Effect of lifelong coenzyme Q10 supplementation on age-related oxidative stress and mitochondrial function in liver and skeletal muscle of rats fed on a polyunsaturated fatty acid (PUFA)-rich diet.

This study investigates aging-related changes in lipid peroxidation and functionality in liver and skeletal-muscle mitochondria in rats fed a diet rich in polyunsaturated fatty acids (PUFA), depending on supplementation or not with coenzyme Q(10) (CoQ(10)). Two groups of rats were fed for 24 months on a PUFA-rich diet, differing in supplementation or not with CoQ(10). At 6 and 24 months mitochondria were analyzed for fatty acid profile; hydroperoxides; alpha-tocopherol; CoQ(9;) CoQ(10;) cytochromes b, c+c(1), and a+a(3) contents; cytochrome c oxidase activity; and catalase activity in cytosol. Results of this study showed for the supplemented group an age-associated decrease in the peroxidizability index, an increase in catalase activity in skeletal muscle, and modulation of the aging-related changes in different mitochondrial electron-transport-chain components in skeletal muscle. These findings provide mechanisms to explain the effect of CoQ(10) in extending the life span of animals fed a PUFA-rich diet.

Fatty acid composition of nuts--implications for cardiovascular health.

It is well established that, due to their high content of saturated fatty acids (SFA), the intake of meat and meat products is strongly associated with elevated blood cholesterol concentrations and an increased risk of hypertension, diabetes and cardiovascular diseases. Conversely, the intake of foods rich in unsaturated fatty acids, such as those contained in most vegetable fats and oils and oily fish, is associated with improved lipid profiles, a lower potency of intermediate biomarkers of atherosclerosis and lesser incidence of cardiovascular diseases. There are persuasive evidences that dietary substitution of monounsaturated fatty acids (MUFA) or n-6 polyunsaturated fatty acids (PUFA) for SFA lowers blood cholesterol and may have beneficial effects on inflammation, thrombosis, and vascular reactivity. MUFA may have an advantage over PUFA because enrichment of lipoprotein lipids with MUFA increases their resistance to oxidation. Marine n-3 PUFA have a number of anti-atherosclerotic effects, including anti-arrhythmic properties and, at relatively high doses, reduce serum triglycerides. These effects appear to be shared in part by vegetable n-3 PUFA. Nuts are natural foods rich in unsaturated fatty acids; most nuts contain substantial amounts of MUFA, while walnuts are especially rich in both n-6 and n-3 PUFA. Healthy fats in nuts contribute to the beneficial effects of frequent nut intake observed in epidemiological studies (prevention of coronary heart disease, diabetes, and sudden death) and in short-term feeding trials (cholesterol lowering, LDL resistance to oxidation, and improved endothelial function).

Factors influencing the intake and plasma levels of calcium, phosphorus and magnesium in southern Spain.

OBJECTIVE: The aim of the study was to assess factors influencing the intake and plasma levels of calcium (Ca), phosphorus (P) and magnesium (Mg) in an adult population from southern Spain, in order to identify patterns of intake and groups at risk for deficiency. METHODS: A cross-sectional survey was carried out in Andalusia, a western Mediterranean region in southern Spain. Nutrient intakes were studied in a random sample of 3,421 subjects (1,747 men, 1,674 women) between 25 and 60 years of age. Blood samples were obtained for biochemical assays in a random subsample of 354 subjects (170 men, 184 women). Food consumption was assessed by a 48-h recall. Concentrations of Ca, P and Mg were measured in plasma. Information about level of education, smoking habit, alcohol consumption and physical exercise was collected with a structured questionnaire. RESULTS: Intakes were below two-thirds of the RDA in 39.52% of the sample for Ca, and in 32.31% for Mg. Gender, age, educational level, obesity, smoking, alcohol use and physical activity were associated with differences in nutrient intakes. Plasma concentrations were below the reference value in 14.81% of the sample for Ca, and in 8.82% for Mg. Obese persons [body mass index (BMI) >/= 30 kg/m(2)] consumed less Ca, P and Mg, and had lower plasma Ca concentrations (P < 0.05) than non-obese persons. BMI showed an inverse correlation with plasma concentrations of Ca (r = -0.21, P < 0.05). CONCLUSION: Our results provide an estimate of the intake of Ca, P and Mg in the adult population of southern Spain. Of the factors that affected the intake of these nutrients, logistic regression analysis showed that only female gender and older age were associated with the risk of low plasma Ca concentrations.

