According to the saying, we’re best advised to beware of Greeks bearing gifts. But if they’re bringing round something for dinner, it might be worth taking this advice with a pinch of salt. A new study published in the British Journal of Cancer provides strong evidence that cancer is less common amongst people who eat ‘Mediterranean’ diets.
This research comes from a Greek research team working as part of the EPIC study, the largest study on diet and cancer ever undertaken. EPIC looks at the diets of half a million people from 10 different European countries (we’re funding the two UK centres in Oxford and Norfolk), and the Greek arm alone includes over 25,000 people.
The researchers graded these people on a scale of 0-9 according to how closely their diet matched the typical Mediterranean pattern, including:
- eating lots of fruit, vegetables, legumes, nuts, cereals and fish
- eating less red or processed meat and dairy products
- eating comparatively more monounsaturated fats than saturated fat
- drinking moderate amounts of alcohol
They found an increase of 2 points on this scale led to a reduction in the overall risk of cancer by 12 per cent. This could be achieved by combinations of different dietary choices, like eating substantially more vegetables and less red meat, or eating more legumes and substituting butter for olive oil in cooking.
It’s been common knowledge for a some time that what we eat affects our risk of cancer. But it’s been much more difficult trying to pin down whether specific foods affect our odds of getting cancer. Our diet contains so many different foods and nutrients that it can be very difficult to isolate any effects due to a single one.
To get around this, an alternative approach is to look at entire dietary patterns. The odds of eating certain foods and nutrients tend to be linked. For example, people who eat large amounts of fruit and vegetables also tend to eat lots of fibre. By looking at these dietary patterns, scientists can try and work out how a person’s diet as a whole affects their risk of cancer.
This approach allows for the fact that different foods can interact to affect our risk. For example, the EPIC study has previously found that fibre’s protective effect against bowel cancer is especially strong in people who eat a lot of red or processed meat.
Another recent result also looked at dietary patterns. It gave thousands of people four different scores based on how well their diets matched four different patterns of healthy eating (including Mediterranean diets). It found that men with the highest scores in any of these scales slashed their risk of bowel cancer by more than a quarter.
But one major problem with studies looking at dietary patterns is that they don’t tell you whether the individual components could necessarily protect you from cancer.
For example, Mediterranean diets include eating lots of fish, and relatively little red or processed meat. Other studies have consistently shown that red and processed meat can increase the risk of bowel cancer, but there is much weaker evidence for a protective effect of fish.
Things are even more controversial when it comes to alcohol. It’s true that moderate amounts of alcohol (and we’re talking about only a couple of units a day here) could reduce the risk of heart disease in older men and women.
But many studies have consistently shown that alcohol also causes cancer. And when it comes to cancer, there’s no “safe level” of drinking, or evidence that any amount or type of alcohol could protect against cancer. Even red wine – supposedly ‘good’ alcohol – increases your risk.
The point we’re trying to make is that typical Mediterranean eating habits can act as a rough guide for a cancer-preventing diet, but there are probably going to be ways of tweaking it to reduce your risk even further.
But, alcohol aside, the general Mediterranean pattern is very much in keeping with Cancer Research UK’s advice of eating a healthy, balanced diet. Media stories on diet and cancer like to focus on the effects of so-called superfoods (remember Henry’s post on fruit?) but it’s much more likely that a generally healthy diet will do the most good.