Study: Avocados Change Belly Fat Distribution in Women

Liz Ahlberg Touchstone wrote . . . . . . . . .

An avocado a day could help redistribute belly fat in women toward a healthier profile, according to a new study from the University of Illinois Urbana-Champaign and collaborators.

One hundred and five adults with overweight and obesity participated in a randomized controlled trial that provided one meal a day for 12 weeks. Women who consumed avocado as part of their daily meal had a reduction in deeper visceral abdominal fat.

Led by Naiman Khan, an Illinois professor of kinesiology and community health, the researchers published their study, funded by the Hass Avocado Board, in the Journal of Nutrition.

“The goal wasn’t weight loss; we were interested in understanding what eating an avocado does to the way individuals store their body fat. The location of fat in the body plays an important role in health,” Khan said.

“In the abdomen, there are two kinds of fat: fat that accumulates right underneath the skin, called subcutaneous fat, and fat that accumulates deeper in the abdomen, known as visceral fat, that surrounds the internal organs. Individuals with a higher proportion of that deeper visceral fat tend to be at a higher risk of developing diabetes. So we were interested in determining whether the ratio of subcutaneous to visceral fat changed with avocado consumption,” he said.

The participants were divided into two groups. One group received meals that incorporated a fresh avocado, while the other group received a meal that had nearly identical ingredients and similar calories but did not contain avocado.

At the beginning and end of the 12 weeks, the researchers measured participants’ abdominal fat and their glucose tolerance, a measure of metabolism and a marker of diabetes.

Female participants who consumed an avocado a day as part of their meal had a reduction in visceral abdominal fat – the hard-to-target fat associated with higher risk – and experienced a reduction in the ratio of visceral fat to subcutaneous fat, indicating a redistribution of fat away from the organs. However, fat distribution in males did not change, and neither males nor females had improvements in glucose tolerance.

“While daily consumption of avocados did not change glucose tolerance, what we learned is that a dietary pattern that includes an avocado every day impacted the way individuals store body fat in a beneficial manner for their health, but the benefits were primarily in females,” Khan said. “It’s important to demonstrate that dietary interventions can modulate fat distribution. Learning that the benefits were only evident in females tells us a little bit about the potential for sex playing a role in dietary intervention responses.”

The researchers said they hope to conduct a follow-up study that would provide participants with all their daily meals and look at additional markers of gut health and physical health to get a more complete picture of the metabolic effects of avocado consumption and determine whether the difference remains between the two sexes.

“Our research not only sheds a valuable light on benefits of daily avocado consumption on the different types of fat distribution across genders, it provides us with a foundation to conduct further work to understand the full impact avocados have on body fat and health,” said study coauthor Richard Mackenzie, a professor of human metabolism at the University of Roehampton in London.

“By taking our research further, we will be able to gain a clearer picture into which types of people would benefit most from incorporating avocados into their diets and deliver valuable data for health care advisers to provide patients with guidance on how to reduce fat storage and the potential dangers of diabetes,” Mackenzie said.

Source: University of Illinois at Urbans-Champaign

Avocados are a Healthy Option Super Bowl Sunday and Year-round

Karina Ioffee wrote . . . . . . . . .

This Super Bowl Sunday, millions of Americans will reach for avocados to make guacamole, a standard go-to snack for game day. But that green goodness can offer plenty of other benefits that make them a heart-healthy food option year-round.

Rich, creamy and satiating, avocados travel well, are versatile in the kitchen and are packed with vitamins.

Just one avocado has high amounts of fiber, potassium, magnesium, folate, vitamin C and vitamin K. Research shows people who eat avocados are less likely to develop metabolic syndrome, a cluster of conditions that can increase the risk of heart disease, stroke and Type 2 diabetes.

Avocados also are an excellent source of monounsaturated fat, which can help promote a healthy blood lipid profile, a measure of types of fat in the blood. A 2015 study published in the Journal of American Heart Association found that eating one avocado a day as part of a moderate-fat diet resulted in lower “bad” LDL cholesterol.

“Avocados are definitely a food I would include in a heart-healthy dietary pattern because it’s rich in soluble fiber and healthier fats,” said Maya Vadiveloo, assistant professor of nutrition and food sciences at the University of Rhode Island in Kingston.

“If you replace calories in your diet that come from animal fats and tropical oil with sources of monounsaturated fat like avocados, you’re going to have many beneficial effects on cardiovascular health.”

Believed to have originated in Mexico, there are now hundreds of avocado varieties around the world, although Hass appears to be the most popular in the United States, where they are grown mostly in California, Florida and Hawaii. According to the Hass Avocado Board, an industry trade group, 69% of U.S. households, about 80 million, bought avocados in 2019.

Super Bowl fans in the U.S. are estimated to consume nearly 48,000 metric tons of avocados in guacamole form, according to Tridge, a global food and agriculture market analysis company. In one day, that’s more than half a month’s worth of avocado imports.

But avocados are not calorie-free. A medium avocado averages about 240 calories and 24 grams of fat, according to the California Avocado Commission. Yet, unlike red meat or cookies, avocados are a source of healthy fat that can be eaten in place of “bad” saturated fat in a typical diet.

