Interview

Fighting for the tooth

The sugar industry is up in arms over new WHO dietary guidelines. Steve Iliffe asked Aubrey Sheiham to assess the industry’s arguments

Big Tobacco is in retreat before an alliance of science and aggrieved citizens, and Big Sugar may be next in line. The recent joint report of the Food and Agriculture Organisation (FAO) and the World Health Organisation (WHO) has annoyed the sugar industry, which is lobbying hard against its recommendations and even threatens to challenge US financial support for WHO. But its aggressive response may have backfired, because it seems to mimic the bullying tactics of the tobacco industry.

The sugar industry has two major gripes with the WHO/FAO report. The first is that the report recommends no more than ten per cent of dietary calorie intake should come from sugars, a view which the industry dismisses as unscientific. The second is that WHO did not consider a full economic analysis of the impact of this recommendation before releasing the report in draft form for consultation. But such objections are typical of the industry’s ‘simplistic and misleading approach to science’ and its ‘self-interested approach to global economics’, according to Professor Aubrey Sheiham, of University College London’s department of epidemiology and public health.

The scientific dispute hinges on the relationships between sugar consumption, obesity (which may lead to heart disease and diabetes) and dental caries. WHO’s expert committee has no doubt that sugar consumption contributes substantially to the obesity epidemic, and recommends a limited intake accordingly. The industry deploys complex arguments against this, stating that sugar consumption (in the UK) has remained stable for a long period of time, while in the US it amounts on average to about 11 per cent of calorie intake – not enough to account for the massive increase in the American waistline.

But those who consume more sugar tend to be thinner than those who consume more fat, says the website of British Sugar plc (‘the portal site for sugar users’). And sugar makes you feel full, so you eat less, and gives energy, so you do more. People who reduce their sugar consumption increase their fat consumption, and so gain weight more easily. The obesity epidemic is due to inactivity and excess fat consumption, argues the sugar lobby. And the responsibility for obesity belongs to the individual, who should eat sensibly and take more exercise.

Professor Sheiham contests these arguments forcefully. First, data on sugar consumption is notoriously error-prone, with up to 20 per cent under-reporting of consumption, especially by fat people. The relationship between high sugar intake and thinness is spurious, he says. Second, sugar is burned off as energy faster than fat, so eating sugar preserves fat. And third, using population trends to challenge the causal role of sugar is ‘scientifically feeble’ – we do not think that falling rates of lung cancer prove that tobacco is not carcinogenic.

The same logic applies to the less life-threatening problem of dental decay, which is promoted by sugar and inhibited by fluoride. According to British Sugar, dental decay has decreased dramatically while sugar consumption has remained stable so that by 1994, 50 per cent of 5-year-olds had never had a filling -- compared with only 7 per cent 20 years earlier. The change is due to fluoride in toothpaste, and the concentration of dental decay (80 per cent in 20 per cent of the population) proves the problem is not sugar, but poor education and inadequate dental hygiene, it says.

Not so, counters Professor Sheiham. About 80 per cent of older teenagers have dental decay, and over time most new caries appear in the 80 per cent of the population whose teeth are thought to be free of decay. Dentists favour the 80:20 theory because it permits them to concentrate on the ‘high risk’ group, but most cases fall outside this group. Sugar consumption has fallen, not stayed static, because of the success of sugar-free baby foods and diet drinks, and together with fluoride in toothpaste this has reduced dental decay. But, adds Professor Sheiham, ‘a further small reduction in sugar consumption would mean that we need visit the dentist only once in five years’.

Responsibility for avoiding obesity and dental decay may be individual, but the profits of the sugar industry are corporate. The American Sugar Alliance (“backing America’s beet, cane and corn farmers”) estimates that sugar and corn sweeteners combined generate $21bn dollars of economic activity in 42 US states, annually. Around 372,000 jobs are reliant on this industry, which releases into the US food supply 65 pounds of sugar per person each year. The US has found a way of making its surplus of grain profitable, converting it into sweeteners, and is self-sufficient in sugars. The UK subsidises beet farmers and exports sugar on the world market, competing with third world producers and driving prices down.

Given all this, it is not surprising that the industry is fighting to maintain sugar consumption. And it is entirely predictable that the industry should gain entry to WHO scientific debate through the International Life Sciences Institute (founded by Coca-Cola, Pepsi-Cola and other food giants), funding research on the one hand and lobbying hard through organisations like the Sugar Association and the National Soft Drinks Association on the other. Of course, diversification of agricultural production away from sugars in the US and the UK would be healthier for the population and allow third world countries to produce the sugar that is needed, but would be unthinkable to commercial interests.

WHO has encountered the sugar industry before, with a report published in 1990, and saw off the commercial lobby then, but the industry’s power is greater now. Will WHO be able to maintain its scientific objectivity? The political power of the sugars industry is formidable, says Professor Sheiham. The Tory party lost the industry’s financial backing in the early 1990s when it failed to block expert reports on healthy eating that urged lower sugar consumption, and he has even encountered a Labour Co-op MP anxious about the commercial implications of healthy living advice. When you hear a politician or a professional disparage efforts to control over-consumption of sugars, he suggests you ask about their connection to the industry.