View all posts

Why Avocados Are Healthy: The Science Behind Everyone's Obsession

By Michelle Darian, MS, MPH, October 20, 2019

vegetarian avocado toastAvocados have been attracting attention from bloggers and dietitians alike—and for good reason! They're versatile: they can be sliced in sandwiches, diced on salads, smashed on toast or turned into guacamole. And their benefits in the body are equally as versatile: they can help your heart, eyes, and even waistline. Let’s take a deeper dive into why paying the extra $1.95 for guac gets you so much more than an elevated burrito.

 

One avocado contains more than half of your daily fiber

One avocado contains a whopping 14g of fiber![1] According to the USDA Dietary Guidelines for Americans, the dietary reference intake (DRI) for fiber in adults ranges from 25g-33g/day [2]. Therefore, one avocado can account for around 50% of your daily fiber needs.[2]

Why is fiber so critical? Well, it plays many essential roles in the body. Fiber acts as a scavenger in the intestines by latching onto “bad” cholesterol and removing it from the body before it can be digested. Without fiber, this “bad” cholesterol gets taken up into the bloodstream and deposited into your fat cells or arteries.

Schedule a live demo of the InsideTracker platform

 

And they're full of healthy fats

Avocados are also full of monounsaturated fatty acids, a type of fat widely regarded as healthy, as they help to keep our cells healthy without causing plaque buildup in our arteries like their saturated fat counterparts. In fact, monounsaturated fats actively prevent this buildup from happening. This is important, because plaque buildup could otherwise limit the space for your blood can flow freely through your arteries, making you more prone to diseases of poor heart health like atherosclerosis. 

 

So they're packed with potential for a healthy heart

It's for these reasons that eating avocados has been associated with improved cholesterol levels. A meta-analysis (a study that compares the findings of multiple studies) from 2016 found that swapping out mealtime carbs for an avocado significantly decreased LDL (bad) cholesterol, total cholesterol, and triglycerides.[3,4] The improvements in these cholesterol biomarkers improve your heart health, protecting you from cardiovascular problems later.

A study conducted in 2018 compared eating a breakfast of avocado with an equal amount of calories from carbs.[5] They found that during the 6 hours after consuming the avocado breakfast, the study participants had improved flow-mediated dilation (FMD)—an important marker of heart health—compared to the group who ate the carbohydrate-rich meal.[5]

 

They can reduce inflammationand make your burger healthier!

Avocados' impact on your heart doesn't stop at fat and fiber, though. They're also high in antioxidants, which protect our bodies—including our arteries— from damaging agents. To this end, avocados impart an anti-inflammatory, heart-healthy effect

One study investigated the impact of putting avocado on a hamburger on inflammation levels. Results showed that inflammation levels rose in people who ate a hamburger alone, but stayed the same in those who paired their burger with half an avocado.[6] 

Avocado health benefits

 

Avocados can even improve your vision

Avocados contain the carotenoids lutein and zeaxanthin. You may have heard of these when talking about eye health—they're some of the key components of many eye health supplements on the market. These molecules accumulate in the most central point of your retina, called the macula. Since the retina is the light-sensitive part of the eye, proper macula health is essential for clear vision.

These carotenoids therefore support your vision by building a protective layer on your macula. In short, this layer is protective because it acts as an antioxidant. This can help to delay the onset of age-related vision loss, like age-related macular degeneration [7]. Avocado's contribution of these carotenoids has been confirmed—people who eat an avocado a day significantly improve their macular pigment density after 6 months.[7]

Avocados are a particularly good source of lutein and zeaxanthin because they are more bioavailable (readily usable by the body) than other plant sources.[8] This is because they contain lot of fat, which is necessary for the carotenoids to get absorbed by the body. In fact, one study found that adding an avocado to salad enhanced the absorption of lutein by more than 500% compared to an avocado-free salad.[8]

 

And avocados are great at curbing hunger

Multiple studies have examined the impact that adding or replacing avocados during meals can have on hunger, satiety, and overall caloric intake. Compared to an equal amount of calories from carbs, avocados can help to suppress hunger, both subjectively and on a hormonal level.[9] They're also been shown to increase satisfaction after a meal and decrease the desire to eat.[10]

Improved satiety (fullness) is important because it decreases the desire to reach for those nutrient-poor snacks throughout the day. Plus, who wouldn’t want to feel satisfied after a meal?! So, even though avocados are calorie-dense, they can minimize unhealthy snack choices and lead to a lowering of overall daily caloric intake and cascading health benefits. 

