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Mary Flynn is a nationally recognized expert on the health benefits of extra virgin olive oil. Flynn, a nutritionist, is an associate professor of medicine at Brown University. Over the past decade, she's researched the health benefits of olive oil and created a weight-loss regimen that showcases extra virgin olive oil and vegetables. She spoke with us about the health benefits of extra virgin olive oil, noting - among other things - it's better to cook your vegetables in olive oil versus steaming or boiling them.

How did you become focused on extra virgin olive oil in your research?

I became interested in the mid 1980's. I'd read the papers from the so-called Seven Countries Study. The results showed that men on Crete ate more than 40 percent of their calories from fat, but it was mainly olive oil.

Their heart disease rate was 80 percent less than American men, who ate slightly less total fat - but mainly as red meat. The focus in the U.S. was just starting to be on low-fat diets. I didn't see low-fat diets as being useful for long-term weight loss. The Seven Countries Study made me think - maybe it's not fat in the diet, but the source of fat.

Why is olive oil so important in your plant-based olive oil diet?

The core of my diet is plant foods. Because olive oil is the juice of an olive, it fits in quite nicely. All plant products contain phytonutrients, which protect the plant from things like ultraviolet rays, herbicides, pesticides, etc. In humans, phytonutrients have been tied to lowering the risk of chronic disease and to alleviating certain chronic diseases. The more plant products you consume, the healthier your diet.

How is cooking vegetables in extra virgin olive oil better than steaming/boiling?

From a health standpoint, fat is needed to absorb certain phytonutrients. There are two main families of phytonutrients that are very healthy: carotenoids and glucosinolates. Carotenoids give color to plant products. Glucosinolates are found in vegetables in the cruciferous family, such as cabbage, cauliflower, broccoli, Brussel sprouts, and kale.

Both carotenoids and glucosinolates have been shown to possess powerful cancer-fighting proteins when there are sufficient amounts in the body. Both need fat to be absorbed, so steaming or boiling vegetables with carotenoids or glucosinolates means they don't get into your body. Cooking in olive oil means you'll get the health benefits of olive oil, plus you'll absorb the healthy components. In addition, olive oil makes vegetables taste so much better than plain. I find people eat more vegetables when they use olive oil to prepare them.

What advice would you give to people who want to prepare more healthy meals?

Include olive oil and use it to cook vegetables. My rule of thumb is 1 tablespoon of olive oil per cup of vegetables. I recommend 2 tablespoons of olive to make a dinner, so you would then be using at least 2 cups of vegetables. The meals I recommend include olive oil, vegetables, plus a starch (pasta, rice/grains, potato); if you want to add poultry or seafood, fine.

But I encourage people to eat a main meal that is plant-based, olive oil-rich two to three times a week for dinner. I think it's also easier to lose weight when you eat less animal protein. Including meat, poultry, or seafood daily means you're exceeding your daily protein needs. Extra protein isn't stored as protein, but is instead converted to fat and stored as fat. Eating plant-based meals means that you are getting enough protein, but not more than you need; so body weight is lower and weight loss is easier.

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