Ask a Dietitian

As seen on BCTV 09 September, 2003

Food additives and preservatives

Risk and Benefit Management

According to Health Canada and the FDA, the inclusion of additives to food products are only considered if their benefits outweigh the risks (prevention of food-borne illness vs. cancer risk). However, it is the manufacturers’ responsibility to use as little as possible to achieve the desired effect. The good news is, food additives make food safer from a microbiological point of view. For example, nitrites prevent botulism risk from sliced deli meats. Food additives also make it possible to have a wider range of food choices, more convenience with foods and more economical choices. The bad news is that some people have become sick and there have been allegations regarding asthmatic responses to additives and the possible carcinogenicity of some. For example, nitrites are converted into nitrosamines in the stomach and possibly become carcinogenic. Food additives have also lead to the availability of more “junk foods” with lower nutrient densities. However not all additives are culprits, some like ascorbic acid (vitamin C) act as antioxidants to preserve foods and prevent spoilage and provide a health benefit as well.

The best way in which to manage your intake of additives and preservatives is to eat mostly fresh and unprocessed foods and limit your intake of foods that contain many preservatives and additives. Read your labels carefully.

Nitrites

Nitrites are antimicrobial agents that are added to foods such as hot dogs and cured meats and poultry. The purpose of this additive is to enhance the flavor by inhibiting rancidity, as well as protecting against bacterial growth such as the botulinum toxin that can cause death. This is clearly a beneficial additive, but does have controversial negative effects. Nitrites can be converted to nitrosamines in the human body, which can cause cancer in animals if the levels of nitrites in the food products are high. However, minimal amounts of nitrites are used by the food industry in order to achieve the necessary function. As well, vitamin C is commonly used in curing meat to minimize the conversion to nitrosamines. Nitrosamine formation has not yet been shown to cause cancer in humans.

Nitosamine-related compounds can also be found in the beverage beer, however the quantity in beer does not make a huge impression as a whole to one’s exposure to this compound. In fact cigarette smoking, car interiors and cosmetics produce far greater nitrosamine levels in comparison, and people are exposed to various levels of these each day. However, it is important to be aware of these effects and eat foods that contain nitrites in moderation.

Sulfites

Sulfites are anitioxidants that prevent oxidation, off flavors, odors and colour changes in many processed foods, drugs and alcoholic beverages (most notably in wine). Sulfites can have some adverse effects for certain people, and therefore the Food and Drug Administration (FDA) prohibits its addition to foods intended for raw consumption as well as requiring the declaration on labels of those foods and drugs containing sulfite addition. Sulfites can appear on labels as Sulfur dioxide, Sodium sulfite, Sodium bisulfite, Potassium bisulfite, Sodium metabisulfite and Potassium metabisulfite. Another hazard that sulfites present, is their destruction of the B vitamin thiamin (used in energy metabolism), and is thus prevented by the FDA from their addition to enriched grain products, that are rich sources of this vitamin.

Grape lovers should take note that they are the one raw food that may be legally treated with sulfites. So wash your grapes thoroughly in order to limit your exposure to this additive.

BHA and BHT

BHA and BHT are common food additives that are used to prevent rancidity by acting as an antioxidant. They are added to foods such as baked goods and snack foods. While vitamins C and E remain the most important dietary antioxidants as a defense against cancer, several tests have shown that animals exposed to large amounts of BHT in the presence of carcinogens, did develop less cancer compared to controls. However, this additive should not be relied upon as one’s only source of antioxidant, as the amounts added to foods are too small to impact the defense system.

What are all those ingredients in low fat dressings?

The ingredient list of some of your favorite salad dressings can be a little confusing due to all those long incomprehensible names that frequently appear. Typically I recommend that if you need a dictionary for more than 1 ingredient you probably shouldn’t eat the product. Here is an example of an ingredient list for a low fat salad dressing, with a little explanation of the purpose of those ingredients.

Kraft Ranchers Choice (half the fat) – Ingredient list

All of these added preservatives and additives have been approved by Health and Welfare Canada, in the Food and Drug Regulations division. To be labeled as a food additive it must be “any chemical substance that is added to food during preparation or storage to achieve a particular technical effect”, according to Health Canada’s definition, (1990). Therefore studies have been conducted and proven that these ingredients have not shown any harmful affects from human consumption.

Even so, many people are turned off by the idea of consuming these ingredients and avoid products commonly assumed to contain these additives, such as low fat products. However, not only low fat products contain preservatives. Here we look at the original Kraft ranch salad dressing and can see that when comparing to the above list, the differences between the two versions are minimal. Here oil is the first ingredient instead of corn syrup in the low fat version.

Kraft Ranch original

Ingredients Soybean Oil, Water, Sugar , Vinegar , Egg Yolks , Salt , Contains Less Than 2% Of: , Skim Milk , Garlic Juice , Natural Buttermilk Flavor Salt, Buttermilk, Maltodextrin, Vinegar, Lactic Acid, Food Starch-Modified, Natural Flavor, Citric Acid , Lipolyzed Cream , Karaya Gum , Cultured Cream , Monosodium Glutamate , Xanthan Gum, Sorbic Acid, Calcium Disodium EDTA, Phosphoric Acid , Polysorbate 60 , Lacitc Acid , Spice , Dried Parsley , Lemon Juice Concentrate , Natural Flavor

If these ingredients are a concern for you, make sure you are always checking labels as all additives must be present on the ingredient list.

Here are some suggestions for your own dressings that are easy to make and are free from additives and preservatives!

Roasted Red Pepper Vinaigrette

Low Fat Creamy Italian Dressing