Dissecting "The Healing Power" of Prayer

The Vancouver Sun recently published a piece about the healing power of prayer. Stories like these seem to pop up in every paper every few years, and they rarely introduce any new information or evidence. Seasoned skeptics cringe whenever they see a prayer-healing headline. Articles on this topic seem to run the gamut from totally credulous to solidly critical. Unfortunately, the critical ones are rare. READ THE ARTICLE HERE

Now, like most people, I’m a total layperson when it comes to medical stuff. But that doesn’t mean I have to ask an expert every time I see one of these articles. A lot of the skeptical assessment can be done long before you need to get into the nitty-gritty science. Since the journalist who wrote this article only quoted people credulously, and did not offer any critical assessment of their claims, we’ll have to do the work ourselves. Assesing a story on any alternative medical treatment, whether it’s prayer, homeopathy, or magnets, involves a few skeptical tools. Once you are familiar with these tools, you can easily do your own assesments of these types of claims.

When I see an article on any type of “alternative” or “complementary” treatment, I like to pull four questions out of my skeptical toolkit. 1. What are the actual claims? 2. Can they be tested? 3. Have they been tested? 4. How were they tested? Until you can get satisfactory answers to all of these questions, don’t put any stock into a medical claim. Let’s use these questions to analyze this article.

1. What are the actual claims?

OK, well from the headline the claim would seem to be that prayer has the power to fix your physical ailments. After all, healing is the act of regaining physical health, right? Well, you may notice in the article that some people entertain a different definition of “heal”. In fact, the article makes a lot of different claims about the power of prayer.

I compiled the claims I could find and created a shortlist:

- Prayer connects us with God, or some other transcendent life force.
- Prayer heals by returning us to “wholeness”
- Prayer gives our spirit peace.
- Prayer gives hope
- Prayer relaxes, lowers blood pressure, and decreases heart rate
- Prayer reduces headaches
- Prayer helps wound healing.
- Prayer “boosts” immune system functions

If our goal is to evaluate prayer as a medical treatment, we need to sort out the claims that apply. Let’s move on to the next step.

2. Can they be tested?
OK, lets go through the short list:

- Prayer connects us with God, or some other transcendent life force.
While this claim may have religious or philosophical implications, it doesn’t specify any effect that we could measure in the physical world. How can we tell when someone is more connected to God? What physical effects would this have on someones health? Since we can’t specify what the physical effects would be, we can’t test this scientifically. Since medicine is the science of healing, this claim is not a medical one and so it is irrelevant to our evaluation of prayer as a medical treatment.

- Prayer heals by returning us to “wholeness”
- Prayer gives our spirit peace.

I think you will agree that these claims also cannot be measured scientifically, and so we can leave them to the philosophers and ignore them for the purposes of a medical discussion.

- Prayer gives hope
Isn’t a prayer usually an expression of hope? “Dear god, please heal me”, etc. So…hoping for things has a positive effect on hope. I’m just gonna give this one away as a freebie. I don’t think we need to test it.

- Prayer “boosts” immune system functions
This is a tough one. What exactly does “boosting” the immune system mean? If you were sick with something that your immune system is able to fight, it seems like this would be a good thing. But why would we want our immune system to work harder than normal? If it’s something our immune system can’t fix, then why would we want this? What if you have an auto-immune disease where your immune system is attacking your own body? You definitely don’t want to boost it then. And is it really clear what “boost” means? We would need a better definition of this claim in order to create a test, so let’s cross this one off of the list.

- Prayer relaxes, lowers blood pressure, and decreases heart rate
- Prayer reduces headaches
- Prayer helps wound healing

These all seem like testable claims. A control group study could be done for each of these criteria.

Now, it may seem like we’ve dismissed a lot of their claims already. You might be thinking, if science can’t be used to test so many of these claims, does that mean we should really dismiss them? But remember that these claims are supposed to be medical, and levels of health can be measured. If the claims can’t be measured, then they aren’t really health claims.

Let’s move on and see if any of the remaining claims stand up to science.

3. Have they been tested?
In the article, one of the quoted experts refers to a review of 1,200 studies on religion and health. Unfortunately he doesn’t cite any of them. Now we could give up here. If the article isn’t gonna bother discussing the details of the proof that exists, it’s not a very useful article. After all, the burden of proof should be on the one making the claims.

But, if we’re really interested we’ll have to go looking for ourselves. As a lay people, we don’t all have medical journals on our coffee tables, but we can do a little googling to see what’s out there. After a some searching, I came across several studies about prayer and healing. Let’s analyze them in the next step.

4. How were they tested?
- Prayer relaxes, lowers blood pressure, and decreases heart rate
When I googled for prayer and blood-pressure, I found references to a couple studies that showed that religious people were more likely to have lower blood pressure[1][2]. Now, I haven’t even looked into the credibility of the data, but I can already see that for the purposes of what we are looking for, we don’t have to. Although the results are interesting, they show a correlation but not causation. From the same data you could equally find that having low blood pressure makes you more religious. Also, it doesn’t prove that prayer was the key. Perhaps it was waking up early each Sunday that was the significant factor. A controlled study would need be done to isolate prayer as the factor.

Here is another study that did control for prayer [3]. But after reading, I quickly found different problems. The experiment was not double blind, and their control group did not have a placebo to test against. This means that the study did not eliminate the placebo effect or the expectations effects of the subject and experimenter. If you’re not familiar with these effects, wikipedia is a good resource. Making sure studies are double-blind and placebo-controlled is an important part of medical research. If the study did not show that prayer works better than placebo, then it really hasn’t shown anything.

- Prayer reduces headaches
I couldn’t find any studies that controlled for this.

- Prayer helps wound healing
I found references to one study that showed positive results of prayer on coronary patients [4][5]. However, later experiments were unable to reproduce the effect [6][7] or even showed a negative effect [8]. Perhaps there were some flaws in how the first studies were done (as some have pointed out), or perhaps they were statistical anomolies. Another possibility is that there was another effect going on in the first studies that was not controlled for. This is known as a confounding variable. Bottom line, if the effect is not reproducable in later prayer studies, then prayer is not the thing causing the effect.

After all of this, what are we left with? Absolutely no proof that prayer heals.

Update: While I was working on this article, the Sun reposted this story online with a milder headline “Expressions of faith can be therapeutic”. I wonder what prompted the change.

Comments are closed.

  • Melany Hamill

    Melany proudly uses the titles of both geek and nerd. As a science-enthusiast and fan of debate, Melany likes to get her facts straight. She graduated from the University of British Columbia with a degree in Chemical Engineering. Since then her career path has meandered to its current spot as a project manager at a video game studio. Melany lives near beautiful Vancouver, British Columbia. She is not seeking treatment for her caffeine addiction.