08 fevereiro 2006

Should we swallow this?

The health food section at my local supermarket seems a bit of a reproach, when you eventually find it sandwiched between instant packet sauces and speciality olive oils. This is where you can buy products made by the Food Doctor. His cereal, fruit and seed bars may consist of 26.6% sugar in its various guises and cost 75p each; they are, however, "designed for a balanced metabolism". Most of the food here makes similar claims for itself. But an unspoken question hangs uncomfortably over the shelf flyer: if this is healthy, what does that make the products in all the other aisles?
Well, some of them have now started making claims for themselves too. Over in yoghurts you can buy pots of Danone's Activia with its patented bifidus "digestivum" bacteria. You've probably seen it advertised on television. Cod Latin names may clog up the brain, but this bacterium is "clinically proven to help improve digestive transit". Which presumably explains why it is twice the price of ordinary yoghurt. The same company's Actimel yoghurt drink, with the bacterium L. casei "imunitass", wants to "help support your body's natural defences". (For some reason cod Latin in France is different; Danone sells the same bacterium in the drink there as "defensis".)

These products are described as as "probiotic"(see glossary). No one is quite sure who first coined the word. In the 1950s,veterinary reports talked of pig feed with probiotic-added bacteria to help the animals gain weight faster. The current use of the word aims at something rather different, though, and seemed to come into vogue in the mid 1990s. Müller, meanwhile, has just launched a Vitality yoghurt drink which it calls not only probiotic but "prebiotic" (see glossary), with added omega-3 fatty acids from fish oil "for the functioning of the brain".

Walk down a different aisle in the supermarket and you'll find a different cure. In among the yellow fats, as food manufacturers call them, a tub of own-label sunflower spread costs just 38p per 500g. For 13 times the price, you could buy Benecol Light, one of the newer brands of spread that are "clinically proven" to reduce cholesterol. Its main ingredient by weight is water, followed by sunflower oil and other oils, vitamins, colouring and flavouring and other additives, a list very similar to the cheap brand. But Benecol also contains 7% plant stanols, that "lower bad cholesterol ... as part of a healthy diet and lifestyle". These are primarily hydrogenated sterols (see glossary) made from the wood pulp of pine trees. Plant sterols are also presumably what make Flora pro.activ's cholesterol-lowering spread 11 times the price of the cheap brand. Pro.activ's hydrogenated sterols come primarily from soybean oil. The Flora leaflet says pro.activ spread is "clinically proven to lower cholesterol in just three weeks ... when moving to a healthy diet".

Some academics and nutritionists call this new category of processed foods "techno foods". Market analysts have come up with the more clinical term "nutraceuticals", to acknowledge the blurring of the lines between hi-tech food production and the drug industry. (Pharmaceutical companies are heavily involved in these new products. GlaxoSmithKline, maker of Lucozade sport and energy drinks, now leads the way in drinks that make health claims, while Johnson and Johnson owns the company that makes Benecol.)

But the term preferred by the food industry is "functional foods". Several multinational manufacturers such as Nestlé, Unilever, Danone and Kraft have invested heavily in these, and little wonder: the market was worth $9.9bn in 2003, and is predicted to grow by 16% a year. Nestlé's head of nutrition summed up the trend, telling the Economist in December 2003 that his company was "moving from an agrifood business to an R&D-driven nutrition, health and wellness company".

This raises that uncomfortable thought again: if these are functional foods, is the rest of our industrialised diet not functional?

The pioneer in functional foods was undoubtedly Yakult, made by the Japanese company of the same name. It burst upon the European market in the 1990s as a fermented milk drink with an added strain of healthy bacterium, Lactobacillus casei Shirota. The strain had been isolated by Yakult's Dr Minoru Shirota in the 1930s and marketed in Japan as good for the digestion. It was sold in pharmaceutical form from 1975. Then it was launched in the UK in 1996, in what look like toy milk bottles. Sales took off, helped by £40m worth of extensive marketing in the UK alone. French multinational Danone was quick to follow with Actimel, which now outsells Yakult; and now Danone has formed a strategic alliance withYakult, owning 20% of its shares.

