HC Deb 04 February 1954 vol 523 cc695-706

9.59 p.m.

Dr. Barnett Stross (Stoke-on-Trent, Central)

The Parliamentary Secretary of the Ministry of Food will remember that I put a question to him the other day about cola drinks. He was good enough to give me an answer and to extend it in part when I asked him a supplementary question. He told me that he had no information as to the ingredients of these drinks.

It being Ten o'Clock, the Motion for the Adjournment of the House lapsed, without Question put.

Motion made, and Question proposed, "That this House do now adjourn."—[Mr. Kaberry.]

Dr. Stross

As I was saying, the Parliamentary Secretary was aware or had been informed that the measure of acidity of cola drinks was 2.6. This matter was to be studied through his Committee on Food Standards, and it was hoped soon to consider the position generally, including the question of acidity. He further told me that the level of acidity of these drinks was only slightly more than the level of acidity for soft drinks generally.

Before I go further may I say that I did note when he gave us the definition in terms of hydrogen ion concentration that he was misreported in "The Times," for the answer was given correctly in HANSARD. I heard him give it correctly. The answers which the Parliamentary Secretary gave me were, I think, important.

There have been experiments with regard to this matter in the U.S.A., and I believe that, in spite of these experiments and investigations, very little publicity was given in the Press. There is an organisation there called the Consumers Union, and they are interested essentially in what people consume and what is in it. They reported on a number of drinks of this kind. I have the facts here, and it may well be that the Parliamentary Secretary has other drinks which have been analysed and can tell us about them. Assuming that the pH of water is 7, club soda was given at 4.7, sarsaparilla, 4.0, root beer, 3.4 and bottled orangeade, which I presume is a somewhat synthetic drink, 3.2, and the colas they give as 2.4, although I think most of us have found in the literature that it is 2.6. These figures suggest one thing with certainty, and that is that cola drinks are the most acid of all the mineral drinks which I have mentioned. There may be others used which are appreciably more acid than cola, although I doubt it, because the acidity of cola drinks is roughly that of vinegar, and I doubt if there is any other drink on the market which has more acidity than vinegar.

I have mentioned that the critical acidity measurement is pH 3.5 for most people, and the reason is that if anything is more acid than that the saliva of the mouth of a human being cannot neutralise or buffer it. Experiments in connection with this were conducted by Professor Dr. McCay who was professor of nutrition at Connell University, New York. It was in 1943 that he became interested, and he was then advising the United States Navy on nutritional and health matters. He gave evidence in 1950 before a Select Committee of Congress which was investigating the use of chemicals in food products. His analysis of cola drinks was as follows: Phosphoric acid .055 per cent, sugar 10 per cent., some caffein—he did not state the amount, and I have not got it—and some colouring matter and water and, I presume, flavouring.

In giving his evidence, Dr. McCay quoted what experiments he had conducted on the teeth both of humans and of animals. Human teeth he had of course immersed in solutions for different lengths of time, and he said that in two days human teeth in Coca-Cola became very soft. Of course, everybody knows that is true because it is easily proved. I proved it myself the other day, and if the Parliamentary Secretary is interested I can show him the specimens. I am obliged to my hon. Friends the Members for Wolverhampton, North-East (Mr. Baird) and Penistone (Mr. McGhee) for providing me with a number of teeth for experiments.

Brigadier F. Medlicott (Norfolk, Central)

But is that not an entirely artificial test? If the same procedure were adopted with other liquids, would not more damage be sustained?

Dr. Stross

I was about to say that nobody holds a drink of cola or lemonade or anything else which may be acid in his mouth for two days before he swallows it, and I will now refer to the real tests, which are of much more interest. They are tests which may be described as in vivo, tests on rats, dogs and monkeys. The tests on monkeys are particularly interesting, because these animals can be taught to drink in exactly the same way as human beings drink—from a cup. Evidence given in 1950 to this Committee of Congress was that after six weeks rats which had been given some Coca-Cola to drink with their food each day showed most extensive erosion of their molar teeth. With orange juice they showed only very slight marking on the teeth, and there was none at all with tomato juice or water.

The next experiment was one of six months. After a similar experiment for six months, erosion by phosphoric acid was such that the tops of the molar teeth were only slightly above the level of the gum. The teeth had been eroded away. There was some erosion with orange juice, very little with tomato juice, and of course none with water. I hope no one will be scared of drinking orange juice, the acidity of which, I am told, is about one-tenth of that of cola drinks. The danger must be almost nil, and I am sure the human mouth can neutralise it or buffer it perfectly well.

