Long life to olive oil and wine! Long life with olive oil and wine?

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Last but not least, good commentary:

Journal of Hypertension:Volume 26(2)February 2008p 186-187

Long life to olive oil and wine! Long life with olive oil and wine?

[Editorial commentaries]

Versari, e; Ghiadoni, Lorenzo; Taddei, Stefano

Department of Internal Medicine, University of Pisa, Italy

Correspondence to Stefano Taddei, Department of Internal Medicine,

University of Pisa, Via Roma 67, 56100 Pisa, Italy Tel: +39 050

992914; fax: +39 050 553407; e-mail: s.taddei@...

It is well known that among European countries, those in the

Mediterranean area, including Italy, France, Spain, and Portugal show

a lower mortality for cardiovascular diseases compared to those in

Northern Europe and even more to those in Eastern European countries

[1]. The most likely explanation for this phenomenon is related to the

Mediterranean diet. Indeed, the Scientific Advisory Committee of the

American Heart Association underscores the importance of a

Mediterranean-style diet to obtain a beneficial effect on the onset

and progression of cardiovascular disease [2]. Recently, this diet was

demonstrated to be associated with an improvement in endothelial

function and a reduction of markers of systemic vascular inflammation

in high-risk patients [3].

Traditional Mediterranean diet is rich in vegetables, fruits, cereals,

and legumes, with relative low meat consumption. Calories from fat are

25-35% and saturated fats are only 7-8% of total calories. The main

source of fat is represented by olive oil, which has been demonstrated

to have antiatherosclerotic properties. These are partly related to

its content in cholesterol-lowering monounsaturated fatty acids, and

partly to the nonsaponifiable fraction (0.5-1%), containing vitamins

such as & #945;- and & #947;-tocopherols, & #946;-carotene, phytosterols, pigments,

terpenic acids, flavonoids (e.g. luteolin and quercetin), squalene and

other phenolic compounds [4]. The most abundant olive oil phenols are

the secoiridoid oleuropein, hydroxytyrosol

(3,4-dihydroxyphenylethanol), and tyrosol. These cathecholic compounds

show a potent antioxidant activity [4].

Another fundamental component of the Mediterranean diet is represented

by wine. Ethanol, in general, has a whole range of cardiovascular

protective effects when consumed in low to moderate doses, with

favorable changes in lipid metabolism, insulin sensitization,

antioxidant effects, inhibition of platelet aggregation, improvement

in endothelial function, and anti-iflammatory property [5]. Besides

ethanol, wine appears to be more cardioprotective than beer, and in

particular, red wine has components such as polyphenols and quercetin,

with putative additional beneficial effects over white wine [6,7].

In the present issue of the Journal of Hypertension, Papamichael et

al. [8] report the results of a study evaluating the combined

postprandial effects of wine and olive oil on wave reflections and

central hemodynamics. Fifteen healthy subjects consumed, on different

days, four standard meals containing 50 g of olive oil and 250 ml of

wine, in a randomized cross-over study design. The authors used the

four possible combinations with two types of wine (red and white) and

two types of olive oil (green and refined), rich and poor in

antioxidants, respectively. Arterial stiffness was evaluated by

applanation tonometry and aortic pulse wave analysis under basal

conditions and 1, 2 and 3 h postprandially, calculating aortic blood

pressures, and augmentation index (AIx). Firstly, all combinations

were able to decrease AIx compared with control group. Moreover, the

combinations containing red wine were characterized by a more

prolonged effect compared with those with white wine. Finally, all

combinations induced a significant decrease in central blood pressure

values. The authors conclude that combined consumption of wine and

olive oil provides beneficial effects on postprandial hemodynamics.

The present study might have important clinical implications. Firstly,

postprandial state, mainly after a high-calorie meal, is characterized

by a rise in blood glucose, triglycerides and free fatty acids [9]. As

a consequence, the overload with caloric substrates overwhelms the

Krebs cycle inside adipocytes, and muscle cells and the cellular

levels of NADH reach a level that cannot be processed through the

oxidative phosphorylation. The increase in mitochondrial proton

gradient that follows drives the transfer of single electrons to

oxygen, producing superoxide anions and other radicals [9].

Eventually, the postprandial state is a high oxidative stress state

that triggers various proatherosclerotic mechanisms, including

endothelial dysfunction, vascular inflammation, sympathetic activity,

thrombogenicity, and oxidation of LDL [9]. As reported by Papamichael

et al. [8], an increase in arterial stiffness might also follow a

standard meal, probably in relation to the mentioned mechanisms.

Although theoretically transitory in relation to the postprandial

state, these phenomena are conceivably greatly relevant in human

atherothrombosis when repeated multiple times during the day, and it

is calculated that Americans spend most of their waking time in

postprandial state [9]. Therefore, the implementing of strategies to

reduce the postprandial dysmetabolism might confer a potential

protection on the cardiovascular system. The result of the study by

Papamichael et al. [8] together with data present in the literature

suggests that some of the components of the Mediterranean diet might

'naturally' protect through their antioxidant activity as well as

other still unknown mechanisms.

Secondly, the authors did not find astounding differences among the

study intervention regimens. Although evidences are not strong yet,

red wine is usually considered more cardioprotective than white wine.

Indeed, in human studies de-alcoholized red but not white wine

possesses cardiovascular benefits [6], likely related to the presence

of polyphenols, such as resveratrol in red wine. The study by

Papamichael et al. [8] was able only to demonstrate a longer duration

of the protection against AIx increase in the two study groups

assigned to red wine as compared to those assigned to white wine. It

is, however, worthy of note that AIx and arterial stiffness are

integrated indexes of complex mechanisms affecting the large arteries

structure and function [10]. Therefore, it is not surprising that the

benefit obtained with red wine on these parameters is only modest,

considering that only the acute effect was investigated. It is likely

that a study design with a prolonged treatment period and longer

follow-up might unveil additional benefit achievable with various

combinations of different types of wine and oils also on parameters of

large arteries function such as AIx.

Another important issue concerns the putative underestimation of the

effect of the used dietary regimens in a healthy population such as

that studied by Papamichael et al. [8]. It is conceivable that in

higher risk populations a stronger discriminative power would allow

detection of differences among the groups.

In conclusion, the paper by Papamichael strengthens the hypothesis

that the combination of two main components of the Mediterranean diet,

olive oil and wine, can be a valid tool to prevent vascular damage,

and in particular, arterial stiffening, apparently in part

independently from the type of the nutrient (red versus white wine,

green versus refined oil). Whether the combination of oil and wine is

superior to each of the two, however, cannot be derived from the

study. Finally, the long-term significance of this finding is not

known and should be further investigated.

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