Magda Maranesi

Is the Mediterranean lifestyle still a reality? Evaluation of food consumption and energy expenditure in Italian and Spanish university students

OBJECTIVE To evaluate the correspondence of diet and lifestyle to the Mediterranean model in two groups of Italian and Spanish university students. DESIGN A cross-sectional nutritional survey to determine BMI, dietary habits (FFQ), energy daily expenditure and lifestyle (SenseWear Armband; BodyMedia Inc.), and to define the Mediterranean diet quality index (MDQI) in the different student groups. SETTING Bologna (Italy) and León (Spain). SUBJECTS The survey was carried out on 210 (105 Italian; 105 Spanish) university students (mean age 27.0 (sd 3.8) years) of two different Mediterranean areas, Bologna (Italy) and León (Spain). RESULTS The frequency of consumption of some food groups showed differences related to nationality and gender. Some classic Mediterranean foods such as cereals and vegetables were generally consumed more frequently by Italian students; others such as fish and pulses by Spanish students. Percentage of overweight was higher among Spanish students in spite of their higher physical activity level. CONCLUSION Young generations seem to give up the traditional Mediterranean dietary pattern, adopting new dietary trends. Overweight appears to be related not only to physical activity level, but also to the poor MDQI.

The effect of dietary lipid changes on the fatty acid composition and function of liver, heart and brain mitochondria in the rat at different ages

A correlation between dietary lipids and cellular enzyme activities is a problem that has only been partially addressed by nutritionists. Therefore, changes in the fatty acid composition and the activities of some key metabolic enzymes (ubiquinol-2-cytochrome c reductase (EC 1.10.2.2), cytochrome oxidase (EC 1.9.3.1) and ATPase (EC 3.6.1.3)) in the mitochondria of liver, heart and brain of rats fed on diets differing extensively in their polyunsaturated fatty acid compositions have been investigated. The results showed that fatty acid compositional changes brought about by the dietary differences were associated with extensive changes in the activities of these key enzymes in the mitochondria. The extent of the influence differed considerably with the period over which the diets were fed. The role of dietary lipids to effect changes through the preservation of membrane structural integrity is discussed.

Dietary Selenium for the counteraction of oxidative damage: fortified foods or supplements?

Since any significant modification in the Se status, leading to changes in the activity of the seleno-enzymes, may have important consequences on the susceptibility of tissues to oxidative stress, considerable efforts have been made upon increasing Se dietary intake. In this respect, an important debate is still open about the bioavailability and the effectiveness of Se, and more generally nutrients, in supplements compared with foods. Using male Wistar rats, we have compared the effectiveness of two different diets in which an adequate Se content (0.1 mg/kg) was achieved by adding the element as sodium selenite or as component of a lyophilized Se-enriched food, in the counteraction of an oxidative stress induced by intraperitoneal administration of adriamycin. Both Se-enriched diets were able to reduce the consequences of the oxidative stress in liver, mainly by increasing glutathione peroxidase activity. This increase was more evident in rats fed on the diet enriched with the lyophilized food, probably due to the different chemical forms of Se, or to other components of the food itself. Although further studies are needed, data herein presented may contribute to the characterization of the effectiveness of Se from different sources, foods or supplements, in the light of dietary advice to the population concerning improvement of Se intake.

Effect of Cultivar on the Protection of Cardiomyocytes from Oxidative Stress by Essential Oils and Aqueous Extracts of Basil (Ocimum basilicum L.)

Notwithstanding the wide range of biological and pharmacological activities reported for sweet basil (Ocimum basilicum L.), many discrepancies are still present in the evaluation of its health-promoting properties. These discordances could be at least in part due to insufficient details of qualitative and quantitative composition, connected to the ample variability of this species. Furthermore, many investigations have been carried out in vitro, with few data available on the effectiveness in biological systems. In this study, the protective effect of essential oils and water-soluble extracts derived from three different cultivars of sweet basil has been evaluated in cultured cardiomyocytes. To verify the effectiveness of supplemented oils/extracts in counteracting oxidative damage, cardiomyocytes were stressed by the addition of hydrogen peroxide. The results indicate that (a) in vitro antioxidant activity is not predictive of biological activity and (b) basil can yield extracts with substantially different protective effects, in relation to composition and extraction techniques. Variation among different cultivars has also been detected.

Interaction between vitamin B6 deficiency and low EFA dietary intake on kidney phospholipids and PGE2 in the rat

Vitamin B6 is involved in the metabolism of long chain polyunsaturated fatty acids and phospholipids. We have studied the interaction between pyridoxine deficiency and low amounts of dietary essential fatty acids (EFA) in the rat. The fatty acid composition of kidney phospholipids of pyridoxine deficient animals shows a decrease of 20:3 n9 and an increase of 20:4 n6 in comparison with control and pair fed animals. This variation of fatty acid composition could be due to the simultaneous effect of vitamin B6 deficiency, which reduces the oxidation of linolenate, and of a low intake of EFAs which stimulates delta-6-desaturase. The dietary treatment also influences kidney Prostaglandin E2 (PGE2) levels which are higher in vitamin B6 deficient animals. This effect could be correlated with a higher response to sympathetic stimulation caused by the simultaneous presence of vitamin B6 deficiency and low EFA availability. Also the higher level of arachidonate could be involved in promoting PGE2 synthesis.

