Young Ju, Ph.D.

You have probably already heard that avocados are good for you.  Just how can this fruit (not a vegetable) improve your health, especially your heart health?

Avocado and Its Nutrients

Avocado consumption in the U.S. has been increasing since the 1970s.  In the US, the average person consumed about 2.2 pounds in 2000 and about 8.4 pounds in 2021 (1). Avocados are nutrient-dense fruits that are considered a good fat source. Most of the calories per serving are from fat (72 out of 80 calories) (2). The fat in avocados is mainly oleic acid (a monounsaturated fatty acid) which is categorized as a good fat; olive oil is also high in oleic acid.  

In 2018, the U.S. Food and Drug Administration supported the health claim (3) that consuming oils containing high levels of oleic acid (at least 70%) may reduce the risk of coronary heart disease. This means consuming 1.5 tablespoons or 20 grams per day. Avocado oil is one of the oils eligible to make this claim. Some studies show that replacing foods high in saturated fat (such as butter, cheese, yogurt, and meat, etc.) with those rich in unsaturated fats (such as avocados, nuts, and seeds) helps lower blood LDL-cholesterol (“bad” cholesterol) levels, a key negative contributor to coronary artery disease (4, 5). (For more information on cholesterol, see the January Newsletter.)

A 30-year (1986–2016) follow-up study with 110,487 participants found that avocado eaters (2 servings per week) had a lower risk of cardiovascular disease compared to non-avocado eaters (6).

Avocados also contain other nutritional components that could contribute to heart health including:

• dietary fiber–up to 20% of the daily recommended intake level

• vitamins Bs, C, E, and K,

• potassium (higher than that in 1 medium banana) 

• magnesium 

• phytosterols aka plant sterols (Although phytosterols are structurally very similar to cholesterol, phytosterols inhibit cholesterol absorption from animal food and lower cholesterol and LDL-cholesterol levels.)

• other bioactive compounds

Avocado Products

Avocados are mostly consumed fresh.  In addition, avocados are processed for the production of oil, mashed avocado, powdered avocado, packaged slices and pieces, frozen avocado, juice, and dried avocado, etc.  Avocado oil can be used in no-heat recipes, such as adding to salads or smoothies.  It can also be used for high-heat cooking such as baking, grilling, and frying.

An avocado has a large seed which, although not eaten, contains good amounts of various nutrients including omega-3 fatty acids, oleic acid, and bioactive compounds.  Due to its nutritional value, avocado seed powder and extracts are being used in various food applications such as instant soups, beverage products, emulsion, tea, supplements, natural preservatives, and dietary fiber, etc. (7).  Many studies have shown that avocado seed flour or seed extracts have various health benefits, including lowering cholesterol levels (8).

Avocado Dietary Supplements

Dietary supplements made from processing avocados and seeds are available. Ingredients and serving size vary widely from one product to another. These supplements claim to improve antioxidant activities, immune system, joint health, and heart health.

Potential Adverse Effects

Although avocados can be a healthy fat source, overeating could cause weight gain. People with a tree pollen allergy (such as birch) or a latex allergy which is associated with avocado allergy should be cautious about eating avocado and avocado products. Avocados have been reported to decrease the effect of warfarin (a blood thinner) and might increase the risk of clotting. Avocados may increase cholesterol levels in people with a rare genetic disorder (sitosterolemia) that increases absorption of fatty substances from plant foods and accumulation of fatty substances in arteries. 

Overall, avocados are a good food source of nutrients including oleic acid.  Research suggests that substituting unhealthy fats with avocado or avocado oil can help lower LDL-cholesterol levels and reduce a risk of heart disease.  And I always recommend that you read processed food labels to see what ingredients are included that may be of benefit to you. 

REFERENCES

1. Per capita consumption of fresh avocados in the United States. https://www.statista.com/statistics/257192/per-capita-consumption-of-fresh-avocados-in-the-us/#:~:text=U.S.%20per%20capita%20consumption%20of%20fresh%20avocados%202000%2D2021&text=The%20U.S.%20per%20capita%20consumption,approximately%208.43%20pounds%20in%202021.

2. U.S. Department of Agriculture. Avocado, raw. https://fdc.nal.usda.gov/fdc-app.html#/food-details/1102652/nutrients

3.  U.S. Food and Drug Administration. FDA Completes Review of Qualified Health Claim Petition for Oleic Acid and the Risk of Coronary Heart Disease. https://www.fda.gov/food/cfsan-constituent-updates/fda-completes-review-qualified-health-claim-petition-oleic-acid-and-risk-coronary-heart-disease

4. Nogoy, K.M.C., Kim, H.J., Lee, Y.H., Zhang, Y., Yu, J., Lee, D.H., Li, X.Z., Smith, S.B., Seong, H.A., Choi, S.H. High dietary oleic acid in olive oil‐supplemented diet enhanced omega‐3 fatty acid in blood plasma of rats. Food Sci Nutr. 2020, 8(7): 3617.

5. Dreger, M.L., Cheng, F.W., Ford, N.A. A Comprehensive Review of Hass Avocado Clinical Trials, Observational Studies, and Biological Mechanisms. Nutrients 2021, 13:4376.

6. Pacheco, L.S., Li, Y., Rimm, E.B., Manson, J.E., Sun, Q., Rexrode, K., Hu, F.B., Guasch-Ferre, M. Avocado Consumption and Risk of Cardiovascular Disease in US Adults. J Am Heart Assoc. 2022, DOI: 10.1161/JAHA.121.024014.

7. Banger, S.P., Dunno, K., Dhull, S.B., Siroha, A.K., Changan, S., Maqsood, S., Rusu, A.V. Avocado seed discoveries: Chemical composition, biological properties, and industrial food applications. Food Chemistry 2022, DOI: 10.1016/j.fochx.2022.100507.

8. Dabas, D., Shegog, R.M., Ziegler, G.R., and Lambert, J.D. Avocado (Persea americana) seed as a source of bioactive phytochemicals. Current Pharmaceutical Design 2013, 19:6133.            

People with high cholesterol and at risk of heart disease should talk to their healthcare providers about heart health management strategies. This information is provided for your reference and you use at your own risk; you should rely on your medical professional for medical advice.