Efficacy of Walnuts and Hazelnuts on the Modification of the Lipid Content of Erythrocyte Membranes in Obese Children. A Randomised Controlled Trial.

Obesity is a problem of ever-growing importance, especially in industrialized countries, widespread both in adults and in the pediatric population.

Children and obese adolescents, like adults, have an increased risk, compared with normal-weight peers, to develop high blood pressure, insulin resistance, diabetes, hyperlipidemia, fatty liver disease and the resulting long-term complications. This cluster of metabolic and hemodynamic risk factors, which is known as metabolic syndrome, greatly increases the risk of cardiovascular events in adults. Cardiovascular disease is the leading cause of mortality and morbidity in developed countries and are becoming even in developing countries. Atherosclerotic disease is the pathophysiological basis of cardiovascular events. Atherosclerosis is a multifactorial disease whose early stages of subclinical damage are documented much earlier in cardiovascular events with non-invasive tests. The determination of the indices of arterial stiffness (PWV, Pulse Wave Velocity; AI, Augmentation Index, SI, Stiffness Index) is possible through techniques currently used for the determination of vascular function even in children. The alteration of the elastic properties of the arteries has been described previously in obese children and adolescents and is considered initial marker atherosclerotic vascular damage. Fats particularly saturated fats, without adequate intake of polyunsaturated fat, may facilitate the development of obesity.

The consumption of some specific foods including dried fruit (in a broad sense including walnuts, hazelnuts, almonds, cashews, etc.) within a reduced calorie diet is considered to be a promising approach in the prevention and care of the different components of the metabolic syndrome. The nuts and hazelnuts are rich in potentially beneficial substances including unsaturated fatty acids, especially omega-6 (present in both) and omega-3 (present only in nuts), L-arginine, fiber, minerals, vitamin E, fitosetrols and polyphenols.

Several clinical trials have already shown in adults a potential beneficial effect of the addition of different types of nuts (walnuts, hazelnuts, cashews, pistachios, etc.) on the characteristics of the metabolic syndrome also through their possible antioxidant and vasoactive effect .

In children, some epidemiological studies have associated a higher consumption of nuts with reduced risk of hypertension, dyslipidemia, obesity and fasting glucose alteration.