Search

Objective: To assess whether consumption of 500 m1 of blueberry juice or cranberry juice by healthy female subjects increased plasma phenolic content and antioxidant capacity. Design: Latin square arrangement to eliminate ordering effects. After an overnight fast, nine volunteers consumed 500 ml of blueberry juice, cranberry juice or a sucrose solution (control); each volunteer participated on three occasions one week apart, consuming one of the beverages each time. Blood samples were obtained by venipuncture at intervals up to four hours after consumption of the juices. Urine samples were also obtained four hours after consuming the juice. Results: Consumption of cranberry juice resulted in a significant increase in the ability of plasma to reduce potassium nitrosodisulphonate and Fe(III)-2,4,6-Tri(2-pyridyl)-s-triazine, these measures of antioxidant capacity attaining a maximum after 60-120min. This corresponded to a 30% increase in vitamin C and a small but significant increase in total phenols in plasma. Consumption of blueberry juice had no such effects. Conclusion: The increase in plasma antioxidant capacity following consumption of cranberry juice could mainly be accounted for by an increase in vitamin C rather than phenolics. This also accounted for the lack of an effect of the phenolic-rich but vitamin C-low blueberry juice. Sponsorship: Funded by the Scottish Executive Rural Affairs Department and the Danish Government. Descriptors: vitamin C; phenolics; cranberry; blueberry; antioxidant capacity, Introduction Diets rich in fruits and vegetables are believed to protect against various diseases common in the western world such as cardiovascular disease and several forms of cancer. This beneficial [...]

Boosting dietary levels of polyunsatured fatty acids (PUFAs) may bring about positive changes in cholesterol profiles, according to research designed to establish the impact of changing dietary PUFA intake on indices of oxidative stress. Urinary thiobarbituric acid reactive substances, an index of oxidative stress, showed a substantial fall in both groups on a 5% PUFA diet, indicating a decline in oxidative stress. However, increasing dietary levels of PUFAs could have a negative impact on some indices of lipid peroxidation.

A new study investigates whether consumption of 100 ml of whisky or red wine by healthy male volunteers increases antioxidant capacity and plasma total phenol content. Results show that antioxidant capacity and plasma total phenol content both increased within 30 min of consumption of wine and whisky. The outcome is compatible with the proposal that the risk of coronary heart disease is decreased with moderate alcohol consumption.

The effect of vitamin E supplementation on vitamin E and polyunsaturated fatty acid (PUFA) concentrations in red blood cells (RBC) among smokers was investigated. Thirty male smokers and 30 male nonsmokers were recruited in a study to analyze the effects of vitamin E, RBC PUFA composition and smoking on the susceptibility of the cells to lipid peroxidation. Results showed that the levels of essential fatty acids (EFA) in RBC were higher in nonsmokers than in smokers. Vitamin E supplementation increased the RBC EFA concentrations in smokers.

The effects of cooking and germination on the vitamin C content of beans and pulses rationed to refugee communities with vitamin C deficiency were evaluated. The vitamin C content of different legumes was examined after germination in light and dark using high-pressure liquid chromatography. Results showed that there was a considerable increase in vitamin C concentrations among several species of pulses following germination in both light and dark after cooking. This increase in vitamin C quantities differed significantly between species.

Selenium plays a role in the body's anti-oxidant defense system and may aid in preventing cardiovascular disease. A study on the selenium status of Scottish adults suggested that as much as 90% of the subjects have selenium intake lower than the recommended values. A further study is warranted as the low levels of plasma selenium reported does not correspond to the normal RBC selenium levels obtained.

Use of data from World Health Organization records for 19 western European and five developed, non-European countries in a study of the relationship between national food and nutrient supplies and the rates of mortality due to coronary heart disease (CHD) in men aged less than 65 revealed that the low incidence of CHD in several European countries with high saturated fatty acid consumption is probably the result of dietary alpha-tocopherol. The consumption of vegetable oils, vegetables and wine is inversely proportional to the incidence of CHD while dairy products are positively associated with CHD.

The presence of oxygen and polyunsaturated fatty acids (PUFA:H) in the biological system suggests that lipid peroxidation effects the aetiology of numerous diseases through a pathway involving deformation in cell structure and activities. It is demonstrated that many clinical conditions are ascribed to enhanced lipid peroxidation. Progress of clinical conditions, such as coronary heart problems, is ascribed to free radical invasion of biological molecules, and can be arrested by enhanced dietary administration of antioxidants which block lipid peroxidation activity.

Tsang C, Higgins S, Duthie GG, et al. Br J Nutr 2005;93:233-240. The effects of moderate red wine consumption on the antioxidant status and indices of lipid peroxidation and oxidative [...]

Presents a study which looked at effects of smoking, vitamin E supplementation and red blood cells PUFA composition on the susceptibility of the cells to lipid peroxidation in adult males. Detailed information on the methodology used to conduct the study; Discussion based on the results of the study.