The idea of adding specific nutrients or substances to processed foods to make them healthy is not new of course. In 1940, the government decided that the over-refining of flour was depriving the nation of vital nutrients and ruled that vitamin B1 should be put back into bread. Millers are now required to fortify flour not just with B1 but also with B3, iron and calcium. The new wave of breakfast cereals, breads, and even fresh fruit juices, milk and eggs that are marketed as healthy because they have added vitamins, minerals or essential fatty acids such as omega-3, are simply continuing the tradition. The problem is, they hardly ever restore everything the factory processes or intensive farming have taken out. During the milling of grain to white flour, for example, the 20 or so vitamins, minerals and essential fats present in the original wheat grain are reduced by at least half.

Intensively reared cows kept indoors produce milk that is lower in omega-3 essential fatty acids than organic ones that graze on grass. Again, industrial hens lay eggs that are lower in nutrients than those that are genuinely free range. In one study, farmyard hens in Greece were found to lay eggs with 20 times more omega 3 than US factory hens. Omega-3-enriched functional eggs such as Stonegate's "Intelligent Eating" brand are produced, however, by feeding hens a novel diet that includes tuna or salmon oil ... They trade on the association between general deficiency in essential fatty acids and impaired brain development.

"The question is, how much do these functional foods actually deliver," says Dr Alex Richardson, the Oxford researcher, who has carried out the largest trial to date on the effects of omega 3 on children's behaviour. "From the research so far, EPA [another omega-3 fatty acid] seems to be more effective than DHA for brain function but we can't be sure. And you would need to drink nearly two-and-a-half litres of semi-skimmed clever milk to get the benefits we saw in our study, or 50 omega-3 enriched eggs a day might just about get you there."

Kath Dalmeny of the consumer watchdog the Food Commission is equally unimpressed. "What the food industry is doing is taking out the wonderful nutrients nature provides in the right combinations and sticking some of them into expensive products and pills and selling them back to us. You shouldn't need all this stuff if you are eating lots of fresh, plant-based foods."

Stonegate's marketing manager Richard Langdon argues, however, that many people don't eat well and are short of nutrients. "We're not claiming that we improve the intelligence of your children but we're helping make up a deficiency."

The efficacy of probiotics is little clearer. In the old days, beneficial gut flora could be boosted by the live cultures found in plain yoghurt. However, industrial processing of cheap yoghurt with its high-speed machinery pumps the culture along miles of pipes and kills the live micro-organisms.

Today's probiotic foods claim to act by restoring the balance of microflora in the digestive tract. Many of the dairy-based functional foods contain lactobacillus and bifidobacterium bacteria, which are already naturally present in the gut and aid digestion. The theory is that eating extra good bacteria top them up and keep bad bacteria at bay. But does it work?

A report for the Food Standards Agency on probiotic products found that some of the added bacteria did not actually survive in the digestive system to reach the parts they were supposed to help. The strain used in Yakult was one of those that survived in some tests but not in others. The Japanese company says, however, that it has its own independent research to support its claims.

Danone, too, points to extensive research on the value of its probiotics and says various studies are underway to show that its added bacteria survive. It concedes however that "results reported by individual Actimel users can be as individual as their gut flora profile and overall diet and other lifestyle factors."

The independent Drugs and Therapeutics Bulletin says that the evidence as to whether probiotics work is patchy in relation to the gut and non-existent in terms of improving general wellbeing. The evidence for probiotic effect was strongest for helping with diarrhoea caused by antibiotics and infections or with flare-ups of inflammatory bowel disease. "There are a lot of, how shall we put it, interesting claims out there. We don't know whether they are true or not," says Michelle Smythe, of the Which? food campaign team. Which? wants products properly evaluated by regulators before they are sold.

One of Smythe's concerns is that probiotic foods claiming to be good for you are often high in other unhealthy ingredients. Two thirds of the probiotics Which? looked at were high in sugar, for instance Actimel has 14% added sugar, while Yakult has 18%. But without sweetening, these probiotics full of very sour bacteria would be simply "unpalatable", as Yakult puts it.

Proposals were brought before the European parliament last year to prevent foods that are high in fat, sugar or salt making other health claims, and to ensure that any health claims were proved before the products reached the shelves, but they were rejected. New proposals to introduce an approvals scheme that would replace the current voluntary code of practice come back to the EU next month, but there has been heavy lobbying from industry to stop it, according to Smythe.

