Centuries after its invention cash is still king. According to a study published in the American Journal of Consumer Research, shoppers at supermarkets should avoid using credit cards if they want to put less junk food in their baskets and more fruit and vegetables.

The reason is as simple as it is obvious – payment in cash requires the purchaser to physically part with his or her money and whatever Shakespeare said, there is nothing sweet about the sorrow of parting. In the words of the researchers: ‘cash payments are psychologically more painful than card payments, and this pain of payment can curb impulse purchases.’

There are sound reasons to believe that the unhealthiness of plastic applies to more than just the careless purchasing of junk food. Although much of our present economic malaise can be laid at the feet of greedy and irresponsible bankers, we consumers are not without blame.

It was us who went hog wild during the great asset bubble, shopping until we dropped, only to pick ourselves up and set off shopping again. And what made it all so easy, so painless, so carefree and thrilling? Why, plastic of course.

At the height of the boom, in 2004, consumer indebtedness broke through the £1 trillion barrier, and about a quarter of that was accounted for by credit cards. Amusingly (if your sense of humour runs to the sardonic), Charles Bean, the Bank of England’s chief economist, marked the £1 trillion milestone with the memorable comment that it didn’t mean UK households were sitting on a ‘time-bomb’, since an increase in borrowing had been matched by an increase in financial assets. Four years later, the time bomb went off, leaving consumers shell-shocked to this day.

Interestingly (if your sense of humour runs to the ridiculous), that same Mr Bean is today urging us all to rush once more into the breach and spend, spend, spend.

Of course, a rise in consumer confidence would be good for the economy. But asking debt-laden consumers to return to the fray is rather like asking a hunter who has been bitten on the backside by a grizzly bear to go back into the woods.

However, when we do finally venture out from behind our sofas, ashen-faced and trembling, and head back to the shops we should heed the words of the American Journal of Consumer Research and leave our credit cards behind.

In this age of austerity, only cash is completely safe, being painful to part with and thereby inducing caution. Debit cards, although still tainted by an ersatz quality, are advisable for larger purchases, but credit cards should be avoided entirely.

However, if our future economic stability and well-being might be enhanced by making shopping a painful experience, many retailers are to be congratulated on anticipating events so selflessly and shrewdly. Look no further than lower Oxford Street, which provides a vivid foretaste of what awaits those poor mortal souls destined to spend their eternity in perdition.

Shopkeepers who fill their premises with deafening music and employ assistants trained, like the ancient mariner, to stop one in three and fix them with a glittering eye, are also doing their bit to dampen down the urge to buy.

So too are the supermarkets. Having long ago trained us to forage for the goods we wish to buy, picking them off the shelves ourselves, they now expect us to pass through automated checkouts, doing our own scanning.

It is difficult to decide which is worse – a shop staffed by importunate assistants or a supermarket with no assistants at all. Either way, retailers are moving in the right direction with admirable vigour.

Similar meritorious developments are occurring with online shopping, which for a while threatened to undo the good work of the High Street by encouraging people to buy. Now, however, it’s likely that a great many potential shoppers are being deterred by huckstering emails relentlessly urging them, among other things, to revive or enlarge their sexual potency.

But not all the news is good. A new version of Monopoly is being launched this Christmas with credit cards instead of paper money. ‘Do not pass Go. Do not buy salted crisps and fizzy drinks.’