Study Highlights Bioavailability Gap in Oilseeds
A recent study conducted at the Federal University of São Paulo (UNIFESP) in Brazil has shed light on the nutritional limitations of nuts, revealing that the presence of essential minerals in oilseeds does not guarantee their absorption by the human body. Published in the journal Química Nova, the research focused on Brazil nuts (Bertholletia excelsa) and cashews (Anacardium occidentale), two widely consumed nuts in Brazil, to evaluate the bioavailability of key minerals during simulated digestion.
Bioavailability, as defined by the researchers, is the fraction of a mineral that is actually released during gastrointestinal digestion and potentially available for absorption. The study underscores a critical distinction between the total mineral content of a food and the amount that the body can actually use.
Methodology: Simulating Human Digestion
The research team, led by chemist and associate professor Angerson Nogueira do Nascimento, employed an in vitro gastrointestinal digestion assay to mimic the conditions of the human digestive tract. This approach allowed them to assess the bioaccessibility of four essential minerals: copper, magnesium, manganese, and zinc. These minerals play vital roles in the body, from red blood cell formation and immune function to bone health and antioxidant defense.
After selecting samples of Brazil nuts and cashews, the scientists first determined the total concentration of these minerals. They then subjected the nuts to simulated gastric and intestinal digestion, measuring how much of each mineral was released and potentially available for absorption.
Key Findings: Only Partial Release
The results indicated that the total mineral content in nuts does not equate to what the body can absorb. For instance, while Brazil nuts are known for being rich in selenium, the study focused on copper, magnesium, manganese, and zinc. The digestion process released only a portion of these minerals, with some being more bioaccessible than others. The researchers highlighted that factors such as the food matrix, the presence of fiber and phytates, and the specific conditions of the digestive tract can significantly influence mineral release.
Professor Nascimento emphasized the importance of this line of research: "The line of research I've been developing focuses on evaluating the actual nutritional value of the minerals present in the diet. In this context, we study foods of great economic importance in Brazil. Our group not only determines the total quantity of elements present in foods, but also uses assays that simulate gastric and intestinal digestion processes on those samples."
Implications for Nutrition and Health
These findings have important implications for dietary recommendations and nutritional science. Many people consume nuts as a healthy snack, believing they are getting a full dose of minerals. However, this study suggests that the actual nutritional benefit may be lower than expected. The researchers call for a more nuanced understanding of food composition, moving beyond total mineral content to consider bioavailability.
The study also points to potential strategies to enhance mineral absorption, such as processing methods (soaking, roasting) or combining nuts with other foods that can improve bioavailability. For example, vitamin C is known to enhance iron absorption, and similar interactions may exist for the minerals studied.
Future Research Directions
The UNIFESP team plans to expand their research to other oilseeds and food matrices, as well as to investigate the effects of different processing techniques on mineral bioaccessibility. They also aim to explore the impact of individual digestive health on nutrient absorption, as variations in gut microbiota and digestive enzyme activity can further influence bioavailability.
This study serves as a reminder that the nutritional value of food is not solely determined by its composition but also by how the body processes it. As the field of nutritional science advances, such insights will help refine dietary guidelines and improve public health outcomes.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