Some of the health claims made for functional foods have been evaluated by regulators, though. The plant sterols that claim to lower cholesterol needed EU safety approval as novel food ingredients before they could be used, and extensive clinical trials have been conducted on their effects. The government's expert committee on novel foods concluded they were effective in lowering cholesterol but advised that foods to which they have been added "are suitable only for 'at risk' groups, namely those who have been advised by their GP to reduce their blood cholesterol levels by altering their diet." The committee also emphasised the other ways of lowering blood cholesterol - cutting down on biscuits, cakes, pies, sausages and dairy fats, taking regular exercise, and, if necessary, drugs.

For those without high cholesterol, sterol products are less suitable as they interfere with the absorption of key nutrients. The carotenoids, needed to make vitamin A and, to a lesser extent, vitamin E, are affected.

What all these functional foods do is medicalise food. The labelling used echoes the language of drugs. Flora pro.activ yoghurt drinks are labelled "one a day", as are Benecol's. The leaflet that comes with Flora pro.activ spread follows the format of the advice leaflets that come with medicines, covering such questions as: "What happens if I have less than three portions a day? How long should I continue eating Flora pro.activ?" Answer, of course, stick with it long term.

Both Unilever, manufacturer of Flora, and Benecol deny that manufacturers are encouraging consumers to think of foods as medicines. Benecol's director of regulatory affairs, Colette Short says: "Benecol came about as a public health initiative in Finland, where rates of heart disease are very high and it was backed by the Finnish government. We reiterate that it should be part of a healthy diet." But should they be promoted to those who do not have a diagnosed problem? She is reluctant to be drawn. "They are for people who have high blood cholesterol." But what about the general population? "They are for health maintenance."

Unilever's nutrition expert, Anne Heughan, argues that two thirds of the population have high cholesterol, a risk factor for heart disease, and that for them Flora pro.activ is a great help. "There is scientific consensus that 2g of plant sterols will reduce your blood cholesterol by an average of 10%. Of course, healthy diets are very, very important but generally people cannot get better than a 5% reduction on healthy diets. But I don't see this as a drug at all. It's marketed as a food."

The worry for Dr Mike Rayner, director of the British Heart Foundation's health promotion research group at Oxford University, is that these products not only appeal to the healthy wealthy - those who generally need them least - but are also a distraction. "They are not something government should be encouraging. It's true that 67% of the population have cholesterol levels above five, but that's what used to be considered normal in Britain until recently. These products are very expensive and you have to eat a lot of them. I don't think they do harm in themselves but if they make you think you don't have to cut down on saturated fat, which is the most important thing, they are unhelpful."

Food manufacturers have been squeezed in the past couple of years, both by supermarkets' demands for lower prices on standard lines and by shoppers' growing wariness of processed food. Functional foods, sold at a high premium, represent a way of restoring profit margins while also wrapping brands in a glow of general health. It is no coincidence that the companies most active in developing functional foods are those who most want to dissociate themselves from cheap unhealthy products. Coca-Cola has developed sports drinks and waters with added minerals, while PepsiCo has been marketing Tropicana juices with a growing number of added nutrients.

We fall for all the marketing partly because we are confused by all the messages about diet and partly because we all want a magic bullet. But Marion Nestle, professor of Nutrition Studies at New York University, and author of Food Politics, has little time for the delusion. "No functional foods can ever replace the full range of nutrients in fruits, vegetables and whole grains, nor can they overcome the detrimental effects of diets that are not healthful. The primary beneficiaries are most likely to be the companies that make them. The degree of benefit to the public is much less certain," she says.

That won't stop the bullets coming. Watch out for the new one - functional confectionery. "Infused with skin-supporting cranberry-seed oil for omega 3/6/9, blueberries, lutein, lycopene, beta-carotene, astaxanthinis" - Health by Chocolate is on its way from America.

Glossary of terms

Sterols Sterols (and stanols) are plant compounds derived from oils, trees and leaves. They have a similar chemical structure to cholesterol so that when they are eaten they seem to partially block the uptake of cholesterol from the gastrointestinal tract. This leads to a reduction in cholesterol levels in the blood stream.

Probiotic Probiotics are live micro-organisms such as bacteria added to food that is claimed to top up the good bacteria in the gut and help digestion.

Prebiotics Prebiotics are non-digestible carbohydrates that claim to favour the growth of beneficial microflora in the large bowel.

[From The Guardian]

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