Guacamole lovers take note: Eating avocados daily along with a healthy diet may be good for your heart, new research found.
Those who ate an avocado along with a cholesterol-lowering, moderate-fat diet reduced their so-called “bad” cholesterol by 10 percent compared with people on an average American diet, according to an industry-funded study today in the Journal of the American Heart Association.
Consumers sometimes shy away from the fruit because they are high in calories. Yet eating an avocado, which contains about 200 calories, instead of the average 180 calories in desserts Americans consume daily helps replace saturated fats that can raise heart attack and stroke risks with healthier unsaturated fats, said senior study author Penny Kris-Etherton.
“Even though 200 calories is an appreciable amount, there certainly is room in the U.S. diet for these nutrient-dense foods that are high in calories if Americans take out all those empty calories they are eating,” Kris-Etherton, a professor of nutrition at Pennsylvania State University in State College, said in a telephone interview. “If you’re going to have a diet high in mono-unsaturated fats, include some avocados.”
It’s unclear why cholesterol was lowered in those who consumed avocados, she said. Researchers are uncertain if the benefit is unique to the avocado or if it’s similar to the heart-healthy effects seen in nuts and other plant foods.
Today’s study, the first to examine the avocado’s benefit on heart health, was funded by the Hass Avocado Board, which didn’t have a role in the design of the study, the interpretation of the data or approval of the paper, the authors said. Kris-Etherton, head of the American Heart Association’s Nutrition Committee, is also a member of Hass’s Avocado Nutrition Science Advisors group.
Researchers in the study included 45 people ages 21 to 70 who were overweight or obese yet otherwise healthy. For two weeks, they consumed an average American diet with about a third of calories coming from fat. They were then assigned to one of three cholesterol-lowering diets -– a moderate-fat diet with and without a daily avocado where 34 percent of calories came from fat, including 17 percent from mono-unsaturated fats, and a low-fat diet where 24 percent of calories came from fat, including 11 percent from mono-unsaturated fats.
After five weeks on the moderate-fat or low-fat diets, the researchers compared participants’ cholesterol levels. They found that those on the moderate-fat diet who ate an avocado daily benefited the most in lowering their low-density lipoprotein (LDL), or bad cholesterol. Those on the moderate-fat diet that didn’t eat an avocado daily reduced their LDL cholesterol by 5.8 percent, while those on the low-fat diet lowered it by 5.3 percent, Kris-Etherton said.
Hass avocados, which are the most commonly eaten variety in the U.S., were used in the study. They have bumpy green skin that turns black as it ripens. They differ from Florida avocados, which are larger and smoother.
More than 1.85 billion pounds of Hass avocados were consumed in the U.S. last year, up 10 percent from 2013 and almost triple from 2004, according to Emiliano Escobedo, executive director of the Irvine, California-based Hass Avocado Board, in an e-mail.
Avocados aren’t a mainstream food in the U.S., and they can be expensive, especially at certain times of the year, Kris-Etherton said.
“Most people do not really know how to incorporate them in their diet except for making guacamole,” which is typically eaten with calorie- and sodium-laden corn chips, Kris-Etherton said.
She recommended eating the fruit with salads, vegetables, sandwiches, lean protein foods or by itself.
This story about the LDL-lowering properties of avocados included significant detail on the cost of avocados, something lacking from competing stories that we reviewed. However, it didn’t get to the bottom of what the findings mean for consumers. If they follow the advice suggested in the story — eating an avocado a day — how is that likely to affect their risk of a heart attack or stroke? The headline and first sentence state that eating avocados may be good for the heart. How do we know that?
Obesity and cardiovascular disease are reaching near epidemic proportions in the United States, and the average American diet is a major contributing factor. The study reported on here suggests that modest changes in diet could have important public health implications. It found about a 10% reduction in LDL cholesterol when participants ingested a moderate-fat diet with the addition of an avocado. That’s roughly half the LDL cholesterol drop seen with the starting dose of one of the statins.
The story provides both qualitative and quantitative information on the costs of avocados. “Avocados aren’t a mainstream food in the U.S., and they can be expensive, especially at certain times of the year, Kris-Etherton said.” Retail prices for Hass avocados rose to an average $1.25 each as of Dec. 19, up from $1.23 a year earlier, according to the U.S. Department of Agriculture.” Competing stories lacked this information.
The story notes: “Those who ate an avocado along with a cholesterol-lowering, moderate-fat diet reduced their so-called “bad” cholesterol by 10 percent compared with people on an average American diet, according to an industry-funded study today in the Journal of the American Heart Association.” But how big is this 10% drop in terms of the LDL scores that many readers are familiar with? The story doesn’t say. The story also doesn’t provide any sense of what the decrease means in terms of an individual’s risk of heart attack or stroke. Those are the outcomes that people should care about most.
The story does suggest that consumers will need to take some nutrient-poor foods out of their diets if they’re going to accommodate increased consumption of high-calorie avocados. That addresses the main concern associated with more avocado intake — weight gain.
The story provides a good description of the study and the participants. But that’s where it ends. How strong was the study design? What are its limitations? How important is the 10% reduction in LDL? What are the implications to reducing cardiovascular risk? The story would have to do more here to earn a satisfactory rating.
No disease mongering here.
We aren’t provided with an independent source of information in the story, and therefore we’ll rate this unsatisfactory. Unlike the competing Medical News Today story, however, Bloomberg clearly spoke to one of the study authors and didn’t rely entirely on a press release. In addition, the authors’ potential conflicts of interest are noted including participation in Hass’s Avocado Nutrition Science Advisors group.
The story notes that it’s uncertain if the benefits seen are “unique to the avocado or if it’s similar to the heart-healthy effects seen in nuts and other plant foods.” We’ll call this nod in the direction of alternatives sufficient for a satisfactory. However, given the ubiquity of statin drugs, we would have liked to have seen some comparison of the effects seen in this study with those attained via statin therapy. An independent expert could have easily provided that information had the story consulted one.
The story makes it clear that avocados are indeed available and provides pricing information to boot. We would have liked to have seen some acknowledgment that there are areas where avocados may be more difficult to find.
The role of avocados in the lowering of total and LDL cholesterol has been studied previously. The author lists several notable studies in the reference list of the article. Several parts of the study including the methods of determining the changes in the various forms of LDL cholesterol were novel. However these were not highlighted in the story.
One of the study researchers is interviewed, so we can be certain the story wasn’t based entirely on a news release.