It has become clearer and clearer that diets high in saturated fat and trans fats are associated with health problems. I have written about many different research studies that link diets high in these types of fats with heart disease and stroke. Recently, however, a very well designed study shows a clear connection between Alzheimer's Disease and an increased intake of saturated and trans fat.

Certainly in the last few years it has become easier for consumers to know exactly what to do about their diets. Back when I started eating healthy and changing my style of cooking, all fats were bad. We now know that there is more to it than this simple statement, and this research on Alzheimer's is a good example of how the type of fat is the important factor in eating for good health.

Let me be clear that eating a lower fat diet is good for you, first and foremost, because this means eating fewer calories. I have written a number of times about how important a lower calorie diet can be in living longer and living better. Reducing fat is one of the easiest steps to making such changes in your life.

That said, you can also make substantial changes in your risk of disease by eating less saturated fat and working to eliminate trans fats. Saturated fats are found in animal fats and eating lean meats can help you control your intake. Often it is saturated vegetable fats that have been created through hydrogenation that are a major source of saturated fat in many people's diets. Hydrogenation also creates a high percentage of trans fats which is the other culprit in so many diseases.

Martha Morris and her colleagues (Arch Neurol 2003; 60:194-200) studied 815 senior citizens to evaluate the role diet might play in Alzheimer's Disease. They found a clear correlation between diets high in saturated fat and trans fats and the risk of Alzheimer's Disease. The results showed almost double the risk of Alzheimer's dementia in those eating the most of these types of fats. They looked at other factors to see if these might change the results, and there was no difference based on cholesterol intake or the use of Vitamin E, Vitamin C or beta carotene. Interestingly, total fat didn't matter