Age-related mitochondrial DNA deletion in rat liver depends on dietary fat unsaturation.

We fed male Wistar rats lifelong on virgin olive (rich in the monounsaturated oleic acid) or sunflower (rich in the polyunsaturated linoleic acid) oil-based diets. At 6 and 24 months, liver mitochondria were analyzed for a mitochondrial DNA (mtDNA) deletion, reactive oxygen species, antioxidants, and ultrastructural alterations. An aging-related increase in the relative amount of the deletion was observed for both dietary groups, being higher in animals fed sunflower oil. Oxidative stress was lower in virgin olive oil-fed animals. Aging led to higher superoxide dismutase, catalase, and glutathione peroxidase activities and increased alpha-tocopherol and coenzyme Q. Mitochondria from aged animals fed sunflower oil exhibited a lower number of cristae and a higher circularity. Results suggest that the age-related increase of the relative amount of deleted mtDNA depends on fat unsaturation. Moreover, the studied mtDNA deletion was correlated with mitochondrial oxidative stress and ultrastructural alterations.

Coenzyme Q concentration and total antioxidant capacity of human milk at different stages of lactation in mothers of preterm and full-term infants.

Coenzyme Q10(CoQ10) in human milk at different stages of maturity in mothers of preterm and full-term infants and its relation to the total antioxidant capacity of milk is described for the first time. Thirty healthy breastfeeding women provided colostrum, transition-milk and mature-milk samples. Coenzyme Q, alpha-, gamma- and delta-tocopherol, fatty acids and the total antioxidant capacity of the milk were analyzed. Coenzyme Q10 was found at higher concentrations for colostrum (0.81+/-0.06 vs. 0.50+/-0.05 micromol/l) and transition milk (0.75+/-0.06 vs. 0.45+/-0.05 micromol/l) in the full-term vs. the preterm group (similar results were found for total antioxidant capacity). Concentrations of alpha- and gamma-tocopherol were higher in the full-term group and decreased with time. In conclusion, CoQ10 is present in breast milk, with higher concentration in mothers of full-term infants. CoQ10 in breast milk decreases through lactation in mothers delivering full-term infants. Also, CoQ10, alpha- and gamma-tocopherol concentration in human milk directly correlates with the antioxidant capacity of the milk.

Factors associated with obesity in an adult Mediterranean population: influence on plasma lipid profile.

OBJECTIVE: The aim of the study was to identify factors associated with obesity, and their influence on plasma lipid profile in an adult Mediterranean population. DESIGN: The data were obtained from a cross-sectional epidemiological survey. SETTING: The study population resided in Andalusia, a western Mediterranean region in southern Spain. SUBJECTS: The survey was carried out with a random sample of 3421 subjects (1747 men, 1674 women) between 25 and 60 years of age. Blood samples were obtained for biochemical assays in a random subsample of 340 subjects (167 men, 173 women). INTERVENTIONS: Food consumption was assessed by 48-h recall. Height, weight, triceps, biceps, subscapular and suprailiac skinfolds, mid-upper arm, waist (WC) and hip circumferences, glucose, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides were measured. Information about lifestyles was obtained with a questionnaire. RESULTS: Of the adult population we studied, 18.9% were obese (body mass index [BMI] > or = 30 kg/m2). A larger proportion of men than women were overweight, but the opposite was found for obesity. Mean plasma lipid values were not modified significantly by obesity or lifestyle factors, and were within the normal range. Sex, age, physical exercise and lower educational level were associated directly with the risk of obesity, and smoking was associated inversely with the risk of obesity. In obese smokers WC and waist-hip ratio were larger, and levels of HDL-cholesterol were lower (p < 0.05) than in obese nonsmokers. Glucemia was higher in obese persons who consumed alcohol (p < 0.05) than in obese persons who did not consume alcohol. The risk of hypercholesterolemia and high levels of LDL-cholesterol was associated only with age, and the risk of low levels of HDL-cholesterol was associated only with high WC. CONCLUSION: Our results provide an estimate of the prevalence of obesity in the adult population in southern Spain, and of the associated factors. Sex, age, leisure-time physical exercise and educational level appear to influence obesity. Only age and WC but not BMI were associated with a risk of dyslipidemia. No dietary associations were observed between energy or macronutrient intake and plasma lipid concentrations in overweight or obese persons.

