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What’s really in your food - introduction

In January 2005, a New Zealand newspaper ran a series of articles called ‘What’s in your food?’. Unfortunately, in the opinion of New Zealand Food Safety Authority and its experts, the articles were flawed in many areas of food safety. This response is for the benefit of consumers who may have concerns arising from the articles. A shorter response that was supplied to the newspaper is here.

What’s really in your food

Andrew McKenzie

Executive Director

Our consumers demand safe food and New Zealand depends on food exports for much of its economic survival. Our food must be, and is, the best of the best. Government knows this, producers and manufacturers know this, and much effort and resource goes into ensuring it stays that way. Regulators internationally would be very happy to find their own industries meeting the extremely high levels of compliance we find in New Zealand.

It is unfortunate that much of the ‘information’ the articles provided was misleading or incorrect. While we recognise there was some attempt to present all sides of an issue, no indication of the weight or validity of the evidence supporting each case was given. Giving equal (or in some cases more) weight to a single, often out-dated or not widely accepted, study as was given to the views of the world’s leading food and health organisations, including the United Nations FAO and WHO and peer-reviewed research, does not give consumers the information they need to make an informed judgement.

Distinguishing between ‘good’ and ‘junk’ science is not easy. One definition of junk science is: ‘faulty scientific data and analysis used to advance special and, often, hidden agendas’. ‘Good’ science follows the scientific method (observe, develop hypothesis, test the validity, refine the hypothesis, repeat testing and refinement until the hypothesis fits the phenomenon). Sound science involves peer-review, ensures that tests are repeatable, and that data, analysis and interpretation robust. This work can take decades, is slow and rarely makes gripping reading. Junk science is just the opposite – the studies are poorly conducted, the results not repeatable, the research not accepted by peers, and the results often sensational.

One lone study does not provide fact, particularly when all the other research on the subject suggests otherwise. When Edmund Blackadder notes that he thought it was “common maritime practice for a ship to have a crew”, Captain Rum replies, “Opinion is divided on the subject. All the other captains say it is. I say it isn’t.”

When it comes to food safety, NZFSA sits, as do all of its international counterparts, firmly with the other captains. Reporting purporting to show that the ‘scary stuff’ is out of control or unknown is sailing with Rum.

While nothing in life can ever be guaranteed 100% safe, New Zealand food is of an exceptional standard. We are accepted world-wide as a trusted producer of safe food with more than 80% of what we produce exported to some of the most discerning consumers (and their demanding regulators) in the world. We can confidently claim it is indeed among the safest in the world.

Before addressing some of the specific issues raised, I would stress that the New Zealand Food Safety Authority was set up in 2002 with just one purpose – to protect consumers, both in New Zealand and in our trading partner countries. Our role is to ensure that food sold in New Zealand is safe and that our vital reputation as a producer and exporter of safe food is enhanced. We have no agenda, nor axes to grind, and our comments are provided to help reassure consumers about what really is in their food and what it all means.

Chemical residues

All foods potentially have chemical residues because chemicals of one kind or another are used in their production. However, in New Zealand, levels are well below recommended international levels and we have a status that any nation would be proud of.

Statements that New Zealand has a ‘bad’ residue status are simply wrong. Direct comparisons with other countries should be made with considerable caution because different agricultural chemicals are used in different countries, simply because environments differ. What might be needed in tropical Florida might not be needed in New Zealand, and vice versa. In addition, different crop pests require different chemicals, and different doses. Wherever we sit in absolute terms (and that can never be known because of the many variables), surveillance reports show it is amongst the very best in the world. Rather than being ‘bad’, we are, indeed, ‘excellent’.

Simply comparing Maximum Residue Limits (MRLs) in different countries (as appears to have been the basis for the statement) does not give any indication of the potential intake of an agricultural chemical. This is because such a comparison does not take into account either how much of the food is eaten (generally specific to a country), nor how much of a particular crop has been treated with the chemical (again specific to each country and dependent on factors such as pest pressure during each growing season). Concern should only arise when the potential intake exceeds the Acceptable Daily Intakes (ADIs). After all, ‘it’s the dose that makes the poison’.

