(Of course, it is a paradox…. Paradox number 112, or thereabouts)
As a nod to a regular contributor to this blog, who lives not far from the area, I thought I should write about the Sami. When I was younger we would probably have called the Sami ‘Eskimos’ – because anyone who lived north of the Arctic circle and dressed in fur was, clearly, an Eskimo. This term is now, I believe, a dread insult. A bit like calling a Scotsman an Englishman, or an Austrian a German. Or, I believe, a Canadian an American. Wars have been fought over less.
The Sami, unlike the Inuit, who reside mainly in North America, live in the North of Scandinavia: Northern Sweden, Norway and Finland and suchlike. In what used to be called Lapland. However, we now call the Lapps, the Sami (please keep up), so do they live in Samiland?
What I know about the Sami is that they obviously enjoy the cold, eating reindeer and smoking. They must do other things too, but I am not entirely sure what. This makes them very similar to the Inuit, who also enjoy: the cold, eating seals, caribou, and smoking. Neither the Sami, nor the Inuit, have the least interest in eating vegetables. I suppose there may be the occasional frozen carrot – or suchlike – from Iceland (that is a UK based joke).
Apart from not eating vegetables, smoking, and eating lots of fat, the Inuit and the Sami have one other thing in common. You can probably guess what it is. Yes, they both – those that live a traditional lifestyle anyway – have a very low rate of death from heart disease.
This came to my attention during an e-mail discussion I was having about whether the human brain required any glucose – at all. Those taking part were the usual suspects, Richard Feinman, Gary Fettke, Nina Teicholz, Jimmy Moore, Jason Fung, Tim Noakes etc. [Yes, good bit of name dropping there].
The consensus was that the human brain could use Ketone bodies for much of its energy requirement. However, there was an absolute need for about forty grams of glucose per day. The final statement on this matter, the one everyone seemed to agree on anyway, was as follows:
1) The brain requires no dietary glucose. It has a requisite use of 40 grams/day, but these grams can easily be provided from glycerol, and normal ingestion of not particularly high amounts of protein in a high fat, zero carbohydrate diet.
2) But this is a time dependent situation. Short term fasting will not be a problem for most otherwise healthy people. However, more prolonged starvation will eventually kill you as the brain will pirate 40 grams of glucose/day from protein and lipid, until you have neither fat stores, nor adequate diaphragm or heart muscle left to survive.
Don’t worry, there were about a thousand papers quoted in creating these statements, so the science seems robust. This discussion started because I had an interest in how hunter gatherers, who ate no carbohydrates, kept their brains going. What was the mechanism by which the Massai, Inuit and Sami, power their brains with glucose, if they don’t eat any carbohydrates?
Well, it seems that you can get a certain amount of glucose from fat. Fat is made up of triglycerides, and each triglyceride contains three fatty acids and one glycerol molecule. Two glycerol molecules stuck together (by the liver) makes one glucose molecule.
In short, pure fat does contain some glucose, which can be used to power the brain. However – assuming you are eating no carbs – the brain requires more glucose than can be provided by the glycerol held in triglycerides. Thus, you still need to convert some dietary protein into glucose. If you are not eating any food at all, the body will need to break down muscle to get at the protein required to synthesize glucose.
To cut a very long story short, the end point of the discussion was an agreement that you do not actually need to eat any carbohydrates to remain heathy. The body, and the brain, can get all the glucose it requires from glycerol and dietary protein.
The reason why I was interested in this issue was that ‘the absolute need for carbohydrates’ is a ‘fact’ that is thrown at me from time to time by ‘experts.’ I have always known they were wrong, because there are people e.g. the Massai, who never eat any carbohydrates, and remain far healthier than any expert I have ever cast my eyes upon. However, I wanted to be sure of the facts.
