To the Editor:
Letters to the Editor are Welcome
Letters to the Editor may be submitted at https://ees.elsevier.com/andjrnl for consideration regarding manuscripts published within the past 6 months. Letters should be no more than 500 words, can contain up to 20 references, and should include a funding disclosure, conflict of interest disclosure, and copyright/authorship form. All letters will be subjected to editorial review and decision before acceptance.
I am writing to comment on the article “Intake of lycopene and other carotenoids and incidence of uterine leiomyomata: a prospective ultrasound study” (121;1). I was not surprised that no relationship was found for carotenoid intake and prevention of uterine leiomyomata, because intake is likely not a valid measure for blood levels of carotenoids as maximal absorption of carotenoids is highly dependent on dietary fat. The study assessed total fat intake and did not find an effect, but total fat intake would not indicate whether the dietary fat was included at the time of consumption of the carotenoid-containing food.
Dietary carotenoids are absorbed with the chylomicron, so dietary fat would need to be present when the carotenoid-containing food is consumed, because negligible quantities of carotenoids are absorbed without dietary fat.
1
Cooking carotenoid-containing foods into fat further increases carotenoid absorption, possibly because of an increase in carotenoid bioavailability.2
In addition, the type of fat consumed may be critical to the biological activity of the carotenoid once it is absorbed. A study comparing tomato products cooked into extra virgin olive oil or sunflower oil showed similar levels of carotenoid absorption with either fat; however, only when olive oil was used was a significant increase in plasma antioxidant activity seen, whereas no antioxidant effect was found with sunflower oil.3
Likely the sunflower oil, because of its high polyunsaturated fat content, actually increased plasma oxidation, whereas the predominately monounsaturated fat content of extra virgin olive oil would not increase oxidation. In addition, the phenol content of extra virgin olive oil would contribute additional antioxidant effects.4
, 5
, 6
, 7
Dietary advice to the public will fail to produce the expected health benefits if the health message is not complete. Advice to increase the consumption of “dark” produce, which has been the public message for increasing carotenoid intake, has been made by health organizations for a long time. However, failing to include that the dark produce must be consumed with fat, and cooking the produce into fat would be preferable to simply adding fat, means the potential health benefits of carotenoids will not be realized because of limited bioavailability and subsequent increase in blood levels without fat. Advice to cook vegetables into extra virgin olive oil would have the added benefit of an improved taste of vegetables, which could lead to an increase in vegetable consumption.
8
References
- 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: 396-403
- Increases in plasma lycopene concentration after consumption of tomatoes cooked with olive oil.Asia Pac J Clin Nutr. 2005; 14: 131-136
- Consumption of tomato products with olive oil but not sunflower oil increases the antioxidant activity of plasma.Free Radic Biol Med. 2000; 29: 1051-1055
- Changes in LDL fatty acid composition as a response to olive oil treatment are inversely related to lipid oxidative damage: The EUROLIVE study.J Am Coll Nutr. 2008; 27: 314-320
- Postprandial LDL phenolic content and LDL oxidation are modulated by olive oil phenolic compounds in humans.Free Radic Biol Med. 2006; 40: 608-616
- Effects of differing phenolic content in dietary olive oils on lipids and LDL oxidation: A randomized controlled trial.Eur J Nutr. 2004; 43: 140-147
- Effects of dietary extra virgin olive oil on serum lipid resistance to oxidation and fatty acid composition in elderly lipidemic patients.Bratisl Lek Listy. 2003; 104: 218-221
- 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: 1155-1161
Article info
Publication history
Published online: February 18, 2021
Accepted:
December 22,
2020
Received:
December 18,
2020
Footnotes
STATEMENT OF POTENTIAL CONFLICT OF INTEREST The author has no current funding in the area of extra virgin olive oil; however, she has done research on the health benefits of extra virgin olive oil in the past that had partial funding from Cobram Estates, Australia.
FUNDING/SUPPORT There is no funding or financial support for this work.
Identification
Copyright
© 2021 by the Academy of Nutrition and Dietetics.
