So far we’ve looked at serum cholesterol among Eskimos/Inuit (Serum Cholesterol Among the Eskimos and Inuit, July 1, 2011) and !Kung San bushmen (Serum Cholesterol Among African Hunter-Gatherers, July 5, 2011). The Inuit, who live in the Arctic and eat a high-fat low-carb diet, generally had serum TC over 200 mg/dl unless parasitic diseases were common and life expectancy was short. The !Kung San, who live in sub-Saharan Africa and eat more carbs, were below 160 mg/dl and ridden with parasitic diseases and short life expectancy.
I thought I’d wrap up the hunter-gatherer cholesterol series by looking at some tropical populations outside Africa. These peoples may help us evaluate the merit of several explanations that have been put forth for variations in serum cholesterol:
- Genetic differences. Africans tend to have lower cholesterol than non-Africans, wherever they live. Is the difference genetic? Chris Masterjohn believes genetic differences might account for up to a 30 mg/dl difference in TC. Emily Deans suggests LDL receptor variants are the most important alleles.
- Dietary differences such as fat intake. For decades it was said that higher fat diets produce higher TC, and this was the favored explanation for variations in serum cholesterol. However, when these ideas were tested in clinical trials, diet-induced changes in TC were inconsistent.
- Infectious disease burden. Eukaryotic pathogens such as protozoa, worms, and fungi – ie, pathogens that have mitochondria and therefore can metabolize fat and ketones – are often able to take up human lipoproteins from blood and use their fats and cholesterol for their own purposes. This tends to lead to low TC in people with a high burden of parasites. Is parasite burden the key to hunter-gatherer cholesterol levels?
We started this detour (see Did Hunter-Gatherers Have Low Serum Cholesterol?, June 28, 2011) to evaluate the claims of S. Boyd Eaton, Loren Cordain, and collaborators [1], [2], [3], [30]. Their papers tended to promote the following syllogism:
- Diet determines TC.
- Low TC is healthy.
- Hunter-gatherers had low TC.
- Therefore, hunter-gatherer diets are healthy.
So to conclude today’s post, I’ll review: Which of these four theses is supported by the data?
Australian Aborigines
There are a fairly large number of papers on cholesterol levels in Australian aborigines. Unfortunately, the vast majority are from journals, such as the Medical Journal of Australia and the Australian and New Zealand Journal of Medicine, to which I don’t have electronic access.
Therefore I’ll just cite one, a 1957 paper from Schwartz et al in the Australian Journal of Experimental Biology and Medical Science. [31]
This paper looked at aborigines from central Australia. Occupying marginal territory, they were still living a hunter-gatherer lifestyle. But there weren’t many animal foods available, nor seafoods:
The animal fat intake of the Central Australian aborigines from the Haast’s Bluff region involved in this present study is decidedly low when compared with the average intake of white Australians. This low intake of fat results both from a scarcity of fat itself, and also from demands made upon available supplies by native customs. It is likely that the males eat more animal fat than the females, because of their readier access to it after hunting, but the difference is probably small. Wichitty grubs (larvae of several species of Xyleutes moths) are an important source of fat for both women and children, however. Somewhat less than 10 p.c. of the calories in the aboriginal diet is derived from animal fat, i.e. less than one-third of the calories so derived in the white Australian diet (N. B. Tindale, personal communication). [31]
To get even 10% of calories from animal fat, they had to eat a lot of grubs.
So did this low-fat diet produce high or low cholesterol?
Serum cholesterol: … There is no significant difference between the mean values for aboriginal male (217.0 mg/dl) and aboriginal female (207.9 mg/dl). [31]
This is right in line with the levels in Eskimos and Inuit, and in the minimum mortality range of 200 to 240 mg/dl.
Australian aborigines were said to have a mean TC of 146 mg/dl (male) and 132 mg/dl (female) in Eaton et al [1]. Australian aborigines were deleted from the list of hunter-gatherers with low cholesterol in a subsequent Cordain et al paper [2]. I don’t know why this was, but I can say that at least some Australian aboriginal populations had TC over 200 mg/dl.
