Avocados aren’t exactly every-day fare for most Americans. Most people think of guacamole and other Mexican or Southwestern dishes in relation to them. They’re far more versatile than that, however, and new research suggests that finding more ways to get them in our diets may benefit gut health.
Avocados are most often considered vegetables, but they are actually rich and healthy fruits. They’re high in monounsaturated fat and dietary fiber, a fairly unique combination in the food world. Now, a new research study from the University of Illinois has found that eating avocados can improve your gut health. The findings were published in the Journal of Nutrition.
However, Sharon Thompson, lead author on the paper and a graduate student in the Division of Nutritional Sciences at Illinois, said the research didn’t illustrate the mechanism responsible for the improvement.
“We know eating avocados helps you feel full and reduces blood cholesterol concentration, but we did not know how it influences the gut microbes, and the metabolites the microbes produce,” said Thompson.
Overall, people who consumed avocado daily in their meals had a more diverse microbiome (community of gut microbes,) than those in the study who did not consume avocados daily. The researchers also found that the daily avocado eaters had far more of the gut microbes that break down fiber and produce metabolites supportive of gut health.
“Microbial metabolites are compounds the microbes produce that influence health,” Thompson says. “Avocado consumption reduced bile acids and increased short chain fatty acids. These changes correlate with beneficial health outcomes.”
163 overweight or obese adults (BMI at least 25kg/m2) ate one control meal per day, replacing either breakfast, lunch or dinner. One group ate an avocado at each of those meals, the other did not. All participants were between 25 and 45 years old.
They reported how much of each replacement meal they finished. They also recorded everything they ate every four weeks. Their blood, urine and fecal samples were taken throughout the 12-week study period.
Previous research has looked for connections between eating avocados and weight loss. For this study, however, participants were not asked to restrict calories or change their eating habits, with the exception of the replacement meals provided in the study.
Hannah Holscher, assistant professor of nutrition in U of I’s Department of Food Science and Human Nutrition, said this study’s sole purpose was to explore the impact of eating avocados on gut micriobiota.
“Our goal was to test the hypothesis that the fats and the fiber in avocados positively affect the gut microbiota. We also wanted to explore the relationships between gut microbes and health outcomes,” Holscher says.
It’s well-known that avocados are high in fat. This caused the group eating them with their replacement meals to eat more calories than the control group. Researchers noted, however, that they also excreted more fat in their stool.
“Greater fat excretion means the research participants were absorbing less energy from the foods that they were eating. This was likely because of reductions in bile acids, which are molecules our digestion system secretes that allow us to absorb fat. We found that the amount of bile acids in stool was lower and the amount of fat in the stool was higher in the avocado group,” Holscher explains.
Different types of fats affect the gut microbiome differently. The fat in avocados is heart-healthy monounsaturated fat. Equally or more important, as Holscher notes, soluble fiber is important to gut health. You’ll find 12 grams of fiber in a medium-sized avocado. With the recommended fiber consumption being 28 to 34 grams a day, avocados can help you reach that goal.
“Less than 5% of Americans eat enough fiber. Most people consume around 12 to 16 grams of fiber per day. Thus, incorporating avocados in your diet can help get you closer to meeting the fiber recommendation,” she notes.
Getting enough fiber is not just good for you, it’s crucial for your gut microbiome, too, Holscher states. “We can’t break down dietary fibers, but certain gut microbes can. When we consume dietary fiber, it’s a win-win for gut microbes and for us.”
Holscher’s research lab specializes in dietary modulation of the microbiome and its connections to health. “Just like we think about heart-healthy meals, we need to also be thinking about gut healthy meals and how to feed the microbiota,” she explains.
Avocados aren’t just good for making guacamole. They’re energy (calorie) dense and full of important micronutrients like fiber and potassium.
“It’s just a really nicely packaged fruit that contains nutrients that are important for health. Our work shows we can add benefits to gut health to that list,” Holscher says.
Apparently, avocados are not just for guacamole anymore! Try using them to make salad dressings or even grill up some slices. You can find lots of recipes pretty easily. Try some and make your gut microbes happy!
Keep the faith and keep after it!
Journal Reference – Sharon V Thompson, Melisa A Bailey, Andrew M Taylor, Jennifer L Kaczmarek, Annemarie R Mysonhimer, Caitlyn G Edwards, Ginger E Reeser, Nicholas A Burd, Naiman A Khan, Hannah D Holscher. Avocado Consumption Alters Gastrointestinal Bacteria Abundance and Microbial Metabolite Concentrations among Adults with Overweight or Obesity: A Randomized Controlled Trial. The Journal of Nutrition, 2020; DOI: 10.1093/jn/nxaa219