Monday, October 17, 2011

Book review: Perfect Health Diet

Perfect Health Diet is a book that one should own. It is not the type of book that you can get from your local library and just do a quick read over (and, maybe, write a review about it). If you do that, you will probably miss several important ideas that form the foundation of this book, which is a deep foundation.

The book is titled “Perfect Health Diet”, not “The Perfect Health Diet”. If you think that this is a mistake, consider that the most successful social networking web site of all time started as “The Facebook”, and then changed to simply “Facebook”; which was perceived later as a major improvement.

Moreover, “Perfect Health Diet” makes for a cool and not at all inappropriate acronym – “PHD”.

What people eat has an enormous influence on their lives, and also on the lives of those around them. Nutrition is clearly one of the most important topics in the modern world - it is the source of much happiness and suffering for entire populations. If Albert Einstein and Marie Curie were alive today, they would probably be interested in nutrition, as they were about important topics of their time that were outside their main disciplines and research areas (e.g., the consequences of war, and future war deterrence).

Nutrition attracts the interest of many bright people today. Those who are not professional nutrition researchers often fund their own research, spending hours and hours of their own time studying the literature and even experimenting on themselves. Several of them decide to think deeply and carefully about it. A few, like Paul Jaminet and Shou-Ching Jaminet, decide to write about it, and all of us benefit from their effort.

The Jaminets have PhDs (not copies of their books, degrees). Their main PhD disciplines are somewhat similar to Einstein’s and Curie’s; which is an interesting coincidence. What the Jaminets have written about nutrition is probably analogous, in broad terms, to what Einstein and Curie would have written about nutrition if they were alive today. They would have written about a “unified field theory” of nutrition, informed by chemistry.

To put it simply, the main idea behind this book is to find the “sweet spot” for each major macronutrient (e.g., protein and fat) and micronutrient (e.g., vitamins and minerals) that is important for humans. The sweet spot is the area indicated on the graph below. This is my own simplified interpretation of the authors' more complex graphs on marginal benefits from nutrients.


The book provides detailed information about each of the major nutrients that are important to humans, what their “sweet spot” levels are, and how to obtain them. In this respect the book is very thorough, and also very clear, including plenty of good arguments and empirical research results to back up the recommendations. But this book is much more than that.

Why do I refer to this book as proposing a “unified field theory” of nutrition? The reason is that this book clearly aims at unifying all of the current state of the art knowledge about nutrition, departing from a few fundamental ideas.

One of those fundamental ideas is that a good diet would provide nutrients in the same ratio as those provided by our own tissues when we “cannibalize” them – i.e., when we fast. Another is that human breast milk is a good basis for the estimation of the ratios of macronutrients a human adult would need for optimal health.

And here is where the depth and brilliance with which the authors address these issues can lead to misunderstandings.

For example, when our body “cannibalizes” itself (e.g., at the 16-h mark of a water fast), there is no digestion going on. And, as the authors point out, what you eat, in terms of nutrients, is often not what you get after digestion. It may surprise many to know that a diet rich in vegetables is actually a high fat diet (if you are surprised, you should read the book). One needs to keep these things in mind to understand that not all dietary macronutrient ratios will lead to the same ratios of nutrients after digestion, and that the dietary equivalent of “cannibalizing” oneself is not a beef-only diet.

Another example relates to the issue of human breast milk. Many seem to have misunderstood the authors as implying that the macronutrient ratios in human breast milk are optimal for adult humans. The authors say nothing of the kind. What they do is to use human breast milk as a basis for their estimation of what an adult human should get, based on a few reasonable assumptions. One of the assumptions is that a human adult’s brain consumes proportionally much less sugar than an infant’s.

Yet another example is the idea of “safe starches”, which many seem to have taken as a recommendation that diabetics should eat lots of white rice and potato. The authors have never said such a thing in the book; not even close. "Safe starches", like white rice and sweet potatoes (as well as white potatoes), are presented in the book as good sources of carbohydrates that are also generally free from harmful plant toxins. And they are, if consumed after cooking.

By the way, I have a colleague who has type 2 diabetes and can eat meat with white potatoes without experiencing hyperglycemia, as long as the amount of potato is very small and is eaten after a few bites of meat.

