Rose Prince: Variety's the spice of longer life in France

'It's that sinking feeling again, as the country and its farmers begin to absorb the implications of the foot-and-mouth outbreak'

There will be the inevitable inquiry into what went wrong, and individuals will be blamed. But we are beginning to see, time and again, that the real disease in farming was the decision, 50 years ago, to intensify food production. A full larder has come at the cost of poor husbandry, environmental damage and a society that suffers from a high rate of cardiovascular illness, obesity and cancers. These problems are shared with the United States, from where we have gleaned some of the more disgraceful methods of food production. What rankles is how other nations can be well-fed and healthy and live to a grand old age, too.

There will be the inevitable inquiry into what went wrong, and individuals will be blamed. But we are beginning to see, time and again, that the real disease in farming was the decision, 50 years ago, to intensify food production. A full larder has come at the cost of poor husbandry, environmental damage and a society that suffers from a high rate of cardiovascular illness, obesity and cancers. These problems are shared with the United States, from where we have gleaned some of the more disgraceful methods of food production. What rankles is how other nations can be well-fed and healthy and live to a grand old age, too.

Take the French. They eat more saturated fat than the British and Americans but have a lower rate of mortality from cardiovascular illness. This has been framed as the French paradox. The enigma irritates the US Department of Health in particular, which continues to advise eating a low-fat diet to combat obesity. Baffled scientists are frequently sceptical about the French paradox, but you only have to go to France, take a look at your companions in a food establishment and, yep, they're eating everything, and they're still skinny.

The paradox has been explained by the fact that the French drink up to four glasses of wine a day. But that cannot be the reason, because wine drinking has dropped by a third, while the death rate is dropping, too. There is now a view that it is the sheer variety in the French diet that is the key, and it's the strongest argument yet.

The Human Nutrition Programme at the University of Michigan led a research programme into French dietary diversity. Very few studies of this kind have been undertaken. After all, it is more commonly the sickness, not the "wellness", of a nation that is scrutinised. Professor Adam Drewnowski's study closely observed the eating habits of 837 French adults in the Val-de-Marne region, south-east of Paris.

Over six months they were asked about everything that passed their lips, plus where they shopped - market, supermarket or high street. Seasonal food fluctuations were also recorded. Points were awarded - the more diverse the diet, the higher the scores. Ninety per cent of the subjects scored highly, compared with 33 per cent of Americans asked for similar information. "In particular, and under the present definition of variety, the most varied [French] diets were also highest in energy and fat," wrote Drewnowski.

The narrowness of the American diet is becoming an embarrassment to the industrialised world - and in Britain we are moving in the same direction. The study's findings point towards the unpleasant realisation that the drive to standardise, mechanise and cheapen food production in the US is literally killing people. Meal times for one in four people in the States have been devalued to a take-away burger once a day, according to Fast Food Nation by Eric Schlosser, an alarming book exposing the production methods of burger chains, in particular McDonald's. It claims that fast-food companies are fuelling an epidemic of obesity, with all the ensuing health problems.

Meanwhile in France, M et Mme Average are deciding what to have for dinner. Shall they have a dish of eggs? And if they do, will they have them pochés, soufflés, brouillés, or perhaps au jus or à la crÿme - to name just a few options. Then, which of the hundreds of varieties of vegetables shall they choose? That's easy. The ones that looked their best today, the ones in season. There's little need for the year-round Kenyan bean in the land of the French bean, where they continue to show us how a broad variety of nourishment gives a slim chance of an early heart attack.