A cheap item of food has been identified as a secret to living to 100 years old by a leading chef. Greek American chef Diane Kochilas claimed beans have a beneficial impact on humans and can lead to a longer life. The vegetable can be bought at supermarkets for a low price, with Tesco charging £1.30 for 200 grams of fine beans. Sainsbury’s sell a similar product for £1.25 and shoppers can pick up 220 grams of green beans for just 89p. Kochilas revealed the food is “palliative” and can even prevent Type 2 diabetes. She said: “Bean consumption helps heart health by lowering cholesterol because b…