Coenzyme Q10 protects from aging-related oxidative stress and improves mitochondrial function in heart of rats fed a polyunsaturated fatty acid (PUFA)-rich diet.

Coenzyme Q(10) supplementation on age-related changes in oxidative stress and function of heart mitochondria in rats fed a polyunsaturated fatty acid (PUFA)-rich diet was investigated. Two groups of rats were fed for 24 months on a PUFA-rich diet, differing in supplementation or not with coenzyme Q(10). Animals were killed at 6, 12, or 24 months. Fatty-acid profile, hydroperoxides, alpha-tocopherol, coenzyme Q, catalase and glutathione peroxidase activities, and cytochromes a+a(3), b, c+c(1) and cytochrome c oxidase activity were measured. Coenzyme Q(10)-supplemented animals showed lower hydroperoxide levels; higher content and/or activity of alpha-tocopherol, coenzyme Q, and catalase; and a slightly lower decrease in mitochondrial function. According to that, previously reported positive effects of coenzyme Q supplementation on the life span of rats fed a PUFA-rich diet might be a consequence, at least in part, of a lower oxidative stress level and perhaps, to a minor extent, of a smaller decrease in mitochondrial function.

Life-long supplementation with a low dosage of coenzyme Q10 in the rat: effects on antioxidant status and DNA damage.

Life-long low-dosage supplementation of coenzyme Q(10) (CoQ(10)) is studied in relation to the antioxidant status and DNA damage. Thirty-two male rats were assigned into two experimental groups differing in the supplementation or not with 0.7 mg/kg/day of CoQ(10). Eight rats per group were killed at 6 and 24 months. Plasma retinol, alpha-tocopherol, coenzyme Q, total antioxidant capacity and fatty acids were analysed. DNA strand breaks were studied in peripheral blood lymphocytes. Aging and supplementation led to significantly higher values for CoQ homologues, retinol and alpha-tocopherol. No difference in total antioxidant capacity was detected at 6 months but significantly lower values were found in aged control animals. Similar DNA strand breaks levels were found at 6 months. Aging led to significantly higher DNA strand breaks levels in both groups but animals supplemented with CoQ(10) led to a significantly lower increase in that marker. Aged rats showed significantly higher polyunsaturated fatty acids. This study demonstrates that lifelong intake of a low dosage of CoQ(10) enhances plasma levels of CoQ(9), CoQ(10), alpha-tocopherol and retinol. In addition, CoQ(10) supplementation attenuates the age-related fall in total antioxidant capacity of plasma and the increase in DNA damage in peripheral blood lymphocytes.

Nutrient intake adequacy in schoolchildren from a Mediterranean area (southern Spain). Influence of the use of the school canteen.

The aim of the present study was to compare dietary adequacy in 521 schoolchildren in Granada (Spain) with national recommendations and to determine possible differences regarding gender or the use of the school canteen. A food record was used for four consecutive days to evaluate the intake of nutrients and foods. With regard to boys' and girls' intake of the main groups of foods, we observed a tendency for the boys to consume greater quantities of dairy products, cereals, potatoes, and fruit, although the differences were not statistically significant. The children who lunched at school consumed fish, eggs, dairy products, vegetables, and cereals more frequently than those who did so at home. The mean daily intake of energy and nutrients indicates that the studied population exceeded the recommended limits in the proportion of energy derived from protein and fat, while carbohydrate intake was slightly deficient. The children who lunched at school showed a more favorable profile for energy and nutrient intake, with a significantly higher intake of energy, carbohydrates, total fat, polyunsaturated fatty acids (PUFA), monounsaturated fatty acids (MUFA), vitamins B, and E, and calcium, with respect to the children who had lunch at home.

Dietary fat type (virgin olive vs. sunflower oils) affects age-related changes in DNA double-strand-breaks, antioxidant capacity and blood lipids in rats.

