May 31, 2008

Traditional Mediterranean diet protects against diabetes

The Traditional Mediterranean Diet Protects Against Diabetes, Study Suggests:
ScienceDaily (May 30, 2008) — The traditional Mediterranean diet provides substantial protection against type 2 diabetes, according to a study published on British Medical Journal website.

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Current evidence suggests that such a diet has a protective role in cardiovascular disease, but little is known about its role on the risk of developing diabetes in healthy populations.

The SUN prospective cohort study involved over 13 000 graduates from the University of Navarra in Spain with no history of diabetes, who were recruited between December 1999 and November 2007, and whose dietary habits and health were subsequently tracked.

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During the follow-up period (median 4.4 years) the researchers from the University of Navarra found that participants who stuck closely to the diet had a lower risk of diabetes. A high adherence to the diet was associated with an 83% relative reduction in the risk of developing diabetes.

Interestingly, those participants who stuck strictly to the diet also had the highest prevalence of risk factors for diabetes such as older age, a family history of diabetes, and a higher proportion of ex-smokers. This group of participants was therefore expected to have a higher incidence of diabetes, but this was not the case. If fact, say the authors, they had a lower risk of diabetes, suggesting that the diet might provide substantial protection.
BMJ, doi:10.1136/bmj.39561.501007.BE (published 29 May 2008)

Adherence to Mediterranean diet and risk of developing diabetes: prospective cohort study

M Á Martínez-González, professor of epidemiology and chair1, C de la Fuente-Arrillaga, research assistant1, J M Nunez-Cordoba, research fellow1,2, F J Basterra-Gortari, research fellow1,3, J J Beunza, assistant professor1, Z Vazquez, research assistant1, S Benito, research assistant1, A Tortosa, research fellow1, M Bes-Rastrollo, assistant professor1

1 Department of Preventive Medicine and Public Health, Medical School-Clinica Universitaria, University of Navarra, Pamplona, Spain, 2 Department of Preventive Medicine and Quality Management, Hospital Virgen del Camino, Pamplona, Spain, 3 Department of Endocrinology, Hospital of Navarra, Pamplona, Spain

Correspondence to: M Á Martínez-González mamartinez@unav.es

Objective To assess the relation between adherence to a Mediterranean diet and the incidence of diabetes among initially healthy participants.

Design Prospective cohort study with estimates of relative risk adjusted for sex, age, years of university education, total energy intake, body mass index, physical activity, sedentary habits, smoking, family history of diabetes, and personal history of hypertension.

Setting Spanish university department.

Participants 13 380 Spanish university graduates without diabetes at baseline followed up for a median of 4.4 years.

Main outcome measures Dietary habits assessed at baseline with a validated 136 item food frequency questionnaire and scored on a nine point index. New cases of diabetes confirmed through medical reports and an additional detailed questionnaire posted to those who self reported a new diagnosis of diabetes by a doctor during follow-up. Confirmed cases of type 2 diabetes.

Results Participants who adhered closely to a Mediterranean diet had a lower risk of diabetes. The incidence rate ratios adjusted for sex and age were 0.41 (95% confidence interval 0.19 to 0.87) for those with moderate adherence (score 3-6) and 0.17 (0.04 to 0.75) for those with the highest adherence (score 7-9) compared with those with low adherence (score <3). In the fully adjusted analyses the results were similar. A two point increase in the score was associated with a 35% relative reduction in the risk of diabetes (incidence rate ratio 0.65, 0.44 to 0.95), with a significant inverse linear trend (P=0.04) in the multivariate analysis.

Conclusion Adherence to a Mediterranean diet is associated with a reduced risk of diabetes.

3 comments:

Maju said...

Great! Enviroment 1 : genes 0 (in this particular match).

In fact it's very interesting how habits can effectively counter a harmful gene and preserve a mutation that otherwise would be supressed by selection. And how that happens "intuitively", not by medical prescription.

mathilda said...

Yet the Saami eat non stop red meat and seem just fine. No higher rates of CHD and lower rates of cancer.

Personally, my whole family is insulin resistant and prone to gluten intolerance, so I won't be keen on any diet with a lot of carbs or grain in it.

Neither will most of the recently hunting and gathering people on the planet. Pima Indians and Aborigines beware, a med style grain based diet will make you obese and diabetic at light speed.

These studies never mention that CHD is very strongly linked to diabetes and metabolic syndrome, with refined carbs being pinpointed as the main offender.

For sanity's sake, eat like your ancestors did. If they haven't spent the last 10,000 years on a grain based diet, you shouldn't either.

Maju said...

Yet the Saami eat non stop red meat and seem just fine.

They must eat something else than meat, at least mushrooms, fish and berries. But you are seemingly right that hunter-gatherer peoples with heavy meat diet seem to do ok.

Anyhow, important elements of the so-called Mediterranean diet are not just "grains" (cereals and legumes, I understand) but also vegetables and oil (instead of lard or butter, wich is known to be horrible for cholesterol), as well as fish. Sweets are mostly out of this diet.

Even if you are coeliac, you can still eat maize, rice and legumes, right? Potatoes are also a good source of gluten-free carbs.

...a med style grain based diet will make you obese and diabetic at light speed.

That makes no sense: the highest rates of obesity by far are in the USA, where diet is not grain-based at all. Sweets and refined carbs may be associated but a major problem is certainly (in addition to sedentarism, probably the main cause actually) a huge consume of animal fats, present in most foods, salty or sweet, meat based or not.

The WHO has been recommending for decades now some 60% carbohydrates in any healthy diet, some suggest it should be even higher (specially to reduce excess fat). Additionally your ancestors probably ate loads of grains: bread and other cereal-based meals were much more common in the past, after all the Saami may have never gone throygh agricultural Neolithic but most other European peoples, including Germans and Brits have. In the Middle Ages bread was the base of any meal, even in places where now it's seldom eaten. It was integral bread mostly though.

So if you are going to eat like your farmer ancestors, you should eat loads of grain, as well other foods.