Kitavans
Kitavans preserved their hunter-gatherer lifestyle until recently, and Staffan Lindeberg and colleagues were able to assess cholesterol levels using modern procedures. They reported serum total cholesterol in men of 4.7 mmol/l (182 mg/dl) and in women of 6.1 mmol/l (236 mg/dl), for a male-female average of 5.4 mmol/l (209 mg/dl). [32]
Health in Kitava was generally good, although life expectancy was only 45 years [33]. Causes of death were infectious disease (notably malaria) and accidents such as drowning and falling from coconut trees.
So we have another tropical, high-carb population with normal (200 to 240 mg/dl) serum cholesterol.
New Zealand Maoris
New Zealand Maoris are probably genetically similar to Australian aborigines and Kitavans. I didn’t survey the literature on New Zealand Maoris. However, I did come across one paper [35] that led me to an interesting 1980 study of Maoris by Dr Robert Beaglehole [36].
The study was quite simple:
The relation between serum cholesterol concentration and mortality was studied prospectively over 11 years in 630 New Zealand Maoris aged 25-74. Serum cholesterol concentration was measured at initial examination in 1962-3 in 94% of the subjects and whether each was dead or alive was determined in 1974. The causes of death were divided into three categories: cancer, cardiovascular disease, and “other.” [36]
Mean serum cholesterol was 5.50 mmol/l (213 mg/dl) among women, 5.82 mmol/l (225 mg/dl) among men, for a population mean of 219 mg/dl.
Dr Beaglehole found that mortality increased as serum cholesterol decreased. Mortality was 40% to 70% higher in Maoris with TC of 160 mg/dl than in Maoris with TC of 260 mg/dl.
The association with cancer mortality was strongest: cancer mortality was 9.6% among the low-TC group (TC < 5.1 mmol/l = 197 mg/dl), 5.8% among the medium-TC group, and 3.5% among the high-TC group (TC > 5.8 mmol/l = 224 mg/dl).
West Malaysian aborigines
Just to balance the above studies I looked for a paper showing low serum cholesterol in an aboriginal population. I found a 1972 paper by Burns-Cox et al studying aborigines in West Malaysia. [37]
Like other traditional populations living active lives, these aborigines were lean and free of heart disease. They ate a high-carb diet:
Coronary heart disease has never been found in Malaysian aborigines. We report the position regarding some of the risk factors usually associated with coronary heart disease in 73 adult aborigine men.
They lived a physically active life on a diet largely of unrefined carbohydrate in the jungles of central West Malaysia. None was obese and blood pressures remained low at all ages. [37]
Their serum cholesterol levels were low – 141 to 156 mg/dl:
While the mean serum cholesterols were low, varying between 141 and 156 mg/100 ml at different ages, the mean fasting serum triglyceride levels of 135 to 164 mg/100 ml were comparable with those found in the West. This may have been due to their high carbohydrate intake. [37]
They were mostly healthy – except that they were infested with intestinal worms and malaria:
The aborigines are thin, extremely fit physically, and for many centuries have lived in the dense hilly jungles of central West Malaysia. They have a high rate of infestation with intestinal worms and malaria but appear well nourished. Their diet consists chiefly of hand-milled rice as a staple, supplemented with cassava, millet, maize, fish, and fruit, nearly all of which they grow or gather themselves. Dairy produce is taken only in very small quantities in the form of reconstituted powdered milk and it is the large volume of starchy foods which accounts for their bulky diet. [37]
Once again, we find that low serum cholesterol is associated with a high burden of eukaryotic pathogens.
Another feature that this population shares with the !Kung San is small stature. Mean averaged 5’1” (155 cm) in height and averaged 105 lb (48 kg) in weight.
Conclusion
Let’s look at the four parts of the syllogism I’ve attributed to Eaton and Cordain:
Diet determines TC. Wrong. It looks like burden of parasites is the major determinant of serum cholesterol in hunter-gatherers and human populations globally.
Low TC is healthy. Wrong. It is associated with high infectious burden, small stature, high mortality, and short lifespan.