Do I disagree with some of the things that the authors say? Sure I do, but not in a way that would lead to significantly different dietary recommendations. And, who knows, maybe I am wrong.

For example, the authors seem to think that dietary advanced glycation end-products (AGEs) can be a problem for humans, and therefore recommend that you avoid cooking meat at high temperatures (no barbecuing, for example). I have not found any convincing evidence that this is true in healthy people, but following the authors’ advice will not hurt you at all. And if your digestive tract is compromised to the point that undigested food particles are entering your bloodstream, then maybe you should avoid dietary sources of AGEs.

Also, I think that humans tend to adapt to different macronutrient ratios in more fundamental ways than the authors seem to believe they can. These adaptations are long-term ones, and are better understood based on the notion of compensatory adaptation. For instance, a very low carbohydrate diet may bring about some problems in the short term, but long-term adaptations may reverse those problems, without a change in the diet.

The authors should be careful about small errors that may give a bad impression to some experts, and open them up to undue criticism; as experts tend to be very picky and frequently generalize based on small errors. Here is one. The authors seem to imply that eating coconut oil will help feed colon cells, which indeed seem to feed on short-chain fats; not exactly the medium-chain fats abundantly found in coconut oil, but okay. (This may be the main reason why indigestible fiber contributes to colon health, by being converted by bacteria to short-chain fats.) The main problem with the authors' implied claim is that coconut oil, as a fat, will be absorbed in the small intestine, and thus will not reach colon cells in any significant amounts.

Finally, I don’t think that increased animal protein consumption causes decreased longevity; an idea that the authors seem to lean toward. One reason is that seafood consumption is almost universally associated with increased longevity, even when it is heavily consumed, and seafood in general has a very high protein-to-fat ratio (much higher than beef). The connection between high animal protein consumption and decreased longevity suggested by many studies, some of which are cited in the book, is unlikely to be due to the protein itself, in my opinion. That connection is more likely to be due to some patterns that may be associated in certain populations with animal protein consumption (e.g., refined wheat and industrial seed oils consumption).

Thankfully, controversial issues and small errors can be easily addressed online. The authors maintain a popular blog, and they do so in such a way that the blog is truly an extension of the book. This blog is one of my favorites. Perhaps we will see some of the above issues addressed in the blog.

All in all, this seems like a bargain to me. For about 25 bucks (less than that, if you trade in quid; and more, if you do in Yuan), and with some self-determination, you may save thousands of dollars in medical bills. More importantly, you may change your life, and those of the ones around you, for the better.

15 comments:

Steve Parker, M.D. said...

At the Perfect Health Diet blog, I especially like the "Around the Web" feature.

Thanks, Ned, for sharing your thoughts on the book. Readers will find extensive recent posts on the "safe starch" issue at the PHD blog.

-Steve

Paul Jaminet said...

Thank you, Ned, for a delightful (to me) review. To be spoken of with Einstein and Curie, and our project compared with Facebook, is beyond an author's hopes. I'm glad you liked the book.

You're quite right about our goals - a "unified theory of nutrition" is a good way to put it - eliminate toxins and optimize nutrients. It's surprising that few or no nutritional experts seem to think in such terms, or be willing to undertake a systematic exploration of which diets would do that.

On the AGEs, I would agree that dietary AGEs seem to be digested well, but other toxins may be created in high heat cooking (acrolein has gotten a lot of blame as a health threat). The discussion in the book surely needs revision and fleshing out, but I think the conclusion that gentle cooking is preferable will probably stand.

Re the coconut oil, I will have to look back at what the book says; it probably needs revision too. I think our thinking there, admittedly poorly researched, was not that intestinal cells absorb and metabolize MCTs directly, but that MCTs go to the liver where they are ketogenic, and colonic cells readily absorb ketones from the blood and benefit from them, as they do short-chain fats like butyrate. However, in looking at the literature now, I find that this may be an interesting topic that deserves deeper research, especially because the relative metabolism of butyrate (SCFA) vs beta-hydroxybutyrate (ketone) seems to differ in cancer, and these papers may shed light on dieting for cancer. (A few papers: http://www.ncbi.nlm.nih.gov/pubmed/2753323, http://www.ncbi.nlm.nih.gov/pubmed/9687542).

