In an article published in the journal Nutrients, scientists have described the effectiveness of a specific diet containing fruit, avocado, whole grains, and trout in controlling inflammation and oxidative stress in obese individuals.

Study: Effect of 8-Week Consumption of a Dietary Pattern Based on Fruit, Avocado, Whole Grains, and Trout on Postprandial Inflammatory and Oxidative Stress Gene Expression in Obese People. Image Credit: Natalia Lisovskaya/Shutterstock

Background

Obesity and being overweight have become public health issues worldwide. According to recent estimates, more than 1.9 billion people are overweight globally, which includes over 650 million with obesity. Obesity increases the risk of cardiovascular disease and metabolic diseases, including diabetes and cancer.

Functional impairment of adipose tissue in obese people is associated with the induction of a chronic low-grade inflammatory state, which in turn is responsible for developing chronic diseases.

Strict adherence to a healthy lifestyle, including a healthy diet and daily physical activity, is the key to managing body weight. The Mediterranean diet and the Nordic diet are examples of healthy diets that are known to reduce obesity-related inflammation and oxidative stress.

In the current study, scientists have evaluated the impact of fruit, avocado, whole grains, and trout-based diet on postprandial expression of inflammation- and oxidative stress-related genes in obese people residing in Colombia.

Study design

A total of 44 obese individuals (body mass index: > 30 kg/m²) without diagnosed chronic diseases were enrolled in the study. Of all participants, 25 followed the experimental diet, and 19 followed the control diet for eight weeks.

The experimental diet was composed of predominant foods of the Colombian coffee-growing zone, including fruits, avocados, whole grains, and trout. The control diet was composed of food items usually consumed by participants daily, including high-saturated fat foods, processed carbohydrates, and low-fiber foods.

Upon completion of the dietary intervention, the postprandial expression of inflammation- and oxidative stress-related genes (NFKB1, RELA, IKKA, MMP9, TNF, IL1β, IL6, and NFE2L2) was measured 0-4 hours after meal intake.  

Important observations

The assessment of various clinical parameters of the participants after eight weeks of dietary intervention revealed a significant reduction in body weight and body mass index (BMI) in individuals following the experimental diet. No such effect was observed among individuals following the control diet.

Inflammation- and oxidative stress-related gene expression

The real-time polymerase chain reaction (RT-PCR) based assessment of postprandial gene expression revealed that the experimental diet significantly reduces the expression of three inflammation-related genes, including nuclear factor kappa B subunit 1 (NFKB1), interleukin 6 (IL6), and IL1β.

Regarding oxidative stress-related genes, a significant reduction in nuclear factor erythroid-derived 2-like 2 (NFE2L2) expression was observed after the 8-week experimental diet intervention. No such effect was observed following the control diet.

Comparison analysis

The study compared the expression levels of tested genes with various biochemical parameters.

A significant positive correlation was observed between the NFKB1 expression and blood triglyceride level 4 hours post-meal among individuals following the experimental diet. Among participants in the control diet group, a significant positive correlation was observed between the IL1β expression and blood insulin level 4 hours post-meal.

Study significance    

The study highlights the importance of a healthy diet in reducing obesity-related inflammation and oxidative stress through gene expression regulation. The dietary intervention studied here is rich in typical fruits from the Colombian coffee region, avocado, whole grains, and trout.

As mentioned by the scientists, specific nutrients in the diet, including healthy fatty acids from avocado and trout, might have direct effects on transcription factors that control the expression of obesity-related genes.

Fruits included in the studied diet are a rich source of vitamins and phenolic compounds. Antioxidant properties of these nutrients might have a direct beneficial impact on oxidative stress-related gene expressions.  

Overall, the study indicates that consuming a diet based on fruit, avocado, whole grains, and trout for eight weeks could be beneficial in controlling obesity-related complications.  

Journal reference:

• Diana María Muñoz-Pérez. (2023). Effect of 8-Week Consumption of a Dietary Pattern Based on Fruit, Avocado, Whole Grains, and Trout on Postprandial Inflammatory and Oxidative Stress Gene Expression in Obese People. Nutrients. https://www.mdpi.com/2072-6643/15/2/306 doi: https://doi.org/10.3390/nu15020306