Dear Dr. Roach: I have seen numerous articles extolling the advantages of eating nuts because they are a good fat. I often have wondered if it matters whether the nuts are raw or roasted. Would you please explain the difference and the impact on ones health? D.O.
Answer: Scientists believe that nuts are healthy for us based on three different types of evidence. One is called epidemiological: People who eat nuts live longer and have less heart disease than people who dont eat nuts. This suggests nuts are good for you, but its not definitive. People who eat nuts may do other healthy things, which could be the real reason they live longer (this is called confounding).
A second line of evidence comes from watching what happens to factors that we believe are related to disease. People who add a reasonable amount of nuts to their diet often have improvements in their cholesterol levels. They also help some people lose a few pounds, possibly because the fat and protein in nuts makes them more filling than the (often processed) starches many people eat. This is also not definitive, because there are treatments that lower cholesterol but dont make people live longer or improve health.