Climate-based variability in the essential fatty acid composition of soybean oil

Authors: Bukowski, Michael; Goslee, Sarah

Submitted to: The American Journal of Clinical Nutrition
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2023
Publication Date: 11/30/2023
Citation: Bukowski, M.R., Goslee, S.C. 2023. Climate-based variability in the essential fatty acid composition of soybean oil. The American Journal of Clinical Nutrition. 119:1. https://doi.org/10.1016/j.ajcnut.2023.08.024.
DOI: https://doi.org/10.1016/j.ajcnut.2023.08.024

Interpretive Summary: Predicting the impact of climate change on human nutrition is challenging because most studies focus on yield, which is easier to measure than nutritional content. Focusing on the essential fatty acid content in the American diet, which is largely derived from soybean oil, we built a model from publicly available data linking daytime high temperature to essential fatty acid content in soybeans. We applied this model to climate data across the United States over a 6-year period and showed significant decreases in essential fatty acid content with higher daytime high temperatures, specifically in a-linolenic acid (ALA). This model was combined with yield data to formulate three model oils that demonstrated that oil from higher temperature climates may have diminished ALA content which would put many people at risk of insufficient intake of this nutrient. This model appears to be the first of its kind, and we discuss in this paper how it can be improved to provide better insight to stakeholders in nutrition and industry.

Technical Abstract: Soybean oil is a major source of linoleic and a-linolenic acid in the American diet, but concentration of these essential fatty acids may vary with changing climate. We modeled this change using 233 data points from 16 studies providing fatty acid composition data with daytime high temperatures ranging from 15 °C to 40 °C. Over this range linoleic and a-linolenic acid decreased from 55 to 30 g/ 100 g oil and 13 to 3.5 g/ 100 g oil. Application of the model to daytime high temperatures from two different growth periods over a six-year period showed significant (p<0.05) regional, inter-year, and intra-year variation in essential fatty acid content. Using national yield data, we developed model oils based upon three top producing regions of the United States and showed that climate-based variation may result in many populations not achieving adequate daily intake of a-linolenic acid.