Glyoxal and methylglyoxal, called glykotoxins are formed when sugar-containing foods are heat-treated, and are therefore found in many different foods and beverages. Glyoxal and methylglyoxal are also formed in the body and the formation is proportional to increasing blood glucose level. Diabetics, which have a higher blood glucose level, have higher formation of these glycotoxins. Glycotoxins are harmful through two different mechanisms: 1) the formation of advanced glycation end products (AGEs) and 2) direct binding to DNA. Elevated levels of AGEs is linked to increased risk of complications of diabetes, including atherosclerosis (plaque formation in the blood vessels) and various cancers.
A mouse model which spontaneously develop atherosclerosis were used to investigate whether the two glycotoxins glyoxal and methylglyoxal increases plaque formation in the aorta. In this study the glycotoxins did not contribute to the development of atherosclerosis, although an increase in the formation of AGEs were observed.
To investigate whether glyoxal can cause cancer, we used a mouse model that spontaneously develops tumors in the intestine and is sensitive to carcinogenic compounds. Glyoxal did not cause an increase in the number of tumors. However, the glyoxal-exposure did cause the tumors to grow faster, which indicates that glyoxal have tumor growth-promoting properties. We also examined glyoxal in diabetic mice that spontaneously developed intestinal tumors. Here, we also observed that exposure to glyoxal increased tumour growth, but not to a greater extent than in non-diabetic mice. In addition, exposure to glyoxal increased the number of tumors in diabetic mice.
We are exposed to glycotoxins every day through food and drink, and there is need for more research in this field, especially for diabetics who are believed to be a sensitive group for these substances.
This project will contribute valuable information concerning the negative health effects of dietary exposure to two food processing contaminants, the glycotoxins methylglyoxal (MGO) and glyoxal (GO). The health outcomes in focus are cardiovascular disease and colon cancer - two widespread lifestyle diseases. It has been implicated that MGO and GO are genotoxic in vitro, and might therefore be human carcinogens. Cardiovascular disease has been linked to increased levels of advanced glycation end products ( AGEs), and MGO and GO are precursors of AGEs. The focus of previous research has been on the increased endogenous formation in people living with diabetes and diabetic complications. There is limited research on negative health effects of glycotoxins from food and their effect in the general public or diabetics. This project will fill this gap in knowledge regarding glycotoxins from food and adverse health effects. In addition, the dietary intake of MGO and GO will be estimated, and food items with high c oncentration will be identified. The outcome of the project will be communicated to scientific community, key user-organizations and consumers in general.