Wednesday, February 03, 2010

Lipoprotein(a) Bantu recap

Just to recap from a few years ago, there are two well studied villages in Tanzania. One has a diet which is subsistence agriculture and so complex starch based, the other is also mostly starch based but supplemented with half a kilo of fish a day. Their daily food intake is approximately described in this Lancet paper:

"Daily energy intake was similar in the two populations (2196 kcal [9·19 MJ] in the fish-diet group vs 2109 kcal [8·82 MJ]). There was no difference in salt intake (4·4 vs 4·0 g daily). In the fish-diet group, 23% of energy intake was from fish with consumption of 300-600 g daily (three to four fish meals per day). Among the vegetarians, most energy was derived from complex carbohydrates (82% compared with 70% in the fish-diet group) such as maize and rice. The proportions of energy derived from protein were 11% and 18%, respectively, and those from fats 7% and 12%. "

The vegetarians are as close to an ideal version of a low fat vegetarian diet as you can get. I don't know much about Ornish's ideas but I'm guessing this comes as close to doing it "correctly" as you can. Exercise too!

The fishermen on the lake shore seem closer to the Kitavans in their macronutrient intake. Still high carb, but not quite up at the 82% of calories mark eaten by the vegetarian farmers...

Using blood pressure as a surrogate for CV health, the fish eaters appear to beat the complex carb group quite convincingly:




So, if you are on an extremly low fat vegetarian diet and your blood pressure isn't doing what it's supposed to do, don't blame yourself. Eat some animals.

Pauletto's group think it is specifically the omega three lipids which have the beneficial effects on BP, but I'm not so sure. If you eat a diet based on fish and seal alone, and virtually zero carbs, you still get this increase in blood pressure with age. Despite the omega three fatty acid intake being very high.

The comparison comes from Paal Røiri's 2005 discussion paper "Eskimo-kostholdets betydning for dødeligheten av hjerteog karsykdommer". We have this table of blood pressure changes with age, rising from just over 100mmHg systolic in childhood to around 150mmHg over the age of 60.




Either extreme does not appear to be ideal. It looks like the upper tolerable limit of unrefined complex carbs seems to be some where above 70% of calories but below 80%. Living down at 4% might not be perfect either. But I digress.

The striking difference between the two Bantu groups is in Lp(a) level. Obviously the vegetarians have higher Lp(a) levels than the fish eaters, as you would expect from their slowly rising blood pressure with age.

You can see that the vegetarians have a median value for Lp(a) of 27mg/dl where as the fishermen have a median of 14mg/dl.




The assumption is that the high Lp(a) is bad and is furring up their arteries and putting up their blood pressure as they age.

Probably genetic. Bad genes mean the farmers have short kringle IV repeats and so their high Lp(a) sets about giving them their just desserts.

Maybe.

Peter

20 comments:

arnoud said...

Genetic? The two villages in Tanzania have been separate with no mingling for 100's of generations?

Mike said...

I think he was being sarcastic, arnoud.

Excellent post, Peter; I'm interested to hear your thoughts (or posted research) on hypertension in Inuit populations with extremely low carb/high O3 intake.

Peter said...

They intermarry all the time. The wife moves to the husband's village. Hence the Maybe.

Next post soon. I will eventually get around to what Lp(a) actually does do, but the ground work comes first.

Peter

Peter said...

Mike, I've not really thought about this except in the most general terms. But it's seems possible that very high omega three PUFA might eventually tend towards oxidising in situ, requiring Lp(a) to sort out the mess, plus their ascorbate intake is phenomenally low, also requiring Lp(a)....

Peter

zach said...

I cannot imagine living solely on grains and starches. Don't get me wrong I like sweet potatoes, I just want them drowned in butter.

Dr. B G said...

*haa*

Nice posts!! Actually I wish I had a little Lp(a) because I then probably would not be prone to colds as I am (despite vitamin D etc) since it is SUPER for tissue repair and immunity. See below 'Lp(a): from ancestral benefit to modern pathogen?' ... hedgehogs and humans...

http://qjmed.oxfordjournals.org/cgi/reprint/93/2/75.pdf

Greg said...

