The Mediterranean diet faith is struggling on
That eating like a traditional Greek or Southern Italian is good for you is now widely believed. We must not let it upset our faith that mainly Nordic populations such as Iceland, Finland and Australia have the longest lifespans, must we?
The faith has come under heavy attack in the medical journals lately. In 2011, for instance a Dutchman named Piet van den Brandt found that the diet had some benefit to women but none to men. Icelandic men should marry Greek women, or something.
That finding doesn't seem to have fazed our dogged Dutchman, however. He has just found that the diet helps to prevent breast cancer -- but only a minority of cancers in post-menopausal women. Still a pretty thin finding for him, I would think.
And it may even be true. A diet that does not bother most people can be bad for some subsets of people. A Southeast Asian diet rich in peanuts can kill some allergic Westerners, for instance.
I should note that the layman's report below overstates the findings. The connection between diet and ER negative breast cancer was extremely weak -- to the point of negligibility. It is certainly not enough to influence anyone's diet. The connection was statistically significant only by virtue of the large sample size. And the connection between diet and ER positive breast cancer was not even statistically significant. So the layman's summary immediately below is essentially fake news.
Report below plus abstract:
Eating a Mediterranean diet rich in vegetables, nuts, fish and olive oil cuts the risk of getting a deadly form of breast cancer by 40 per cent, a study has found.
The diet – which keeps white bread, red meat and sweets to a minimum – significantly reduced the likelihood of oestrogen-receptor negative breast cancer in post-menopausal women.
The cancer is more likely to prove fatal than other types. It is often harder to treat than hormone-sensitive cancer. Nearly a third of the 55,000 women in the UK diagnosed with breast cancer each year have this form. Around 11,400 women die from breast cancer in the UK every year.
A typical Mediterranean diet includes high intakes of plant-based proteins such as nuts, lentils and beans, whole grains, fish and 'healthy' monounsaturated fats such as olive oil.
Refined sugars and saturated fat are kept to a minimum.
Professor Piet van den Brandt, from Maastricht University in the Netherlands, led the study of 62,000 women over 20 years. He said: 'Our research can help to shine a light on how dietary patterns can affect our cancer risk.
A Mediterranean diet only had a weak non-significant effect on the risk of hormone-sensitive oestrogen-receptor positive breast cancer, the study published in the International Journal of Cancer found
Mediterranean diet adherence and risk of postmenopausal breast cancer: results of a cohort study and meta-analysis
Piet A. van den Brandt et al.
The Mediterranean Diet (MD) has been associated with reduced mortality and risk of cardiovascular diseases, but there is only limited evidence on cancer. We investigated the relationship between adherence to MD and risk of postmenopausal breast cancer (and estrogen/progesterone receptor subtypes, ER/PR). In the Netherlands Cohort Study, 62,573 women aged 55–69 years provided information on dietary and lifestyle habits in 1986. Follow-up for cancer incidence until 2007 (20.3 years) consisted of record linkages with the Netherlands Cancer Registry and the Dutch Pathology Registry PALGA. Adherence to MD was estimated through the alternate Mediterranean Diet Score excluding alcohol. Multivariate case–cohort analyses were based on 2,321 incident breast cancer cases and 1,665 subcohort members with complete data on diet and potential confounders. We also conducted meta-analyses of our results with those of other published cohort studies.
We found a statistically significant inverse association between MD adherence and risk of ER negative (ER−) breast cancer, with a hazard ratio of 0.60 (95% Confidence Interval, 0.39–0.93) for high versus low MD adherence (ptrend = 0.032). MD adherence showed only nonsignificant weak inverse associations with ER positive (ER+) or total breast cancer risk. In meta-analyses, summary HRs for high versus low MD adherence were 0.94 for total postmenopausal breast cancer, 0.98 for ER+, 0.73 for ER− and 0.77 for ER − PR− breast cancer. Our findings support an inverse association between MD adherence and, particularly, receptor negative breast cancer. This may have important implications for prevention because of the poorer prognosis of these breast cancer subtypes.