The Olive Oil Debate Continues…Why?

(Christina’s Note: Like you, my head hurts from the constant debate over extra virgin olive oil. So I asked nutrition expert Anthony Dissen to break it all down for us. Maybe it finally puts this debate to bed. Speriamo…we hope. Thanks, Anthony!)

I have worked as a Registered Dietitian Nutritionist for the past 13 years, and as a community health educator for the past 17 years. And during this time I have been privileged to focus my career on teaching and counseling others on the importance of good nutrition and healthy eating habits, especially eating a plant-based diet rich in whole and minimally processed foods. As a vegan myself for over 20 years, and someone who works his best to live his life from a macrobiotic perspective, I can tell you I regularly have the topic of “health” at the forefront of my mind. Over the past several decades, a wellspring of research and scholarship has been published that encourages us all to fill our plates with vegetables, whole grains, fruits, legumes, and nuts and seeds, while minimizing or outright avoiding highly processed foods and animal products. Books have been published, documentaries produced, and non-profit organizations have been founded that all share a single message: getting folks to load up on plants!

And yet, as is true of most schools of thought, there are going to be disagreements. Now in medicine and in academic research, we welcome this debate. As new evidence and research is discovered, guidelines are updated, and recommendations are changed. Our guidance and education is supposed to be based on the best evidence that we have available to us. And we adapt and change the ways in which we practice and teach as that evidence changes over time. At least that is the goal.

Within those circles of professionals and laypeople alike that work to advocate for a more plant-based diet, there is one topic that has frankly shocked me in its ability to divide, confuse, and enrage people. This topic, surprisingly enough, is olive oil. For decades the health benefits of olive oil, specifically extra virgin olive oil, has been documented. A cornerstone of the Mediterranean diet, the use of extra virgin olive oil provides significant benefits to health, wellbeing, and just as importantly, culinary delight. And yet many have focused their work with seemingly one goal in mind: to say that extra virgin olive oil in one’s daily diets is not only lacking in benefit, but is actively contributing to chronic disease.

At the beginning of 2022, a study was published in the prestigious Journal of the American College of Cardiology stating that higher intakes of olive oil was associated with a lower risk of death. Over 60,000 people in the United States were followed for 28 years who were free of heart disease or cancer at the beginning of the study. Now one might think this publication would further entice and encourage people to drizzle some extra virgin olive oil over their salad greens with delight. But an article published the following month on a very popular plant-based website says quite the opposite. In spite of the ever increasing body of evidence showing the benefits of olive oil consumption, this article claims that nothing has changed, and that people who identify as members of the whole food, plant-based community should contain to abstain from olive oil.

This article continues by saying that an editorial written in 2019 by a former surgeon turned anti-oil advocate provides all the evidence needed that olive oil is not associated with better health, especially better heart health. Should you decide to read this editorial (please note – an editorial, not new peer-reviewed research), you will see research cited that is several decades old. In the field of science and research, several decades old research immediately raises a red flag, as this means that the information being provided may have been shown to be unsubstantiated with further years of data. One such study, published in 2000, not only involved an incredibly small number of study participants (only 10 individuals – compare that to the 60,000 people studied in the JACC study), but was rather poorly designed, and did not reflect the actual ways in which people consume olive oil. What is more, the one dietary intervention in this study that did show a more realistic use of olive oil in cooking (olive oil used as a dressing on salad along with bread and vinegar) showed no negative effects. Sadly, this website failed to mention this part of the study.

If we look at more recent research, we see a very different story. A 2012 study in The American Journal of Clinical Nutrition following over 40,000 people found that those consuming about 2 tablespoons a day of extra virgin olive oil had a decreased risk in overall cause of death and death from cardiovascular disease. A 2014 article in Lipids in Health and Disease looked at 32 different cohort studies which collectively included over 840,000 people! They found that those consuming olive oil showed a decrease risk in stroke, cardiovascular events, and all cause risk of death. And a 2018 study looking in Endocrine, Metabolic & Immune Disorders found that extra-virgin olive oil consumption was associated with better cholesterol, blood pressure, less of a spike in blood sugar, better insulin secretion, and a better blood lipid profile. When looking at research of those people living in Sardinia and the Nicoya Peninsula, homes of two of the Blue Zones, we see that salads and other vegetables are regularly prepared with olive oil and similar fats, according to a 2020 study published in Nutrients.

In addition to the direct effects that extra virgin olive oil can have on our health, we also know that people who use it in their cooking tend to consume more vegetables and other whole plant foods! The authors of the study published in JACC noted that participants who ate more olive oil tended to be more likely to consume lots of vegetables and fruits than those who consumer little to no olive oil at all.  So this means that foods like extra virgin olive oil may not only have a beneficial impact on our health in of themselves, but it may also be a helpful vehicle for increasing other healthy foods in the diet, like vegetables, legumes, and whole grains.

This being said, why do we still hear these messages telling us to toss our bottles of olive oil in the dumpster? Well, in the immortal words that Stephen Sondheim gave us in the musical Gypsy “You Gotta Get a Gimmick!” And this anti-olive oil message is a great gimmick. But good healthcare practice and nutrition education shouldn’t be gimmicky. It should be based on the best evidence we have available.

At the end of the day, if someone deeply wishes to avoid olive oil in their daily diets, they can certainly do so. But this olive abstinence is not a necessary habit to commit to in the pursuit of better health. So if you, like me, adore the richness and the peppery bite of a good quality extra virgin olive oil, continue to do so with perhaps a little sigh of relief. Enjoy it with great mindfulness and pleasure, coupled with the peace of knowing that it may just be giving your body a little extra something good.

Anthony Dissen, MPH, MA, RDN, CPH