Bad Science etiketine sahip kayıtlar gösteriliyor. Tüm kayıtları göster
Bad Science etiketine sahip kayıtlar gösteriliyor. Tüm kayıtları göster

24 Ekim 2015 Cumartesi

Science and zealots: How to detect bad science and how to detect zealots.

Last night, I got banned from Zoë Harcombe's blog. More on that later. Meanwhile, this...
From http://capisho.blogspot.co.uk/2013/07/science-vs-faith.html

I re-read It's all about ME, baby! (1997 - present) and there's something important missing.

In 2005, I discovered Lyle McDonald. Before this happened, I had the following beliefs:-
1. If something works for me, it must work for everyone else.
2. If someone with qualifications states a fact, it must be true.
3. If someone without qualifications states a fact, it must be false.
4. If a study confirms my beliefs, it must be true.
5. If a study contradicts my beliefs, it must be false.

Sound familiar?
1. is a "Hasty generalisation" fallacy.
2. is an "Appeal to authority" fallacy.
3. is an "Ad hominem" fallacy.
4. & 5. are a "Cherry-picking" fallacy.

Suffice it to say, Lyle bitch-slapped the fallacies out of me. Thank you so much! Read Lyle's site, if you want to learn.

How can studies conflict with each other so much?


Having read a number of conflicting studies, here are some of the tricks that bad studies use:-

1. Fudge the methodology:-
In a meta-study (a study of studies), to make something that's bad (e.g. some saturated fats/fatty acids) look harmless or to make something that's good (e.g. Vitamin D) look useless, fudge the inclusion criteria so that only studies using low intakes or a narrow range of intakes are used, so that the RRs are either close to 1 or have 95% CI values above & below 1. In addition, include studies that show both positive and negative effects (due to them looking at different types of saturated fats/fatty acids, say), so that the overall result is null.

In a study, use a different type of the thing being studied (but bury this fact somewhere obscure so that it's easily missed) to get the opposite result. E.g. To make "carbs" look bad, use a test "carb" that comprises 50% simple carbs (sugars) and 50% complex carbs (high-GI starches, preferably), thus guaranteeing a bad result.

2. Fudge the statistics:- e.g. Regression toward the mean. I'm not a stats nerd, but there are many ways to lie with statistics.

3. Make the abstract have a different conclusion from the full study (which you hide behind a pay-wall), by excluding the methodology and results.


Back to Zoë Harcombe: I left some comments on Jennifer Elliott vs Dietitians Association of Australia.

My M.O. for detecting zealots is by using a slowly, slowly, catchee monkey approach. I left a comment supportive of low-carb diets, because:-

For people with Insulin Resistance, low-carb diets DO ameliorate obesity, postprandial sleepiness and postprandial hyperglycaemia.

Was that loud enough?

I added that I thought the first priority should be to tackle the causes of the Insulin Resistance, because reversing a condition is better than ameliorating it.

My comments were helpful, with links to blog posts showing the above and how to reverse T2DM in 8 weeks. I then went for the throat, criticising Jennifer Elliot, as the article she wrote contained cherry-picked references. I included three more links to my blog as supportive evidence. This resulted in the removal of all but one of my comments (and the comment that remained had the link removed) and the addition of the following:-

"Zoë Harcombe says:
Nigel – too many comments purely trying to get traffic to your site – link above removed; other comments spammed. You’re now spammed.
Best wishes – Zoe"

The correct word is "banned", Zoë! Low-carb zealot successfully detected.

It's not a problem if a lay person becomes a low-carb zealot, but it is a problem if a Health Professional/Fitness Trainer becomes one. Cognitive bias and a refusal to accept contradictory evidence are not good traits for someone who's supposed to be practising evidence-based health/fitness.

5 Eylül 2014 Cuma

When bad science goes...pretty much the same!

After the previous post, you may have got the impression that things are getting worse. Hmmm!
From http://covermyfb.com/covers/27316/say%2Csee+and+hear+no+evil

Hat-tip to James Beckerman, MD for https://twitter.com/jamesbeckerman/status/507544419847786496, which refers to Comparison of Named Diet Programs Finds Little Difference in Weight Loss Outcomes.

