrong.

Part 1. Marijuana and medicine assessing the science

by Michael Simpson
2020-09-14
3 Comments
Cancer, Cannabis, Neurological, Pharmaceutical, Pseudoscience

I suspect, like legal same sex marriage, social norms are changing across the USA (and the world), which has lead to the decriminalization of marijuana in 23 states and the District of Columbia for some medical conditions. The US Federal Government, has shown little enthusiasm in enforcing Federal law about cannabis, although the Federal government retains the highest authority in regulating certain drugs like marijuana. So let’s look at marijuana and medicine assessing the science critically.

It’s clear that rational people still want regulations for marijuana, including prohibitions against public smoking (I don’t want second hand cannabis smoke wafting over me or my children, as much as I don’t want to inhale other people’s tobacco smoke). And a safe society would have strict regulations that would forbid marijuana smoking by individuals who have roles in public health and safety like physicians, pilots, mass transit drivers, and others.

But I think those would be reasonable boundaries for legalization of cannabis that would be reasonable to most people. But this is not the point of this article.

As the push to legalize marijuana for personal or medical use gains traction in the USA, there has developed a strong belief, unsupported by evidence, of the value of the medical uses of cannabis. What is troublesome is that the pro-marijuana side seems to make claims about the medical uses of cannabis that appear to be only tenuously supported by real scientific evidence.

In fact, some of the claims are downright dangerous. The reasons for pushing this is probably, though I can only speculate, to make it appear that marijuana is some miracle product, so let’s speed up the legalization of it. It’s like the Food Babe telling us that kale is the miracle food, except that kale isn’t illegal. It does taste awful (but again, not the point).

Because of the amount of scientific information, this article is part 1 of a 5-part series about marijuana and medicine – assessing the science. For detailed analysis of various aspects of the science of marijuana and medicine, check out each of the subtopics:

Part 2 – Marijuana and cancer
Part 3 – Marijuana and neurological disorders
Part 4 – Marijuana health risks
Part 5 – Summary of marijuana and medicine

Part 2. Marijuana and cancer – assessing the science

This is Part 2 of a series of six articles discussing marijuana’s use in medicine and health care. In this part, we discuss marijuana and cancer – probably one of the most passionate and controversial “debates” associated with the use of cannabis.

It’s clear that there are numerous claims about the value of marijuana in preventing or treating various cancers. But what are facts? And what is smoke?

In this article, I’ll look at some of the more prominent claims, along with a skeptical analysis of those claims.