Researchers from Texas A&M University and elsewhere have assessed the biochemical, histological and molecular effects of whole pecans (Carya illinoinensis) and pecan phenolic extracts on the development of early and late alterations in metabolic organs of mice through a preventive strategy and an interventionary one.
Pecans (Carya illinoinensis) are considered a functional food due to the high content of polyunsaturated fatty acids, dietary fiber and polyphenols. Image credit: Tseiu.
Obesity is the major risk factor for metabolic syndrome, characterized by glucose intolerance, hepatic fat accumulation and increased circulating lipids and which if left untreated leads to chronic diseases such as cardiovascular diseases and type 2 diabetes mellitus.
Several underlying causes of the metabolic derangements during obesity have been proposed, including adipose tissue dysfunction, increased hepatic lipogenesis, reduced skeletal muscle mitochondrial content and activity and microbiota dysbiosis (altered microbial diversity and composition).
However, the temporal appearance and the prominence of each of these metabolic alterations is still not clear.
The U.S. and Mexico are two of the countries with the highest rates of obesity worldwide.
In average obesity prevalence among U.S. adults was ~42.4% in the period 2017–2018 in both men and women and overall estimated projections of ~50% adults by 2030.
Similarly, in Mexico it was reported that >30% of the adult population was obese by 2018 with estimated projections of ~54% and 37% for men and women by 2050.
These numbers, and the fact that in both countries cardiovascular disease and type 2 diabetes are the leading cause of mortality, demand an intensification of efforts in studying the mechanism that leads from obesity to metabolic syndrome in order to develop novel preventive and therapeutic strategies to prevent these diseases.
One of these strategies comprises the consumption of functional foods containing beneficial bioactive compounds such as fruits, vegetables, grains and nuts as part of the regular diet that could potentially exert health-promoting effects against the metabolic syndrome.
Pecan nuts originally from the US and Mexico have received much attention due to their unique chemistry of condensed and hydrolysable tannins, polyunsaturated fatty acids and high antioxidant levels, as well as to clinical studies showing a decrease in LDL oxidation, LDL cholesterol lowering effects, and improvement of cardiometabolic risk factors.
However, these studies were based on a limited dose range of ~42-90 g pecan/day, which corresponds to the FDA recommended daily consumption of nuts of 42.5 g or approximately twice this amount.
“Obesity and diabetes numbers are increasing in modern society worldwide, and the trend in high fat diet consumption is one of the main reasons besides lifestyle and genetic predisposition,” said Texas A&M University’s Professor Luis Cisneros-Zevallos, senior author of the study.
“People are searching for healthier options, and we have now shown pecans are a healthy tool consumers have in their hands.”
The study authors applied pecans and high fat diets to mice models and found that pecans increased energy expenditure and reduced dysbiosis and inflammation.
They confirmed that pecans modulate adipose tissue lipolysis and mitochondrial oxidative metabolism in liver and skeletal muscle.
The anti-inflammatory properties of pecans reduced low-grade inflammation that leads to chronic inflammation and the development of a range of prevalent diseases.
This also shows pecans maintain body weight and prevent diabetes despite consuming a high fat diet.
The new functionality can make pecans a superfood, which can be consumed directly or utilized in the growing markets of functional foods and dietary supplements.
“This observation is key when designing strategies for studies, the more we know of unique functionalities of pecans, the more possibilities to create healthier products,” Professor Cisneros-Zevallos said.
“Pecans are of economic and historical importance to Texas and the U.S., and their production provides stability to farmers.”
“This work will aid in the development of novel uses and products from pecans.”
The study is published in the journal Nutrients.
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Claudia Delgadillo-Puga et al. 2023. Pecans and Its Polyphenols Prevent Obesity, Hepatic Steatosis and Diabetes by Reducing Dysbiosis, Inflammation, and Increasing Energy Expenditure in Mice Fed a High-Fat Diet. Nutrients 15 (11): 2591; doi: 10.3390/nu15112591
