Are food preservatives bad for you? – Eleanor Nelsen
Food doesn’t last. In days, sometimes hours,bread goes moldy,apple slices turn brown,and bacteria multiply in mayonnaise. But you can find all of these foodsout on the shelf at the grocery store,hopefully unspoiled,thanks to preservatives. But what exactly are preservatives?How do they help keep food edibleand are they safe?There are two major factors that causefood to go bad:microbes and oxidation. Microbes like bacteria and fungiinvade foodand feed off its nutrients. Some of these can cause diseases,like listeria and botulism. Others just turn edibles into a smelly,slimy, moldy mess. Meanwhile, oxidation is a chemical changein the food’s moleculescaused by enzymes or free radicalswhich turn fats rancidand brown produce, like apples and potatoes. Preservatives can prevent both typesof deterioration. Before the invention of artificialrefrigeration,fungi and bacteria could run rampant in food. So we found ways to create an inhospitableenvironment for microbes. For example, making the food more acidicunravels enzymesthat microbes need to survive. And some types of bacteria can actually help. For thousands of years, people preservedfood using bacteriathat produce lactic acid. The acid turns perishable vegetablesand milkinto longer lasting foods,like sauerkraut in Europe,kimchi in Korea,and yogurt in the Middle East. These cultured foods also populate yourdigestive track with beneficial microbes. Many synthetic preservatives are also acids. Benzoic acid in salad dressing,sorbic acid in cheese,and propionic acid in baked goods. Are they safe?Some studies suggest that benzoates,related to benzoic acid,contribute to hyperactive behavior. But the results aren’t conclusive. Otherwise, these acids seem to beperfectly safe. Another antimicrobial strategy is to adda lot of sugar, like in jam,or salt, like in salted meats. Sugar and salt hold on to waterthat microbes need to growand actually suck moisture outof any cells that may be hanging around,thus destroying them. Of course, too much sugar and saltcan increase your risk of heart disease,diabetes,and high blood pressure,so these preservatives are best in moderation. Antimicrobial nitrates and nitrites,often found in cured meats,ward off the bacteria that cause botulism,but they may cause other health problems. Some studies linking cured meats to cancerhave suggested that these preservativesmay be the culprit. Meanwhile, antioxidant preservativesprevent the chemical changesthat can give food an off-flavor or color. Smoke has been used to preserve foodfor millenniabecause some of the aromatic compoundsin wood smoke are antioxidants. Combining smoking with salting was aneffective way of preserving meatbefore refrigeration. For antioxidant activity without a smoky flavor,there are compounds like BHTand tocopherol,better known as vitamin E. Like the compounds in smoke,these sop up free radicalsand stave off rancid flavorsthat can develop in foods like oils,cheese,and cereal. Other antioxidants like citric acidand ascorbic acidhelp cut produce keep its colorby thwarting the enzyme that causes browning. Some compounds like sulfites can multitask. They’re both antimicrobialsand antioxidants. Sulfites may cause allergy symptomsin some people,but most antioxidant preservativesare generally recognized as safe. So should you be worried about preservatives?Well, they’re usually near the endof the ingredients listbecause they’re used in very small amountsdetermined by the FDA to be safe. Nevertheless, some consumersand companiesare trying to find alternatives. Packaging tricks, like reducingthe oxygen around the food can help,but without some kind of chemical assistance,there are very few foods that canstay shelf stable for long.