Plasma micronutrient status is improved after a 3-month dietary intervention with 5 daily portions of fruits and vegetables: implications for optimal antioxidant levels

Abstract

To explore the effects of increasing fruit and vegetable intake and the resulting effects on levels of circulating micronutrients in a community-dwelling population with an already high consumption of fruits and vegetables, 112 volunteers (86% women) underwent targeted dietary counseling for three months. At the beginning of the study and after 4, 8 and 12 weeks a food frequency questionnaire was filled in, and plasma levels of dietary antioxidants as well as biomarkers of oxidative lipid and protein damage were determined. Compared to baseline, especially the intake of fruits was significantly improved after 3 months of intervention, and mean plasma levels of lutein, zeaxanthin, β-cryptoxanthin, lycopene, α-and β-carotene, retinol, α-tocopherol, vitamin C and vitamin B6 were increased. Biomarkers of oxidative stress remained unchanged. Thus, a nutritional counseling program is capable of improving plasma levels of antioxidants even in a health-conscious population. A decrease in biomarkers of oxidative stress, however, does not occur. FindingsDietary habits are an important instrument of active care for maintaining the population's health due to the association between antioxidant-rich food intake and the occurrence of age-related diseases [1]. A large part of the population, however, does not meet the recommended daily intake of five portions of fruits and vegetables http:/ /www.5aday.com. Research is still needed on micronutrient requirements for optimal health and adequate vitamin intake. Identification of the conditions favoring initiation and maintenance of a healthy nutrition, especially so in adult working populations as target groups of preventive activities, has become a major health priority.One-hundred twenty-nine employees of a University Hospital in Düsseldorf, Germany, were recruited in the present study. All study participants gave their informed signed consent and followed an intervention plan consisting of 4 two-hour sessions for three months: baseline, T0; 4 weeks, T1; 8 weeks, T2; and 12 weeks, T3. In the sessions, guided by a nutritionist and a physician, participants were motivated to consume at least five portions of

Lycopene and Cardiovascular Diseases: An Update

“…More recently, a study on the supplementation with purified lycopene [224] confirmed that at high dose of 30 mg lycopene/day decreased DNA oxidative damage in lymphocytes and urinary 8-hydroxy-deoxyguanosine while no significant differences were observed for glucose, lipid profile and other biomarkers of lipid peroxidation. Conversely, the study of Polidori et al [230] showed that a good nutritional program (3 month dietary intervention), while improving plasma levels of antioxidants, did not provoke a decrease of oxidative stress biomarkers.…”

Association between oxidative stress and nutritional status in the elderly

“…The authors concluded that the surprising behavior of the MDA may be the result of insufficient ingestion of antioxidants from the diet and could be associated to the insignificant (p>0.05) increase in the levels of α-tocopherol. 92 This same biomarker (MDA) was analyzed in a study conducted in Spain. The authors identified that the ingestion of cooked vegetables above 154.9 grams and moderate ingestion of wine (150 mL) are protectors against oxidative damage (plasmatic MDA).…”

Tomato Phytonutrients Balance UV Response: Results from a Double-Blind, Randomized, Placebo-Controlled Study

“…The plasma was stored at –80°C until analysis for carotenoids such as lycopene, α-, and β-carotene by high-performance liquid chromatography, as previously described [6, 17, 18]. In addition, the colorless carotenoids phytofluene and phytoene were measured because these precursors of carotenoids absorb radiation in the UV range [19, 20].…”