According to the Consumer Report of 1950, experiments on humans were conducted by Professor McCay himself. He attempted to reproduce the experiments on human volunteers, but this was abandoned as an experiment because of the sensitivity which developed in the teeth and which made it impossible to continue. He said he deplored the use of carbonated drinks which were as acid as this, not only for those who might have their teeth damaged as a result—and he was quite satisfied that teeth were damaged—but on account of peptic ulceration and. as far as young children are concerned, because there was caffein in the drink and young children should not have repeated doses of caffein. He said, I would not use it in the Navy or anywhere else, if I could escape its use. He also said, If you have got a friend who has got a gastric ulcer, and he is trying to drink a bottle of coke, he will get into trouble. I want to make it quite clear at once to the House that I have not picked out this drink in order to make any specific attack upon it and it alone. Other drinks, for example, apple juice, grape juice, sweetened grapefruit juices, I am advised, have a high acidity—3.1 hydrogen ion concentration; and it means that there is a risk of teeth erosion if those are taken in excess each and every day over a very long period.

But we have the right to bring this matter up, because if the experimental work which I am quoting is true, it means that we are subject to an assault upon our teeth, or are to be in the near future now that sugar is unrationed and the cola drinks are likely to be drunk much more frequently; and this is an assault from which we can be protected. It is my thesis that drinks which erode the teeth are harmful and that it may well be possible, by altering the composition and using the influence of the Ministry of Food, to get an alteration in the acidity. Surely a decrease in the acidity could easily be effected by some alteration in the composition of these drinks. We shall then not have the same problem. I am asking the Parliamentary Secretary to use his influence in two ways. I want him to insist on the formula being published on the label. We ought to know how much sugar and phosphoric acid is in these drinks. I do not mind which drinks they are, and if there is caffein in them we should be told how much.

Brigadier Medlicott roses

Dr. Stross

No, I cannot give way. The hon. and gallant Member knows how limited is my time. The reason I advocate this labelling is not because everyone reading these things will at once become wise and protect himself or herself, but those of us in the know, like doctors, dentists and so on, will understand the significance and be able to tell people what it means.

May I give an example of what I mean? Both here and in the United States food for cattle and animals generally is accurately and fully labelled, and that means the average literate or educated hen or cow can read on the labels what it is eating, whereas we poor humans, who are supposed to be educated, are left in the dark and we do not know what is happening to us. I am suggesting labelling, but I am not asking for legislation, which, of course, would be out of order. But we will have something more to say about that in the near future when a very interesting Bill comes before this House for consideration.

If I might be allowed in the time available, I should like to quote again a question which was put by one of the members of Congress to Dr. McCay. This was: I want to say to you, Sir, that I have had a doctor right here in Washington prescribe a small amount of cola beverage for my baby. Now, how did that come about? The answer he got was this: Well, they probably have not read the literature about cola beverages. It is a very restricted literature; it has not even been able to get into the Press, so what does the American public know about it. It is not declared on the bottle. They are as ignorant as I was in 1943 about the composition of the beverages. How would the public ever know if it cannot get into the Press? There is no way for them to know. That gives me an opportunity to say this. Although one Question only was asked in the House, there has been an appreciable amount in the British Press. It is a good thing that I am able to say that. Why should we have anything to be afraid of? These drinks may be harmful, but if they were altered in composition they could become more popular than they were before, particularly if we all know that they can become beneficial rather than harmful.

I was told this in a Sunday newspaper by the managing director of an organisation who is bottling these cola beverages in Britain: Hundreds of millions of people, both grown-ups and children, have been having Coca-Cola for more than50 years without any harmful results. I should have thought that the most conclusive clinical evidence that anyone could get. That is what I have seen reported in answer to the view I expressed to the Parliamentary Secretary the other day.

This gentleman wants an answer, and I am going to tell him a few facts. Let us compare the state of teeth in America at the First and then at the Second World War. Evidence was given during the First World War before this Committee of Congress that hardly any dentures were made for G.I.s in the Army. In the Second World War in the peak month 102,000 dentures were made by Army dentists for soldiers.

