"Despite the stereotype that Americans are eating more unhealthful foods that leave them vulnerable to assorted diseases a new study suggests the opposite may be true. Harvard researchers report that they found evidence that better diets since  have saved more than one million people from dying prematurely. They also believe improved diets have significantly cut diabetes and heart disease and even slightly trimmed cancer cases.  The findings paint a surprising picture of American health. But study author Dong Wang a graduate student with the departments of nutrition and epidemiology at Harvard T.H. Chan School of Public Health in Boston cautioned that its not time to declare victory in the battle against unhealthy eating. The overall American diet is still poor he said. Huge room exists for further improvement. The researchers wanted to understand how changes in the American diet in the st century affected health over time. To get insight into the answer they analyzed the results of seven health and nutrition surveys including almost  adults aged  and older between  and . The researchers ranked diets on a healthy eating scale from  poor diet to  perfect diet. From  to  the overall rating increased from  to .  On the positive side over time Americans ate more fruit whole grains nuts and legumes and polyunsaturated fatty acids Wang said. They also ate less trans fats sugarsweetened beverages and juice and red and processed meat. But the intake of salt actually went up. The researchers extrapolated their findings and estimated that the improvement in diets prevented over one million premature deaths and lowered heart disease cases by almost  percent type  diabetes cases by nearly  percent and cancer cases by just over  percent. According to Wang the study findings suggest that healthier diets lower the risk of death in a variety of ways. Among other things improved diets appear to lower the risk of chronic diseases and boost the survival of people who have those conditions. Even a year or two of a better diet appears to have the power to affect survival rates he said. The study authors didnt analyze whether their estimates match up to actual death rates in the United States. But other research has pinpointed a decline in death rates in this century Wang said. Dr. Sonia Anand a professor of medicine and epidemiology at McMaster University in Hamilton Canada praised the study saying its reasonable to link changes in diet to death rates in this way. But she said nutrition research like this has limitations because it relies on peoples memories of what they ate. As a result she said its crucial to look at a variety of studies and see if trends hold up. According to study author Wang trans fats have been almost eliminated from the food supply so what is needed next is more taxation on sugary drinks and more regulations requiring salt to be reduced in food. He also said the government can do more to improve diets for the poor who havent seen the same level of improvements as other groups. One option he said is to increase the number of farmers markets that accept food stamps. The study is published in the November issue of Health Affairs.  More information For more about healthy eating visit the U.S. Centers for Disease Control and Prevention http_eating. SOURCES Dong Wang graduate student departments of nutrition and epidemiology Harvard T.H. Chan School of Public Health Boston Sonia Anand M.D. Ph.D. professor medicine and epidemiology McMaster University Hamilton Canada November  Health Affairs"