March 31, 2005 – Do you think you are committing a sacrilege when you serve your salad with an oil vinaigrette? Rest assured: this would allow optimal absorption of the nutrients contained in the vegetables that compose it.
In a small clinical trial involving seven healthy young adults, researchers at the University of Iowa found that absorption of carotenoids (alpha and beta-carotene, and lycopene) is optimal when ‘we eat its vegetables accompanied by fat.
To reach this conclusion, they asked the subjects to eat three times a salad consisting of spinach, romaine lettuce, carrots and cherry tomatoes. At least two weeks had to elapse between the consumption of each salad, and subjects had to restrict their consumption of fat during the three days preceding this meal. The salads were accompanied by 60g of either fat-free, low-fat (6g canola oil) or regular (28g canola oil) dressing.
Analysis of blood samples collected every hour for 12 hours after ingestion showed that the addition of the regular dressing significantly increased the absorption of alpha and beta-carotenes, and slightly that of lycopenes. The low-fat dressing produced a similar effect, but less, and the fat-free one resulted in almost no absorption of nutrients. The authors conclude that it would be desirable to consume at least 5 g of fat when eating vegetables.
Too much or too little fat?
According to nutritionist Hélène Baribeau, it was already known that carotenoids, which are soluble in fatty substances, need them to be well absorbed by the body. According to her, this study is especially important for people who follow a low-fat diet: “They should consume fat with their vegetables, ideally good oils,” she says.
On the other hand, she adds that for people who already benefit from sufficient fat intake, it is not necessary to increase the amount of fat ingested even more.
Green vegetables (spinach, broccoli) as well as carrots and sweet potatoes are good sources of carotenoids.
Martin LaSalle – PasseportSanté.net
According to Prevention.
1. Brown MJ, Ferruzzi MG, Nguyen ML, Cooper DA, Elridge AL, Schwartz SJ, White WS, Carotenoid bioavailability is higher from salads ingested with full-fat than with fat-reduced salad dressings as measured with electrochemical detection, American Journal of Clinical Nutrition, August 2004, Vol. 80, No 2, 396-403.
