As bees buzz off, malnutrition increases in developing world

For those of us fortunate enough to live in developed countries, dwindling bee populations could just mean reduced choice at the greengrocer. But for those in developing countries, it presents a very real risk: malnutrition.

Populations of many pollinator species - not just bees - have declined in recent years. Recent studies have shown that these pollinators are responsible for up to 40% of the world’s supply of nutrients.

New research has found that in some populations, the disappearance of pollinators could push as many as 56% of people over the edge into malnutrition. In parts of Mozambique, for instance, many people are barely able to meet their micronutrient needs, especially vitamin A. If crops in these regions fail to be pollinated, many people will go without food - and will be susceptible to the ‘hidden hunger’ associated with vitamin and mineral deficiencies.

“The take-home is: pollinator declines can really matter to human health, with quite scary numbers for vitamin A deficiencies, for example, which can lead to blindness and increase death rates for some diseases, including malaria,” said University of Vermont scientist Taylor Ricketts, who co-led the study.

“This is the first study that quantifies the potential human health impacts of animal pollinator declines,” said Samuel Myers from Harvard University, who also co-led the study. “To evaluate whether pollinator declines will really affect human nutrition, you need to know what people are eating.”

The study examined the full pathway from pollinators through to detailed survey data about people’s daily diets in parts of Zambia, Mozambique, Uganda and Bangladesh.

“How much mango? How much fish? And from that kind of data we can find out if they get enough vitamin A, calcium, folate, iron and zinc,” said Ricketts. From there, the scientists were able to determine the likely impact a future without pollinators would have on these diets.

For parts of the developing world, that could mean “an increase in neural tube defects from folate deficiency or an increase in blindness and infectious diseases from vitamin A deficiency, because we have transformed our landscapes in ways that don’t support animal pollinators any more”, said Myers.

“We find really alarming effects in some countries for some nutrients and little to no effect elsewhere,” said Ricketts. Bangladesh is likely to experience little change, the researchers say, because so many people are already malnourished. The Zambian diet already contains so much vitamin A that a reduction isn’t expected to push many people below the threshold.

The study was published in the 9 January issue of the journal PLOS ONE.