Study subjects who agreed to eat an avocado a day showed marked improvement in their overall diet quality by increasing their consumption of other healthier foods. Some previous studies have highlighted the health benefits of avocados, but this is the first to show that eating one every day improved the rest of the consumer’s overall diet.
“Avocados are a nutrient-dense food, containing a lot of fiber and other important nutrients,” explained Kristina Petersen, associate professor of nutritional sciences at Penn State University (PSU). “We wanted to see if regular intake of this food would lead to an increase in diet quality,”
To test their hypothesis, Petersen and fellow researcher Penny Kris-Etherton, a retired Evan Pugh University Professor of Nutritional Sciences, recruited 1,008 participants and split them into two distinct groups. The first was asked to eat as they normally would while keeping their overall avocado consumption to a minimum. The second group was tasked with eating an avocado a day but otherwise were not instructed to make overt changes to their diet or lifestyle.
Because only about 2% of Americans eat an avocado a day, the researchers wondered if doing so would have a measurable effect on the rest of their diet.
“Previous observational research suggests avocado consumers have higher diet quality than non-consumers,” said Petersen. “So, we developed this study to determine if there is a causational link between avocado consumption and overall diet quality.”
After a 26-week trial period, the researchers reached out to all of the participants individually to determine the results. This involved asking each participant what they had eaten in the previous 24 hours. Responses were gauged against the Healthy Eating Index, which measures how closely they adhered to the Dietary Guidelines for Americans. Closer adherence to these guidelines was considered an increase in overall diet quality. The results were measurably positive.
“We found that the participants who had an avocado per day significantly increased their adherence to dietary guidelines,” Petersen said. “This suggests that strategies, like eating one avocado per day, can help people follow dietary guidelines and improve the quality of their diets.”
While many nutritionists cite avocados’ health benefits, including their high levels of fiber, vitamins, protein, and “good” fat, the researchers found the improvement in the rest of the diet to be even more significant. Switching to an avocado-a-day regimen not only improved the amount of produce consumed on its own, but it also appeared to replace significantly less healthy foods. In effect, the avocado addition had two distinct benefits that improved overall diet quality.
“We determined that participants were using avocados as a substitute for some foods higher in refined grains and sodium,” Petersen said. “In our study, we classified avocados as a vegetable and did see an increase in vegetable consumption attributed to the avocado intake, but also participants used the avocados to replace some unhealthier options.”
According to the study’s published results, this type of measurable change should help dieters improve or even avoid bad health outcomes associated with poor diets. This includes diet-related conditions like heart disease, type 2 diabetes, and kidney disease, just to name a few.
Along with the avocado-a-day diet, Petersen was involved in previous research that showed benefits from regular consumption of pistachios. Moving forward, the researchers say they are hoping to explore even more foods that may have the unexpected benefit of improving the overall quality of one’s diet.
“In studies like this one, we are able to determine food-based ways to improve diet quality, but behavioral strategies are also needed to help people adhere to dietary guidelines and reduce their risk of chronic disease,” Petersen said.
Christopher Plain is a Science Fiction and Fantasy novelist and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him directly at christopher@thedebrief.org.