Eating the basic "caveman diet" of berries, nuts, lean meat and fish significantly lowers the chance of suffering a heart attack or stroke, says a new study.
Researchers at the Karolinska Institute in Sweden discovered that eating like our ancestors also helps lower blood pressure, reduces the risk of diabetes, thins the blood and leads to weight loss.
Stone age cavemen lived on a diet lacking in cereals, dairy products and refined sugar for centuries before farming developed and some scientists believe that the human body is still best suited to this kind of food.
The researchers tested the benefits of a Stone Age diet on volunteers who ate nothing but caveman rations for 21 days. Food included fresh or frozen fruit, berries or vegetables, lean meat, unsalted fish, canned tomatoes, lemon or lime juice, spices and coffee or tea without milk or sugar, for three weeks.
All dairy products were banned as well as beans, salt, peanuts, pasta or rice, sausages, alcohol, sugar and fruit juice. However, participants were allowed up to two potatoes a day.
They were also given some dried fruit, cured meats and a portion of fatty meat as a weekly treat.
After three weeks the volunteers were assessed for weight, body mass index, blood pressure and cholesterol and the results compared with those taken before the experiment.
Volunteers who effectively stuck to the diet showed an average weight loss of five pounds while their body mass index had dropped.
Blood pressure readings also showed a marked improvement while levels of a chemical, which can lead to blood clots dropped by an astonishing 72 per cent.
Dr Per Wandell, who led the study, said that the research proved that even short-term use of the diet had "favourable effects" on the major risk factors for heart disease.
However, he warned that the lack of certain foodstuffs could have other impacts on overall health.
"One negative effect was the decreased intake of calcium (from dairy goods, which could be a risk factor for osteoporosis later in life," the Telegraph quoted him, as saying.
The study is published in the current issue of the European Journal of Clinical Nutrition.