The headline: Drinking champagne could reduce risk of sudden cardiac arrest, study suggests.

But does the study actually suggest that?

The full text article. For some reason scientific articles don’t get linked to in newspaper stories.

The study used data from the UK biobank and the authors attempted to reduce confounding and show causality through Mendelian randomisation.

However, the authors acknowledge that confounding is due to much more than genetics. Despite the Mendelian randomisation, it doesn’t seem that confounding was handled well in this study.

Now it may well be that alcohol intake improves cardiovascular health. More likely they are both associated with socialising and higher socioeconomic status, which have positive effects on health in many ways, and may themselves be the result of better health.

The study found a stronger protective association for wine and champagne than for beer and cider. This suggests an underlying association with socioeconomic status and socialising: people who drink wine and champagne will tend to be richer and socialise more than beer and cider drinkers. Further evidence of this is that loneliness and isolation were negatively associated, as were depression, tenseness and other negative feelings.

The study also found that using a computer reduced risk of cardiac arrest. However, playing computer games raised the risk. So what does that say about using computers? Not much I suspect.

Using sunscreen had lower risk, which was likely due to higher sun exposure and taking more holidays.

Hand-grip strength had the second strongest protective association (just behind forced expiratory volume). Does this mean that exercising your hands will the reduce risk of cardiac arrest? Maybe a little bit but probably less than going for a walk. More likely hand-grip strength reflects underlying fitness.

Unfortunately cross-sectional studies using public data are always prone to confounding, and seldom identify primary causes.

They lead to data dredging for associations that are trivial, spurious or incidental. They throw up all these unhelpful headlines that cause confusion and distrust, while doing little to reduce health burdens. They take away resources from higher quality longitudinal studies.

In any case, the difficulty in reducing health problems is with effecting lifestyle and societal changes, not identifying risk factors. We have a pretty good idea of which things are good and bad for health.

The problem is that most people don’t follow the guidelines. And ultimately if people want to engage in unhealthy behaviours that’s their choice.