Anyway, time to return to the Sami. For, during this lively discussion, someone posted up two papers on the Sami that I had not seen before. Both papers noted that the Sami, despite having very high cholesterol levels, a high level of smoking, a high fat diet and almost zero carbohydrate intake – and suchlike – had a very low rate of cardiovascular disease.
This was particularly interesting for a couple of reasons. Firstly, most of the Sami live in Finland, and the Finns – at one time – had the highest rate of heart disease in the world. Not only that, but the Sami live in an area of Finland, North Karelia, which had the highest rate of heart disease in Finland. The worst of the worst.
In addition, the Sami had considerably worse ‘traditional’ risk factors for heart disease than the surrounding population. Higher cholesterol and LDL, high fat diet, far more smoking etc.
‘The finding of high cholesterol and high prevalence of smoking the Sami area are compared with the reference rate, and high cholesterol in the Samis and Finns in the north, conforms with similar observations. in studies performed previously. As the classic risk factors indicate a high risk of CHD in the north, other factors, possibly the antioxidants, are important in the low CHD mortality there.’1
[Antioxidants and their impact on CHD were studied in the Heart Protection Study (HPS), and found to have no effect on CHD whatsoever. Whilst this study was done by Rory Collins, and has many issues, the data on the lack of impact of antioxidants on CHD appear robust].
Other researchers have also tried to establish why the Sami have such a low rate of CHD/IHD. As noted in the paper ‘‘Low mortality from ischaemic heart disease in the Sami district of Finland’:
‘An exceptionally low mortality from IHD was found here in the Sami district of Finland and an exceptionally high mortality in a neighbouring Finnish area, a 2-3-fold contrast or even wider, depending on age and time. No difference in IHD of this magnitude between areas located so close to each other has previously been described in the literature.’2
Of course, they looked for the reasons.
‘Reasons for the rarity of IHD in the Sami district of Finland
Our current knowledge of cardiovascular risk factors cannot explain the low mortality from IHD in the Sami district of Finland. Serum cholesterol is, in fact, relatively high in the far north of Finland, and it is higher in the Sami than the Finns, the same being true of the prevalence of smoking, while the low blood pressure frequently found in the far north and among the Sami would be insufficient to cause any substantial reduction in the risk of IHD. Similar differences in serum cholesterol, blood pressure and smoking have also been found between Norwegian Sami and Norwegians of Finnish ancestry. Serum high density lipoprotein cholesterol (HDL)is usually similar in both ethnic groups, although a Finnish study found even lower HDL-total cholesterol ratios in the Sami, which would indicate an elevated risk of IHD… The high serum cholesterol in the Sami can be attributed to their fatty diet.’
In short, the Sami live in area of Finland that had the highest rate of heart disease in the world. Their risk factors were worse than the surrounding population (LDL 4.45mol/l on average), yet their heart disease rate remained very low. It was postulated that this was due to a high intake of antioxidants, but the impact of antioxidants on heart disease has been subjected to large double blind placebo controlled trial, and antioxidants were found to have no impact on heart disease.
At this point you may cry, enough of finding populations that eat a high fat diet, have high LDL levels and low rates of heart disease. It is like shooting fish in a barrel. Not that the experts pay the slightest attention to such contradictory facts. They merely label such findings a ‘paradox’ and move on. But I thought it was interesting. Another nice shiny nail in the cholesterol hypothesis. ‘You call it a paradox, I call it a contradiction… let’s call the whole things off.’
Next, my series on what truly does cause heart disease continues.
1: ‘High serum alpha-tocopherol, albumin, selenium and cholesterol, and low mortality from coronary heart disease in northern Finland’: P. V. LUOMA, S. NAYHA, K. SIKKILA & J. HASSI. Journal of lnternal Medicine 1995; 237: 49-54
2: Simo Nayha: ‘Low mortality from ischaemic heart disease in the Sami district of Finland.’ Soc. Sci. Med. Vol. 44 No. 1, pp. 123-131, 1997
P.S. I am feeling much better, thanks for those who were concerned over my welfare.