Preservatives & Obesity

Over 65 percent of Americans older than 20 years are overweight and 34 percent are obese, the Centers for Disease Control reports. It is an epidemic that many experts consider America's greatest health problem. There are many theories about the root causes of this epidemic. One theory is that processed foods high in preservatives increase our appetites. But research shows it may be the additives, especially monosodium glutamate (MSG), that are to blame.

Evidence

• Often mistaken for a preservative, MSG is a flavor additive found in almost all processed foods. Research indicates that MSG could be harmful to the brain and may be linked to obesity. Scientists at the University of North Carolina (UNC) found that people who consume large quantities of MSG are more likely to be obese, even if they get the same amount of exercise and calories in their diets as people who do not use MSG.

Experiments

• In one experiment, scientists injected rats with MSG. The MSG caused their pancreases to triple insulin production, resulting in obese rats with type 2 diabetes. In another experiment at Complutense University, Madrid, scientists found that rats given large doses of MSG experienced a 40 percent increase in appetite and significant weight gain. Both experiments support the theory that the obesity epidemic and the prevalence of MSG in our diets are linked.

Argument

• The UNC research was challenged. A five-year study in China found that people who used 2.9 to 9 times more MSG in their diets did not gain more weight than those who consumed less. Published in The British Journal of Nutrition, research in the study concluded that, "These findings indicate that when other food items or dietary patterns are accounted for, no association exists between MSG intake and weight gain."

Considerations

• Though there is controversy over the direct effects of MSG on obesity, researchers do agree that processed, packaged foods loaded with MSG and preservatives tend to also be high in fat, salt and calories. Frequent consumption of these foods is bound to cause weight gain leading to obesity. In fact, recent research has found that overeating, not lack of exercise, is the main reason that so many Americans are overweight or obese.

Choices

• Doctors agree the best way to keep weight off is to make healthy eating choices and watch your calories. By staying away from packaged, processed foods, avoiding frequent, fat-loaded, fast food meals and choosing to eat fresh, low-fat foods, you can win the battle with weight gain. Consult with a health professional to determine how many calories and carbohydrates and how much fat and sugar you should have in your diet.

Warning

• MSG is an excitotoxin, meaning it stimulates brain activity in a negative way. Clinical studies have shown that it may lead to long-term illnesses such as Alzheimer's and Parkinson's. However, the short-term effects are well documented, including perspiration, headaches, facial numbness or tingling around the mouth, heart palpitations, chest pain and shortness of breath.