Dispelling nutrition myths, ranting, and occasionally, raving

Will an avocado a day keep the doctor away?

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Avocado photo by Paree on Flickr. Used under a Creative Commons Licence.

Last week everyone was all excited about new research touting the health benefits of avocados. The gist of it being that everyone should eat an avocado a day to lower improve their cholesterol profile. Now, I love avocados, but I still had to take a look at the study myself.

The first thing I noticed was that the research was “supported by a grant from the Hass Avocado Board” and that the lead author, Dr Kris‐Etherton, is a member of the Avocado Nutrition Science Advisory. According to one of the news items I heard, she insisted that she still would have published the research if it had not shown avocados to impart special benefits on cholesterol levels. Despite this, it’s still a significant red flag to me that the research was supported by the Avocado Board.

This was also a rather small study, looking at 45 individuals over five weeks. While the results were interesting, a larger study would be needed to draw any definitive conclusions. What were these interesting results? Bearing in mind that dietary adherence was self-reported, 90% allegedly stuck to their prescribed diets, and all participants maintained their starting weights. Participants were assigned to one of three treatment diets: low-fat, moderate-fat, or avocado. All three diets were found to lower LDL-C and total cholesterol. However, the avocado diet decreased both (LDL-C and TC) significantly more than the low- and moderate-fat diets. The avocado diet was also the only diet found to decrease the number of small, dense LDL particles (the really bad guys).

Okay, so avocados may impart health benefits. Does this mean we should all exponentially increase our grocery bills and start eating an avocado a day? Probably not. The participants in the study were predominantly white, overweight and obese, healthy Americans. If you’re not part of that group, the results may not apply to you. The study also only ran for five weeks and did not incorporate other life style changes such as exercise and weight loss. We can’t say if eating an avocado a day would impart the same health benefits to someone of a lower weight, different ethnicity, or disease state. We also don’t know if the benefits would continue beyond five weeks or if eating an avocado every day would be more beneficial than increasing exercise and/or losing weight. What about the effects of all three of these together?

Avocados are delicious and full of good nutrients. I don’t want to discourage anyone from eating them if they enjoy them. However, they are expensive, and their use in the treatment of conditions such as elevated cholesterol needs further investigation before we start prescribing an avocado a day.

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Author: Diana

I'm a registered dietitian from Nova Scotia, living and working in Ontario, Canada. My goal is to help people relearn how to have a healthy relationship with food.

3 thoughts on “Will an avocado a day keep the doctor away?

  1. Although I don’t eat an avocado a day, I eat them often. I’m glad it’s a healthy habit!

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  2. You mentioned “health benefits for a different ethnicity”. Is there sound science to back up that someone’s ethnicity has an effect on how the body reacts? I’m genuinely curious. I’ve been reading your blog for a while now and really appreciate how you break down studies to take out the bias and uncover faulty/problematic findings.

    As someone who has never identified as white, living with the long-term effects of racism has me side-eyeing when ethnicity is brought in as a health category. Ethnicity is subjective. What does it mean? Where we were born? Where our parents were born? Our ancestral roots? The colour of our skin? Which racial category we are forced into based on our physical appearance?

    During a recent routine spirometry test for my asthma, I was asked what is my ethnicity. My choices (of which I could only choose one) were White, Black, First Nations, Latin American, Asian, and other. When I pressed for the reason for the question the nurse claimed the size of lungs vary from one group to another. (Umm.) When I pressed further, my health provider was brought in to explain that the spirometry database was connected with a study that used ethnicity as one of the identity markers to compare what the norm is.

    I find that to be highly suspect. I’m Latina. Born in Canada. My parents were born in Chile. I have pale skin. My ancestors are Indigenous (Mapuche and Quechua) and European (Spanish and Italian). Which Latinxs were included in this asthma study? Given the list I was asked to choose from, Latinxs can fit into each of these categories. It is way more complex than simply saying we are Brown people. We are also White, Black, Asian, Native, all of the above.

    Sorry for derailing the conversation. But it’s this and so many other microagressions that make so many of our people mistrust the medical community. Would really love to know if you have any insight on this. (Also, love your blog!)

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    • I can imagine how frustrating that must be!

      There is reason to believe that different ethnicities, genders, ages, etc, react differently to various nutrients and have different health needs.

      For example, people from some ethnic backgrounds are far more likely to be lactose intolerant than others. Women and men metabolize alcohol differently.

      Unfortunately, most research focuses on white people, often white men. It’s a significant limitation in research. While it may not be a big deal in studies of avocados it can be a concern when studying the effect of supplements or medications.

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