Mediterranean diet to the rescue

A very large, very longitudinal study suggests it helps even obese people avoid the increased overall mortality associated with high BMI.

A Mediterranean-like diet can mitigate an obese person’s increased risk of an early death, research suggests.

According to a new study published in the journal PLOS, people who were obese who ate a Mediterranean diet negated their increased overall mortality risk to be on a par with people of normal weight.

And it wasn’t just explained by heart disease. The risk of CVD mortality in the obese group was reduced but still higher than the normal weight group.

The longitudinal cohort study also proved that diet was more important than weight at the other end of the BMI spectrum. A lower BMI did not appear to counter the elevated mortality associated with a low adherence to a Mediterranean-like diet.

According to this research at least, it would seem diet is the most important factor when it comes to living longer.

It is well established that the Mediterranean diet, high in vegetables and olive oil, is beneficial for health. What these study researchers wanted to know was whether the benefits of eating a diet such as this could counter the disadvantages to mortality from that very prevalent risk factor, obesity.

So they enlisted over 79,000 patients, both men and women, average age 61 years, from two different Scandinavian data registries. They documented a substantial amount of baseline information including a detailed account of their daily diet. They then followed them for the next 21 years!

Over the duration of the study, 38% of the cohort died.

When they analysed the data, comparing the diets of the 10% of the cohort who were obese with the almost half of the study population who were normal weight, they were able to make their conclusions about the relative importance of diet and weight.

“Obese individuals with high adherence to a Mediterranean-type diet did not experience the increased overall mortality otherwise associated with a high BMI, although a higher CVD mortality remained,” the study authors wrote.

The researchers suggest a mechanism which might explain the protective benefit of the Mediterranean diet in obesity. High BMI is thought to increase the risk of mortality through mechanisms such as hypertension, insulin resistance, hyperlipidaemia, low grade inflammation and oxidative stress. As it happens, these are the same areas where the Mediterranean diet has been proven to be beneficial.

The fact that those people who ate Mediterranean diets and were obese still had a higher CVD mortality than those people of normal weight who were eating their olive oil and tomatoes simply showed that CVD had more risk factors than could be modified by diet alone. The CVD mortality was better with the diet than without – the diet just didn’t totally counter the risk factors conferred by obesity on the cardiovascular system.

It’s an interesting study, and, as the study authors point out, unique.

“Ours is the first large cohort study examining the combined association of BMI and a Mediterranean-like diet with rates of mortality,” they said.

They concede the study’s observational design as a limitation of the research.

Nonetheless, given the prevalence of overweight and obesity in the developed world, and given the limited success we appear to be having in countering this “epidemic” (the term we use to bandy around before it got superseded by an actual pandemic), these new research findings could well find their way into general practice consultation.

“These results indicate that adherence to healthy diets such as a Mediterranean-like diet may be a more appropriate focus than avoidance of obesity for the prevention of overall mortality,” the study authors concluded.

This piece was originally published at Healthed.