Scientists have created the first-ever tool to measure how much plastic sneaks into your diet—helping uncover hidden health risks and paving the way for smarter food choices.
Research: Plastics in human diets: development and evaluation of the 24-h Dietary Recall — Plastic Exposure and the Dietary Plastics Score. Image Credit: Elena_E / Shutterstock
In a recent study published in the journal Frontiers in Nutrition, researchers developed and evaluated the 24-hour dietary recall–plastic exposure (24DR-PE) tool to assess dietary plastic exposure. The study involved 422 participants from the PERTH Trial in Perth, Australia. To validate the tool, researchers collected urinary samples alongside dietary recall data, aiming to correlate plastic exposure scores with actual plastic metabolites in the body.
Plastic is a synthetic material produced from fossil carbon-based feedstock. It is malleable and light and extensively used in commercial, consumer, and construction materials, including food products. Dietary intake is a considerable source of human exposure, as plastic is used in food packaging, preparation, processing, and consumption.
Plastic chemicals enter the human body via ingestion, absorption through the skin, and inhalation. Plastic chemicals have been associated with a higher risk of cardiovascular disease, metabolic syndrome, and other chronic conditions. Despite the extensive human exposure to plastics, a comprehensive method to assess dietary plastic exposure is lacking.
The Study
In the present study, researchers designed and developed the 24DR-PE tool to capture dietary exposure to plastics. The team, which included clinical researchers with qualifications in dietetics and nutrition, collaborated with an information technology (IT) specialist to develop a Research Electronic Data Capture (REDCap) program to gather data via an interview. The 24DR-PE tool development and evaluation involved three phases.
The first phase commenced with a literature review, followed by a review of existing methods to be modified to examine plastic exposure. Weekly meetings were held to discuss the literature and household dietary practices. The automated multiple-pass method (AMPM) was used to collect details on dietary plastic exposure. However, modifying the AMPM to the level of detail needed for the study was not feasible.
As such, the researchers developed an in-house AMPM-based computer-assisted tool. Because integrating nutrition analysis software (into REDCap) was not feasible, the database was formatted to enable export into the nutrition analysis software. This allowed for calculating nutrition and energy intake from the data acquired through the 24DR-PE tool.
In the second phase, healthy adults participating in a trial in Perth, Australia, were enrolled for interviews. Each participant completed two dietary recall interviews within one week—one in person and one via telephone—to capture both weekday and weekend dietary intake. Interviews were conducted twice within a week by trained, practicing dieticians for 45–60 minutes. The first interview was in-person, and dietary intake data was collected on the preceding weekday. The second was telephonic on a Monday to obtain dietary intake on the weekend.
In the interview, participants were asked to recall all items consumed in the past 24 hours and whether it was a typical intake day. They also provided details on water consumption, including the source, volume, and drinking vessel (e.g., glass, plastic, ceramic, or metal). Moreover, they were asked to specify whether they consumed any of the commonly forgotten foods. The time of eating occasions was also recorded. In addition, the interviewers collected descriptive information on each item or ingredient, including brand names, packaging, storage, preparation, cooking, and consumption.
Plastic Exposure Assessment & Scoring
The third phase was the evaluation of the 24DR-PE tool. This tool also introduces a Dietary Plastics Score, a novel metric designed to quantify adherence to a low-plastic diet, which may inform future dietary guidelines and public health policies. This involved an automated summary of plastic exposures and an estimation of dietary plastics score. After the interview, the program automatically transformed common measurements (e.g., milliliters, cups) into gram weights.
Each food and beverage item was scored based on its packaging, storage, preparation method, and consumption materials. The Dietary Plastics Score was then calculated using a structured matrix that categorizes high-risk foods and behaviors, such as consuming individually packaged foods, microwaving in plastic, or using plastic utensils. These data offered an overview of the quantity of each item consumed and the material(s) used in food preparation, packing, storage, and intake.
These details were used to assign binary scores into a dietary plastics scoring matrix, which was developed using available literature on high-risk foods and behaviors. A dietician completed the scoring matrix using the auto-generated data. The dietary plastics score lacked a maximum because the scoring matrix did not limit the number of eating occasions or food items. Nevertheless, a lower score implied lower (dietary) plastic exposure.
Challenges & Future Research
While the tool provides a comprehensive assessment, researchers noted challenges such as the lengthy interview process, potential recall bias, and the need for further validation using urinary plastic metabolite analysis. Future studies may incorporate stool sample analysis to assess microplastic exposure.
Conclusions
In sum, the study developed the 24DR-PE tool to collect comprehensive data about dietary exposure to plastics. It considered all consumer dietary practices and food packaging aspects and integrated these data into an online platform to enhance data accuracy and completeness. The development of this tool represents a significant step toward quantifying dietary plastic exposure, and its potential validation using biological samples will further strengthen its utility. This tool improves accuracy in portion size estimations and minimizes the odds of missing data compared to recalls. Overall, the tool will support research into the effects of ingested plastics, facilitate surveillance of dietary plastic exposure, guide dietary recommendations, and inform policy changes.