Thursday, 17 April 2014

Death by Food Pyramid review

School holidays means a few more minutes each day for sitting and reading for fun - something of a luxury for me lately. While I had a few books to choose from, I decided to read Death by Food Pyramid by Denise Minger.



I should preface any book review, no matter how amatuerish, by saying that I'm not the type of person who can trudge through any book, no matter how uninteresting, just for the satisfaction of saying "I read it". If a book doesn't hold my attention past the first 10 pages, I simply don't read it. 

To provide an example of my almost-ADHD-mentality, I am familiar with Denise's blog and her widely acclaimed take-down of the China Study. I got through the first one third of that particular post before losing interest, not because it was unconvincing but because I didn't need convincing. If a weird-looking vego is spruiking bullshit, just say so, I don't need the 5,000 words of logic.


I put off buying Death by Food Pyramid (DBFP) because I thought I wouldn't learn much - y'know, the food pyramid is built on lies and corrupt stooges, blah blah blah. And while that theme certainly plays a big part in the story, Denise's determination to convey it in a way that exudes impartiality and thoroughness is refreshing. I like her style of writing and enjoyed learning about the nice people such as Luise Light and also the salivary amylase section.

There is probably something for almost everyone in DBFP, and if I was to be really picky, I'd say she tries a bit too hard to please everyone (including the vegans) with tips on supplementing a nutritionally-void diet and taking things a bit easy on Mr Keyes. In saying that, she is up front about the book not being a 'you must eat this way' type of thing, which is what distinguishes it from thousands of others. 


There does seem to be a few favourable nods to the paleo mob but if you're a hard core low carber looking for confirmation bias, then you may be slightly disappointed. Denise tip-toes on the side of caution when it comes to red meat and digesting lots of saturated fat. In fact she seems to ignore Low Carb High Fat (LCHF) diets almost entirely, which I thought was slightly odd. Her comments toward the end about low carb diets and thyroid seemed like an unnecessary afterthought. 

Despite DBFP being a good read, there were some negatives, the first (very picky, I know) being the foreword. I've learned a lot from Chris Masterjohn and I think he's a very smart man, but his foreword was awkward. I don't think I've ever read one that spent so much text explaining to the reader how much schooling he's done and how many websites he writes for. The word "I" is written 18 times and "my" 20 times. 
Not a great way to start a book.

The second negative - when a book I'm reading brings up Apolipoprotein E4, I get a little excited, especially if i wasn't expecting it. But to be brutally honest, I was disappointed by the flippant way Denise treated the subject. I'm not sure why she bothered if all she was going to do was repeat the same guess work and vague caution of so many others. 

The reason she brought up ApoE in the first place was due to genetic factors playing a role in which diet suits us best. A logical topic to discuss, however the general idea she seemed to be conveying was that if you were in possession of one or more E4 alleles, then you should probably take it easy on saturated fat.

I don’t agree with that but I concede that she may be correct because no one really knows the truth with any certainty. But she doesn't sound convincing when she references Yadong Yang et al for her statement; "And worse, some human studies-albeit observational- support the idea that a high saturated fat intake may increase heart attack risk for ApoE4 carriers, especially for folks stuck with two copies of the allele".

Given her considered explanation of how to read a science paper, I was puzzled. Maybe I'm just suffering from a bad case of Dunning-Kruger, but Yang et al just reads like one of the thousands of papers that equate 'higher' LDL cholesterol with increased risk of heart attack. 

Yang et al kept an eye on a few thousand Cost Ricans (some who'd had a heart attack and an equal amount who hadn't) and tested their cholesterol after putting them under headings of "low saturated fat diet" and "high saturated fat diet". Details of how they actually kept track of diet composition was sadly lacking but despite this all-too-typical exclusion, that the "high saturated fat diet" people had higher cholesterol should not be surprising to anyone. 

But if you're on the "I don't believe in the lipid hypothesis but I still base my beliefs on numbers on a lipid panel" team then you may also note they also had lower triglycerides and higher HDL. 

If you're on the "so fucking what?" team, then you may be as baffled as I was. If they'd actually recorded cardiac events or deaths, then fine, but they didn't. Exactly how they calculated "risk of myocardial infarction" is beyond me, but comments such as "well-established association between saturated fat-intake and risk of MI" didn't fill me with great confidence of their non-bias. 


That Denise is so thorough in pointing out faults in studies but thinks we should accept this as a good one is bizarre. I just didn't get it at all.

Denise also says “folks carrying at least one copy of ApoE4 have significantly higher rates of heart disease and Alzheimer’s” “as well as notably higher LDL levels”. The references being:

HanniaCampos, Michael D’Agostino, and José M. Ordovás, “Gene-Diet Interactions andPlasma Lipoproteins: Role of Apoliporpotein E and Habitual Saturated Fat Intake,”Genetic Epidemiology 20, no. 1 (2001)

and

Full text of Campos et al is not available to poor people but the abstract suggests they studied 420 Costa Ricans, of which 6% (about 25) had E4. They divided them all into two groups - low saturated fat diet (8.6% of energy) and high saturated fat diet (13.5% of energy). The high(er) fat diet didn’t do the E2 people any favours but the E4s had lower VLDL and higher HDL and also larger LDL particles.

I’m not sure why those results are a bad thing for E4s.  

Song et al is a meta-analysis, and not a particularly good one in the opinion of Anoop et al, who wrote “However, these data were observational and confounding biases might have affected the pooled estimates. There are potential chances of argument toward the fact that the true genetic effects of APO E genotypes on CHD cannot be quantified from any pooling or meta-analysis of studies with heterogeneous samples.”


Anoop et al concluded “Several studies have established the APO E ε4 allele as a risk allele for cardiovascular diseases while others do not find any association.

Look, I could just be extremely biased and desperate to hold on to my fantasy that people with Apolipoprotein E4 are not born to be vegans, but the references and the statements from Denise on this topic appear to be quite feeble.

Due credit goes to her for stating “Even if you carry the ApoE4 gene, it doesn't mean dietary cholesterol and fat are cruel substances out to kill you”, but that brief message gets lost and seems completely at odds with her commentary.

“It may well be that ApoE4 carriers do best on diets that emphasize leaner animal products”. I honestly don’t get these types of comments. Very smart people who say them are on the one hand suggesting that the diet-heart hypothesis is pure dribble and then turning around and saying “oh, but if you have ApoE4, it’s totally true”.

Am I missing something? Correlation doesn't equal causation unless you’re an E4 club member? Honestly, if you don’t know why E4 plays a role in AD and CVD (and no-one seems to), then just say so.

In the words of Anoop et al – “apo E remains enigmatic to date and needs to be explored further in order to elucidate its precise role in cardiovascular and cerebrovascular diseases.”

Summary

While I've blabbered on about the ApoE stuff, I've probably blown it out of proportion given that it represents just a few pages of the book. Overall I think Death by Food Pyramid is well worth the money and time. Entertainment, an engaging story and impartiality is what you’ll get, strong opinions and a clear directive as to what you should eat is not. If the latter is what you want, you'll be disappointed.

Rating - 7/10 

A nice quote - "The burden is on our own shoulders to stay educated, informed, shrewd,
critical, proactive, and unyielding in the face of the Goliaths that loom before us."

Disclosure - my care factor (zero) prevented me from actually reading the bits on "staying healthy when animal foods are off the menu" and "plant-based diets".

No comments:

Post a Comment