It is known that the consumption of fruit and vegetables, rich in phytochemicals, has many health benefits. Most scientific studies have been carried out on specific plants such as garlic, cabbage, citrus fruits and tomatoes. Many of these studies have shown that a intake of the specific botanical source is associated with decreased oxidation of DNA and a decreased level of lipid peroxidation markers. The effect of the intake of a botanical diversity of fruits and vegetables is not well studied. The aim of this study was to determine the antioxidant effect of botanical diversity of diets rich in fruits and vegetables. The antioxidant effect was determined by measuring the oxidative biomarkers for lipid peroxidation and DNA damage on 106 women. Urinary 8-isoprostane F2-alfa was measured as an indicator of lipid peroxidation. DNA oxidation was evaluated by measuring the concentration of 8-hydro-2-deoxyguanosine in the lymphocytes.The participants received either a diet containing fruits and vegetables from mainly 5 (low botanical diversity diet) or 18 (high botanical diversity diet) botanical families. The women consumed daily about 9 servings of fruits or vegetables.
The researchers found that only women on the high botanical diversity diet showed a significant reduction of DNA oxidation. Only these women showed a significant (12%) decrease of 8-hydro-2-deoxyguanosine. Both diets resulted in a reduction of lipid peroxidation as shown by a 15 percent decreased of urinary level of 8-isoprostane F2-alfa.
The study concluded that botanical diversity of the fruits and vegetables plays a role in the biological effect of antioxidant phytochemicals. The consumption of smaller quantities of many phytochemicals may result in more health benefits than the consumption of larger quantities of fewer phytochemicals. This result is also underlines the common knowledge that moderation and variety of food sources are important for health.
Source: Thompson HJ, Heimendinger J, Diker A, O'Neill C, Haegele A, Meinecke B, Wolfe P, Sedlacek S, Zhu Z and Jiang W. Dietary botanical diversity affects the reduction of oxidative biomarkers in women due to high vegetable and fruit intake.. Journal of Nutrition. 2006 August;136(8):2207-12