Sun Jan 25 2026 
What to look for when buying extra virgin olive oil.
First thing to look for on the label is the wording “extra virgin olive oil”. If “extra virgin” is not included, it will definitely not have health benefits. The health benefits of extra virgin olive oil are due to compounds naturally found in the oil called “phenols” and the phenol content depends on the olive used to make the oil, how the olive is grown and harvested, and then how the olive is made into the oil. There are chemical and sensory tests that can be done when the oil is produced that would test if the oil meets the standards for “extra virgin”. The chemical tests are done in a lab and to see if the oil contains or does not contain certain compounds. The sensory tests are done by people trained to know what good quality extra virgin olive oil should smell and taste like. To be “extra virgin” the olive oil has to be first press and cold press, so those are just marketing terms. Once the oil is bottled, how the product is treated when shipped, in the store, and in your home can all effect the quality of the oil. The bottle should also post a date for when the olives were harvested / made into oil. The best case is you would buy and consume an extra virgin olive oil that is from the current year, but certainly by the “best if used by” date. If you are in the United States, there are many excellent extra virgin olive oils from California. The best California extra virgin olive oils have the seal of the California Olive Oil Commission and / or have a label saying they are a member of the Olive Oil Commission of California. Look on the extra virgin olive oil company’s website to see if they list the time it takes for their oil to be made from the time the olives are picked. Less than eight hours is the best. You should also buy the size bottle that is appropriate for the number of people who will use the bottle. You can determine this by looking at the number of tablespoons listed on the label, dividing this by two, which is the minimum tablespoons per day each person should be consuming. Then divide that number by the number in the household. It is best to buy a size bottle that can be consumed in one month/ 30 days by the household once it is opened. How to use and store your olive oil to maintain the health benefits. The phenols in the extra virgin olive oil, which provide the health benefits, are lost with oxygen, light, and heat, with oxygen causing the most lost. 1 To avoid excess exposure of the oil to oxygen, make sure you replace the cover on the bottle as soon as you use the extra virgin olive oil when pouring it out; and when you add extra virgin olive oil to a pan for food preparation, cover the pan or add the food quickly to avoid excess exposure to the air. You do not need to heat the oil up before adding the food; you can heat the oil and the food together. Any damage from light is greatly decreased by buying olive oil in a bottle that is not clear glass, and most olive oil companies do not use clear glass any longer but some did in the past so just remember to keep the extra virgin olive oil in a bottle that is not clear glass.
The issue of heat pertains to cooking with extra virgin olive oil. Years ago, someone started the myth that you cannot cook with extra virgin olive oil. The early studies used a fry temperature (170°C) and boiled the oil for hours. Several of the studies did not even test extra virgin olive oil, but listed “refined” olive oil in the study Methods. In addition, it somehow became part of this myth that when testing the oil you bring the oils to smoke point; but we don’t cook at smoke point so that is not a helpful test. I think many people are beginning to realize that this is erroneous information but you may still hear someone who does not know the literature say you shouldn’t cook with olive oil. Yet not only can you cook with extra virgin olive oil, it has been shown to be the healthiest oil to cook with. A study that compared cooking with high quality extra virgin olive oil, virgin olive oil (similar to extra virgin but does not meet all the sensory standards), olive oil (which would be refined olive oil), canola oil, rice bran oil, grapeseed oil, coconut oil, high oleic peanut oil, sunflower oil, and avocado oil found that the high quality extra virgin olive oil was the safest oil to cook with as it produced the least amount of harmful particles when heated. 2 The results of this study showed that the least healthy oil to cook with was canola oil as the heating of canola oil led to a rapid production of polar compounds, which are unhealthy to consume. How to daily use extra virgin olive oil. The benefits start at 2 tablespoons per day, but consuming more is better. I think it is best to use the extra virgin olive oil to cook vegetables, for several reasons. First, preparing vegetables in olive oil really improves the taste of the vegetables so you are likely to eat more vegetables. We eat for taste so if we like the way a food tastes, we will eat it again and likely eat it more often. You cannot eat too many vegetables. I have found in my research protocols that when I instruct study participants to use extra virgin olive oil, they eat more vegetables and they eat them more often. 