Holy Guacamole! (Why Avocados Are Just That Great)

Thanks to the nutrition program, I made a foray into monograph writing. My favorite fruit before my first monograph project was the avocado. After finishing the monograph, the avocado has pretty much sealed its place as my favorite fruit.

History

The avocado, Perseus americana, is deeply rooted in the human diet with archeological evidence indicating its consumption began nearly 10,000 years ago in Coaxcatlan, Pueblo, Mexico. The earliest varieties of avocado trees migrated to Mesoamerica sometime in 16,000 B.C., continuing to drift further into South America through trade; and domestic cultivation of Perseus likely began in 3100 B.C. in the Supa Valley of Peru. The avocado is even featured on the Mayan calendar! (1)

In the 16th century, when the Spanish began colonizing South and Central America, the avocado was distributed all over the Americas, Europe, and parts of Asia. The Spanish thought the avocado was delicious and wrote extensively about it, even noting the avocado’s use in indigenous medicine. As the avocado was cultivated and introduced to other parts of the world, three varieties of Perseus americana emerged: Mexican, West Indian, and Guatemalan. (1) 

Rudolph Hass was a postman in Southern California that planted avocados in his family’s orchard on a whim. In 1935, he patented his variety of avocados, the Hass avocado, which is now California’s main avocado crop. (2) California is the main producer of avocados in the United States, followed by Florida and Hawaii. (3) Internationally, Mexico produces the most avocados and is expected to produce 1.8 million metric tons in the 17/18 fiscal year. (4)

Nutrient Rich

Avocados are an excellent source of monounsaturated fatty acids (MUFAs), which are considered to be heart protective fats. (5) It is the only fruit that has MUFAs! (6) In addition to MUFAs, avocados are an excellent source of vitamin E, lutein, glutathione, b-sitosterol, folate, potassium, magnesium, and fiber. Consuming avocado with foods that contain carotenes, lycopene, or vitamins A, D, E, or K enhances the absorption of those phytonutrients and vitamins. (6,7) 

Health Benefits

Cardiovascular Health

The American Heart Association considers the avocado to be a heart healthy, fatty food. High low-density lipoproteins (LDL) levels and high non-high density lipoprotein (HDL) levels are associated with an increased risk of developing cardiovascular disease and having a heart attack or stroke. (8) In a randomized, controlled trial, it was found that consuming one avocado a day as part of a balanced diet had greater LDL and non-HDL lowering effects compared to a standard American diet, a moderate fat diet, and a low-fat diet. The total percent of calories consumed from fat was the same for the standard American diet, the moderate fat diet, and the diet that included one avocado a day. (5) 

A meta-analysis published in 2016 came to a similar conclusion. Diets that include avocados can lower LDL, triglycerides, and total cholesterol while increasing HDL. The heart health benefits of avocados may even be comparable to olive oil or nuts, regular consumption of which may decrease the risk of having a stroke or heart attack. (9)

Aging

Lutein, a carotenoid found in avocados, is one of the few antioxidants that can cross the blood brain barrier.  The amount of lutein in the brain is measured by the amount of lutein in macular pigment—referred to as macular pigment density—which is found in the macula of the eye (the back of the eye by the retina). As people age, cognition and memory often decline. However, nutritional interventions can improve cognition and memory. Older adults in a randomized, controlled study were asked to consume one medium sized avocado per day for six months. Two other groups were asked to consume one medium sized potato or one cup of chickpeas daily. At the end of the study, the participants who consumed an avocado every day experienced greater improvements in cognition and memory compared to the other two groups. The avocado group experienced increases in HDL cholesterol too. (10) 

Weight Management

Meals that contain fat, fiber, and protein are known to promote satiety (fullness), in part because they do not cause spikes in blood glucose. They are considered "slow fuels.” Fiber is especially important because it will slow down the digestion and absorption of carbohydrates and sugars in food, thereby promoting stable blood sugar levels. (11) Avocados are an excellent source of fiber, containing approximately 5 grams of fiber in one half of a medium sized avocado.

Some researchers have suggested that for people who want to lose weight and struggle with large snacks between meals that the addition of avocado to a meal can decrease the desire to eat for up to 5 hours later. Adding one half of a medium sized avocado to a meal is enough to increase satiety. (12) Additionally, an NHANES study that evaluated 17,567 adults in the United States found that avocado consumption is associated with healthy diets, higher HDL levels, lower body weights, and smaller waist circumferences. (13)

Serving Suggestions

One third of a medium sized avocado (approximately 50 grams) is 80 calories and is considered a serving. (6) However, it is not unreasonable to consume up to a whole medium sized avocado a day as a part of a balanced diet to enjoy its health benefits. (5) One serving—one third of a medium sized avocado—contains 15% of the daily value of vitamin B5 and 10% of the daily value for folate, vitamin K, and copper. (6)

Selection, Preparation, and Storage

Avocados are ripe and ready to consume when they feel slightly soft if gently squeezed. It is a good idea to purchase firm, unripe avocados if they will not be consumed within a couple of days. To ripen avocados at home, store them in a brown paper bag at room temperature for 2-5 days or until ripe. (14) It is ok to purchase non-organic avocados. When sampled by the Environmental Working Group, less than 1% of the sample were found to have pesticide residue. There are no genetically modified avocados. (15)

When ready to consume, avocados can be cut in half, the seed removed, and the skin peeled away. (9) The flesh can be carved out with a spoon too. Great care should be taken when removing the seed. It is easy to cut a fingertip or the hand when attempting to remove the seed with a knife. In order to avoid any injuries, remove the seed by hand or with a spoon. If the whole avocado is not consumed right away, a little lemon or lime juice or vinegar can be sprinkled on the cut side in order to prevent it from turning brown. (9)

Recipes

Avocados are easily enjoyed by themselves with a sprinkle of salt as quick snack, or they can be delicious additions to any meal or recipe.

