Research Review
(1) Study Examines Latex Transfer to Food in Packaging
Source: http://www.medicinenet.com
A UK study reports in the Journal of the Science of Food and Agriculture that a third of food packaging tested was found to be contaminated with latex and that, in some cases, the latex was transferred to the food. In fact, one brand of chocolate biscuit contained 20 times the amount of latex that can cause a reaction —it is believed that as little as a billionth of a gram (1 ng/ml) can be enough to cause a reaction in those people who are allergic to latex.
Researchers in this study measured the presence of four major latex allergens in 21 types of food packaging for fruits and vegetables, meat, confectionary, pastry and dairy products. The highest latex levels were found on ice-cream wrappers. One ice-cream wrapper had more than 370 ng/ml of latex, and the ice cream itself contained approximately 14 ng/ml.
On inquiry one company told the researchers that it sprayed entire wrappers with latex adhesive, so that the wrappers could be sealed with minimum wastage.
Experts of the UK Latex Allergy Support Group (LASG) Advisory Panel indicate that these findings are significant “… For a few people, natural rubber latex is a very strong allergen and, for these individuals, there is no safe level of exposure. Latex transfer to food could account for some currently unexplained reactions", says LASG representative, Graham Lowe.
Why latex?
Allergies to latex rubber have only been recognised in the last 20 years. The reasons for the allergy are uncertain, but the increased use of latex gloves in health care settings like hospitals in the last 12 years and changes in manufacturing practices (due to increased demand) are probable contributors.
The risk of developing latex allergy increases with frequent exposure
Most people who are allergic to latex have had frequent exposure to latex over many years. The majority are nurses, doctors, dentists, or patients who have had a number of operations, such as those with spina bifida. Many are also allergic to other substances such as grass pollens or dust mite proteins. In other words, they usually already have other allergic disease such as asthma or hay fever or eczema of the skin.
Latex is used in a large number of products
Latex or natural rubber is the substance obtained from the sap of the Hevea brasiliensistree. After the addition of preservatives and stabilisers, it is dipped into a mould, then heated and dried. During manufacturing, chemicals are added to render latex elastic and stable to heat by vulcanisation (heating in the presence of sulphur). Further chemicals are added for strength and durability, including mercaptobenzothiazole, thiurams and carbonates. Sometimes a dry powder lubricant (usually corn-starch) is added to the surface of the latex to prevent the rubber surfaces from sticking together. Allergic reactions can occur to latex protein as well as the chemicals added to it, but not to cornstarch itself. When gloves are worn, however, latex protein can be leached from the glove and stick to the cornstarch particles. When gloves are changed, these particles can become airborne and spread latex allergen into the local environment.
Many commercial products contain natural rubber latex. These include bandages, baby bottle teats, baby dummies, rubber bands, clothing elastic, rubber toys, rubber grips and a wide range of medical equipment. Allergic reactions usually occur after exposure to “dipped products” like gloves, balloons and condoms. Products made from crepe rubber (like shoe soles) are unlikely to cause allergic reactions.
By contrast to natural latex rubber, synthetic rubber is produced from petrochemicals, and does not contain allergenic latex proteins. Products containing synthetic rubber (like most latex paints) do not cause allergic reactions.
“Immediate” allergic reactions are most serious
Immediate allergic reactions (also known as Type 1 or IgE antibody–mediated) are the most serious adverse reactions to latex. In people who have developed sensitivity to natural latex proteins, contact with latex releases the irritant chemical “histamine” into the tissues. The result is itching and hives with direct contact, like after wearing rubber gloves, or itchy swollen lips, face or tongue after blowing up balloons, and other forms of allergic reactions.
Latex allergic individuals may also be sensitive to certain foods
Some proteins in latex are present in foods as well. Latex-allergic people sometimes find that some foods cause an itchy mouth or throat swelling. The most common foods described are banana and avocado and sometimes kiwi fruit, passion fruit, plums, strawberry, tomato or other fruits. These foods need to be avoided by people if they cause problems.
Reducing the risk of latex allergy in the future
Manufacturers are trying to produce latex products containing less allergen. As more of these products become available, the risk of reactions in latex sensitive individuals will decrease, and it is likely that fewer people will develop latex allergy. In the meantime, increased awareness of latex allergy and its risk factors should help to reduce the frequency of latex allergy.
For further information contact the Australasian Society of Clinical Immunology and Allergy (ASCIA) at http://www.allergy.org.au/ which is the peak professional body of Clinical Allergists and Immunologists in Australia and New Zealand.
