This study provides critical insights into the complex interplay between dietary choices, health outcomes, and environmental impacts.
In a recent study published in JAMA Network Open, researchers looked at the effects of adopting a Planetary Health Diet (PHD) on human and environmental health, with a focus on Chinese Singaporeans in particular.
Diets high in plant-based foods and low in animal products are highly recommended by the PHD. While previous studies have proposed methods for measuring adherence to PHD, they have mostly focused on Western societies and have not considered the caloric requirements at the individual level.
The study drew upon data from the Singapore Chinese Health Study (SCHS), which enrolled individuals without a history of cardiovascular disease or cancer, primarily Cantonese or Hokkien-speaking permanent residents of Singapore, between 1993 and 1998. The participants were followed up until 2020 using record linkage data.
Researchers developed a grading system to evaluate PHD adherence and its associated benefits for environmental and human health. PHD scores were calculated based on standardized food frequency questionnaires, capturing the consumption of 14 dietary elements in the PHD as well as individual calorie intake. These scores were then used to assess the environmental implications of the diet.
The study also estimated the Total Water Footprint (TWF), land utilization, and greenhouse gas (GHG) release using the China Health and Nutrition Survey database. These metrics provided insights into the diet’s environmental impacts, revealing effects per gram of food item consumed.
Among the 57,078 participants, aged on average 56 years with 56% being female, a total of 22,599 deaths were reported during a median follow-up of 23 years. The median PHD score was 55 points, indicating a tendency towards low adherence to PHD principles.
Noteworthy was the finding that adherence to unsaturated fats, fish, and fruits within the PHD was reported in over 80% of participants. While higher PHD scores were associated with a 7% reduction in GHG emissions, they also led to a 10% increase in land usage and an 8% rise in TWF.
Moreover, individuals with higher PHD adherence tended to be younger (average of 54 years), female, more educated, non-smokers, non-alcoholic consumers, and physically fit compared to those with lower adherence. Total grains, fish, and red meat were the primary contributors to GHG emissions, while grains played a significant role in land utilization and TWF.
The study concluded that increased adherence to the Planetary Health Diet was linked to a reduced risk of death from chronic diseases. However, this positive health outcome came with environmental trade-offs. While PHD adherence led to reduced GHG emissions, it was also associated with increased land utilization and water footprints.
This study provides critical insights into the complex interplay between dietary choices, health outcomes, and environmental impacts. As global discussions around sustainable food systems continue to gain momentum, findings like these contribute valuable information for policymakers, health professionals, and individuals seeking to make informed decisions about their diets.
It emphasizes the need for balanced approaches that prioritize both human health and environmental sustainability in dietary recommendations.