A new study conducted by researchers from Northwestern University explored the health benefits and risks of a popular health habit – juice cleanses.
While many consumers try to consume only fruit and vegetable juices for a few days as a means of improving their health or losing weight, the researchers found that there are some health risks to consider.
Their work found that after just three days of juicing, consumers can negatively impact their gut health and mouth bacteria in significant ways.
“Most people think of juicing as a healthy cleanse, but this study offers a reality check,” senior author Dr. Melinda Ring said in a news release.
“Consuming large amounts of juice with little fiber may lead to microbiome imbalances that could have negative consequences, such as inflammation and reduced gut health.”
A look at the study
To determine how juice cleanses can affect consumers’ health, the researchers had 14 adult participants follow one of three diets for three days – one group consumed only juice, one group had juice and whole foods, and a third group ate only plant-based foods.
The researchers checked several metrics to understand how the diets impacted the participants’ health – stool samples, saliva samples, and inner cheek swabs. They did this at several different intervals – before the study started, after a pre-study elimination diet, after the three-day diets, and two weeks after the diets.
The results
Ultimately, the study revealed that participants that only consumed juice for three days fared the worst in terms of health compared to the other two groups.
In their gut and saliva samples, the researchers found that these participants had higher levels of bacteria that could increase the risk of inflammatory conditions, cardiovascular disease, colorectal cancer, periodontal disease, and gingivitis, as well as negatively affect gut permeability.
When looking at the other two groups, these changes weren’t evident. The group that had both juice and whole food had slight changes to their bacterial make-up, while the plant-based foods group experienced positive changes to their bacterial make-up.
The researchers also explained that the nutritional make-up of the juices affected the participants’ health. The results showed that consuming only juice was associated with an excess of a bacteria known as Bacteroides, which prevents the body from processing fiber. With less fiber, the participants produced higher levels of bacteria that produce sugar – Proteobacteria.
With these important nutrient levels thrown off, it can create havoc on both the gut and oral microbiome, which leads to subsequent health concerns.
“If you love juicing, consider blending instead to keep the fiber intact, or pair juices with whole foods to balance the impact on your microbiome,” Dr. Ring suggested in the news release.