Hunter-gatherers had low TC. Some did, some didn’t. So let’s look at a specific claim, this from the classic Cordain-Eaton paper from 2002, “The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic” (thanks, Rob!):
Over the past 64 y, anthropological research has consistently demonstrated relatively low serum cholesterol and triaglycerol levels among indigenous populations that derive the majority of their diet from animal products. [30]
Wrong. Anthropological research has not consistently demonstrated low serum cholesterol and triglycerol levels from hunter-gatherers, regardless of whether the primary dietary source was animals (Eskimo/Inuit) or plants (Kitavans, Central Australian aborigines). Rather, those with high parasite burdens had low cholesterol, regardless of diet, and healthy populations without parasites had serum cholesterol over 200 mg/dl regardless of diet.
Therefore, hunter-gatherer diets are healthy. True! Except insofar as dietary practices, such as the Eskimo practice of eating raw intestines from recently killed animals, predisposed them to picking up parasitic infections.
Overall I think the data should dispose us to look toward infectious burden, rather than genetics or diet, as the primary determinant of serum cholesterol among hunter-gatherers. If genetic differences influence mean TC among hunter-gatherer populations, it is probably because of evolutionary adaptations to local pathogens, such as the heavy parasite burden in sub-Saharan Africa.
Related Posts
The posts in this series are:
- Did Hunter-Gatherers Have Low Serum Cholesterol?, Jun 28, 2011
- Serum Cholesterol Among the Eskimos and Inuit, Jul 1, 2011
- Serum Cholesterol Among African Hunter-Gatherers, Jul 5, 2011
- Serum Cholesterol Among Hunter-Gatherers: Conclusion, Jul 7, 2011
- Low Serum Cholesterol in Newborn Babies, Jul 7, 2011
References
[1] Eaton SB, Konner M, Shostak M. Stone agers in the fast lane: chronic degenerative diseases in evolutionary perspective. Am J Med. 1988 Apr;84(4):739-49. http://pmid.us/3135745. Full text: http://www.direct-ms.org/pdf/EvolutionPaleolithic/EatonStone%20Agers%20Fast%20Lane.pdf
[2] O’Keefe JH Jr, Cordain L, Harris WH, Moe RM, Vogel R. Optimal low-density lipoprotein is 50 to 70 mg/dl: lower is better and physiologically normal. J Am Coll Cardiol. 2004 Jun 2;43(11):2142-6. http://pmid.us/15172426.
[3] Konner M, Eaton SB. Paleolithic nutrition: twenty-five years later. Nutr Clin Pract. 2010 Dec;25(6):594-602. http://pmid.us/21139123. Full text: http://ncp.sagepub.com/content/25/6/594.full.
[30] Cordain L et al. The paradoxical nature of hunter-gatherer diets: meat-based, yet non-atherogenic. Eur J Clin Nutr. 2002 Mar;56 Suppl 1:S42-52. http://pmid.us/11965522.
[31] Schwartz CJ et al. Serum cholesterol and phospholipid levels of Australian aborigines. Aust J Exp Biol Med Sci. 1957 Oct;35(5):449-56. http://pmid.us/13499168. Full text: http://www.nature.com.ezp-prod1.hul.harvard.edu/icb/journal/v35/n5/pdf/icb195747a.pdf.
[32] Lindeberg S et al. Cardiovascular risk factors in a Melanesian population apparently free from stroke and ischaemic heart disease: the Kitava study. J Intern Med. 1994 Sep;236(3):331-40. http://pmid.us/8077891.
[33] Lindeberg S et al. Age relations of cardiovascular risk factors in a traditional Melanesian society: the Kitava Study. Am J Clin Nutr. 1997 Oct;66(4):845-52. http://pmid.us/9322559.
[35] Walker AR. Cholesterol and mortality rates. Br Med J. 1980 May 31;280(6227):1320. http://pmid.us/7388525.
[36] Beaglehole R et al. Cholesterol and mortality in New Zealand Maoris. Br Med J. 1980 Feb 2;280(6210):285-7. http://pmid.us/7357343. Free full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1600122/?tool=pubmed.
[37] Burns-Cox CJ et al. Risk factors and the absence of coronary heart disease in aborigines in West Malaysia. Br Heart J. 1972 Sep;34(9):953-8. http://pmid.us/4116420.
via this link:
Hi Paul,
Just a quick comment on the lineage of the New Zealand Maori. There ancestors are closer to the natives of Hawaii and are more similar to the peoples of the north-eastern Pacific. In terms of appearance, they are far more robustly built than the Kitivan, ni-Van, Aborigine peoples. My observations of the ni-Van (in Vanuatu) are that they are a finer build compared to Maori, not unlike the peoples of the West Indies.