The key, said Vadiveloo, is to enjoy avocados in moderation. “Avocados are a high-calorie food, so people do tend to avoid it instead of using it in a more portion-controlled way.”

In addition to guacamole, avocados can be slathered on toast or tossed into salads, smoothies, dressings, omelets and just about anything.

In recent years, growers have introduced the single portion avocado, which averages 160 calories and half the fat of a regular size avocado. That also helps reduce chances of spoilage, a problem with larger avocados that tend to brown when left uneaten for too long, Vadiveloo said.

Besides heart health, this delicious fruit – yes, it is a fruit – could have other benefits.

Avocados are high in carotenoids, the antioxidant plant pigments responsible for bright hues in fruit and vegetables. Studies show two of the carotenoids in avocados, lutein and zeaxanthin, could help reduce the risk of eye disease. Research also has shown adding avocados to other vegetables, say in a salad or salsa, helps the body absorb more nutrients.

So, go ahead and enjoy guacamole this Super Bowl Sunday, but don’t forget avocados the rest of the year too, albeit in moderation, Vadiveloo said.

“Nobody is saying have unlimited amounts of avocado in place of leafy greens, but if you supplement a salad with an avocado instead of bacon or cheese, it’s a healthier choice that keeps total energy balance in mind.”

Source: American Heart Association

An Avocado a Day Keeps Your Gut Microbes Happy

Marianne Stein wrote . . . . . . . . .

Eating avocado as part of your daily diet can help improve gut health, a new study from University of Illinois shows. Avocados are a healthy food that is high in dietary fiber and monounsaturated fat. However, it was not clear how avocados impact the microbes in the gastrointestinal system or “gut.”

“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,” says Sharon Thompson, graduate student in the Division of Nutritional Sciences at U of I and lead author on the paper, published in the Journal of Nutrition.

The researchers found that people who ate avocado every day as part of a meal had a greater abundance of gut microbes that break down fiber and produce metabolites that support gut health. They also had greater microbial diversity compared to people who did not receive the avocado meals in the study.

“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.”

The study included 163 adults between 25 and 45 years of age with overweight or obesity – defined as a BMI of at least 25 kg/m2 – but otherwise healthy. They received one meal per day to consume as a replacement for either breakfast, lunch, or dinner. One group consumed an avocado with each meal, while the control group consumed a similar meal but without the avocado. The participants provided blood, urine, and fecal samples throughout the 12-week study. They also reported how much of the provided meals they consumed, and every four weeks recorded everything they ate.

While other research on avocado consumption has focused on weight loss, participants in this study were not advised to restrict or change what they ate. Instead they consumed their normal diets with the exception of replacing one meal per day with the meal the researchers provided.

The purpose of this study was to explore the effects of avocado consumption on the gastrointestinal microbiota, says Hannah Holscher, assistant professor of nutrition in the Department of Food Science and Human Nutrition at U of I and senior author of the study.

“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.

Avocados are rich in fat; however, the researchers found that while the avocado group consumed slightly more calories than the control group, slightly more fat was excreted 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 have differential effects on the microbiome. The fats in avocados are monounsaturated, which are heart-healthy fats.

Soluble fiber content is also very important, Holscher notes. A medium avocado provides around 12 grams of fiber, which goes a long way toward meeting the recommended amount of 28 to 34 grams of fiber per day.

“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.

Eating fiber isn’t just good for us; it’s important for the 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.

Avocado is an energy-dense food, but it is also nutrient dense, and it contains important micronutrients that Americans don’t eat enough of, like potassium and fiber.

“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.

Source: The University of Illinois

Study: Daily Avocado Consumption Improves Attention in Persons with Overweight, Obesity

Liz Ahlberg wrote . . . . . . . . .

A diet including daily avocado consumption improves the ability to focus attention in adults whose measurements of height and weight are categorized as overweight or obese, a new randomized control trial found.

Researchers at the University of Illinois at Urbana-Champaign conducted the 12-week study, published in the International Journal of Psychophysiology.

“Previous work has shown that individuals with overweight and obesity are at higher risk for cognitive decline and dementia in older age,” said kinesiology and community health professor Naiman Khan, who led the study. “We are interested in whether dietary approaches may have benefits for cognitive health, especially in midlife.”

The Hass Avocado Board and the U.S. Department of Agriculture’s National Institute of Food and Agriculture supported this work.

Avocados are high in lutein, a dietary component associated with cognitive benefits. Though avocado consumption’s benefits have been studied in older adults and children, no randomized controlled trials had studied its cognitive effects on adults with overweight or obesity, despite 70% of the American adult population falling into that category, said graduate student Caitlyn Edwards, the first author of the study.

In the new study, the researchers provided 12 weeks of daily meals to 84 adults with overweight or obesity. The meals were identical in calories and macronutrients, but one group’s meals included a fresh avocado every day, while the control group had no avocado in their meals.

At the beginning and end of the study, the participants completed three cognitive tests to measure attention and inhibition. In addition, the researchers measured lutein levels in the participants’ serum and in their retinas, which is associated with the lutein concentration in the brain.

