Packaged and processed foods, such as cakes, cookies, candies, chocolate, yogurt, and marshmallows, often contain unfamiliar animal ingredients, so may be a special concern for vegetarians due to the likelihood of such additions.[3][5] Often, prior to purchase or consumption, vegetarians will scrutinize products for animal-derived ingredients.[5] Vegetarians' feelings vary with regard to these ingredients. For example, while some vegetarians may be unaware of animal-derived rennet's role in the production of cheese, and may therefore unknowingly consume the product,[3][6][7] other vegetarians may not take issue with its consumption.[3][4]
^ Key TJ, Fraser GE, Thorogood M, Appleby PN, Beral V, Reeves G, Burr ML, Chang-Claude J, Frentzel-Beyme R, Kuzma JW, Mann J, McPherson K (1999). "Mortality in vegetarians and nonvegetarians: detailed findings from a collaborative analysis of 5 prospective studies". The American Journal of Clinical Nutrition. 70 (3 Suppl): 516S–524S. doi:10.1079/phn19980006. PMID 10479225.
A study by the Institute of Preventive and Clinical Medicine, and Institute of Physiological Chemistry looked at a group of 19 vegetarians (lacto-ovo) and used as a comparison a group of 19 omnivorous subjects recruited from the same region. The study found that this group of vegetarians (lacto-ovo) have a significantly higher amount of plasma carboxymethyllysine and advanced glycation endproducts (AGEs) compared to this group of non-vegetarians.[119] Carboxymethyllysine is a glycation product which represents "a general marker of oxidative stress and long-term damage of proteins in aging, atherosclerosis and diabetes" and "[a]dvanced glycation end products (AGEs) may play an important adverse role in process of atherosclerosis, diabetes, aging and chronic renal failure".[119]
^ Jump up to: a b Keevican, Michael (November 5, 2003). "What's in Your Cheese?". Vegetarian Resource Group. Archived from the original on March 18, 2018. Retrieved March 18, 2018. Many vegetarians don't consider that some of the cheeses they are eating could actually contain unfamiliar animal ingredients. That's right cheese, a common staple in many vegetarian diets, is often made with rennet or rennin, which is used to coagulate the dairy product.