This study was designed to investigate the possible effect on DNA double-strand breaks, antioxidant capacity and blood lipids of feeding rats lifelong with two different dietary fat sources: virgin olive oil (rich in the monounsaturated oleic acid) or sunflower oil (rich in the polyunsaturated linoleic acid). No changes in mean or maximal lifespan were observed. Overall, aging led to increased levels of plasma cholesterol, triglycerides, phospholipids, total lipids, polyunsaturated fatty acids and DNA double-strand breaks. All these parameters were higher in animals fed on sunflower oil diet. Aging diminished total antioxidant capacity with both diets, but in a lower extension for virgin olive oil diet. A very good inverse correlation (r= -0.715; P < 0.01, for sunflower oil group and r= -0.535; P < 0.01 for virgin olive oil group) between DNA damage and total antioxidant capacity was found. These results allow to conclude that dietary fat type should be considered in studies on aging, since the intake of oils with different polyunsaturation levels directly modulates total antioxidant capacity of plasma, DNA damage to peripheral blood lymphocytes and lead to important changes at the lipid metabolism level. In the present study best results were found after intake of virgin olive oil, which suggest the possible use of that edible oil to provide a healthier aging.

Coenzyme Q supplementation protects from age-related DNA double-strand breaks and increases lifespan in rats fed on a PUFA-rich diet.

This study investigates the usefulness of a long-term supplementation with coenzyme Q(10) in rats from the point of view of lifespan, DNA double-strand breaks and to assess whether this supplementation might attenuate oxidative alterations related to PUFA-rich diets, which would allow to preserve beneficial aspects of PUFA on health avoiding their deleterious aspects. Supplemented animals showed higher concentration of coenzyme Q(10) in liver mitochondria, lower levels of DNA double-strand breaks in peripheral blood lymphocytes. Animals supplemented on coenzyme Q reached a significantly higher mean life span (11,7% higher, i.e. 2,5 months) and a significantly higher maximum life span (24% higher, i.e. 6 months) than non-supplemented animals. These results suggest that a long-term supplementation with a small dosage of coenzyme Q(10) might represent a good anti-aging therapy in rats fed on a PUFA-based diet.

Effects of lifestyle modification and lipid intake variations on patients with peripheral vascular disease.

The aim of the present study was to evaluate the effects of diets enriched in monounsaturated fatty acids (MUFA) (olive oil) or MUFA plus n-3 polyunsaturated fatty acids (PUFA) (olive oil plus fish oil), associated with an intervention program that focused on lifestyle habits, physical performance, plasma lipids, and lipoprotein composition in patients with peripheral vascular disease (PVD). A 15-month longitudinal nutritional and lifestyle intervention study was carried out with 24 free-living male patients aged 58.0 +/- 2.2 years diagnosed with PVD (Fontaine grade II). The patients were clinically evaluated and counseled to change their dietary and lifestyle habits for six months, after this period they consumed an olive oil-based diet for three months: after a three-month wash-out period, their diet was supplemented with a combination of fish oil and olive oil for the final three months. Lifestyle interventions resulted in a significant decrease in cigarette smoking and an increase in physical activity. Claudicometry was lower at the end of the study than at the beginning. Intake of the fish oil supplement led to significant changes in lipid lipoprotein composition, decreasing low-density lipoprotein (LDL) cholesterol. The lifestyle intervention program, together with a high intake of olive plus fish oil, seems to produce important beneficial effects in nutritional management, physical performance, and clinical parameters of PVD patients.

Aging-related oxidative stress depends on dietary lipid source in rat postmitotic tissues.

We investigate mitochondrial-lipid peroxidation of mitotic (liver) and postmitotic (heart and skeletal muscle) tissues of rats fed lifelong on two different lipid sources: virgin olive oil (monounsaturated fatty acids) and sunflower oil (n - 6 polyunsaturated fatty acids). Two groups of 80 rats each were fed over 24 months on a diet differing in the lipid source (virgin olive oil or sunflower oil). Twenty rats per group were killed at 6, 12, 18, and 24 months; liver, heart, and skeletal muscle mitochondria were isolated and the lipid profile, hydroperoxides, vitamin E, and ubiquinone as well as catalase activity measured. Lipid peroxidation was higher in postmitotic tissues, and sunflower oil led to a higher degree of polyunsaturation and peroxidation. The levels of alpha-tocopherol adapted to oxidative stress and preferentially accumulated during aging in heart and skeletal muscle. In conclusion, the type of dietary fat should be considered in studies on aging, since oxidative stress is directly modulated by this factor. This study confirms that postmitotic tissues are more prone to oxidative stress during aging and proposes a hypothesis to explain this phenomenon.