It is also worth noting that chemical residues may now be found more frequently because as technology improves, we can find smaller and smaller amounts of anything in more and more places. Thus, older food residues surveys might not show residues simply because the sensitivity of the available methods of analyses at that time was not good enough to detect the very low levels that might have been there. Future surveys may find even more food samples with chemical residues in them – the important thing is how much is found, and how often, not that it is there.

However, despite this far greater ability to detect ever smaller amounts, our 2003/04 Total Diet Survey shows a significant reduction of nearly 10% in the number of chemical residues we found, continuing the trend over the last decade, despite almost double the number of analyses and almost twice the number of samples.

Adding residues

Calculations that show total parts per million of pesticides and contaminants in certain foods are toxicologically meaningless because it is both the particular substance and the amount that matters. Some chemicals are essentially harmless even in very large amounts; others are quite harmful in very small ones. And we would be incredibly surprised to find a lettuce with 16 ppm of pesticides! Our own comprehensive surveys and results would suggest that this figure is nonsensical. The table has no meaning in the real world. You may as well add the number of shoes in a wardrobe and conclude that the owner has that number of feet.

Chicken and antibiotics

A nice little myth, but completely untrue. Chicken is not ‘chock full with antibiotics’. When we test for chemical residues, we target the organ that is most likely to contain these because we are looking hard to find as much as we can. There will be lower levels in the other tissues, including the meat. While our extensive testing has, on very rare occasions, found antibiotic residues in chicken livers on very rare occasions, none have been found in chicken meat for many years.

Hormones

Very few farmers in New Zealand use hormonal growth promotants (HGPs). 'Extra’ hormones are not found in meat from animals treated with HGPs. Natural HGPs obviously alter the levels in an individual but are well within the natural distribution in animals – the levels used to treat animals are well below the average natural levels already in their bodies. For the one synthetic hormone occasionally used in New Zealand, meat tissue levels are well below the internationally accepted Codex MRL at any time in the animal’s life and are undetectable at the time of slaughter.

Mercury

Fish everywhere in the world almost always naturally contain mercury – and always have. New Zealand levels are not of concern. However, a developing foetus is potentially more sensitive to the effects of mercury, and we suggest that pregnant women limit their intake of certain high mercury varieties. Our website has information on this and shows the variations in species.

‘Cocktail’ effects

Apart from a few well known effects, extensive research worldwide has not shown that a ‘cocktail effect’ exists. There is evidence that the effects of different chemicals that act by a common mode of action may be additive (that is, 1+1=2) in certain limited situations. However, the concept of a synergistic effect (1+1=3) is much more controversial and there is no scientific proof to support the hypothesis. There was a famous incident where a paper in the journal Science demonstrated synergistic effects of different estrogenic compounds. The author was subsequently found to have falsified his results and was banned from applying for government funding in the US for five years!

Vinclozolin

Vinclozolin has not been registered for use in New Zealand since 1998.

Aspartame

Aspartame in not the subject of huge controversy. Both the highly respected UK Food Standards Agency and the European Commission’s Scientific Commission on Food have recently conducted extensive studies on aspartame and concluded that aspartame is safe. This view is also held by the US Food and Drug Administration as a quick check of their websites will show. Any controversy is mainly fuelled by a number of misleading websites.

Organochlorines

The use of organochlorines in New Zealand was phased out not because of concerns about their safety but rather about their persistence in the environment and environmental effects. The acute toxicity of most organochlorines for humans is very low. The organophosphates that have replaced them, while far less persistent in the environment are, in fact, often more acutely toxic although their use requirements ensure they remain well below the food regulatory limits – which are themselves well below any levels at which there might be the slightest health risk.