References
Australasian Society of Clinical Immunology and Allergy (ASCIA), http://www.allergy.org.au/
Beezhold DH et al, 1996. Clin Exp Allergy; 26: 416-422.
Frankland AW, 1995. Clin Exp Allergy; 25: 199-201
Guillet G, Guillet MH, 2005. Dagregorio G. Contact Dermatitis. Jul: 53 (1):46-51.
Heilman DK et al, 1996. J Allergy Clinical Immunology; 98: 325-330.
Katelaris CH et al, 1996. Medical J Australasia; 164: 711-714.
McAleer PT et al, 1996. Aust Anaesth; 123-141.
Preidt R, 2006. Chemistry & Industry, news release, Aug. 6, 2006.
Pumphrey RSH, 1994. Clin Exp Allergy; 98: 358-360.
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(2) No to sausages … Yes to curry
Imagine a week without bangers and mash, bacon and eggs, a BLT (bacon, lettuce and tomato) salami, hamburger, or a hot dog.
That is the conclusion of researchers from the Karolinska Institute in Sweden who have established a connection between processed meats and stomach cancer.
The Swedish research team analysed the results of 15 studies published over the last 40 years – studies looking at groups of patients with stomach cancer. Their findings are published in the latest Journal of the National Cancer Institute.
They found that, compared to the normal population, those people with stomach cancer were more likely to have processed meats in their diet – foods like bacon, sausages, hot dogs, salami, ham, liver pate, and Devon. They calculated that adding 30 grams of processed meats a day – about a standard half serve - raised the chances of developing stomach cancer by anywhere between 15 and 38 per cent, depending on which type of study they were looking at. The risk was consistently highest for bacon.
They could not prove conclusively that it was the processed meats that were causing cancer – perhaps it was one of more other factors they could not identify. But the results add to a growing body of other evidence linking processed meats to cancer. Last year in a study they were linked to pancreatic cancer, and in other earlier studies, to cancers of the colon and rectum.
How might processed meats cause cancer? It could be the preservatives like salt, sodium nitrite or smoke or additives like phosphate, glutamate or ascorbic acid. Or it could be due to cancer-causing chemicals that form in the manufacturing process – perhaps from the additives and preservatives.
Curry instead
But there is one preservative/flavouring that may actually reduce the risk of bowel cancer – curry, according to a study published in the latest edition of the journal Clinical Gastroenterology and Hepatology.
Researchers from Johns Hopkins University in the US did an experimental study on a small number of people who had polyps in the large bowel.
Polyps are small benign growths – they are common in the bowel and they sometimes go on to become cancer. Most bowel cancers start out as polyps. The researchers looked at five people with a rare inherited condition called Familial Adenomatous Polyposis who get multiple polyps in the large bowel. These people always go on to get bowel cancer.
The five had had their colons removed before they could develop cancer, but still had some polyps left over in parts of the bowel that were not removed. Researchers made a note of how many, and how big, the remaining polyps were. The subjects were then given curcumin, a key ingredient of turmeric, the spice that gives curries a yellow colour; and quercetin, an antioxidant found in onions. They were given 480 milligrams of curcumin and 20 milligrams of quercetin three times a day for six months.
After six months, the polyps were reduced on average in number by 60 per cent and in size by 50 per cent.
More research is needed to know which ingredient is responsible, and whether they reduce not just polyps, but the risk of bowel cancer itself.
Still, for now it is a good enough reason to toss a bag of onions and a couple of jars of curry paste in the trolley as you pass through the supermarket aisles.
Curried vegetables and fish
But what foods to curry? Try curried vegetables - not just onions but potatoes, carrots, pumpkin, cauliflower etc. The more vegetables in the diet, the less the risk of bowel cancer.
If you are a meat-eater mourning the loss of processed meats, try a curried chicken or even better, fish, which contain polyunsaturated fatty acids — also thought to protect against bowel cancer. Take care with red meat — it has been linked to an increased risk of bowel cancer —though the evidence is not as strong as for processed meats. Curried or not, limit your consumption of red meat to no more than 100 grams (equivalent to the palm of your hand), three to four times a week, the Cancer Council advises.
So, there you have it. Forget the snags. Put another curried John Dory on the next bar-b-que.
Source:
Peter Lavelle, 10/08/2006, Health Matters: The Pulse, ABC Online, Australia.
http://www.abc.net.au/health/thepulse/s1710593.htm
Monika
Monika Bhatia
Project Manager and Editor, Quality4life
11 August 2006
