Since late 2016 we have entered the age of disclosures! Fasten your mental safety belt and enjoy the ride! Heretic

Saturday, July 9, 2011

Vegans, dietary fat and Alzheimer's

I like browsing through some vegan discussion groups looking at the papers, publications and studies they use to support their belief system. McDougall's forum is particularly useful because of their tenacity in trying to use science to justify themselves. Experience taught me that such studies are always ambivalent and very often prove a completely opposite views to those of the vegan believers who posted them.

The following study from 2003, did not disappoint me:

Dietary fats and the risk of incident Alzheimer disease.

The abstract looked very foreboding, for example, quote:
Persons in the upper fifth of saturated-fat intake had 2.2 times the risk of incident Alzheimer disease compared with persons in the lowest fifth

Not all is lost fortunately, because of the widely known practice in the medical "science" to print only the politically correct (i.e. false) information in the abstracts while hiding the true albeit inconvenient facts in the full text.

The facts are that the saturated fat data and most of the other results are generally not statistically significant!

The facts are that even when one takes the trend line across saturated fat quintiles and makes it appear statistically more significant than an individual datum (the so-called "p value for the trend") - the resulting p is still much greater than 0.05 and thus is still not statistically significant! Best illustration is the following (upper) portion of the Table 3:

The facts are that if you take the most basic age-adjusted only data (look at the first row called "Age-adjusted+"), there is no clear trend at all since the middle and the second highest saturated fat columns (quintiles) have exactly the same Alzheimer's risk as the lowest reference quintile of saturated fat!  The second and the third row (headed by "Multivariable" and "Multivariable... other fats") above are the more processed data, that seem to exhibit a weak rising trend, albeit also not statistically significant!  One shall always keep in mind that multivariable-corrected trends are dependent upon some specific model-dependent assumptions that may or may not be correct.

It gets more intereseting as one reads down the table. If one takes the above discussed saturated results on faith, beliving that the weak statistics may be reflecting some real underlying trend rather than being some artefacts of the data gathering and processing methodology (as I suspect is the case), then one should also take a notice and state that the rest of the data "proves" (also not statistically significanly) that the total fat consumption, dietary cholesterol intake, animal fat consumption and vegetable fat consumption all seem either not to correlate or to correlate NEGATIVELY (protectively) with the Alzheimer's risk! See the lower portion of the Table 3:

For example, the total fat consumption seems to be protective against Alzheimer's! The second lowest and the middle quintile in consumption of animal produce (indicated by dietary cholesterol!) also have higher Alzheimer's risk than the two highest quintiles! Animal fat consumption seems to show no correlation to Alzheimer - the trend curve is pretty flat except the third row ("Multivariable adjusted for vegetable fats and trans-fats") which shows a weak NEGATIVE (i.e. protective) trend!

Last but not least the bottom group Vegetable fats shows the strongest correlation in the whole study. That correlation is strongly NEGATIVE (protective), that is the more vegatable fat the less Alzheimer's cases! In fact that result, after "Multivariable adjusted for vegetable fats and trans-fats" - is the only one, alongside the omega-6 fat result ( which is basically its subset) that does exhibit a statistically significant trend!

Unfortunately for those who believe in the low fat dogma, this is not a good news! Especially when compared with other sources, see for example this and that.


Melodie said...

Hello, I have a question,

I recently within the last month been enjoying a high-fat, low-carb diet. I feel that my digestive health has really improved in that little time. I also have noticed an increase in endurance during my athletic activities! I did not experience to any degree the 'carb-flu' that many people talk about.

What I want to know is I have come across 'Perfect Health Diet' blog. The author goes through some potential concerns with going very low-carb/or ketogenic (which is pretty much what I'm doing). I think it's interesting to note possible concerns, but I would also like to know your opinion on this matter.

*Note: on the issue of stomach cancer being high in Poland, I don't believe that that is due to any restriction in carb, but rather due to poor soil quality of that country.

Anyways, I felt some concern after reading that. I'm not saying I won't eat any kind of carb such as potatoes or rice, but I just don't really have much appetite for them at the moment. *I don't bother with grains...except for the occasional beer which I def. pay the price for). Please let me know what you think.

p.s. In the past, the way my body 'naturally' responded to food was simply to avoid eating. I would feel very hungry, but it was such a chore to eat. I didn't feel that great when I did, so I currently feel that this woe has made me enjoy food again + being satiated.

Also note: I do eat lots of seafood (fish with skin on), offal, and fatty cuts of meat. I eat chicken w/ skin and bone, and chew the cartilage off the bones. I use coconut milk (still need to get oil). I just use butter for cooking (although want to use coconut oil instead). I use olive oil for dressings, eat some nuts (but don't really have too much of a craving for them). I don't drink milk and have (only within last week) am eliminating cheese and heavy cream to see if it's related to a minor but irritating rash around my nose. (It developed two years ago). I do eat some fruit since it's in season, and I do feel a rush from it.

