NEW YORK, May 9 -- Featuring seasonal fruit and vegetables, oily fish and, above all, a touch of olive oil at every meal, the Mediterranean diet has been lauded by the scientific community for decades. And with good reason, because it's said to help preserve physical and even mental health. Now, a new study suggests that one of its staples, olive oil, is associated with a reduced risk of death from dementia.

Although health professionals and scientists have been extolling the virtues of the vegan diet in recent years, it still hasn't managed to replace the Mediterranean diet in terms of health benefits. Renowned for its variety of foods, rich in seasonal produce and low in refined products and red meat, this diet, also known as the "Cret...