Health – What healthy habits are supported by scientific “weight of evidence”?

First modification: 10/11/2022 – 19:21

One day, a study comes out saying that a food is bad for our health. The following week, another study denies it. Both are signed by scientists who are experts in their field and are sponsored by prestigious universities. Sometimes it’s dairy, sometimes it’s gluten, blueberries, coffee, or the latest superfood trend.

They seem like pieces of a puzzle that are impossible to fit together, and it is not only confusing for people but also for public administrations and their policies to encourage or discourage certain habits. However, a new tool seeks precisely to file the edges to have a vision of the complete puzzle.

It is “Burden of Proof” (which translates as “The Weight of Evidence”), a compendium of studies published in the journal ‘Nature Medicine’ by the Institute for Health Metrics and Evaluation. With a five-star system, they evaluate the correlation between a habit or condition and a disease: one star means that there is no scientific evidence linking this habit to the disease, while five stars show that the relationship is totally direct.

The grace is that, to carry out these evaluations, they took data from dozens of different studies. Thus, they paint a picture that is close to the existing scientific consensus based on the data that has been published so far and give a more reliable idea than a single study.

In this way, some theories that have gained strength in recent years without having the full “weight of evidence” behind them are dismantled, or above all completed. An example is the consumption of red meat, on which the carcinogen label was hung a few years ago. According to studies published thanks to this tool, the correlation between this habit and the risk of developing various types of cancer ranges from one star to two stars, that is, between no evidence or “weak” evidence.

The researchers summed it up: “Although there is some evidence that eating unprocessed red meat is associated with an increased risk of disease incidence and mortality, it is weak and insufficient to make strong or conclusive recommendations. More rigorous research is needed.” to better understand and quantify the relationship between this consumption and chronic diseases”.

Like this example, there are fifty more on the page of the Institute for Health Metrics and Evaluationranging from five stars for the link between smoking and lung cancer to the lone star showing us that there is no proven link between a low-vegetable diet and the onset of type 2 diabetes.