olives, olive oil, and carotenoids

Categories: Articles, Nutritional Information

What can you tell me about olives, olive oil, and carotenoids?

Among their many nutrition benefits, olives contain important amounts of carotenoids. Carotenoids are naturally occurring, fat-soluble pigments that give many whole, natural foods their distinct yellow and orange colors. The best-studied and most famous of the carotenoids is beta-carotene, but hundreds of carotenoids have been identified by scientists and many are also important to our health. Some of the other well-researched carotenoids include alpha-carotene, lycopene, lutein, zeaxanthin, beta-cryptoxanthin, and canthaxanthin.

Lutein and zeaxanthin are especially plentiful in olives with 3.5 ounces of canned ripe olives containing over 500 micrograms of these carotenoids. Beta-carotene is also plentiful in olives, with this same amount containing between 225-250 micrograms.

Because carotenoids are fat-soluble, they are able to be carried along in olive oils when those oils are being extracted from the olives. However, methods of extraction, temperatures used during extraction, and sequence of extraction can all make significant differences in the final carotenoid content of the oil. It can be difficult to predict the exact amount of carotenoids in olive oil due to these processing differences. However, extra virgin olive oil (EVOO) is better able to maintain the original carotenoid content of the olives than other extractions since EVOO is derived from the very first pressing of the olives. This carotenonid benefit is one of the reasons we recommend extra virgin olive oil (EVOO) as your olive oil of choice.

In addition to providing you with its own carotenoids, olive oil may be able to help you absorb carotenoids from other foods. Researchers at Iowa State University looked at carotenoid absorption from salads dressed with fat-free dressings and compared it to carotenoid absorption from the same salads dressed instead with full-fat dressings. Salads are not only popular in a wide range of diets but are also high up on our recommended list at the World’s Healthiest Foods. Many of the World’s Healthiest Foods-including tomatoes, carrots, romaine lettuce, and baby spinach-make great salad components and are also great sources of beta-carotene.

In their research, the Iowa State scientists used canola oil in their full-fat dressing, and they discovered that beta-carotene from the salad ingredients listed above was better absorbed when a full-fat (versus non-fat) salad dressing was included. While we are not opposed to the use of canola oil in salad dressings or other recipes, we think it makes more sense to use extra virgin olive oil in this situation. That extra virgin olive oil will give you the same enhanced beta-carotene absorption since it will provide the additional fat needed to boost absorption. But at the same time, it will provide you with carotenoids of its own! In addition, it will give you several other key phytonutrients (like phenolic antioxidants) and, of course, a great-tasting dressing!

WHFoods Recommendations

Inclusion in a salad dressing is a perfect use for extra virgin olive oil. By avoiding heating of the oil, you are helping to protect its full spectrum of nutrients, and by including it along with a host of carotenoid-rich vegetables, you are increasing the bioavailability of those carotenoids at the same time.

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References

* Artajo LS, Romero MP, Morello JR, et al. Enrichment of refined olive oil with phenolic compounds: evaluation of their antioxidant activity and their effect on the bitter index. J Agric Food Chem 2006 Aug 9;54(16):6079-88. 2006.
* Bogani P, Galli C, Villa M, et al. Postprandial anti-inflammatory and antioxidant effects of extra virgin olive oil. 2007 Jan;190(1):181-6. 2007.
* Fielding JM, Sinclair AJ, DiGregorio G, et al. Relationship between colour and aroma of olive oil and nutritional content. Asia Pac J Clin Nutr 2003;12 Suppl:S36. 2003.
* Galvano F, La Fauci L, Graziani G, et al. Phenolic compounds and antioxidant activity of italian extra virgin olive oil monti iblei. J Med Food 2007 Dec;10(4):650-6. 2007.
* Luaces P, Sanz C, Perez AG. Thermal stability of lipoxygenase and hydroperoxide lyase from olive fruit and repercussion on olive oil aroma biosynthesis. J Agric Food Chem 2007 Jul 25;55(15):6309-13. 2007.
* Samaniego Sanchez C, Troncoso Gonzalez AM, Garcia-Parrilla MC, et al. Different radical scavenging tests in virgin olive oil and their relation to the total phenol content. Anal Chim Acta 2007 Jun 12;593(1):103-7. 2007.
* Sanz C, Luaces P, Perez AG. Processing of Olive Fruit for Enhancement of Carotenoid Level in Virgin Olive Oil. 2007. SHS Acta Horticulturae 744: 377-380. International Symposium on Human Health Effects of Fruits and Vegetables. 2007.
* Schaffer S, Podstawa M, Visioli F, et al. Hydroxytyrosol-rich olive mill wastewater extract protects brain cells in vitro and ex vivo. J Agric Food Chem 2007 Jun 27;55(13):5043-9. 2007.
* Vissers MN, Zock PL, Katan MB. Bioavailability and antioxidant effects of olive oil phenols in humans: a review. Eur J Clin Nutr 2004 Jun;58(6):955-65. 2004.