Oxidative stress in patients undergoing cardiac surgery: comparative study of revascularization and valve replacement procedures.

OBJECTIVE: The aim of this study was to evaluate the time course of oxidative stress markers in plasma and erythrocyte from patients undergoing open heart surgery with cardiopulmonary bypass (CPB) and to examine whether the type of surgical technique used (valve replacement or coronary revascularization) produces any differences in these makers. PATIENTS AND METHODS: Twenty-two patients undergoing cardiac surgery with CPB were divided in 2 groups (valve replacement or coronary revascularization). We took 5 blood samples at different times during cardiac surgery and analyzed thiobarbituric acid reactive substances (TBARS), alpha-tocopherol, coenzyme Q, and retinol in plasma and TBARS (baseline levels and induced by Fe(2+)-ascorbate oxidation), alpha-tocopherol, coenzyme Q and catalase, superoxide dismutase, and glutathione peroxidase activity in erythrocyte. RESULTS: Plasma alpha-tocopherol content decreased after starting CPB in both groups. In contrast, in erythrocytes there was an increase in the activity or concentration of all of the antioxidants. Erythrocyte TBARS contents, both baseline levels and induced levels, were higher in coronary revascularization group. CONCLUSION: Although both groups suffered an increase in oxidative stress after CPB, this increase was higher in coronary revascularization group and therefore the possibility of post-CPB complications could be more severe in this group. As the groups followed a different pattern of antioxidant response, a different therapeutic approach may be required for each.

Oxidative stress in erythrocytes from premature and full-term infants during their first 72 h of life.

OBJECTIVE: The aim of this study was to evaluate the extent of lipid peroxidation and the response of the enzymatic and non-enzymatic antioxidant defence system in erythrocytes from full-term and premature infants at birth, after 3 and after 72 h of life. STUDY DESIGN: Twenty infants were selected and divided in two groups according to their gestational age. Blood samples were taken at birth, at 3 and at 72 h of life, erythrocytes were isolated and the following parameters were measured: fatty-acid profile, coenzyme Q, alpha-tocopherol, hydroperoxides and the activity of the antioxidant enzymes catalase, superoxide dismutase (SOD) and cytosolic glutathione peroxidase (cGPx). RESULTS: For the three studied periods, several differences between full-term and premature infants were found. Premature children showed a higher concentration of hydroperoxides, a lower level of alpha-tocopherol and lower SOD and cGPx activity (except for cGPx at birth). Moreover, n-3 polyunsaturated fatty-acids percentages (essential for good neonatal development) were higher in full term children throughout all the study. CONCLUSION: Results suggest a strong imbalance between oxidants and antioxidants in premature infants during their first 72 h of life, a situation which could lead to several pathologies. Therefore, further research is needed, including possible nutritional intervention (with antioxidant therapy, supplementation of essential fatty acids and other dietary constituents) before and after birth.

Body composition assessed by anthropometry and bioelectric impedance analysis in older persons recovering from cerebrovascular accident.

We investigated body composition in older patients who had experienced a cerebrovascular accident (CVA) and were participating in a recovery program that included physical exercise. We studied 61 persons in two groups. One group consisted of 13 men and 12 women (mean age, 68 years) who were receiving day center care to recover from a CVA that had occurred from six months to one year previously. The second group (control) consisted of 20 men and 16 women (mean age, 68 years) in good health, residing in a retirement home. Most subjects in both groups were able to perform normal activities of daily living without help and showed a high degree of independence (> 60 on the Barthel scale). Bioelectric impedance and anthropometric methods were used to measure the magnitude of changes in fat-free mass and fat mass. Percentage total body fat measured with bioelectric impedance was higher in both groups than when measured anthropometrically. The anthropometric values and bioelectric impedance results in patients who participated in a physical exercise program were similar to the findings in control subjects. The anticipated loss in muscle mass and gain in body fat as a result of inactivity associated with illness was not seen, possibly because of the personalized program of continuous physical exercise. Our comparison of older people recovering from CVA and apparently healthy older people illustrates the benefits of physical exercise in compensating for changes in body composition as a result of immobility during convalescence.

Dietary fat (virgin olive oil or sunflower oil) and physical training interactions on blood lipids in the rat.

