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

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

Phospholipid oxidation and carotenoid supplementation in Alzheimer’s disease patients

Alzheimer's disease (AD) is a progressive, neurodegenerative disease, characterised by decline of memory, cognitive function and changes in behaviour. Generic markers of lipid peroxidation are increased in AD, therefore reactive oxygen species have been suggested to be involved in the aetiology of cognitive decline. Carotenoids are depleted in AD serum, therefore we have compared serum lipid oxidation between AD and age-matched control subjects before and after carotenoid supplementation. The novel oxidised phospholipid biomarker 1-palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC) was analysed using electrospray ionization tandem mass spectrometry (MS) with multiple reaction monitoring (MRM), 8-isoprostane (IsoP) was measured by ELISA and ferric reducing antioxidant potential (FRAP) was measured by a colorimetric assay. AD patients (n=21) and healthy age-matched control subjects (n=16) were supplemented with either Macushield™ (10 mg meso-zeaxanthin, 10 mg lutein, 2 mg zeaxanthin) or placebo (sunflower oil) for six months. The MRM-MS method determined serum POVPC sensitively (from 10 µl serum) and reproducibly (CV=7.9%). At baseline, AD subjects had higher serum POVPC compared to age-matched controls, (p=0.017) and cognitive function was correlated inversely with POVPC (r=−0.37; p=0.04). After six months of carotenoid intervention, serum POVPC was not different in AD patients compared to healthy controls. However, POVPC was significantly higher in control subjects after six months of carotenoid intervention compared to their baseline (p=0.03). Serum IsoP concentration was unrelated to disease or supplementation. Serum FRAP was significantly lower in AD than healthy controls but was unchanged by carotenoid intervention (p=0.003). In conclusion, serum POVPC is higher in AD patients compared to control subjects, is not reduced by carotenoid supplementation and correlates with cognitive function

Nutritional hormesis in a modern environment

Nutrition is a powerful determinant of health and well-being. In the modern environment where energy-rich foods are prevalent, challenges exist to improve diets that will provide an appropriate energy density while maintaining the required nutritional value. A recent concept in nutrition is that components of food which are not abundant in the diet may exert a regulatory effect on physiological and biological processes. Some of these components appear to act as hormetins, i.e., they exert a mild stress and in turn elicit and adaptive response that offers greater health advantages than the stress itself. Therefore, nutritional hormesis play a vital role in the modern aging population by modulating the susceptibility to diseases. Adequate and appropriate dietary levels of hormetic phytochemicals; polyphenols, carotenoids, sulforaphane, and other bioactive compounds have been recognized as activators of intracellular signaling cascades and modifiers of gene expression with health benefits. Research to date has focused on individual hormetins in isolation, however, the bioavailability, bioaccessibility, and potential for interaction of these compounds in combination through acting on distinct intracellular signaling pathways are of significance in the human body. As the modern world’s population ages chronologically, yet biologically at different rates, it is increasingly important to understand how nutrition and hormetins within the diet could reduce risk for age-associated disease. Further work is needed in the field of nutrigenomics to identify the key biochemical targets that are modifiable by hormetins.N/