The entire construction of the study Pollinator Deficits, Food Consumption and Human Health Consequences: A Modeling Study, whose main author is Samuel Myers, founder of the Planetary Health Alliance, is based on a succession of assertions, certainly credible separately, but, aggregated together, develop a paralogism of the post hoc, ergo propter hoc type, that is to say reasoning which consists in claiming that if an event follows another, then the first must be the cause of the second.
So, to put it simply, the study suggests that the decline in pollinating insects would have an impact on agricultural production, which would result in yield losses, thus leading to a drop in the availability of fruits and vegetables, which would itself cause a decrease in the consumption of these foodstuffs. However, this drop in consumption of vegetables, fruits and nuts by the world population would cause, according to the authors of the study, approximately 500,000 premature deaths each year. ” Scientists estimate that this trend [of pollinator decline] has reduced the production of fruits, vegetables and nuts by 3-5% and, conversely, increased serious cases of certain diseases.», Specifies the article. And to mention heart disease, stroke, diabetes and some induced cancers.
To drive the point home, the article takes up the words of an “expert”, Dave Goulson, who assures that, as insect populations continue to decline, “this loss of crop yield will worsen in the future, and this, while the human population will continue to grow to reach at least 10 billion inhabitants ”. “ The problems described here are likely to get worse as the 21st century progresses ,” warns Dave Goulson, professor of biology at the University of Sussex and also trustee of the anti-pesticide association PAN UK .
In short, in an estimated reading time of less than a minute, lepoint.fr offers its readers a good concentration of anxiety-provoking remarks, which are however not based on anything very solid. Moreover, if we follow the strange reasoning of the authors, all agricultural production methods that are not very intensive, and therefore not very productive, such as organic farming, would logically also be responsible for “premature mortality”, even even more significant, since the yield losses are much higher than the 3 to 5% attributed by the authors of the article to the decline of pollinators.
But the most disturbing part of the affair is that a study based on such a paralogism could have been published in a reputedly serious journal such as Environmental Health Perspectives. However, a quick reading of its 12 pages makes it easy to identify its limits…
A made up number
As a preamble, it is interesting to note that the figure of 500,000 deaths, brandished as a title by The Guardian , lepoint.fr, and a few days later by Le Monde , does not appear anywhere in the study. The authors report 427,000 deaths, while specifying to take an uncertainty interval of 95%! In other words, they are counting on a range from 86,000 to 691,000 deaths. Admittedly, if verified, even this figure of 86,000 already points to excess deaths, although this remains marginal compared to the 55 million deaths that occur worldwide each year. However, the analysis of the method used to evaluate this range reveals some surprises…
Indeed, this estimated mortality is entirely attributed to a potential production optimum of fruits and vegetables that would not be reached due to the decline of pollinators . As the consumption of fruits and vegetables provides obvious nutritional benefits (in particular by their vitamin content), it is therefore this missing contribution that would justify these 427,000 premature deaths!
The case of Poland
To illustrate their point, the authors cite the example of Poland, and more specifically of the cultivation of apples, cucumbers and tomatoes, which depend on pollination. “To understand Poland’s missing potential due to insufficient pollination, we first compared Poland’s average crop yields with its potential yield based on a selection of global yields grown on land with a climate similar to that of Poland“, explain the authors. While Poland’s average yield for apples is 12.1 tonnes per hectare, they thus estimate the “achievable” yield at 15.8 t/ha. For cucumbers, the average is 11.5 t/ha against 18.9 t/ha achievable, and for tomatoes, 15.5 t/ha on average against 37.8 t/ha achievable.
How did they get these numbers? Mystery! “We relied on strong empirical field-based work to assume that about a quarter of the difference is due to insufficient pollination,” it reads for any explanation. This allowed the authors to estimate “that if pollinators were abundant and diversified, Poland could produce 8% more apples, 12% cucumbers and 28% more tomatoes.” It must be admitted that all this remains very theoretical.
The reasoning becomes more complicated in the sequel. Indeed, according to the authors, this potential increase in production would have an effect on food prices, which would lead to a change in consumption patterns: Global consumers would also buy and eat differently depending on food prices, taking into account changes in global trade flows. We would therefore consume more apples, cucumbers and tomatoes if there were more of them on the market! If this may possibly be the case in countries where these foodstuffs are lacking, it is difficult to see why the consumption of apples would increase in Poland. And if really it was the case, then, to the detriment of what would it be done?
“Our model suggests that these relatively modest dietary changes would nevertheless have the benefit of reducing preventable mortality from chronic disease,” the authors further advance, suggesting that there would be an automatic replacement of foods of lower nutritional quality (for example, crisps and sodas) with apples, cucumbers and tomatoes. However, nothing in the study justifies the idea that the simple fact of increasing the availability of fruits and vegetables would be enough to modify consumption toward a healthier diet.
However, it is this postulate that then allows the authors to affirm that this increased consumption of fruit and vegetables would, on the one hand, prevent 1,400 deaths per year in Poland, due to the reduction in the risk of stroke (900 deaths averted), cancer (300 deaths) and coronary heart disease (200 deaths), and on the other hand, to reduce mortality from coronary heart disease (1,000 deaths), cancer (500 deaths ) and strokes (200 deaths). Finally, still according to the authors, the Poles would also be led to consume more nuts – but why would they set their sights on nuts and not on peanuts? –, which would lead to the avoidance of 1,700 deaths, all due to coronary heart disease. “In total, it can be estimated that these beneficial dietary changes would prevent 4,700 deaths per year.”
All these rantings border on the ridiculous since nothing allows us to affirm that the increased consumption of apples would not be to the detriment of that of pears, oranges, bananas or grapes. It is therefore difficult to see why there would be fewer cancers or vascular accidents. Yet it is this fragile methodology that allows us to obtain the figure of 4,700 “premature” deaths for Poland, 107,000 for Europe and Central Asia, and 427,000 worldwide.
The height of the ridiculous, it is that following the logic of the authors, the transition to organic farming characterized by its low yields, and therefore by lower production, would cause millions of premature deaths.
The real “appalling record”
Finally, the only positive elements of this work consist in recalling first of all the beneficial role – and already of public notoriety – of the world consumption of fruits and vegetables on health, and then the constant need for an increase in agricultural production. to improve the health of the world’s population. Because we should not forget that, since 2019, undernourishment has continued to increase.
As the latest UN food security report published on July 6, 2022 reminded us, 9.8% of the world’s population is now affected by undernourishment, i.e. nearly one person in ten. That is to say between 700 and 830 million people. Verified figures that impose an “appalling record”!
[Editor’s note: This article has been translated from French and edited for clarity.]
Gil Riviere-Wekstein is an author, editor and member of the French Association of Agricultural Journalists. Follow Gil on Twitter @AEGRW.
A version of this article was posted at Agriculture et Environnement and is used here with permission.