Thanks for another informative post!
I would be very interested if you have found any other studies that show bad long-term effects for very low carb.

I don't think this vegetarian group is anyone's ideal- if it was they would call themselves grainitarians. Calorie-wise, of course they are going to end up consuming significant grain, soy or nut calories, but all the goodness of vegetarianism is supposed to come from the vegetables.

Peter said...

Hmm, yes G, I wonder if that QJM needs working in to this thread... I'll tidy up the genetics next before looking a little more at function...

Greg, I wouldn't really look at these people as a vegetarian "group" attempting an ideal of any sort. They are just a bunch of humans who are doing pretty well on what generations before them have done in the same spot. it doesn't happen to include eating meat, but it works even with grains. They are, as Quinn would say, tribal. They are the product of success, or of "surviving failure" if you have a nasty, brutish and short type view of non Westernised life! What they do is what works now and is derived from what has worked in the past, not some idealistic leaf eating cult a la Ornish.

Peter

Elizabeth said...

I am afraid I have thought hard who to ask this too and once again I am off topic but thought it would be best directed at you and your site Peter.

If I fast overnight and have no breakfast, by the time I break my fast at say 1pm I always eat a protein meal,ie, salmon, foie gras, or meat. I have a strong dip in blood sugar- goes down to about 3.9 from a fasting of say 4.3 towards the end of the fast period. my question is: is this good or bad- does it mean a huge surge of insulin or is it right that insulin is doing its job and kicking in correctly, does it mean too much protein going to glucose (I have alot, say 2pieces ie 40g protein). Is protein virtually the same as carbs in terms of the overall insulin, glucose response?

After eating protein for the evening meal and some fat with it I wake up sweating and hot around 3am. A bit of a pain.....

Am really confused here, please help out anyone.
Thanks,

Chainey said...

"Eskimo-kostholdets betydning for dødeligheten av hjerteog karsykdommer"

Can't argue with that.

Gyan said...

Somehow I cant see vegetarians in Africa?

Why were these people vegetarians, even though inter-marrying with fish-eaters?.

They dont even supplement with a little goat, chicken or an egg, even at festivals?

Also, in evolutionary terms, they are a success. They reproduce, dont they, without much modern medical help?

Peter said...

Hi Elizabeth,

Hard to say, this is not something I ever do. Proteins vary a lot in terms of insulin generation, casein a lot, beef medium and chicken not at all. The fall in blood glucose from 4.3 to 3.9 after breaking a fast looks like a modest increase in insulin inhibiting lipolysis on a background of insulin sensitivity. A blood glucose of 3.9 in a LC eater is not usually symptomatic and you feel fine. It would not need massive amounts of insulin to do this.

If the effect is more marked in the night the hot and sweating might be a stress response to hypoglycaemia but it would probably be corrected by the time you wake up...

Gyan, yes, it seems unlikely but Pauletto's group have multiple publications on these two groups. They don't have electricity but obviously do have enough contact with civilisation to be growing maize and rice.

Hi Chainey!

Peter

David Moss said...

Elizabeth, here's my anecdotal take on it, but it's entirely possible that Peter will simply point out that the science behind it is nonsense.

I too often wake up during the middle of the night if I've had a particularly high protein meal. Or less extremely, if I have a heavy protein meal at 6pm, I'll only experience a rush of energy and awakeness at around 9.30-10pm (most annoying) which I thought might be glucagon raising blood sugar. This is often after a day of only eating fat and feeling quite cold and hungry, but some time after a large dose of protein I typically get a lot hotter and more awake. Since my digestion is often very sluggish indeed, I'd thought that when I wake up a few hours later, it might merely be a delayed version of that effect (although going by what Peter says, perhaps it's hypoglycemia after the aforementioned rise in blood sugar).

Anyway, my solution is to try to get my protein in the day as early as possible and tend to have my 'evening' meal at around 4pm and just to have fat or a small amount of carbohydrate thereafter if anything.