In the Second World War, out of a draft of the first one million men, 188,000 were rejected because they did not have the dental requirement for that first draft. That requirement was merely that six upper teeth and six lower teeth should oppose each other and touch. It was found that if 188,000 men were to be rejected because of that condition, it would be better to do without any dental requirement, and so it was revoked altogether.

The American Dental Association further states that today there are about half a billion cavities in American teeth, roughly half of those in children's teeth and the other half in adults'. It also states that 98 per cent. of the American people suffer from dental caries. That is a very different picture from 50 years ago. I am not saying that acid drinks are the entire cause of this state of affairs. American nutritionists are saying there are two other factors. One is the excessive eating of candy and the other is the denaturing of food, what they call the use of foodless foods. The three factors together are responsible for the change and we should take note of it.

It is always important in matters of this kind not to express excessive enthusiasm, but it is equally important, if one believes that danger faces our constituents, that we should have some care for them. Both in this country and in America, where there is the highest standard of life in the world, where there is the greatest possible variety in choice of foods, and such a highly evolved economy, an enormous amount of money is spent on dental care by the citizens. I suggest that anything which may be inimical to the health of our people, whether it be to their teeth or to their stomachs, or in any other way, deserves the full care of this House.

10.16 p.m.

The Parliamentary Secretary to the Ministry of Food (Dr. Charles Hill)

I am glad that the hon. Member for Stoke-on-Trent, Central (Dr. Stross) concluded with a word of caution, for it is particularly important that we should not regard this assembly as a scientific one, that we should not argue in complicated terms as between doctors, and that we should not arouse apprehensions that are not fully justified by the facts. I am bound to say that as I heard the hon. Gentleman developing his theme, I wondered what the hon. Gentleman the Member for Ealing, North (Mr. J. Hudson) would have thought had he been in his place. I suspect that some of the things said might have driven even that hon. Gentleman to drink in order to escape the horrors that were mentioned.

Dr. Stross

I am sorry, too, that my hon. Friend is not in his place, for he was coming to support me.

Dr. Hill

Well, discretion has evidently played a larger part and the hon. Gentleman has decided to stay away. Reference has been made to the extensive investigations of two men, reported by one of them to a Congressional Committee which was surveying the field of chemical additions to food but which in its report did not think this evidence was of sufficient importance even to mention it there. Let us look at some of the evidence to which reference has been made. Extracted human teeth have been left in Coca Cola. The shortest period reported was 72 hours. What happened? They lost weight due to the attack on the calcium of those teeth. We are expected to infer from this that in the swift passage of acid drinks through the lips and down the throat there is likely to be a danger comparable with that due to an exposure of naked teeth to an acid solution of cola drinks for a period of 72 hours.

And what happened? There was a loss of weight of between 5.5 and 10.2 per cent. in those teeth. The hon. Gentleman should have added that had the fluid in which the molars of his friend were immersed been not a cola drink but fresh lemon juice, the loss would not have been between 5 per cent. and 10 per cent. but would have been 35 per cent. Had the immersion been in grapefruit juice or orange juice—even the orange juice of the Ministry of Food—there would have been a loss of weight in those teeth. Indeed, the hon. Gentleman might have gone on to say that had this been in a neutral solution of citrate, there would have been a loss of weight. Finally, had this immersion been in distilled water there would have been a loss of weight in those teeth and no one has yet attempted to prove, scientifically or otherwise, the peril to our molars which lies in the consumption of so insipid a drink as distilled water.

Dr. Stross

I know that there is not much time, but I hope that the Parliamentary Secretary will not run away on this. Will he talk to us about the effect of drinking normally in these animal experiments?

Dr. Hill

If the hon. Member gives me time, I will get as much of the answer out as I can. These teeth, of course, were extracted. There was no protective layer of much in even on the teeth of his generous friend. They were not washed in the alkaline salivary juice which plays an important part in neutralising the acid. There they were, two lonely teeth of his political friend's, lying helpless for 72 hours in a bath of cola drink. Let us say at once that an experiment conducted under those circumstances is of very little value in determining either the fortitude of the teeth or the power of the solution in which they were immersed. In the experiment which the hon. Member mentioned, the rats were given cola drinks over months. Their teeth eroded. If one makes a little calculation of what would be the equivalent amount of cola drink that would have to be drunk by an adult in order to achieve the same conditions as those represented by the small amount of cola drunk by the modest-sized rat, one would have to conceive a situation in which the adult man drank 25 bottles of cola a day. And what would happen to the average man who drank 25 bottles a day? I know not what would happen to his teeth, but I have a shrewd idea as to the airy congestion which would be found lower down.