Not that this changes the underlying premise of your post here!
Cheers,
Jamie
Wow great series. Does this make you want to modify any of your conclusions from the earlier series on why many paleo dieters seem to experience a rise in cholesterol and what should be done about it?
Thanks, Jamie.
Hi Todd,
No … but that issue is not finished yet.
I think high cholesterol is a different beast than low cholesterol. It is associated with vascular issues – hypertension, atherosclerosis, etc.
Hi Paul. Very nice series.
I’ve been eating 10 to 15 eggs a day for the past few weeks, which means a very high dietery intake of cholesterol, higher than the amount the liver normally produces in a day. Supposing I have a parasitic infection and thus a low TC, how do you think this high cholesterol diet will fare?
Hi Cristiano,
Good question. I’m not sure it’s optimal. What sort of parasite are we talking about — in the gut or systemic? Protozoa or worm?
I might be able to answer this better after next week’s posts which will get into the immune and infection issues.
Best, Paul
And another caveat on NZ Maori — in 1980, and indeed today, few to no Maori were eating anything like a traditional diet (sweet potato, taro, fern root, fish, wildfowl, rats, dog). Rather, they are eating a variant of the standard NZ diet, high in salt, sugar, refined carbs and the usual industrial food. They are certainly no longer hunter gatherers or horiculturalists. As Jamie notes, they’re Polynesians.
There’s been a lot of intermarriage though. Most Maori will have a significant proportion of Anglo ancestry as well. I strongly suspect that anything you see in any recent study of Maori health is thoroughly confounded by their relatively awful socio-economic status in New Zealand. It would be wrong to infer anything about either genes or traditional diets from that study.
The New Zealand Maori are from a completely different population thrust out of South East Asia than the Australian Aborigines. A good reference for this is Jared Diamond’s excellent book Guns, Germs, and Steel.
Otherwise excellent post!
Hi Paul,
I think you may be on to something with the parasite-cholesterol connection. I hope you are going to present data showing an association between intestinal parasite infection and serum cholesterol in individual humans. Just Googling around, there seem to be a few pieces of evidence on it floating around. Also, there are studies on the effect of schistosomiasis on serum cholesterol in mice that are consistent with the idea. I have a paper where they looked at athero; if you don’t have access send me an e-mail and I’ll pass it along.
Energy balance also seems to be an important determinant of serum cholesterol. That issue may not be totally separate from the issue of intestinal parasites, although parasites may have their own separate mechanisms in addition.
I do think it’s important not to read too much into the mortality-cholesterol associations in ecological studies. Less affluent cultures tend to have lower serum cholesterol, and they also lack sanitation and modern medical care. The fact that their mortality is higher probably has little to do with their lower serum cholesterol. If people in the modern US were regularly exposed to malaria, dysentery and other developing nation diseases without proper medical care, our high cholesterol would not prevent our mortality rate from going way up.
Hi Stephen,
Yes, I didn’t want to suggest that the Maoris were hunter-gatherers. In that sense the Maoris are really off-topic. But I thought the paper was interesting, I came across it while researching this piece, and thought I’d throw it in just to show that no matter what diet they’re on, aboriginal peoples from this region are likely to have similar cholesterol.
Thanks, Nick.
Hi Stephan,
I do have solid data, it’ll be up next week.
If we were exposed to malaria, dysentery and parasitic diseases without medical care, our high cholesterol would increase our mortality rate!
Interesting about energy balance. I’ll email you.
Best, Paul
in jan 3 months after starting hi fat med protein lowish carb my tc was 4.1 hdl 1.2.
this week after 6more months of 2 eggs a day at least 2 tablespoons of coconut oil. 1 pot of cream 1/4 pound of hard chees and 10% fat greek style yogurt,a day. bacon ,liver beef lamb mince,plenty raw cocoa powder lots of green tea,fair mount of basmati rice, bananas (at least 4 a day) berries and lots of veg, my TC is now 3.7 and hdl 1.4. tryclicerides always been on the low side too, so maybe genetically im geared for hi fat or maybe its the no gluten and veg oil thing, but thanks for your advice,in the book and on here,still no joy with the psoriasis though .
going to see mazin al kafaji,TCM skin specialist in august.he cleared me 7 years ago for around 18 months,it felt great.