They found that the participants whose diets included avocados improved their performance on one of the cognitive tests, called the Flanker task, which measures attentional inhibition – the ability to maintain focus on the task at hand even in the face of distraction. However, there was no difference in the other two cognitive tests.

“It could be that nutrients in avocados have a specific action in the brain that supports the ability to do this task in particular, or they could be more beneficial for certain cognitive abilities over others,” Khan said. “It’s also possible that with a longer study or different tests, we could see other effects. Other studies have found broader effects in other populations, so it is interesting to see a more specific benefit for this population.”

Another unexpected finding was that, while the participants who ate avocados had higher levels of lutein at the end of the study, the changes in lutein levels were not correlated with their cognitive changes.

“Avocados also are high in fiber and monounsaturated fats. It is possible that these other nutrients may have played a role in the cognitive effects we saw, but we focused on the lutein in our analyses,” Edwards said. “Future analyses may focus on other nutrients found in avocados, or avocado consumption’s impact on other measures such as weight status, inflammation and potential changes in the microbiome.”

Although this study focused on avocados, other dietary sources of lutein, fiber and unsaturated fats – such as green leafy vegetables or eggs – also have potential cognitive and health benefits. The researchers say their study shows that small dietary changes, such as eating avocados, can have measurable impacts on cognitive performance, even when other health behaviors remain the same.

“Our mission is to give people options. There are multiple ways people can eat to optimize brain health,” Khan said. “What we’re learning is that avocados may be one of those fruits that may be neuroprotective in certain ways. This work provides some evidence behind one option people have from a plethora of healthful foods that we can consume.”

Source: University of Illinois at Urbana-Champaign

One Avocado a Day Helps Lower ‘Bad’ Cholesterol for Heart Healthy Benefits

katie Bohn wrote . . . . . . . . .

Move over, apples — new research from Penn State suggests that eating one avocado a day may help keep “bad cholesterol” at bay.

According to the researchers, bad cholesterol can refer to both oxidized low-density lipoprotein (LDL) and small, dense LDL particles.

In a randomized, controlled feeding study, the researchers found that eating one avocado a day was associated with lower levels of LDL (specifically small, dense LDL particles) and oxidized LDL in adults with overweight or obesity.

“We were able to show that when people incorporated one avocado a day into their diet, they had fewer small, dense LDL particles than before the diet,” said Penny Kris-Etherton, distinguished professor of nutrition, who added that small, dense LDL particles are particularly harmful for promoting plaque buildup in the arteries. “Consequently, people should consider adding avocados to their diet in a healthy way, like on whole-wheat toast or as a veggie dip.”

Specifically, the study found that avocados helped reduce LDL particles that had been oxidized. Similar to the way oxygen can damage food — like a cut apple turning brown — the researchers said oxidation is also bad for the human body.

“A lot of research points to oxidation being the basis for conditions like cancer and heart disease,” Kris-Etherton said. “We know that when LDL particles become oxidized, that starts a chain reaction that can promote atherosclerosis, which is the build-up of plaque in the artery wall. Oxidation is not good, so if you can help protect the body through the foods that you eat, that could be very beneficial.”

While previous research demonstrated that avocados could help lower LDL cholesterol, Kris-Etherton and her colleagues were curious about whether avocados could also help lower oxidized LDL particles.

The researchers recruited 45 adult participants with overweight or obesity for the study. All participants followed a two-week “run-in” diet at the beginning of the study. This diet mimicked an average American diet and allowed all participants to begin the study on similar nutritional “footing.”

Next, each participant completed five weeks of three different treatment diets in a randomized order. Diets included a low-fat diet, a moderate-fat diet, and a moderate-fat diet that included one avocado a day. The moderate-fat diet without avocados were supplemented with extra healthy fats to match the amount of monounsaturated fatty acids that would be obtained from the avocados.

After five weeks on the avocado diet, participants had significantly lower levels of oxidized LDL cholesterol than before the study began or after completing the low- and moderate-fat diets. Participants also had higher levels of lutein, an antioxidant, after the avocado diet.

Kris-Etherton said there was specifically a reduction in small, dense LDL cholesterol particles that had become oxidized.

“When you think about bad cholesterol, it comes packaged in LDL particles, which vary in size,” Kris-Etherton said. “All LDL is bad, but small, dense LDL is particularly bad. A key finding was that people on the avocado diet had fewer oxidized LDL particles. They also had more lutein, which may be the bioactive that’s protecting the LDL from being oxidized.”

The researchers added that because the moderate-fat diet without avocados included the same monounsaturated fatty acids found in avocados, it is likely that the fruit has additional bioactives that contributed to the benefits of the avocado diet.

Kris-Etherton said that while the results of the study — published in the Journal of Nutrition — are promising, there is still more research to be done.

“Nutrition research on avocados is a relatively new area of study, so I think we’re at the tip of the iceberg for learning about their health benefits,” Kris-Etherton said. “Avocados are really high in healthy fats, carotenoids — which are important for eye health — and other nutrients. They are such a nutrient-dense package, and I think we’re just beginning to learn about how they can improve health.”

Source: Penn State