Iowa State University scientist has published new research suggesting a spoonful of soybean oil makes vegetables more nutritious.
A new study led by Wendy White, an associate professor of food science and human nutrition, shows that eating salad with added fat in the form of soybean oil promotes the absorption of different micronutrients that adds a range of health benefits, including cancer prevention and eyesight preservation.
The results appeared in American Journal of Clinical Nutrition, and the results may ease the guilt of countless dieters who fret about adding dressing to their salads.
White’s research found out that added oil aided in the absorption of seven different micronutrients in vegetable salad. Those nutrients include four carotenoids — alpha and beta carotene, lutein and lycopene — two forms of vitamins, vitamin E and K. The oil also promoted the absorption of vitamin A. The new study builds on previous research from White’s group that focused on alpha and beta-carotene and lycopene.
Researcher also found that the amount of oil added to the vegetables had a proportional relationship so, adding twice the amount of salad dressing leads to twice the nutrient absorption.
It is not advisable, however, for salad eaters to drench their greens in dressing, but consumers should be perfectly comfortable with the U.S. dietary recommendation of about two tablespoons of oil per day.
The study included 12 college-age women who consumed salads with various levels of soybean oil, a common ingredient in commercial salad dressings. The subjects then had their blood tested to measure the absorption of nutrients. Women were chosen for the trial due to differences in the speed with which men and women metabolize the nutrients.
The results showed maximum nutrient absorption occurred at around 32 grams of oil, which was the highest amount studied. However, White said she found some variability among the subjects.
Research collaborators include Yang Zhou, former ISU postdoctoral researcher; Agatha Agustiana Crane, former graduate research assistant in food science and human nutrition; Philip Dixon, a University Professor of Statistics, and Frits Quadt of Quadt Consultancy, among others.
So, a spoonful or two of salad dressing may indeed help derive the optimum nutritional benefit from the veggies.