Paul – Superb series! I realize you said there is more to the puzzle, but can one take home that a high TC (200-275) isnt something to worry about as long as HDL is high enough (>60) and triGs are low (< 100)? I understand there could be other reasons for high TC, but will a high enough HDL reduce those risks?
Thanks!
I continue to have really high TC (8.8 mmol), high hdl (3.4) and the ratio of total cholesterol to hdl is good (2.6), I am not sure if I should worry about this or not; my doctor still wants to refer me to a specialized lipid clinic in the provincial capital as he finds my cholesterol levels bizarre. I’m not on any cholesterol medications but my doctor thinks I should be. Triglycerides around 0.6 last time I had blood work. I eat relatively high fat, moderate protein, low carb (around 50 to 75 g)to control pre-diabetes. Prior to low-carb diet my FBG was 6.8, now it’s 5.3 but my cholesterol keeps going up. Not sure what should be the priority at this point
Hi Raj,
200-260 is not really high, more normal. Very high TCs I think probably are reflective of a problem.
Hi Karen,
I’m still working on understanding high LDL. See http://perfecthealthdiet.com/?p=2536 and http://perfecthealthdiet.com/?p=2547 for a first cut at the problem.
I would avoid the cholesterol medications but try to understand why the cholesterol is so high. Make sure there’s no malnourishment. Do you have any symptoms of ill health?
Best, Paul
What an excellently written interesting series of posts! Thank you! Best, Claire
Hi Paul,
Loved the series as well (and the initial remark about “withholding all conclusions till the end”–in the often-judgmental world of health blogs, that should be a mandatory line in every entry of every blog).
Now I’m trying to better understand whether my father’s lipid profile. He’s always had very low TC (both HDL and LDL), and I don’t think it’s genetic–I’ve had astronomically high HDL (way above range) long before moving to a more fat-centered diet. His TC also seems to be inversely related to his triglycerides, which are very high (way way above range) and continue to climb. Sorry, don’t have exact numbers before me.
He had his gallbladder removed about 10 years ago due to an acute infection, and appendicitis a year or two later, which saw the end of that organ, too. I believe the low TC preceded removal of those organs. He is very grain-centric; he used to wolf down sliced white bread for breakfast and then got into a long phase of making his own steamed buns (http://en.wikipedia.org/wiki/Man_tou; that these are presumably “traditional” is the bane of my exhortations against them). My recent victory has been getting him to exchange the daily bun occasionally for a sweet potato.
He’s also had a really severe lifetime skin problem that looks a lot like dinosaur skin/erythrodermic psoriasis(?); says he’s had it ever since he was a kid, but is never clear on what exactly the dermatologist tells him. I’m not completely sure it’s an infection, as he doesn’t have flare-ups, so to speak–just worsening in the dry winters, and gradually worsening over the years. However, he has mentioned less-than-sanitary latrines during his schoolboy years, so possibly something picked up during childhood? Out of five siblings, only he and one brother have it; my father’s is much more severe.
So my question is, to what extent do you think these issues are infection-related and require a regimen of antibiotics/supplements? How much can be done on the diet front? I am dutifully still fighting this wheat battle!
Thanks so much for your time!
Hi SC,
I’m sure they’re infection-related. But I have no idea what antibiotic regimen, if any, would be appropriate. The first step is to determine the pathogen(s).
This is where it would be nice to get help from doctors. The low TC indicates he has a eukaryotic pathogen — probably a protozoal parasite. Something like leishmaniasis or amebiasis.
These can have skin manifestations. See if these pictures look at all familiar: http://www.dermatologyinfo.net/english/chapters/chapter12.htm and http://www.dermatologyinfo.net/english/chapters/chapter14.htm.
I would send him to an infectious disease specialist familiar with protozoal diseases and try to get some kind of diagnosis.
Then he should be eating some version of our diet. The most important change would be wheat to rice. Between the likely protozoa and the missing gallbladder, a high carb diet may be best for him.
He needs to be well nourished but not overnourished.