Thanks for taking the time to read this. :-)

Stan (Heretic) said...

I rarely give health advise but I will try to do my best.


Many isses are raised none really adressed. Don Matesz has already flipped from paleo over to some other diet. Poland had always high incidence of stomach cancer, preceeding the Optimal Diet. Saying that "Optimal Dieters have been dying of gastrointestinal cancers at a disturbing rate." is a slight exaggeration. Unless we find the exact number I will remain skeptical to such claims and will categorize it in my "Elvis Alive" folder.

Brain does not use glucose exclusivelky as a fuel. In fact ketone bodies - an alternative brain fuel seems to work much better, see for example this and this

Article said: Throughout my 2 years on this zero-carb diet, I had dry eyes and dry mouth. ...

I used to have dry eyes (bad) on high carb diet for ` 10 years 1990-1999. This cleared within 1 month after adopting a high fat diet in 1999. Never came back.My guess it was cause by some essential fat deficiency. back then I was following a low fat high carb, and whatever fat I ate was mostly "heart healthy" (spit) margarine.

His glucose defficiency explanation is implausible because body will alwys maintain 60-120mg/dl level of blood glucose no matter how much carbs he was eating. In fact an average level of glucose is slightly higher on a high fat low carb diet and it does not fluctuate, so it could not have been the cause of his dry eyes condition. If his blood glucose level went significantly below 60mg/dl (3.3mmol/L) then the first noticeable symptoms would have been convulsons, passing out or coma rather than dry eyes. There are lots of misconceptions. For example a certain blood glucose level is require not only to feed brain but primarily to feed the red blood cells - erythrocites, who live exclusively off glucose (anaerobically). Brain can perfectly well on ketones.

You wrote: p.s. In the past, the way my body 'naturally' responded to food was simply to avoid eating. I would feel very hungry, but it was such a chore to eat. I didn't feel that great when I did,...

This sounds like you were dealing with a serious disease, an eating disorder (anorexia?)

Are you underweight? malnurished?

High fat medium protein low carb diets work very well for situations like that. I recommend reading W.Lutz "Live Without Bread". He provides some clinical cases tudies that you may find useful.

Re: Also note: I do eat lots of seafood (fish with skin on), offal, and fatty cuts of meat. I eat chicken w/ skin and bone, and chew the cartilage off the bones. I use coconut milk (still need to get oil). I just use butter for cooking (although want to use coconut oil instead). I use olive oil for dressings, eat some nuts ...

My comment is that I would add more animal fat to it: add butter in form of sauce, make butter-on- cheese (or cheese-on-butter) sandwiches, add egg yolk dishes (eggnogg, scrabled eggs with 2-4 yolks and 1 white etc, throw excess whites down the sink - do not feed it to dogs or cats raw!). Learn how to make real lard out of pork bellies using slow-cooker (or beef tallow out of beef cuts etc) and use it for cooking of:
- soups, sauces, vegetable stir-fries, low carb cakes etc.

The idea is that 70% of your calories should come from animal fat (not protein!). If your diet is not high enough in fat then it will be higher that should in protein - which is not good.

Hope it helps,

Melodie said...
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Melodie said...
This comment has been removed by the author.
Melodie said...

Thanks for the speedy reply.

I agree, keeping fat intake high, and protein levels moderate is VERY important. I'll def. always ensure that my fat intake is ~70% of calories.

I've almost read your entire blog along with Peter (Hyperlipid) and really appreciate the sources. When I compare what your blog has to say with PHD, or Priaml Wisdoms' (new change), I keep coming back to your studies and just believe that they may be more in line with what I'm looking for.

I personally feel that for some people, ketogenic type diets are optimal, while there are others that can get away with higher glucose levels.

Stan (Heretic) said...


Thank you for the appreciation, I treat this as a personal database "in the cloud" of scientific references and interesting articles. This is why I am always trying to select reasonably solid references otherwise, misinformation or faulty research studies would hurt mostly myself. 8-:)

Animal fat is the key to avoid problems: if in doubt or if something goes not quite right with the diet, the first thing to correct is rectify the fat balance make sure you are consuming between 1.5 to 2.5g/kg of fat per 1kg of ideal body weight per day (and 1g protein and 0.5-0.8g carbs). Secondly, make sure you are not overeating - eat only when hungry, forget about traditional breakfast/lunch/dinner scheduling. That is my experience, other people might find a different method that works for them. We don't need as much calories on the high fat diet. I live on 1500kcal/day, last time I measured it it was varying from 1300-1700kcal/day from a day to day. This is probably about a half of calories of an average N.American adult diet! I understand this may seem too low but this is what does work for me (I am 173cm tall, 67kg, 55yo m.

Note: most people may lose some weight initially which may be unsettling if a person is underweight to start with, this condition is temporary and safe, and normalizes within a year.

There is more info on the Optimal Diet on my old web pages, see for example this seminar page


this seminar page



That might help,