Every few years, usually as soon as some daft American movie grosses $100 million before heading our direction, everyone gets nervous about our intellectual culture and anxiously questions about whether or not we are "dumbing down".
Every few minutes, another branch of a fast-food chain opens somewhere in the world, another faceless, bland supermarket opens its doors, and another variety of crop disappears from our history. Dumbing down has been going on in our food culture - relentlessly, cynically, unstoppably - for decades. And yet, astonishingly, there has not been a widespread debate on this subject. It has never excited the attentions of mainstream commentators.
You might find such issues raised on these pages, or by groups such as Genetic Concern, or in symposiums such as the Oxford Symposium, where, for example, the Australian journalist Cherry Ripe delivered a scintillating paper some years back entitled - this is not a joke - "Starving to death in the Supermarket".
But, away from the prattlings of these pages and other forums, we muddle along as if nothing is happening. A new mega-store with 23 acres of car parking? Sure, all is well with the world. And if Cherry Ripe can't find something decent to eat in the well-lit universe of Tesco-M & S-Sainsbury-Dunnes, well, more fool her.
But everything is not well with the world, as the journalist Maureen Tatlow points out in her first book, Good Enough to Eat - How We Shop, What We Eat.
If that sounds like a curious title, Tatlow soon proves that shopping - informed, educated shopping - is at the very core of our lives as eaters and consumers. She quotes the venerable Sallynoggin butcher, Jack Hick, as follows: "A generation ago, mothers came into the shop with their daughters, and explained to them about the meat, and what was good. That just doesn't happen any more."
Tatlow's book looks at what has been happening in recent decades, and examines how our food culture has become not simply commercialised, but industrialised and, at the same time, brutalised. She tracks the tandem paths of how our increasing ignorance of what we eat has occurred alongside the loss of diversity regarding what we eat.
Good Enough to Eat shows how the multifarious aspects of our food culture are interlinked, and how the chemicalisation of agriculture combined with the commercialisation of shopping, offers us less and less, while simultaneously suggesting that it is offering us greater choice.
This idea of greater choice is, of course, the great con trick of the supermarket multiples. It is, in culinary terms, The Great Lie. Today, we have fewer varieties of food to choose from than our parents had, and we have poorer quality in those varieties.
We have miles of aisles, filled with food that offers no true typicity, no true sense of regionalism, and few true tastes. If you were fussy, truly fussy, if you insisted on food that was reared humanely, knowledgably, without artificial growth promoters and pesticides and herbicides and without chemical adulteration, then you would indeed starve to death in the supermarket.
The value of Tatlow's book lies in its relentless indictment of modern food systems. Like a lawyer - and, interestingly, Maureen Tatlow is married to one - she assiduously presents the case for the prosecution, the book of evidence pieced together bit by bit. The depredations to our lamb, beef, pork, vegetables. The facts about pesticides. The facts about genetic engineering. The details of food poisoning in our culture. The loss of diversity in our agriculture. She writes as someone who has clearly been radicalised by what she has learned while writing the book, although her tone is rarely polemical: the facts speak for themselves.
But Tatlow's book is not all grim news. In the alternative food culture which has sprung up alongside the mass food culture, she finds not just hope, but true quality. You don't have to eat factory cheese when we have so many fine artisan cheesemakers. You don't have to shop in supermarkets when there are specialists who know every detail about everything they sell. Whenever something looks completely bleak, be sure that someone, somewhere, is plotting an alternative.
You need your wits about you in order to do this, but then not having our wits about us has led us to the current position, where so much of our food is just plain bad. Good Enough to Eat is, likewise, valuable as a counter-blast to the school of food writing which is drip-fed by public relations companies, and which dominates so much of the media. It asks fundamental, and serious questions, it urges us to become radicalised about an issue which is, surely, the most important one of our age.
We are what we eat, yet we seem reluctant to draw the obvious conclusion from this aphorism, that if we truly are what we eat, then we have become a pretty sad bunch of couch potatoes, the lot of us.
Good Enough to Eat - How We Shop, What We Eat by Maureen Tatlow (Gill & Macmillan £8.99)