3,4 Try it yourself. Take a vegetable you think you do not like and prepare it with extra virgin olive oil. My rule of thumb is a tablespoon of extra virgin olive oil per cup of vegetables. You can prepare the vegetables stove top or roast them in the oven. For stove top, put the extra virgin olive oil in a pan large enough to contain the amount of the vegetables you plan to cook. Add the vegetables soon after adding the oil to avoid limit the exposure to air. Add some sea salt for flavor. Cook the extra virgin olive oil and vegetables on a medium heat for five to 15 minutes or until the vegetables are cooked as much as you would like. You can also roast the vegetables which would involve preheating an oven to 400-425°F. Cut the vegetables into pieces that are one to three inches, toss with extra virgin olive oil using one tablespoon of olive oil per cup of vegetables, spread on a roasting pan or a baking pan that has sides, add some sea salt and / or herbs and put in the oven and roast for 15 to 30 minutes, or until the vegetables are done as you would like them. Start to check the vegetables after about 15 minutes of roasting as the amount of water in them can change how long they need to cook. Another reason for cooking vegetables in extra virgin olive oil is to make sure you get into your body the components in the vegetables that will decrease your risk of cancer. These components are called carotenoids and they provide the colors of red, orange, and yellow to vegetables. I think that health organizations in the US have done a decent job of getting the word out that deep color of vegetables is important for health benefits. But what the
current messages are missing is that you need fat present with the vegetable to absorb the carotenoids and the more that is fat present, the more of the carotenoids will be absorbed. 5 Eating your vegetables without fat, and extra virgin olive oil is the only healthy fat, likely means that you will eat more vegetables, but it definitely means you will get into your body the components that will help decrease your risk for cancer. I have recommended for years that patients include extra virgin olive oil in their daily diet as part of their meals. I occasionally have patients mention the cost of extra virgin olive oil. I certainly understand that if you are looking at the price of a bottle of extra virgin olive oil and compare it to the cost of a seed oil, or refined olive oil the extra virgin olive oil will always cost more. I suggest that patients consider the cost per tablespoon of the extra virgin olive oil. This can easily be done by dividing the price of the bottle by the number of tablespoons in the bottle listed on the nutrition label. Example: a bottle of extra virgin olive oil that has 25 tablespoons (375 ml bottle) that costs $12.00 would be: 12/25 = 0.48 cents per tablespoon. For this example, you would be spending about a dollar a day to realize some impressive health benefits. I think you will find that the extra virgin olive oil is quite reasonable when you consider the health benefits for the cost of the oil. You can buy very good extra virgin olive oils in retail stores for a very reasonable price. And the price for extra virgin olive oil is not that much greater than what is sold as “olive oil”, which has zero health benefits. Summary:
Look for the wording “extra virgin”, seals that are from the California olive oil industry, and a “best if used by date” that is as far out as possible. Look for extra virgin olive oils that the company website provides how long it takes them to turn the olives into olive oil. Use ones that are less than 8 hours. Use at least 2 tablespoons of olive oil per day to receive the health benefits. Use the olive oil mainly to prepare your vegetables and use at least one tablespoon of olive oil per cup of vegetables.
- Flynn MM WS. Phenol Loss in Heating of Extra Virgin Olive Oil is Dependent on Temperature, time, and Cooking Conditions FASEB. Boston, MA2015:103.
- De Alzaa G RL. Evaluation of chemical and physical changes in different commercial oils during heating. ACTA Scientific Nutritional Health 2018;2(5):2-11.
- Flynn MM, Schiff AR. A Six-week Cooking Program of Plant-based Recipes Improves Food Security, Body Weight, and Food Purchases for Food Pantry Clients Journal of Hunger & Environmental Nutrition 2013;1:73-84.
- Flynn MM, Reinert SE. Comparing an olive oil-enriched diet to a standard lower-fat diet for weight loss in breast cancer survivors: a pilot study. J Womens Health (Larchmt) 2010;19(6):1155-61. (In eng). DOI: 10.1089/jwh.2009.1759.
- Brown MJ, Ferruzzi MG, Nguyen ML, et al. Carotenoid bioavailability is higher from salads ingested with full-fat than with fat-reduced salad dressings as measured with electrochemical detection. Am J Clin Nutr 2004;80(2):396-403. ).