Dispelling nutrition myths, ranting, and occasionally, raving


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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.