Plant-based diets often surface as a healthy choice, and a new real-world study offers some interesting insights into why that might be true.
This research focused on 200 healthy individuals from Thessaloniki, Greece, who avoid meat, fish, dairy, and eggs—essentially adopting a vegan diet—for about 180-200 days each year. It’s tied to a religious practice within Orthodox Christianity.
These Orthodox Christians engage in fasting every Wednesday and Friday, alongside four extended fasting periods throughout the year.
These include 40 days before Christmas, 48 days leading up to Easter (Lent), a range of 8 to 42 days during the Apostles’ Fast, and another 15 days in August for the Assumption of the Virgin Mary.
“This dietary pattern is motivated by religious beliefs and is usually part of the culture people are born into,” noted biostatistician Alexandros Simistiras and his team in a publication in Nature Communications.
They pointed out that during these times of reduced animal products, there’s a significant decrease in animal fat consumption, along with changes in protein intake—all without cutting down on total calories.
From their standpoint, this religious fasting tradition creates a unique environment for analyzing how diet influences gene activity.
“The consistency of this eating pattern allows for comparisons similar to dietary intervention studies,” Simistiras’ team explained.
To provide a comparison, researchers also included 211 participants from the same region who do not adhere to these dietary rules.
The results showed notable changes in body chemistry, particularly in levels of gene expression.
The scientists had previously identified that this tradition led to “extensive metabolic reprogramming, typically producing beneficial health effects, including changes in key immunometabolic proteins, such as the metabolic hormone FGF21.”
What was newly uncovered was that participants practicing the meat-free fast who possessed a specific genetic variant that affects FGF21 levels showed potential physiological signs connected to a process known as adipose tissue beiging. In simpler terms, this means that energy-storing white fat cells could begin to behave more like brown fat cells, which are often burned for heat.
“These findings may suggest that diet-induced FGF21 levels could influence the human process of adipose tissue beiging,” the authors remarked.
Another gene variant linked to regulating a protein essential for cholesterol biosynthesis also exhibited changes after eliminating meat from the diet within just a few weeks.
This same genetic variant seemed to be related to another effect associated with obesity.
“The upregulation of LBR might serve as a compensatory response to the lower cholesterol intake during times of reduced animal product consumption,” the authors observed.
This highlights the intricate relationship between diet and genetics in relation to obesity.
“Those carrying this genetic variant might have a slight advantage against obesity while practicing dietary restrictions,” the authors explained.
“This could help clarify why individuals following similar diets experience different obesity risks, shedding light on the mechanisms that influence dietary differences in disease risk.”
In the end, the study opens up numerous avenues for future research into the complex interactions between diet, genetics, and metabolic health.
It seems that even a short period of avoiding meat and dairy can lead to significant changes.
The findings were published in Nature Communications.