‘Banned’ chemicals

The organophosphates diazinon, dimethoate, methamidiphos and chlorpyrifos have not been “banned” in the US or any other country. There are, however many reasons why chemicals are withdrawn from use.

In a few cases, the US has changed the criteria it applies when deciding if a chemical is acceptable or not, and this has led to manufacturers voluntarily cancelling registrations, particularly where the cancelled uses (e.g. use on a specific crop) has meant that the chemical is no longer commercially viable. Where other countries have not followed the US direction, the decision not to do so has been based on sound science and assessment of risks. Very few chemicals are ‘banned’ world wide – most are managed by risk-based controls.

The most common reason for voluntary deregistration by manufacturers on a country-by-country basis is lapse of patent and the cost of competing with newer alternatives. This is quite different from being ‘banned’ or ‘restricted’.

There are a number of chemicals on a ‘UN list’ that, for occupational health and safety reasons, must be used by trained personnel with specialised equipment. Most farmers in developing countries do not have this expertise or equipment. The chemicals are not ’banned’, simply placed on the UN list to ensure developing countries are aware of the issues. There are no food safety concerns with any of these chemicals when used correctly.

Food colourings

The same applies for food colourings. The reason that some food colourings are not permitted (again, rather than ‘banned’) in some countries is usually that some colours are not traditionally used and manufacturers have never asked to have them registered – usually for purely commercial reasons. Again, there are no food safety concerns with any of these compounds.

Most food colourings, and many other food additives, are categorised as ‘generally regarded as safe’ (GRAS). Examples of GRAS compounds include water and sugar. If a food colouring was a hazard at certain levels, then an Acceptable Daily Intake (ADI) and Maximum Residue Limit (MRL) would be set.

Many food colourings are derived from natural plant products (some of them foods), and many others are merely the natural compounds reproduced by man. They are chemically identical. Why should one be perfectly safe and the other not? This is akin to saying that rain water is safe and distilled water is not. Saying some colourings are “derived from coal tar” is a misleading and irrelevant attribution. It’s like saying that “vinegar is derived from rotting grapes” and calling baking soda “caustic table salt”. Azo dyes are still sometimes referred to as ‘coal tar dyes’ because they were originally extracted from coal tar (a natural product) even though they are now made synthetically. Colourful descriptors are often used by junk scientists to colour the debate – inappropriate, even in a discussion on food colours!

Bread

Chemical residues are very common in bread – in fact we found them in 100% of the samples tested for the 2003/04 Total Diet Survey. This is due to the fact that pesticides are used in the growing and storage of wheat – necessary to prevent the very high risks associated with the growth of weevils, moulds and other pests. These natural pests, and the toxins some produce, have been associated with serious and occasionally fatal illness internationally and the chemicals are used reduce this high risk – without posing any significant risk to human health at the levels we found. In other words, the use of chemicals removes a very real risk, replacing it with one that is insignificant if not non-existent. As all New Zealand grain is usually sourced from a limited number of suppliers, it would be expected that a consistent level of residue would be found around the country.

ADIs

Acceptable Daily Intakes (ADIs) are not controversial and claims that acceptable limits are “little more than a calculated guess” are wrong. While assigning ADIs is not an exact science, the process is well defined and errs on the side of caution. Scientists and international health professionals, including the World Health Organisation, have no issue with them. The only ‘controversy’ is among those who don’t understand – or refuse to understand – the concept.

Pesticides

The articles were written in such a way as to imply that, because surveys find a pesticide residue in one sample of food, that it is always in that food all the time. This is logically not the case, and even a cursory glance at any of the NZFSA survey reports (freely available in full on our website) makes this clear. Indeed, many have no detectable residues at all, and only a tiny proportion of a percent have been found to have residue levels that approach or slightly exceed the maximum regulatory limits.