 

They can also help you lose weight long-term

A 2019 study of over 55,000 people found that healthy people who regularly ate avocado had reduced odds of becoming overweight or obese over time compared to those who do not consume any avocado.[11]

This corroborated the findings of a 2013 study of 17,500 people, which found that avocado consumers had significantly lower body weight, BMI, and waist circumference compared to avocado non-consumers. They also had significantly higher HDL (good) cholesterol than non-consumers. This data was collected over a period of 8 years, and was one of the first to quantify the long-term impact of avocados on health. [12]

Of course, the caloric density of avocados can't be ignored. Many of the studies referenced in this post are of participants who consume one whole avocado each day. Considering one medium avocado contains approximately 320 calories, merely adding avocado on top of a daily diet can lead to quite a bit of excess calorie intake.[1] Therefore, consider eating avocados as a replacement for other sources of fat in your diet, like oils, creams, and cheeses that would otherwise be added to dishes. 

 

A summary of avocados' impact on health:

  • The fiber, monounsaturated fat, and antioxidant content in avocados makes them very heart-healthy
  • Unlike sources of saturated fat, avocados don't contribute to atherosclerosis
  • Avocados can make meals healthier by offsetting inflammation and increasing the absorption of healthy nutrients
  • Avocados can improve vision by protecting the macula in the retina of the eye
  • Avocados can help curb hunger and may therefore contribute to weight loss
  • Avocados are high-calorie, and therefore should replace existing sources of fat in the diet

Learn how your biomarkers affect your body in this FREE e-Book download!

New Call-to-action

References:

[1] Avocados USDA. SNAP Education Connection. [cited 2019 Oct 11]. Available from: https://snaped.fns.usda.gov/seasonal-produce-guide/avocados

[2] Appendix 7. Nutritional Goals for Age-Sex Groups Based on Dietary Reference Intakes and Dietary Guidelines Recommendations - 2015-2020 Dietary Guidelines - health.gov [Internet]. [cited 2019 Oct 11]. Available from: https://health.gov/dietaryguidelines/2015/guidelines/appendix-7/

[3]Peou S, Milliard-Hasting B, Shah SA. Impact of avocado-enriched diets on plasma lipoproteins: A meta-analysis. J Clin Lipidol. 2016 Feb;10(1):161–71.
[4] Colquhoun DM, Moores D, Somerset SM, Humphries JA. Comparison of the effects on lipoproteins and apolipoproteins of a diet high in monounsaturated fatty acids, enriched with avocado, and a high-carbohydrate diet. Am J Clin Nutr. 1992 Oct;56(4):671–7.
[5]Park E, Edirisinghe I, Burton-Freeman B. Avocado Fruit on Postprandial Markers of Cardio-Metabolic Risk: A Randomized Controlled Dose Response Trial in Overweight and Obese Men and Women. Nutrients. 2018 Sep 12;10(9).
[6] Li Z, Wong A, Henning SM, Zhang Y, Jones A, Zerlin A, et al. Hass avocado modulates postprandial vascular reactivity and postprandial inflammatory responses to a hamburger meal in healthy volunteers. Food Funct. 2013 Feb 26;4(3):384–91.
[7] Scott TM, Rasmussen HM, Chen O, Johnson EJ. Avocado Consumption Increases Macular Pigment Density in Older Adults: A Randomized, Controlled Trial. Nutrients. 2017 Aug 23;9(9).
[8] Unlu NZ, Bohn T, Clinton SK, Schwartz SJ. Carotenoid absorption from salad and salsa by humans is enhanced by the addition of avocado or avocado oil. J Nutr. 2005 Mar;135(3):431–6.
[9] Zhu L, Huang Y, Edirisinghe I, Park E, Burton-Freeman B. Using the Avocado to Test the Satiety Effects of a Fat-Fiber Combination in Place of Carbohydrate Energy in a Breakfast Meal in Overweight and Obese Men and Women: A Randomized Clinical Trial. Nutrients. 2019 Apr 26;11(5).
[10] Wien M, Haddad E, Oda K, Sabaté J. A randomized 3×3 crossover study to evaluate the effect of Hass avocado intake on post-ingestive satiety, glucose and insulin levels, and subsequent energy intake in overweight adults. Nutr J. 2013 Nov 27;12:155.
[11] Heskey C, Oda K, Sabaté J. Avocado Intake, and Longitudinal Weight and Body Mass Index Changes in an Adult Cohort. Nutrients. 2019 Mar 23;11(3).
[12] Fulgoni VL, Dreher M, Davenport AJ. Avocado consumption is associated with better diet quality and nutrient intake, and lower metabolic syndrome risk in US adults: results from the National Health and Nutrition Examination Survey (NHANES) 2001-2008. Nutr J. 2013 Jan 2;12:1.