In your breaking-fast case, I wouldn't have been surprised if, after a lengthy fast, you had quite an insulin response as your body tried to replenish depleted stores etc. I'd have thought with a very proteiny meal that after this very short insulin response, your blood sugar would quickly return to normal on account of the glucagon shortly afterwards.

I seem to recall reading some-one suggest that eating lots of fat with protein would blunt the glucagon/insulin response, though I'm not sure whether this is true, but there are a couple of reasons why it seems plausible. Perhaps a relatively fattier meal would have less effect?

(Also Peter, I'm not sure if I've ever commented on your blog before- much of it is over my head- but I'm a longtime reader, so if not, thanks for so many excellent posts).

Peter said...

Hi David, that actually is helpful as you are coming from experience... I would comment re the temperature effect. Protein is highly thermogenic. There are anaesthesia papers using intravenous amino acid infusions to to blunt or reverse the hypothermia that we anaesthetists so commonly induce by accident in our patients!

Delayed digestion and lots of protein arriving at the liver by 2am could easily have you hot at 3am....

Snow has stopped here and there's no rain forecast until later. My boots are calling. Lp(a) will have to wait until after I get back from a look round the northern edge of the Campsies!

Peter

Aaron said...

From what Ornish I've read recently (his Spectrum book), both groups would fit into his dietary recommendations. He advocates most strongly for alternatives to animal products, but he rated fish much more highly than other meats. He'd probably be more than happy if everyone adopted a diet where fat was 12% of the total energy derived, and it was primarily fat from fish. It seems more folks like T. Colin Campbell of the China study would be expecting negative health effects in the fish eating group.

Elizabeth said...

Thank you Peter and David Moss, you are right- I overate big time last night on protein and today have been unbearably hot all day until now when it is wearing off, 19 hours later. I have wandering around geneva in the snow with the coat off which is truly unheard of for me!

The final question then is: if insulin kicks in after the protein meal, which I guess is perfectly nomtal, but, in terms of health and stability one is trying to minimalise insulin spikes, am I mad to be going on all day fasts as it will spike much more in the first meal in the evening? Or, is the evening insulin going to be a normal amount as if at any other time. If you have lunch and raise it a little is it reduced on the second meal after this?

If you began dinner with a glass of red wine or a gin first would that initial sip of carbs be a good idea as it will bring the insulin in and then the protein impact 30 mins later will be lessened? And finally, how much of the protein is simply made into glucogen as with carbs. Are fats the only thing to not go this route?

Wow.. sorry. It just is important to me becasue I do not always feel great after my protein meal and I am trying to resolve it - the true result of the meal only kicks in 5 hours later- hence hot in the night I guess, like you David

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

Hi Peter,

So nice that you're back on a writing jag. I'm hoping that you or Dr. B G might comment on what level of Lp(a) begins to become a concern in the context of a LC, grain-free diet? Mine is above the ref range, but BP is normal. My father had his first MI at age 56.

Elizabeth,

I am wondering if you have experimented with not drinking any alcohol to see if the 'hot in the night' is is any different (it is better for me when I don't drink)? I have experienced 'hot in the night' episodes for years, though they are not as bad now. I had no idea it might be related to high blood sugar, as Peter suggests, but my diet was 60-75% carbs most days for years and before changing my diet my BS was spiking above 150. But even now, and even in winter, I keep the comforter off of my legs most of the night. Also, in my case, alcohol can send me into Hypo territory if I drink on an empty stomach.

Peter said...

Hi Nick,

How high and what's the ref range? I'll get round to this one in two or three or four posts time...

Peter

Nick said...

Hi Peter,

Forgive me, I have been having some trouble sorting out some of the info you (and Dr. B G)have been writing on the topic of Lp(a).

The test I was asking about is referred to as 'Apolipoprotein A-1' and gives a ref range of 94-176 mg/dl. Wikipedia gives me the impression that this may be a bit different measurement than Lp(a), but my lab came back at 179. Obviously very different ranges than the graphs in your most recent posts...

Thank you Peter.

Nick