Antibiotic resistance

Measures of the ‘amount’ of antibiotic used nationally need to be interpreted with caution because the important factor is effectiveness. Resistance is likely to be unrelated to the amount of antibiotic used nationally but rather to the number of treatments given. It is usually an incomplete treatment regime or the decline phase of the drug in the body after the last dose that exposes bacteria to less than lethal doses and thus promotes resistance. Using more antibiotics cannot be inferred to give greater problems and, in reality, is likely to give fewer, as the prescribing veterinarian will ensure an effective treatment regime is given which inevitably requires more drug. The supervision provided by veterinarians as required by the ACVM Act ensures the prudent and effective use of these antibiotics.

New Zealand has not acted ‘reluctantly’ to phase out the use of antimicrobial compounds for growth promoting purposes, and in fact is among the most proactive in the world. Using antibiotics for growth promotion has not been allowed in New Zealand since 2002. All antibiotics relevant to humans and used in food-producing animals must be used only for treatment and prevention of disease, and only on prescription from a registered veterinarian. Antibiotics given to healthy animals have little effect, and are simply an added cost of production which in itself is a powerful disincentive for overuse.

There are limited scientific studies linking antibiotic use in animals to resistance in human pathogens but there is some uncertainty as to the significance of the results. However, because of the potential risk if such resistance did develop, New Zealand takes a precautionary approach. Sturdy requirements are in place to prevent the general use of human medicines in animals, as well as any non-prescription use.

In many countries the classes of compounds included as antibiotics do not include coccidiostats, quinoxalines and flavophospholipids as these have an insignificant role in human therapy. New Zealand includes these in its legal definition of ‘antibiotics’. Thus care is needed when making comparisons between countries that it is done so on equivalent bases.

Spicy foods and throat cancer

A reference to a connection between spicy foods and throat cancer appears to be a confused mix between the still-disputed claims of possible disease promoting and preventing properties of various foods, including additives and colourings, with advice that may be given to patients with firm diagnoses to avoid certain foods to prevent or minimise symptoms. There has been no suggestion of a link between spicy foods and throat cancer.

Mad cow disease

It is true that New Zealand is at risk of mad cow disease, just as it’s true for all livestock producing countries. However, New Zealand has had a comprehensive programme in place for many years to ensure that the disease does not reach our shores; does not amplify among our cattle population if it ever should; and to minimise exposure to humans in the unlikely event that it ever reaches us.

Foodborne illness

Any level of foodborne illness is too high, but figures can be misleading. Are they for all cases of gastroenteritis, not specifically foodborne illness? It is also often not possible to distinguish between gastroenteritis caused by contaminated food and an infection from the environment (e.g., swimming in a river or contact with animals).

Nevertheless, figures do suggest that the New Zealand rate is the highest in the developed world. But suggestion is not fact. Among the many reasons for our ‘high’ figures are that New Zealand, as a small single-state country, has better and more reporting systems than many other nations and reports more types of foodborne illness. For instance, in New South Wales and in a number of countries, campylobacter is not a reportable illness at all, so comparisons are meaningless.

The main cause of most foodborne illnesses is likely to be poor food handling and storage, and poor hand hygiene, not via consumption of meat or any other food. NZFSA has recently launched a far-reaching review of the domestic food regulatory programme to ensure problems here are addressed. This does not address problems created in the home, however.

Proper cooking of meat kills bacteria. Improper cleaning of hands and utensils in the kitchen between handling raw and cooked foods results in cross-contamination. Food too long out of the fridge at too high a temperature encourages growth. The difference is subtle but important – no matter where the bacteria come from (food, soil, pets, flies, food handlers, the atmosphere, unclean surfaces), good food handling (clean, cook, cover, chill) will prevent most foodborne illness.

Campylobacter

“Unfriendly bugs” (or pathogens) are everywhere, not just in soil and plants. They are in the air we breathe. They are part of an animal’s normal gut flora, just as ‘friendly’ strains of E. coli are. Cattle have been known to carry campylobacter for many decades – the organism is part of the natural gut flora of cattle and sheep and most other animals, including pets. It is therefore to be expected that contact with cows, cow faeces and environments containing cow faeces will result in contact with campylobacter. The hygiene of New Zealand’s meat processing is specifically controlled to minimise contamination of meat with faeces.

