By Mary Kate Keyes, M.S.
Brigham and Women's Hospital
The earliest forms of preserving foods were salting and drying. Preserving meant that foods caught or picked in times of plenty could be safely eaten during lean months. Food is still preserved today. That's why a loaf of bread can be kept on the counter for up to two weeks without growing mold. Some canned goods can last on shelves for years.
Additives like preservatives mean we are not eating mold, and our that food will taste better longer. But what does the fine print on food labels reveal about what we are really putting in our bodies?
These preservatives are safe in all foods, according to the U.S. Food and Drug Administration (FDA). This agency regulates additives in the United States. The names of some may look scary, but they are harmless and keep our food safe and delicious.
Ethylenediaminetetraacetic acid (EDTA) — While the name of this chemical is long, its job is quite simple. EDTA chelates, or binds, tiny molecules of metal that come from the machinery used in food factories. If left unbound, these metals could cause oils to go rancid and the colors in food to fade. Examples of foods with EDTA are beverages like flavored waters, which seem to be everywhere these days.
Alpha tocopherol — This is added to food to act as a healthy antioxidant. It also prevents oils from going rancid. (Hint: Alpha tocopherol is just a fancy name for Vitamin E.)
Ascorbic acid and erythorbic acid — These are two other antioxidants. They prevent some foods from spoiling and help keep the color of red foods bright. (Another hint: Ascorbic acid is a fancy name for Vitamin C. Erythorbic acid, while not a vitamin, is like a cousin of Vitamin C.) Jelly is one example of a food that may contain ascorbic or erythorbic acid.
Lecithin — This prevents oils from going rancid. It's also an emulsifier, which means that it helps to keep substances in food from separating. One example of a food with lecithin is snack crackers.
Calcium/sodium propionate — These two chemicals prevent bacteria and mold from growing in baked goods, such as bread. They extend the shelf life of baked goods considerably, and have been in use since the 1930s.
Lactic acid — This acid is added to food to maintain the pH. However, it can also be added as an antioxidant or to prevent bacteria from growing. An example of a food that contains lactic acid is Spanish olives.
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OK in smaller doses
There is no reason to avoid these chemicals altogether, but read the label on foods you and your family eat daily. If you see something from the list below, make it an every-other-day treat. While the evidence is still scant, there may be an association between these additives and increased risk of developing cancer.
Butylated hydroxytoluene (BHT) — This is another preservative that prevents oils from going rancid. Examples of foods that contain BHT include shortening and some cereals.
Sodium benzoate — This chemical is added to drinks such as soda and fruit juice to prevent bacteria and fungus from growing.
Sodium nitrite/nitrate — Thanks to the media, when many of us think of hot dogs we think of nitrates. These preservatives are added to meat and fish to enhance the color and to prevent bacterial growth. One of the concerns with sodium nitrite is that at high temperatures nitrosamines can form. They are carcinogens, meaning they can cause cancer.
Sulfites — These chemicals are used in some foods to keep them from discoloring on the shelf or in the freezer. Examples include some potato products, dried fruits and shrimp. Some people are sensitive to sulfites. To find out if a product contains sulfites, look for sodium bisulfite and sulfur dioxide in the ingredients list.
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Not so hot
These chemicals have been linked to increased cancer risk. The jury is still out on the true risk. Meanwhile, it's a good idea to skip foods that contain these chemicals.
Butylated hydroxyanisole (BHA) — This is yet another chemical that prevents oils from growing rancid. Examples of foods that contain BHA are butter, some cereals, some chewing gums, some snack foods, dehydrated potatoes and beer.
Propyl gallate — This chemical also prevents oils from going rancid. It is often used with BHA and BHT. Foods that contain propyl gallate include potato sticks and chicken soup base.
Preservatives are used in so many of the foods we eat every day that it is close to impossible to avoid them. One sure way to reduce the amount of preservatives in your diet is to increase your intake of fresh foods such as fruits and vegetables. At the same time, you can decrease the amount of processed, shelf-stable foods you eat. Not only will you get healthful nutrients, such as fiber and antioxidants, you will avoid the trans fat and refined carbohydrates that seem to ride the coattails of preservatives. Chose wisely, and preserve your health.
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Mary Kate Keyes, M.S., is a nutrition writer and communications consultant. She is a dietetic intern at Brigham and Women’s Hospital.