This study comes to the opposite conclusion of the study in my previous blog post. As that study was a pile of poo, that must mean that this study is 100% correct, right? Hmmm!

Your enemy's enemy is not necessarily your friend. See What about the Other Weight Loss Diet Study??
"Previous meta-analyses, such as Hession et al, had balanced inclusion criteria that allow us to directly compare low-fat to low-carb diets.  They reported exactly what anyone would expect who is familiar with the weight loss diet literature:

  1. At 6 months, low-carb diets consistently lead to greater weight loss than low-fat diets. 
  2. At one year, the difference has all but disappeared. 
  3. Neither diet produces particularly impressive weight loss at one year or more.
  4. The weight loss effectiveness of typical low-fat diets tends to be modest at all time points.
Oh, well. It could have been a lot worse!
 

2 Eylül 2014 Salı

When good science goes bad, part n+1.

In When good science goes bad , I looked at the effect of funding bias on research.
From https://www.youtube.com/watch?v=sJ5jbxMjexo

Effects of Low-Carbohydrate and Low-Fat Diets: A Randomized Trial has just been published. As expected, low-carbers are positively creaming themselves over it. I instantly smelled a rat, as the full study was behind a pay-wall.

Remembering Krauss' shenanigans with "carbohydrate", consisting of 50% sugars + 50% "complex" carbs (maltodextrin & amylopectin are complex carbs that hydrolyse into glucose so rapidly that they have a GI of 100 on the "Glucose=100" scale.), I suspected dodgy carbs in the "Low-fat" group.

Luckily, David L. Katz, MD, MPH, FACPM, FACP had read the full study, and wrote about it in Diet Research, Stuck in the Stone Age.

As I suspected, it was another "fix-up" job, rigged to make low-carb diets look good, and low-fat diets look bad.

See also:-
Low-carbohydrate vs. Low-fat diets for Weight Loss: New Evidence,
What I Learned By Actually Reading That Low-Carb Is Best Study,
Is low-carb really the best weight loss diet? and
A Question about the latest diet study ...

16 Temmuz 2014 Çarşamba

Jumping through hoops, and my Blog List.

I'm seeing a curious thing. The VLC "camp" seems to be "jumping through hoops" to prove a point.
From http://davidbressler.com/2013/08/26/easier-harder/

From Neuron fuel and function (emphasis & formatting, mine):-
"Ketones and lactate do not drive reverse electron flow through complex I. Glucose can. Palmitate certainly can. What you want from a metabolic fuel depends on the remit of your cell types. Neurons within the brain preserve information by their continued existence.

This is best done by burning lactate or ketones. NOT glucose and, of course, not FFAs.

Anyone who claims that glucose is the preferred metabolic fuel of the brain has not though (sic) about what a neuron has to do and what an astrocyte actually does do. Or much about the electron transport chain."

Basically, glucose is bad mmm-kay. Also, anyone who claims that glucose is the preferred metabolic fuel of the brain is a dumb-ass. Damn our livers & kidneys churning out glucose! Are they trying to kill us?

∴ Carbohydrates are bad and must be avoided at all cost! This, of course, is utter nonsense.

Glucose can drive reverse electron flow through complex I. Can means that it's possible. Is it probable?

On a hypercaloric Western diet of excessive crap-in-a-bag/box/bottle, yes.

On a Kitavan diet of ~70%E from tubers, no.

On a diet of Basmati rice & beans, no.

On a diet of whole fruits, no.

See also Another crash and burn on low carb paleo and CrossFit. Enough of the 'carbs are evil' nonsense. Carbphobia is hurting a lot of people.

I have a list of blogs that I read on a regular basis. As a result of the bad science & cherry-picking displayed in various VLC blogs, I have deleted them from my Blog List.

See also Guest post: Denialism as Pseudoscientific Thinking.