Flashback Friday: The Effects of Avocados on Inflammation

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Studies on Avocados and Inflammation

In the preface of How Not to Die, after bemoaning the fact that I never got taken out to dinner by “Big Broccoli,” I wrote that you’ll never probably see an ad on TV for whole natural foods, because there’s just not much of a markup. They’re not shelf-stable, you can’t brand them, patent them, trademark them. Real food just isn’t as profitable as junk. But, I may have to eat those words: there was evidently a TV ad for avocados, and, during the Super Bowl, no less. Not like avocado-flavored Doritos or something, but an ad for the actual fruit—thanks to billions of avocados sold every year, giving the Avocado Board $50 million, not only for ads, but for research.

I previously touched on their burger study, in which adding avocado blunted the spike in inflammation one gets within hours of eating meat. They added more fat, more calories, but got less inflammation—perhaps because they were adding that fat and calories in the form of a whole plant food, which tends to be packed with antioxidants, which can inhibit the formation of oxidized fats that are formed when meat is cooked and when it hits your stomach acid.

Do Peanuts Have the Same Effect?

Do other high-fat, high-calorie, whole plant foods have the same protective effect? What about peanuts, for example? We didn’t know… until, now. Not to be outdone by Big Guac, the Peanut Institute funded this study with the understanding that most of us spend most of our waking hours “in a postprandial state”—in other words, an after-meal state. And, the fat coursing through our systems from those meals “is a well-recognized risk factor for atherosclerosis,” the #1 killer of men and women, and manifests as “impaired endothelial function”—meaning crippled artery function, within hours of a crappy meal, like a milkshake: 1,200 calories of mostly sugar and heavy cream. Okay, but what if you drank that same milkshake with three ounces of peanuts added? Now, to match up the added fat and protein, they had to add some oil and egg whites, and even threw in a fiber supplement to try to match the nutritional profile of the added peanuts as closely as possible. So, here you have two milkshakes, pretty much same calories, same amount of sugar, same amount of protein, same amount of fat—same amount of saturated fat, same fiber. So, on paper, they should cause the same reaction in the body. But peanuts are whole plant foods, and so, what you don’t see listed here are the thousands of phytonutrients in the peanut milkshake, missing from the non-peanut milkshake. Would it make any difference? That’s what the study aimed to find out.

This is showing artery function before either milkshake is ingested: the ability of our arteries to relax and dilate normally. Within hours of consuming the non-peanut milkshake, all that saturated fat and sugar clamps artery function down about 20%—one milkshake! Okay, but what if you ate the same amount of sugar and saturated fat but with a little real food floating in there? No significant drop. So, the peanuts helped preserve artery function in response to the endothelial insult, a “cardioprotective effect” presumably due to the active phytonutrients in peanuts.

Now, walnuts may work even better. Eat a salami-and-cheese sandwich with some olive oil, and artery function plummets like a third. But, replace that olive oil with the same amount of plant fat in the form of whole walnuts, and you don’t just blunt the effect of the salami-and-cheese, but reverse it—ending up actually better than you started out.

Phytonutrients and Phytochemicals

What about avocados? “Research indicates that [calorie]-dense foods increase inflammation and oxida[tion], thereby contributing to the development of [artery] disease. However, it is not clear whether the high [calorie] load alone, irrespective of the nutritional content of the ingested food, produces [that] postprandial [after-the-meal] oxidative and inflammatory activity.” So, what this study did was compare the impact of high-calorie junk, high-fat, high-sugar ice cream, a “phytonutrient-reduced food”—that’s an understatement­—compared to the effects of the exact same number of calories from a calorie-dense, phytonutrient-rich, whole plant food: avocado. If it’s just the concentration of calories, the concentration of fat, they should have the same effect. They tested reactions to four different meals: ice cream versus avocado, versus just the fat and protein from the ice cream to separate out the sugar, and then just the amount of sugar in the ice cream, to separate out the effects of the saturated butterfat.

So, two pints of ice cream, versus just the cream, versus just the sugar—no fat, versus about four avocados, which ends up having about three times the fat as ice cream, and the same amount of saturated fat, and the same whopping load of calories. Okay, so what happened? Eat the ice cream, or just the sugar-free components, or just the sugar, and the level of oxidative stress in people’s bloodstreams goes up. But “this is not observed after ingestion of a [calorie]-equivalent [whole plant] food.”

“Unlike [the] ice cream, ingestion of the whole-food avocado,” even though it’s packed with calories and fat, “did not produce a rise in oxidative or inflammatory activity,…suggest[ing] that the [after-meal] oxidative stress observed after eating foods such as ice cream may be due to their isolation from [nutrients like] antioxidants.”

Sugar is okay in fruit form, because it comes naturally prepackaged with phytonutrients. Similarly, the fat in whole plant foods, like nuts and avocados, comes prepackaged “with a rich matrix of phytochemicals [and] therefore does not demonstrate the same potential for oxidative damage.”

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• Li Z, Wong A, Henning SM, et al. Hass avocado modulates postprandial vascular reactivity and postprandial inflammatory responses to a hamburger meal in healthy volunteers. Food Funct. 2013;4(3):384-91.
• Liu X, Hill AM, West SG, et al. Acute Peanut Consumption Alters Postprandial Lipids and Vascular Responses in Healthy Overweight or Obese Men. J Nutr. 2017;147(5):835-840.
• Khor A, Grant R, Tung C, et al. Postprandial oxidative stress is increased after a phytonutrient-poor food but not after a kilojoule-matched phytonutrient-rich food. Nutr Res. 2014;34(5):391-400.
• (author unknown). Avocados Could Improve Your Cholesterol - and More. Health and Nutrition Letter, Tufts University. May 2015.
• Hass Avocado Board Annual Report, Year Ended December 31, 2016.
• Cortés B, Núñez I, Cofán M, et al. Acute effects of high-fat meals enriched with walnuts or olive oil on postprandial endothelial function. J Am Coll Cardiol. 2006;48(8):1666-71.

Image credit: tookapic via Pixabay. Image has been modified.

Motion graphics by Avocado Video.