Adopting elements of a Mediterranean-style diet, which is high in fruit and vegetables and low on red meat and dairy produce, can reduce the risk of cancer by almost a quarter, according to a major study of people's eating habits.
It has been thought for some time that making dietary changes such as eating more olive oil and less butter could lead to a significantly lower incidence of heart disease, and now comes detailed evidence of how it can dramatically cut the chances of all types of cancer developing.
The research shows that just two elements of the Mediterranean diet added to daily food intake can cut the possibility of cancer taking hold by 12 per cent. Increase that to six items a day and the prospect of the disease being diagnosed falls by a staggering 22 per cent. Adding two elements to the daily diet could simply be eating more pulses and consuming less red meat.
More than 26,000 Greek men and women were studied over eight years by the scientists who found that consuming high levels of monosaturated fats – the "good" fat found in olive oil – in relation to the "bad" saturated fats found in dairy produce had the single biggest effect in relation to lowering the cancer risk from the diet. More olive oil and less butter reduced the risk by 9 per cent.
"Of the 26,000 people we studied, those who closely followed a traditional Mediterranean diet were overall less likely to develop cancer," said the study leader, Dimitrios Trichopoulos, professor of cancer prevention and epidemiology at Harvard University. "Although eating more of one food group alone didn't significantly change a person's risk of cancer, adjusting one's overall dietary habits towards the traditional Mediterranean pattern had an important effect."
The study, published in the British Journal of Cancer, monitored the prevalence of all types of cancer from stomach and bowel to liver, cervix and brain tumours. They looked at men and women, and took into account other risk factors, such as smoking and lifestyle.
The research is part of the European Prospective Investigation into Cancer, a unique and ongoing look at dietary habits and other biological and lifestyle characteristics of more than half a million people across Europe before they were diagnosed with cancer or other chronic illnesses.
The scientists carried out detailed surveys of each person to study the sort of food they regularly ate and in what quantities.
The nine food groups measured were monosaturated and saturated fats, fruits, vegetables, legumes such as peas and lentils, cereals such as wholegrain bread and pasta, meat, dairy food, fish and alcohol.
"The researchers found that people who more closely followed a traditional Mediterranean diet had a lower incidence of cancer. Importantly, lower risk wasn't only seen by completely adopting the traditional Mediterranean diet, closer conformity also reduced cancer risk. And the more changes, the bigger the effect," said a spokeswoman for Cancer Research UK, which helped to fund the work.
Cancer specialists said the best advice for people to avoid getting cancer was not to smoke, to take regular exercise and eat a balanced diet rich in fruit and vegetables and low in red meat and saturated fats. "This is an interesting study but the best advice for cancer prevention remains to eat a healthy diet, to be regularly physically active and to maintain a healthy weight," said Rachel Thompson, science programme manager for the World Cancer Research Fund. "Looking at all the evidence on diet, people looking to reduce their cancer risk should aim to eat plenty of wholegrains and fruits and vegetables and limit their intake of red meat, salt and energy-dense foods."
Sara Hiom, director of health information at Cancer Research UK, said: "This helps us to understand more about the simple changes a person can make to their diet to reduce their risk of cancer and improve overall health. Although we know that unhealthy diets generally and being overweight are important risk factors for a number of cancers, the link between individual foods or food types and cancer has been less clear.
"This research highlights the importance of maintaining a healthy balanced diet to reduce your risk of cancer. It shows there are a number of things you can do, and there is no one 'superfood' that can stop you developing the disease."
How to eat healthily
The researchers broke the diet down into nine food groups:
HIGH CONSUMPTION: Fruit, vegetables, legumes (peas, beans lentils), cereals (wholegrain bread), monounsaturated fat (olive oil), fish
MODERATE CONSUMPTION: Ethanol (red wine)
LOW CONSUMPTION: Meat, dairy products