Positive Health Online

Abstract

ELMADFA and PARK, Institute of Nutritional Science, University of Vienna, Austria. Ernaehrungswissenschaften@uni.vie.ac  at compared the effects of corn oil and olive/sunflower oil upon DNA damage.

Background

Plant fats and oils are major sources of mono- and polyunsaturated fatty acids, and vitamin E, the major fat-soluble antioxidant in human nutrition. Dietary antioxidants are anticipated to reduce risk of cancer by minimizing DNA damage.

Methodology

The authors conducted a double-blind, study with 20 normal healthy non-smoking males aged 19-31 years. There was a 2-week adjustment period and two 2-week test periods in which diets containing 30% energy as fat included either 80g corn oil (CO) (20 mg alpha-tocopherol, 100 mg gamma-tocopherol) or 80 g olive/sunflower oil (OSO) (24 mg alpha-tocopherol, 2.4 mg gamma-tocopherol). They assessed frequency of sister chromatid exchange (SCE), an indicator of DNA damage. Blood samples for analysis of SCE rate and content of tocopherols were drawn at the beginning (T0), after the adjustment period (T1) and following the test period (T2) in 2 week intervals.

Results

After 2 weeks of corn oil diet, plasma concentration of gamma-tocopherol increased; alpha-tocopherol decreased significantly compared to the olive/sunflower oil diet. Concentration of alpha-tocopherol increased and gamma-tocopherol decreased after the olive/sunflower oil diet. Intake of the corn oil diet was associated with reduced SCE rate and intensity, there no change in SCE with the olive/sunflower oil diet.

Conclusion

The combination of gamma-tocopherol with alpha-tocopherol in the corn oil diet despite the lower alpha-tocopherol equivalents/diene acid equivalents ratio achieved better protection against DNA damage than alpha-tocopherol alone in the olive/sunflower oil diet.

References

Elmadfa I and Park E. Impact of diets with corn oil or olive/sunflower oils on DNA damage in healthy young men. European Journal of Nutrition 38(6): 286-92. Dec 1999.