Hi all! Itās me with the plants once again 
Today I want to share something that I was not very familiar with until recently, but that really caught my attention as a potentially important environmental exposure that we may want to ask about more systematically in our cohorts.
During the most recent LARGE-PD/GP2 Regional Investigators Meeting, Dr. Irene Litvan mentioned the potential importance of incorporating questions about the consumption of certain fruits into our research assessments. This led me down a bit of a rabbit hole, and here is some of what I found.
Annonaceae and parkinsonism
The Annonaceae family includes fruits that are widely consumed in tropical and subtropical regions, including soursop (Annona muricata), among others.
This family of plants contains compounds known as annonaceous acetogenins, which have received considerable attention because of their biological activity, including potential cytotoxic and neurotoxic effects.
More importantly for our field, exposure to Annonaceae has been investigated in relation to atypical parkinsonism and Parkinsonās disease, particularly in Caribbean populations.
What does the evidence suggest?
A recent study by Ribeyron et al. (2026) compared Parkinsonās disease patients from the Caribbean with patients from mainland France. Nearly all Caribbean participants reported exposure to Annonaceae fruits, whereas none of the interviewed participants from mainland France did.
The Caribbean PD group showed more severe motor and cognitive symptoms. Although this type of comparison cannot establish causality, the findings add to the growing body of research suggesting that environmental exposure to Annonaceae may be relevant to disease severity.
Similarly, Nasri et al. (2025) investigated degenerative parkinsonism in French Guiana and the French West Indies. Atypical parkinsonian syndromes were highly prevalent in both regions, although their frequency differed. Importantly, consumption of Annonaceae products was also highly prevalent, particularly in the French West Indies.
The authors suggested that shared environmental exposures, including Annonaceae, may contribute to the presentation sometimes described as Caribbean Atypical Parkinsonism.
Perhaps one of the findings that caught my attention the most came from de Langavant et al. (2022).
The researchers examined 180 Caribbean patients with degenerative parkinsonism and investigated whether cumulative exposure to Annonaceae products was associated with disease severity.
They found that even relatively low cumulative consumption of Annonaceae fruits or juices, as well as consumption of herbal teas derived from these plants, was associated with more severe disease and greater cognitive impairment.
The association was observed across degenerative parkinsonism, including Parkinsonās disease.
Of course, these findings should be interpreted carefully. Observational studies can identify important associations, but they cannot, by themselves, establish causality. At the same time, the consistency of the signal across studiesāand the potential biological plausibility related to annonaceous acetogeninsāmakes this a particularly interesting environmental exposure to consider.
A question for those working with cohorts
This made me wonder whether we are systematically asking our participants about the consumption of these products.
In many regions, particularly in Latin America and the Caribbean, fruits from the Annonaceae family are part of regular diets, and participants may also consume juices, supplements, or herbal preparations without considering them relevant to a neurological research study.
So I would love to hear from the community:
- Do you routinely ask about Annonaceae consumptionāor specific fruits such as soursop, guanĆ”bana, chirimoya/custard apple, anĆ³n/saramuyo, anona/corazĆ³n, atemoyaāin your cohorts?
- Do your questionnaires include dietary or environmental exposure assessments that could capture this information?
- Do you know of any existing Parkinsonās disease datasets that systematically collect information on Annonaceae exposure or consumption?
And perhaps more broadly: what other culturally or geographically specific environmental exposures do you think we should be paying more attention to in large, international cohorts
I would be particularly interested in hearing whether anyone has already collected this type of informationāor whether this is something we should start thinking about incorporating more systematically.
Looking forward to learning from your experiences!