Genetics, Diet or Mass Hysteria?
65DN investigates why so many people in Finland are lactose intolerant.
The first time I bought milk in Finland – looking for the word ‘maito’ – my wife couldn’t believe it. ‘That’s special lactose intolerant milk!’ she spluttered. ‘It’s much more expensive than normal milk.’
In my local branch of SALE, milk is almost the only dairy product on sale that is not ‘Hyla’ – dairy producer Valio’s mark that it is specially adapted for people who can’t cope with lactose. ‘Don’t you have any normal cream?’ I enquired. ‘No, we only have Hyla,’ said the shop assistant, herself slightly surprised.
Dairy is a big part of the Finnish diet. Many Finns drink milk with their evening meals and, clearly, even those who are intolerant hanker after it to the extent that there is a roaring trade in low lactose milk, cream and yoghurt. At a Finnish social event, usually based around coffee, there is always Hyla milk on standby. At many Finnish weddings, the obligatory cream-based wedding cake is usually made with Hyla cream for the sake of the minority who will get stomach cramps, flatulence and diarrhoea if they eat real cream.
And the reason is that quite a large minority of Finns are lactose intolerant, at least by the standards of Northern European countries.
Dr Katri Peuhkari, who researched the issue at Helsinki University, finds that 17 percent of Finns are classified as lactose intolerant. According to research published in Scientific American only 4 percent of native Swedes are lactose intolerant and this is normal for Northern Europe. Southern Europeans have higher levels of intolerance, as much as 40 percent amongst Italians, though it varies from region to region. Non-Europeans tend to have a much higher level of lactose intolerance. Amongst native and African Americans it is about 75 percent and amongst ‘Asian Americans’ (from the Far East) it is as high as ninety percent.
‘If you are lactose intolerant you have hypolactasia. This means you lack the lactase enzyme in your small intestine,’ Dr Peuhkari explains. Lacking this enzyme means that the body cannot metabolize lactose. Becoming intolerant is often a gradual process lasting as much as twenty years. But some people develop it in childhood.
Noomi, 29 from Rovaniemi, is one such person. ‘If I drink milk then soon after I feel a stomach ache and sometimes I start farting and have to go to the toilet!’ she laughs. Unfortunately, she really likes ice-cream and will sometimes eat it along with special pills that suppress her reaction to the lactose.
However, Dr Peukhari notes that though 17 percent of Finns are lactose intolerant, many more ‘probably just think they are’ which partly helps to explain the popularity of Hyla products, which were only developed in the 1970s. ‘When people have a stomach ache, they read all about lactose intolerance and they think that’s what it is,’ she suggests, ‘even though it can be caused by stress or many other factors.’
‘Lactose intolerance was only discovered in the 1960s and, since then, it has become very popular in Finland,’ Dr Peukhari recalls. ‘Finland has a food culture in which we use a lot of milk so this means lactose intolerance comes up in everyday life. In Asia, they don’t use as much milk so it’s less of a problem.’
So why is lactose intolerance in Finland so high for a Northern European country? According to Dr Peukhari, there are a number of possible theories. ‘It may be an inherited feature caused by having different genes,’ she suggests.
According to geneticist D. M. Swallow, in a 2003 article in the Annual Review of Genetics, lactose intolerance is genetic because there are clear regional variations and these seem to reflect the extent of milk consumption thousands of years ago. Even the Romans observed that Northern Europeans drank a lot of milk, which Romans didn’t. The adaptation to milk consumption may have helped people survive famine.
This is directly relevant to Finland. Dr Tuula Tuure, a researcher for the Valio Dairy Company, argues that the Finnish gene pool is quite distinct from the rest of Northern Europe and ‘there is eastern influence and in the east there was very low milk consumption.’
Dr Peukhari speculates that Finland’s relatively late move to agriculture may mean that some people never developed a tolerance of milk and this genetic intolerance can be seen today in people needing to buy Hyla products. Another possibility is that Finland’s founding populations were so small that an adaptation to milk was not able to efficiently spread through the population. ‘The genetic explanation is one hypothesis, but it’s not proven,’ Dr Peukhari emphasises.
Yet another possibility is that it is something to do with the dairy process. Noomi, for example, insists that when she is in holiday elsewhere in Europe she has no problem with their dairy products.
‘Some Finns say that when they are in the Mediterranean they can drink their milk so it could be to do with the dairy process,’ says Dr Peukhari adding, ‘but this has not been studied.’
Or Finland’s intolerance could be to do with the Finnish diet as a whole. ‘Finns eat a lot of rye-bread. This has long carbohydrates which are not absorbed by the gut. It could be the milk reacting with this, so it could be the diet as a whole or a combination of reasons,’ suggests Dr Peukhari.
But am I the only one left asking, ‘Why is it that, if Italians have far higher levels of lactose intolerance than Finns, ice-cream is so popular there?’
For some Finnish researchers, the answer is pretty clear. Lactose intolerance in Finland is little more than mass-hysteria. Helsinki University pharmacologist Prof. Heikki Vapaatalo argues that, ‘Lactose intolerance in Finland has been created by the media. People think they should have these symptoms so they do. It is psychosomatic.’
Prof. Vapaatalo recalled his own research with Malaysians and Indians. According to all tests they were highly lactose intolerant but given milk ‘they had no symptoms whatsoever.’