Exposure to plant biodiversity reduces risk of cancer in children

Large New Zealand birth-cohort study finds statistically significant and dose-dependent association between increased plant diversity and protection against childhood leukaemia

Rubus schmidelioides
Rubus schmidelioides A.Cunn. observed in Hopkins Valley, New Zealand. Photo by jamesmifan (CC BY-NC 4.0)

A diverse gut microbiota is essential for human health, as many diseases are associated with reduced microbial diversity in the intestines. Vascular plants are important habitats for microorganisms such as bacteria, with microbial diversity increasing with plant diversity.

Setting out to test the so-called biodiversity health hypothesis and demonstrate a direct link between exposure to plant diversity and specific health outcomes, this study followed all children born in New Zealand between 1998 and 2013 (and their mothers) from the time of conception to age five, tracking plant exposure while identifying cases of acute lymphoblastic leukaemia (ALL), the most common childhood cancer.

The authors estimated the plant exposure of every child (and mother during pregnancy) based on where they lived and a composite metric of GBIF-mediated plant occurrences, land cover data, a satellite imagery-based vegetation index and census data classifying a location as urban or rural.

After five years, the study identified 264 cases of ALL among the almost 950,000 children tracked. Based on the calculated exposure metrics, the study found that children in the highest tertile of plant diversity had a 35 per cent reduced risk of developing ALL.

Donovan GH, Gatziolis D, ’t Mannetje A, Weinkove R, Fyfe C and Douwes J (2021) An empirical test of the biodiversity hypothesis: Exposure to plant diversity is associated with a reduced risk of childhood acute lymphoblastic leukemia. Science of The Total Environment. Elsevier BV 768: 144627. Available at: https://doi.org/10.1016/j.scitotenv.2020.144627