OBJECTIVE: We investigated whether the intake of virgin olive oil or sunflower oil and performance of physical exercise (at different states) affect plasma levels of triacylglycerols, total cholesterol, and fatty acid profile in rats. METHODS: The study was carried out with six groups of male rats subjected for 8 wk to a diet based on virgin olive oil (three groups) or sunflower oil (three groups) as dietary fat. One group for each diet acted as sedentary control; the other two groups ran in a treadmill for 8 wk at 65% of the maximum oxygen consumption. One group for each diet was killed 24 h after the last bout of exercise and the other was killed immediately after the exercise performance. Triacylglycerols, total cholesterol, and fatty acid profile were analyzed in plasma. Analysis of variance was used to test differences among groups. RESULTS: Animals fed on virgin olive oil had lower triacylglycerol and cholesterol values. Physical exercise reduced these parameters with both dietary treatments. Fatty acid profile showed higher monounsaturated fatty acid proportion in virgin olive fed oil animals and a higher omega-6 polyunsaturated fatty acid proportion in sunflower oil fed animals. Physical exercise reduced the levels of monounsaturated fatty acids with both diets and increased the proportions of omega-3 polyunsaturated fatty acids. CONCLUSIONS: Results from the present study supported the idea that physical exercise and the intake of virgin olive oil are very good ways of reducing plasma triacylglycerols and cholesterol, which is desirable in many pathologic situations. Concerning findings on fatty acid profile, we had results similar to those of other investigators regarding the effect of different sources of dietary fat on plasma. The most interesting results came from the effect of physical exercise, with significant increases in the levels of omega-3 polyunsaturated fatty acids, which may contribute to the antithrombotic state and lower production of proinflammatory prostanoids attributed to physical exercise.

Antioxidant nutrients and adriamycin toxicity.

The anthracycline antibiotic adriamycin (doxorubicin) is one of the most effective chemotherapeutic agents against a wide variety of cancers. However, its use is seriously limited by the development in the heart of acute and chronic toxic effects. Mechanisms of action and toxicity of adriamycin are briefly revised in this review. Among followed strategies to attenuate adriamycin toxicity are dosage optimisation, synthesis and use of analogues or combined therapy with antioxidants. The most promising results come from the combination of the drug delivery together with an antioxidant in order to reduce oxidative stress. Many antioxidants have been assayed with very different results. Among these molecules, metal ions chelators and low-molecular-mass agents that scavenge reactive oxygen species and that are synthesised in vivo have been widely studied. However, the present review will be exclusively focused on the antioxidants that are derived from the diet, in particular the role of vitamin E, vitamin C, vitamin A, coenzyme Q, flavonoids, antioxidant components of virgin olive oil and selenium.

The intake of fried virgin olive or sunflower oils differentially induces oxidative stress in rat liver microsomes.

The effects of non-fried and fried virgin olive and sunflower oils on rat liver microsomal compositional features have been investigated. In addition, plasma antioxidants (alpha-tocopherol and ubiquinone 9) were investigated as well as the possible oxidative modifications suffered by virgin olive and sunflower oils during the frying process. The frying process decreased the content of alpha-tocopherol and phenolics in the oils and increased total polar materials. Sunflower oil was affected to a greater extent than olive oil. In rats, the intake of fried oil led to higher levels of lipid peroxidation and a lower concentration of plasma antioxidants. Microsomal fatty acid and antioxidant profiles were also altered. It seems that a strong relationship exists between the loss of antioxidants and the production of toxic compounds in the oils after frying and the extent of the peroxidative events in microsomes, which were also different depending on the fat source. The highly unsaturated sunflower oil was less resistant to the oxidative stress produced by frying and led to a higher degree of lipid peroxidation in liver microsomes in vivo than virgin olive oil.

Structural damage induced by peroxidation may account for functional impairment of heavy synaptic mitochondria.

Coenzyme Q distribution, as well as respiratory chain features, in rat brain mitochondria depend on mitochondrial subpopulation, brain region and age. Heavy mitochondria (HM) usually display the lowest content of respiratory components and the lowest enzymatic activities and it has been suggested that they represent the oldest mitochondrial population. In this study, we confirmed that HM are considerably compromised in their structure. In fact, HM showed to have the highest hydroperoxide content and the most consistent modifications in their fatty acid pattern with wide loss of fatty acids (or part of them) in the phospholipid moiety. Such situation could explain the typical impairment of HM and could support the hypothesis that they represent an old mitochondrial population.