I do not doubt for one moment the scientific accuracy of the two fellows who did the experiment, or that there was a remarkable difference between what they said to the Congress Council Committee and what they subsequently said in articles in various journals, but, to say the least of it, the evidence is inconclusive. We must, of course, keep a perspective. All acids can corrode teeth. Bless my soul, one of the dangers to teeth lies in the residual pieces of starchy food which lie in the nooks and crannies of the teeth and turn under bacteriological action into acid and damage the teeth. We knew that before.

The hon. Member will agree that we should make it clear that the lower the pH below 7 the higher the acidity, and the assumption here is that because the pH is as low as 2.6 there is particular danger from this kind of drink. The Government Chemist has been good enough to work out for me the pHs of other drinks. The pH of orange barley water is 3 in a dilution of one in three, which I have chosen. The pH of lime-juice cordial is 2.8, lemon squash 2.75, grapefruit 2.7 and orange squash 2.95. Does the hon. Member want to drive those of us who are abstemious to other more powerful drinks on the ground that their ion concentration is less, whatever their other effects may be?

What about eating apples? There is a source of acidity. One can achieve damage to one's teeth by excessive consumption of apples, but for heaven's sake do not let the theoretical problem of securing that there is not too high a level of acidity round our teeth drive us into the situation of depriving ourselves of fruit juice or depriving ourselves of almost every fruit squash and drink in order to guard against the terrible dangers which are alleged to exist from the consumption of a type of drink of approximately the same acidity.

Dr. Stross rose

Dr. Hill

I hope the hon. Member will not interrupt me, as I feel full of my reply.

Investigations have been carried out in this country and it was reported in 1951 to our own Food Standards Committee that British fruit cordials and squashes diluted with four parts of water as usually drunk had a greater erosive action than phosphoric acid drinks. Some people testified about other drinks with more erosive action. Then there is caffein. There is as much caffein in a large bottle of cola drink as in a cup of coffee—and so what?

Dr. Stross

What about the children?

Dr. Hill

Nothing that this House or anybody else can do can compel parents to concentrate the drinking propensities of their children on a drink with a high hydrogen ion concentration. There is no real danger in the caffein content. For the rest, it is sugar, water, phosphoric acid and extracts from cocoa leaves and cola nuts and other flavouring material coloured with caramel.

The hon. Member says they require labelling to indicate to the public the contents. I do not exclude that possibility. I would say that when that requirement was demanded for patent medicines the chemical formula which subsequently appeared on the labels conveyed nothing to the public except a sense of importance which is aroused in some people when they believe they are taking some unusually complicated medicine.

It is going to the Food Standards Committee, but I would make this clear. The fact that soft drinks generally will be scrutinised by that Committee in relation to their ingredients and in relation to their acidity, and generally, does not arise from any fear of frightful dangers to the teeth of people in this country from this kind of drink. It is a matter of general routine. The Food Standards Order is out of date. To the best of ray recollection, it requires the maximum strength of saccharine, the minimum strength of sugar content—in other words, the order is out of date. The Food Standards Committee will consider this whole range of drinks. That fact in no sense means that it is believed that frightful dangers arise from the consumption of such fluids. Let us get this matter perfectly clear. There is always this danger of erosion to teeth by acid foods and drinks. This particular class of drink seems to be in company with other very acceptable types of drink. Do not let us pick out this kind of drink.

It should not be thought that I am expressing an affection for this particular cola drink. I have only tasted it once and I suspect that such joy as I experienced in the tasting was due to another lacing element which had been adventitiously added. Do not let us get this matter out of perspective and out of proportion. It was a depressing thing for me when in this House ten days ago an hon. Friend asked me, "What is pH?," and I had unwillingly to stand here and say, "The negative of the logarithm of the hydrogen ion concentration measured in programmes per litre of solution. "That is the kind of scientific discussion we should not have in this House. We should be careful not to arouse undue fears and anxieties particularly in relation to the consumption of a group of drinks which, in the absence of the hon. Member for Ealing, North, I may dare to think are lacking in attraction to some of us, but which cannot, by and large, be considered to have contributed to our physical undoing or dental downfall.

Question put, and agreed to.

Adjourned accordingly at Twenty-nine Minutes past Ten o'clock.