Vitamin B6 Deficiency and Dietary Fats: Effects on Lipid Composition and Glutathione Peroxidase Activity in Rat Liver

Dietary selenium, vitamin B6 and fatty acids modulate both tissue acyl composition by regulating polyunsaturated fatty acid metabolism and antioxidant defences by influencing glutathione peroxidase activity. Alteration in the intake of one of them could therefore lead to different results depending on the intake of the others. To clarify this complex relationship, in the present study we have evaluated the modifications occurring in fatty acid composition and glutathione peroxidase activity in total liver and liver microsomes of rats fed diets containing the same amount of selenium, but different vitamin B6 content and fatty acid composition. Our data indicate that both acyl composition and glutathione peroxidase activity are greatly influenced not only by vitamin B6 deficiency, but also by the diet unsaturation degree. This study underlines that not only selenium availability but also other nutrients can modulate glutathione peroxidase activity.

Effect of dietary oils containing graded amounts of 18:3 n-6 and 18:4 n-3 on cell plasma membranes

Abstract Rats were fed diets containing a constant supply of lipids (10% by weight) differing from one another in the content of oleic acid (18:1 n-9), linoleic acid (18:2 n-6), and most peculiar 18-carbon polyunsaturated fatty acids, such as gamma-linolenic (18:3 n-6), alpha-linolenic (18:3 n-3), and stearidonic acid (18:4 n-3). Heart plasma membrane fatty acid composition from rats fed the different diets was affected. The diet containing the highest oleic acid content (olive oil diet) and the lowest PUFA content produced a significant decrease of linoleic acid content, while the oleic acid content was significantly lower when diets contained the lowest oleic acid percentage (black currant oil diet). Similarly, liver plasma membrane fatty acid composition was influenced by the different diets; in particular a significant higher content of the 20:4 n-6 was observed when rats were fed diets containing black currant oil (alone or into a 1:1 mixture with olive oil). Finally, the three diets tested influence only to a low level of significancy the fatty acid composition of the brain plasma membrane. Accordingly, the specific activity of 5′-nucleotidase, a typical cell plasma membrane enzyme, was not affected by diets neither in brain, nor in heart membrane preparations. On the contrary, the 5′-nucleotidase activity was highest in the membrane of liver cells from rats fed olive oil. A correlation between 5′-nucleotidase activity and membrane fatty acid composition cannot be stated in the conditions examined, however, possible biochemical mechanisms as the basis of 5′-nucleotidase behavior are discussed.

Influence of dietary fatty acids on phospholipid composition and prostaglandin E synthesis in rat kidneys

The effects of oils with different amounts of n6 and n3 fatty acid precursors and derivatives were evaluated on phospholipid composition and PGE2 synthesis of rat kidneys. Dietary lipids were: olive oil, an olive-blackcurrant-fish oil mixture and a blackcurrant-fish oil mixture. We observed in the kidneys of rats fed the blackcurrant-fish oil mixture a significant decrease in PGE2 synthesis, while arachidonate values did not show significant variations. A decrease of PGE2 synthesis could be due to competitive and inhibitory effects of fatty acids other than arachidonate, observed in the kidney phospholipid composition in our dietary conditions.

Dietary habits and related psychological and social factors: influence on the body weight of elementary school children.

This article studies the alimentary habits of children in relation to their body mass index (BMI) and food preferences, and to underline the influences of cultural and social aspects. The investigation tested 198 children (90 male and 108 female) from Cento (Ferrara), using food frequency questionnaires that were completed by the children. Subjects were subdivided into three groups based on their BMI—normal weight, overweight and underweight—taking into consideration their food frequency and preferences. The correlations between the BMI of children, mothers geographic origin and cultural level revealed differences between boys and girls. The variability of results does not allow precise correlations to be made between food frequency and childrens weight, psychological and social aspects. Some incorrect dietary habits were revealed in the overweight and underweight groups. These could be controlled for and corrected by an alimentary education programme.

Dietary-induced changes in lipid and fatty acid composition can modify chronaxie values in the rat sciatic nerve

The present investigation aimed at clarifying the possible correlations among dietary lipids, peripheral fatty acid composition of nerve lipids and an index of the nervous tissue excitability, the chronaxie. The experiments were performed on female albino rats fed diets containing olive oil (OO) and fish oil (FO) along two generations. Total lipids fatty acid composition of the sciatic nerves from the two groups differed in the proportions of 18:1(n-9), 20:1(n-9), 22-1, 20:5(n-3) and 22:6(n-3). Also the lipid class composition showed significant differences among FO and OO specimens (free cholesterol more concentrated in the OO lipids; triacylglycerols more concentrated in the FO ones). The sciatic nerve isolated from FO rats showed a significant decrease in the chronaxie values if compared to the OO specimens. These results could follow from dietary-induced changes in the perineural permeability and/or possible modifications in the cable properties of the peripheral nerve fibers related to the myelin sheath composition.