To describe cattle as the ‘source of food-poisoning’ is misleading as they are simply one environmental source of a very common bacterium that can cause foodborne illness if food is mishandled.

Contact with cows is generally a low risk in contraction of campylobacteriosis if simple good hygiene (such as proper hand washing) and food handling (such as avoiding cross-contamination) practices are followed.

To ensure that Campylobacter (and almost all other pathogens) are killed, the surface temperature of meat, or the core temperature of minced meat, should be brought to at least 70 degrees for two minutes.

Figures on Campylobacter in chicken are also be misleadingly used. This pathogen has been found on a high proportion of chicken meat, but – and this is the key point – generally in very low numbers. Whether these numbers are sufficient to cause human illness has yet to be determined.

As noted earlier, “unfriendly bugs” (pathogens) are everywhere – if you look hard enough you will find them. What makes people sick is when they are ingested in sufficient numbers to override the body’s defences and so cause infection. We ingest many ‘unfriendly bugs’ daily without any harm. Problems with food occur through abuse – poor hygiene, improper cooking, keeping food too warm for too long. Clean, cook cover, chill!

Interpretations of the importance of the ‘Ashburton study report’ were flawed and the implication that there was a “cover up” because the report was “released quietly” are incorrect. The report is not representative of the entire country. The human cases noted were all gastroenteritis, which may or may not have been caused by foodborne pathogens; and the paper used composite samples for some food groups which provides statistically questionable results. NZFSA’s further nine studies are unrelated to the Ashburton study and are more representative of New Zealand as a whole and are statistically sound. The paper was published in the normal way by the Ministry of Health but simply largely ignored by the press at the time.

Listeria

Figures quoted for listeria were out of date. Recent studies have detected this organism in fewer than one percent of samples of ham. Again, however, it is the number of pathogens which is important and none were found to be at a level high enough to pose a risk to human health. However, cases of listeriosis are recorded in New Zealand, and determining the causes is part of our on-going science programme.

GE Free Oil

There is no need to worry if a food label doesn’t note whether the vegetable oil used in the food is GE free. Oil does not usually contain any genetic material. Oil almost never has any genetic material in it – whether modified or not.

Food Safety Authority action

Suggestions that food safety authorities only act after ‘dead bodies’ have been lined up is patently wrong. If that were the case, we would not have needed to take any action whatsoever over pesticides, antibiotics, environmental contaminants, food additives or any of the other ‘issues’ that concern the food activists, because there are still no ‘dead bodies’ (or even very sick ones) at all. On the contrary, NZFSA takes action as soon as there is credible evidence. Such was the case in 2004 with the lead in cornflour issue, high levels of natural iodine in soy milk with added kelp, and high natural levels of arsenic in hijiki seaweed. We don’t act on assumption and ill-formed belief. NZFSA is also a WHO designated Centre for Food Contaminant monitoring and regularly makes monitoring data available to international fora.

Trust

Consumers don’t need to ‘hope that governments and big business can be trusted’. Government represents its people and no government would want to poison its citizens. It is also clear that any business that wants to kill off its customers won’t be around for very long.

NZFSA backs up its ‘trust’ with an extensive programme of audit, monitoring, surveillance, enforcement and other compliance measures to ensure the industry is functioning as required. All of this is undertaken with extensive stakeholder consultation, including consumer groups, and in as transparent a process as possible.

More information

We encourage people who still have concerns to explore our website (www.nzfsa.govt.nz) or the websites of other reputable food agencies such as the United Nations FAO; WHO expert Codex Alimentarius Commission; the United Kingdom Food Safety Agency, United States FDA or call our freephone number 0800 693 721 to get the facts.