Please let me know if he gets some medical attention. It’s ridiculous that he’s been living with this all his life.
Best, Paul
I guess I should add that starch probably does make up the major part of his diet, but I don’t think he eats that much in absolute terms–he’s definitely no sumo wrestler. Could a high starch proportion really raise trigs through the roof, or do you think it’s really an issue of the wrong kinds of starch (white wheat–he probably eats more of it than white rice)? Thanks!
Oh gosh, thanks for the extremely quick reply. I would say it’s something like the rightmost image under “skin manifestations” in http://www.dermatologyinfo.net/english/chapters/chapter14.htm, or something like http://www.riversideonline.com/source/images/image_popup/mcdc7_erythrodermic_psoriasis.jpg. Will follow up and let you know.
Hi SC,
I think I wouldn’t worry about his trigs yet, infection first. His liver has probably been handling a heavy toxin load produced by the infection for decades. He needs to nourish his liver and help it excrete toxins. Are his liver enzymes elevated?
huh. Interesting -the protozoal and TC link. As I’ve mentioned previously- I had toxo infection in the early 80s and then in the early 90s– my TC was 80! It then stayed low in the 100s for quite awhile. Now, after increasing fat for the past few years, TC is just over 200. Trigs always low in the 30s, HDL in 60-80 neighborhood and the rest being LDL. But wow, interesting link between cholesterol and parasites. Damn bastards.
Hi Ellen,
Seems like the toxo infection must have receded – that’s great news! I wonder if the higher-fat diet might have helped your immune system beat the infection?
@Chris – have you tried a totally dairy and egg free paleo diet for psoriasis? There is some interesting discussion on Robb Wolf’s forum from others who have had success following a strict auto-immune paleo diet.
No grains, legumes, dairy, nuts, nightshades, eggs.
http://robbwolf.com/forum/viewtopic.php?f=14&t=12&hilit=psoriasis
http://robbwolf.com/forum/viewtopic.php?f=14&t=1929&hilit=psoriasis
Have you noticed how ALL the groups of people who are low cholestrol on high fat diets are from highly active lifestyles…?
Is this an exraneous variable that should be factored in as red herring?
You say: “It looks like burden of parasites is the major determinant of serum cholesterol,” but then you say: “It [low cholesterol] is associated with high infectious burden, small stature, high mortality, and short lifespan.” But if the parasites caused the low cholesterol, then why would we blame that other bad stuff on low cholesterol? In particular, when you blame a high infectious burden on low cholesterol, aren’t you arguing exactly the opposite (that the infection caused the low cholesterol)? Also, doesn’t it seem likely (or at least quite possible) that the high infection burden, rather than the low cholesterol, caused all that other bad stuff you mention? I’m not here to advocate low cholesterol, I’m just trying to understand.
Hi Nyx,
I said the parasites cause the low cholesterol, not the other way around. Yes, I do think the parasites/infections cause the ill health. When I say “is associated with” I’m not asserting anything about causality.
Hi,
Thanks for so much knowledge.
To that end I have purchased your book and am enjoying reading it.
How would you approach treating xanthelasma?
Thank you,
Richard
I’d like to know this too, hard to find a clear answer for dietary guidelines for people suffeirng from xanthelasmas.
I’ve had them appear after eating HFLC with plenty of cheating on refined carbs and wondering if sticking to a low carb diet will help them regress… eating more carbs/less fat doesn’t help.
Hi Paul,
If non-HDL cholesterol is low (85 mg/dL), but HDL is high (>70 mg/dL), would this still make you inclined to think parasitic infection? Are the stool tests that a traditional doctor would perform sufficient? I know that some alternative practitioners do stool tests as well.
Thanks so much,
Nikki
Our general MD’s would not extrapolate a parasitic infection from the common blood tests of CMP, Lipids, CBC.
A trained doc can definitely see red flags for parasitic infection, along with a complete symptom and health history, in the blood-work primarily by the CBC differential.
An MD would only order a parasites/ova if it is suspect.
I would think that it is appropriate as well as informational to specify and delineate that when mentionaing traditional diets, to add “unprocessed” adjective, not to be redundant, but to inform the lay reader of the difference.
IMO
But I have enjoyed these articles