Reading a medical study paper
June 22, 2017 1:17 AM Subscribe
Today I read in health news that Temple University has done a study which indicates that extra virgin olive oil may help in some aspects of some indicators for Altzheimer's. However, I can't find critical information in the paper. Do you see it?
In health news today there is the headline "Extra virgin olive oil staves off Altzheimer's, preserves memory, study shows." I found the study itself here. However when I read the study it doesn't say how much oil was given to the mice in the experiment. Could someone who knows how to read medical studies check this for me? Am I just missing it? In addition, I thought studies were published in such a way that others could test the experimentor's work, but in this case how could anyone do that if they don't know how much oil was given?
I ask about this because, with the whole excitement over resveratrol a number of years ago, what apparently got lost in the articles was the fact that, in order to intake the amount of resveratrol the mice did, a person would have to drink gallons of red wine a day. So regardless of the byline, the actual usefulness to peaple was questionable.
Caution to those reading, the study does involve experimental mice. If that disturbs you, you may not want to read it. Thank you!
In health news today there is the headline "Extra virgin olive oil staves off Altzheimer's, preserves memory, study shows." I found the study itself here. However when I read the study it doesn't say how much oil was given to the mice in the experiment. Could someone who knows how to read medical studies check this for me? Am I just missing it? In addition, I thought studies were published in such a way that others could test the experimentor's work, but in this case how could anyone do that if they don't know how much oil was given?
I ask about this because, with the whole excitement over resveratrol a number of years ago, what apparently got lost in the articles was the fact that, in order to intake the amount of resveratrol the mice did, a person would have to drink gallons of red wine a day. So regardless of the byline, the actual usefulness to peaple was questionable.
Caution to those reading, the study does involve experimental mice. If that disturbs you, you may not want to read it. Thank you!
The dose isn't explicitly mentioned. However the EVOO mice were heavier in each month, and that difference was significant at the 10-month point. Looking at Figure 1A, I would speculate the mice enjoyed a generous amount of olive oil.
posted by matthewr at 2:17 AM on June 22, 2017
posted by matthewr at 2:17 AM on June 22, 2017
Best answer: I thought studies were published in such a way that others could test the experimentor's work, but in this case how could anyone do that
There seems to be a significant (p = 0.06?) issue with reproducibility in science these days. With the competition for grants there is little glory/dollars for repeating an experiment. From an outsiders viewing the academic world seems sometimes like a weird satire on what science should be.
posted by sammyo at 4:14 AM on June 22, 2017
There seems to be a significant (p = 0.06?) issue with reproducibility in science these days. With the competition for grants there is little glory/dollars for repeating an experiment. From an outsiders viewing the academic world seems sometimes like a weird satire on what science should be.
posted by sammyo at 4:14 AM on June 22, 2017
Best answer: So regardless of the byline, the actual usefulness to people was questionable.
This is always true of studies in mice. These studies are often treated in the popular press as if they apply to people, but you should never assume that. Here's an NPR piece about how drugs that work in mice often don't work in human studies. Here's a piece in the Guardian on problems with relying on experiments in mice. If you google "mouse studies don't apply to people," you will find many similar discussions.
Now, as a cancer patient, I don't always feel I have time to wait for someone to do the perfect study, so if something isn't totally proven but does not seem to be harmful, I may still add it to my life. This is why I take turmeric. My oncologist has told me multiple times that she's very surprised at how well I've responded to chemo. Do I know it's the turmeric? Absolutely not, but I'm going to keep taking it. So I don't think a person who is very worried about Parkinson's would be wrong to make changes based on this study. It's just important to remember that you can only find out what works in humans by studying humans.
posted by FencingGal at 5:11 AM on June 22, 2017 [3 favorites]
This is always true of studies in mice. These studies are often treated in the popular press as if they apply to people, but you should never assume that. Here's an NPR piece about how drugs that work in mice often don't work in human studies. Here's a piece in the Guardian on problems with relying on experiments in mice. If you google "mouse studies don't apply to people," you will find many similar discussions.
Now, as a cancer patient, I don't always feel I have time to wait for someone to do the perfect study, so if something isn't totally proven but does not seem to be harmful, I may still add it to my life. This is why I take turmeric. My oncologist has told me multiple times that she's very surprised at how well I've responded to chemo. Do I know it's the turmeric? Absolutely not, but I'm going to keep taking it. So I don't think a person who is very worried about Parkinson's would be wrong to make changes based on this study. It's just important to remember that you can only find out what works in humans by studying humans.
posted by FencingGal at 5:11 AM on June 22, 2017 [3 favorites]
Best answer: I'm not a scientist but I'm an academic librarian and often help students with scientific articles. They did not clearly define what they meant by an "EVOO-enriched diet". It should have been in the Methods and Materials section. It is a relevant variable that they manipulated. Did they fail to mention it on purpose? Why didn't their peer reviewers notice? Did they obfuscate the issue with all the detail (mostly irrelevant AFAIK) about the source of the EVOO?
If you're really curious about it just email the authors and ask.
posted by mareli at 7:46 AM on June 22, 2017
If you're really curious about it just email the authors and ask.
posted by mareli at 7:46 AM on June 22, 2017
The usual things to do here would be to search for conference presentation versions of the same study, which might offer more detail, or just to email the first author.
posted by ROU_Xenophobe at 9:06 AM on June 22, 2017
posted by ROU_Xenophobe at 9:06 AM on June 22, 2017
Best answer: I am a biologist, but I don't work with mice. My understanding is that it is difficult to control the mount of a drug when it is supplemented to normal mouse chow, especially given that they are allowed to eat as much as they want ("ad libitum" in the study). What the authors could have done (but didn't), for reproducibility purposes was say what volume of olive oil was added to the chow they received every second day when it was replaced. That wouldn't tell you how much the animals ate, though, which is what you want to know.
posted by quaking fajita at 10:32 AM on June 22, 2017
posted by quaking fajita at 10:32 AM on June 22, 2017
Best answer: You can contact the corresponding author by email and ask if they know. It's possible that they don't, but at least they can give you some idea of the percentage or how the diet was prepared. Of course, know that dose per kg body weight in rodents doesn't translate directly to humans. There are separate formulas for that.
posted by Knowyournuts at 2:11 PM on June 22, 2017
posted by Knowyournuts at 2:11 PM on June 22, 2017
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posted by AlexiaSky at 2:04 AM on June 22, 2017