Is there anything left that we can safely eat?
By Dr Maurice Mckeown
Some of the most important constituents in your food may not be on the label (If there is one). A new US study has found that farmed salmon contain substantial levels of undesirable toxic chemicals (PCB’s Dioxins and Pesticides) - substantially more than their wild counterparts. Salmon from Europe, (Scotland in particular), was identified as worst. US and Canadian fish were next with Chilean salmon at the bottom of the danger list.
Most US supermarket salmon comes from Chile. The researchers suggest that you should only eat Scottish salmon three times a year. Our salmon do not appear to have been included as they are not sold in US supermarkets. It is claimed that Southern Hemisphere fish farms produce fish with contaminant levels which are generally only one eight of their Northern Hemisphere counterparts. Farmed fish are of course also given antibiotics, vaccinations, and substances to dye their flesh a more consumer friendly pink colour.
It appears that the fundamental problem is that by feeding any species of carnivorous fish with food composed mainly of other fish from polluted waters, environmental toxins are magnified. The debate is now focussing on just how dangerous are the levels of these toxins. Environmental and Health agencies have very differing views on safety levels for the substances concerned.
As If that were not enough, it has just been revealed that some UK salmon have also been found to contain a dye called malachite green once routinely used as a fungicide in fish farms. The chemical which has traditionally been used as a fungicide to "disinfect" fish eggs, was banned from use by fish farmers by the UK Government more than two years ago. Malachite green is a substance known to cause cancer and mutations. A major international battle over its use and permitted levels now seems inevitable.
Consumers have choices. They can vote with their teeth. Everyone now believes fish is good for you. Clearly seafood other than salmon can be chosen, but tuna and other big fish have significant mercury levels which can be particularly dangerous for pregnant women. Currently Food Standards Australia / NZ recommends only 4 portions of high mercury fish per week for pregnant women. Shellfish can have neuro toxins, viruses, bacteria and heavy metals like cadmium. Red meat is a possible alternative food. It has however had bad publicity in recent years, but strenuous efforts to link its consumption to various cancers and heart disease are still highly controversial. As long as the cook doesn’t burn the meat its cancer causing potential is probably minimal.
The concerned and knowledgeable consumer may opt for chicken, which is widely acclaimed by dieticians as a superior food. Unfortunately the latest research by the US Department of Agriculture is not encouraging. While most concern in the past has been focussed on the possible presence of growth hormones and antibiotic residues, the reality may be much worse. USDA research has found that chicken is the primary source of arsenic in the US diet. Readers old enough to have read a Victorian melodrama will realise that arsenic is a deadly poison. In fact it is now a well recognised cancer-causing substance linked to a variety of important human cancers. Its presence in water in many regions of the world is a major health problem.
Many readers will wonder how chickens can possibly contain arsenic. The reason, surprising to most of us, is that chicken farmers are allowed to feed it to them (in the US at least), to kill intestinal parasites. To be fair, it has to be pointed out that those who pass judgment on risks to our health do not regard the levels of these substances as specifically hazardous. The US researchers have however carried out a very detailed analysis of just how much arsenic various chicken eaters might be exposed to. Those who eat chicken frequently could be getting significant amounts of the substance.
It is however beyond dispute that arsenic and a whole cocktail of toxic chemicals do end up in our bodies. Last year 270 000 people were diagnosed with cancer in the UK – an all time high. A UK newspaper reported in November the results of a study done by the Worldwide Fund for Nature. They took blood samples from 155 people in 13 UK cities. They found that dangerous man-made chemicals were present in the blood of all the participants. The average number of the various chemicals in an individuals blood was twenty-seven! Seventy different banned chemicals were found overall. Some like DDT have been banned in the UK for over 30 years; but clearly still linger in the environment. The newspaper reported that PCB’s – another banned chemical group, were found in the blood of 99% of the participants.
We can’t all obtain or afford organic products. (Even some organic foods contain contaminants). It seems that the only practical course is Government control and monitoring of the level of key contaminants in important foods. We would all like to know just how much arsenic is in our local chickens and how pure New Zealand farmed salmon is. Our politicians appear determined to protect us from taking too many food supplements in case they harm us. It seems much more likely that toxic chemicals in the food chain pose a vastly greater threat to health. Perhaps their efforts would be better spent trying to ensure that our ordinary food contains minimal amounts of toxic substances.