Easy Guacamole

Serves 6-9 people

  • 3 ripe, medium sized avocados
  • ½ of a jalapeño pepper, finely minced
  • ½ bunch of cilantro, chopped
  • 1 tbs lemon juice and/or lime juice
  • 1 cup bell or sweet peppers or tomatoes (or any other colorful vegetable), chopped in ¼” cubes
  • A pinch of salt

Mash pitted and peeled avocados in a bowl. Add other ingredients and mix well. Enjoy with tortilla chips, on scrambled eggs, in a wrap, or with any meal. 

Quinoa and Veggie Stuffed Avocados

Serves 4 people

  • 2 ripe, medium sized avocados
  • 1 cup quinoa, cooked (follow directions on package)
  • 1 cup cherry tomatoes, slice in half
  • ½ bunch of cilantro, chopped
  • 1 cup cucumber, diced
  • 1 can of garbanzo beans, rinsed and dried
  • 1 tbs cumin
  • Salt and pepper to taste

Slice avocados in half lengthwise. Take out the seeds. The avocados can be scooped out of their skins or served with the skins. Cook quinoa according to directions on the package. Combine the quinoa, tomatoes, cilantro, cucumber, garbanzo beans, and spices in a bowl. (Optional: Roast garbanzo beans for 30-40 minutes in the oven at 350 for a crunchy addition!) Scoop quinoa and vegetable mixture into the avocados and enjoy. 

Reminder: I am a student. This post is for educational and informational purposes only.  I am not a physician or a nutritionist. If you need help modifying your diet and/or have health concerns, please get in touch with a credentialed professional.  

References:

1. Galindo-Tovar M, Arzarte-Fernandez A, Ogata-Aguilar N, and Landero-Torres I. The avocado (Perseus americana, lauraceae) crop in Mesoamerica: 10,000 years of history. Harv Pap Bot. 2007;12(2):325-334.

2. California Avocado Commission. The History of California Avocados. Available at: https://www.californiaavocado.com/the-california-difference/avocado-history. Accessed April 24, 2018.

3. United States Department of Agriculture. Noncitrus Fruits and Nuts: 2016 Summary. Available at: http://usda.mannlib.cornell.edu/usda/current/NoncFruiNu/NoncFruiNu-06-27-2017.pdf. Published June 2017. Accessed April 24, 2018.

4. USDA Foreign Agricultural Service. Global Agricultural Information Network: Mexico, Avocado Annual. Published November 28, 2017. 

5. Wang L, Bordi P, Fleming J, Hill A, Kris-Etherton P. Effect of a moderate fat diet with and without avocados on lipoprotein particle number, size, and subclasses in overweight and obese adults: A randomized, controlled trial. J Am Heart Assoc. 2015;4:e001355. doi:10.1161/JAHA.114.001355

6. California Avocado Commission. Avocado Nutritional Information. Available at: https://www.californiaavocado.com/nutrition/nutrients. Accessed April 25, 2018.

7. Unlu N, Bohn T, Clinton S, and Schwartz S. Carotenoid absorption from salad and salsa by humans is enhanced by the addition of avocado or avocado oil. J Nutr. 2005;135(3):431-436. doi:10.1093/jn/135.3.431.

8. Goff DC Jr, Lloyd-Jones DM, Bennett G, et al. 2013 ACC/AHA guideline on the assessment of cardiovascular risk: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;63:2935–2959.

9. Peou S, Milliar-Hasting B, Shah S. Impact of avocado-enriched diets on plasma lipoproteins: A meta-analysis. J Clin Lipidol. 2016;10(1):161-171. doi: 10.1016/j/jacl2015.10.011.

10. Scott T, Rasmussen H, Chen O, and Johnson E. Avocado consumption increases macular pigment density in older adults: A randomized, controlled trial. Nutrients. 2016;9:919. Doi:10.3390/nu9090919.

11. Briley J and Jackson C. Chapter 8: Balancing Blood Sugar. In: Food as Medicine Everyday. Portland, OR. NUNM Press; 2016. 101-110.

12. Wien M, Haddad E, Oda K, and Sabate J. A randomized 3x3 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;12:155. doi: 10.1186/1475-2891-12-155.

13. Fulgoni V, Dreher M, and Davenport A. 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;12:1. doi: 10.1186/1475-2891-12-1.

14. California Avocado Commission. How to Choose and Use and Avocado. Available at: https://www.californiaavocado.com/how-tos/how-to-choose-and-use-an-avocado. Accessed April 26, 2018.

15. Environmental Working Group. EWG’s 2018 Shopper’s Guide to Pesticides in Produce. Available at: https://www.ewg.org/foodnews/summary.php#clean-fifteen. Published April 10, 2018. Accessed April 26, 2018.