The influence of protein on longevity is a great issue and one we've been intending to address for a long time, but aging is such a complex issue it's been hard to find the time to get started. Next year! The big effect is the usual U-shaped one, where protein deficiencies or excesses shorten lifespan. Within the bottom of the U, however, there is evidence in animal studies for trade-offs, with higher protein improving fertility and athleticism and short-term performance generally but lower protein increasing longevity and some disease resistance. Whether this occurs in humans is hard to confirm, but I think it's likely the mechanisms are shared.

Thanks again for a great review and yes, it will be great to explore issues with you! We're always looking to refine our ideas and correct mistakes.

Best, Paul

Arthur said...

Thank you for an excellent review of my favourite book about healthy eating. I also like your points about AGEs and compensatory adaptation.

Beth@WeightMaven said...

What Arthur said!

Glenn said...

I never fail to be enlightened by your blog. Thanks for posting this review, Ned.

Ned Kock said...

Thank you Steve, Arthur, Beth, and Glenn.

Ned Kock said...

I’m glad you liked the review Paul, and thanks for the new info and links. Of those issues raised, one of the most important in my view is that one related to protein intake and longevity. Many people are interested in that.

Here is another counterpoint to the notion that increased protein intake leads to decreased longevity. A BMI of 25 is generally associated with the lowest mortality:

http://bit.ly/fWdsPC

Now, we know that as people age they generally tend to lose body mass (contrary to popular opinion), primarily due to loss of lean body mass, which seems to outpace body fat gain.

Increased protein consumption seems to counter that, and this appears to be related to both bone and muscle retention, contributing to a higher BMI.

So it is not unreasonable to conclude that the relatively high BMI of 25 is associated with retention of lean body mass with age, even as body fat gradually increases as well, leading to the perception that the fat are the ones living the longest.

Of course I am not talking about 600 g/d of protein. These seniors seem to have done quite well in terms of bone retention at around 85-90 g/d:

http://bit.ly/f1Pi3T

David Isaak said...

Hi, Ned--

Nice reiew, and good points about protein and LBM maintenance.

We both know, of course, that BMI is only a vague proxy for body composition, and that composition is more likely to be the factor affecting health.

One thing that continues to bother me about BMI, though, is the J-shaped curve with longevity. I certainly believe that such a curve exists, but I think the dangers of being underweight are greatly overestimated.

A number of studies suggest that the causality runs the other direction at low BMIs--that is, many of those people have low BMIs because they are afflicted with wasting diseases, particularly pulmonary diseases.

And, of course, all of those people are mixed in with fit, naturally thin people, and the skinny-fat people you discussed in your previous BMI post...sigh.

michael plunkett said...

type two and hypoglycemic when eating small amounts of starch ??? This doesn't sound right- being hypoglycemic means Blood Sugars are too LOW, not high and comes from being to dependent on drugs to control sugars- never from diet. If he or she is Hypog- eat more tators quickly and adjust Meds.

Ned Kock said...

Hi David. O Primitivo sent me this link a while ago. They make a point that is consistent with your view of the left side of the J curve of BMI vs. mortality.

http://www.ncbi.nlm.nih.gov/pubmed/19299006

Ned Kock said...

Hi Michael. Not hypo, simply not hyper. Glycemic load is not the same as glycemic index.

David Isaak said...

Thanks for the link!

In addition to smoking, TB (not so common in the US and UK, but on the rise again), and COPD (not uncommon) also tend to be "wasting" diseases. And, co course, in Africa one ofthe common names for AIDS is "slim."

In any case, your review has made me want to read PHD...although, alas, it does not seem to be on Kindle!

Anonymous said...

Hey Paul, any word on a kindle version becoming available? Time-line?

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Ellen Sanders said...

Thank you so much for sharing this book review. I'm thinking to buy it, because I want to choose a weight loss diet, but I don't know which one... what's good for me, so I need to read more about this subject!
I'm sure that I will find something that will fit perfectly for me!