Olive oil consumption, plasma oleic acid, and stroke incidence: the Three-City Study.

OBJECTIVE: To determine whether high olive oil consumption, and high plasma oleic acid as an indirect biological marker of olive oil intake, are associated with lower incidence of stroke in older subjects. METHODS: Among participants from the Three-City Study with no history of stroke at baseline, we examined the association between olive oil consumption (main sample, n = 7,625) or plasma oleic acid (secondary sample, n = 1,245) and incidence of stroke (median follow-up 5.25 years), ascertained according to a diagnosis validated by an expert committee. RESULTS: In the main sample, 148 incident strokes occurred. After adjustment for sociodemographic and dietary variables, physical activity, body mass index, and risk factors for stroke, a lower incidence for stroke with higher olive oil use was observed (p for trend = 0.02). Compared to those who never used olive oil, those with intensive use had a 41%(95% confidence interval 6%-63%, p = 0.03) lower risk of stroke. In the secondary sample, 27 incident strokes occurred. After full adjustment, higher plasma oleic acid was associated with lower stroke incidence (p for trend = 0.03). Compared to those in the first tertile, participants in the third tertile of plasma oleic acid had a 73% (95% confidence interval 10%-92%, p = 0.03) reduction of stroke risk. CONCLUSIONS: These results suggest a protective role for high olive oil consumption on the risk of stroke in older subjects.

Increased selenium intake in elderly high fish consumers may account for health benefits previously ascribed to omega-3 fatty acids.

OBJECTIVE: To examine relationships between fish consumption and plasma selenium (Se) and red blood-cell fatty acid (RBC FA) profile in aged subjects. We hypothesised that the importance of Se has been underestimated when interpreting the beneficial effect of fish consumption on health. DESIGN: Cross-sectional analysis of data from a prospective cohort study. SETTING: The EVA study in Nantes, France (1991-2002). SUBJECTS: 200 subjects aged > or = 69 y with information on RBC FAs, plasma Se and completed food frequency questionnaires. METHODS: We examined correlations between the most abundant FAs, Se and number of fish meals per week. Linear regression models were used. RESULTS: Plasma Se was negatively correlated with RBC omega6 poly-unsaturated FA (PUFAs) and positively with omega3 PUFAs. Plasma Se, RBC omega3 PUFAs, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) increased with fish consumption. Conversely, levels of omega6 PUFAs were lower in the highest fish consumption group. All associations between plasma Se and fish consumption remained significant when adjusting for omega6 PUFAs alone or additionally for age, sex, education, diabetes, hypertension, dyslipidemia, cardiovascular diseases, and broad food categories (meat, eggs, dairy products, cereals, fruit and vegetable). Associations between omega3 PUFAs and fish also remained significant in the same model independently of Se. In linear regression models adjusted for demographic indicators, fish consumption explained only 2.6% of the variance in RBC omega3 FAs (6.2% for omega6) but as much as 15% of the variance in plasma selenium. CONCLUSIONS: The observed health benefits of fish consumption in the elderly could be related not only to the increase in omega3 FA intake but also to other nutrients such as selenium. It is important to consider this observation when interpreting associations between fish consumption and health status in the elderly, particularly with regard to brain function.

Dietary patterns and risk of dementia: the Three-City cohort study.

BACKGROUND: Dietary fatty acids and antioxidants may contribute to decrease dementia risk, but epidemiologic data remain controversial. The aim of our study was to analyze the relationship between dietary patterns and risk of dementia or Alzheimer disease (AD), adjusting for sociodemographic and vascular risk factors, and taking into account the ApoE genotype. METHODS: A total of 8,085 nondemented participants aged 65 and over were included in the Three-City cohort study in Bordeaux, Dijon, and Montpellier (France) in 1999-2000 and had at least one re-examination over 4 years (rate of follow-up 89.1%). An independent committee of neurologists validated 281 incident cases of dementia (including 183 AD). RESULTS: Daily consumption of fruits and vegetables was associated with a decreased risk of all cause dementia (hazard ratio [HR] 0.72, 95% CI 0.53 to 0.97) in fully adjusted models. Weekly consumption of fish was associated with a reduced risk of AD (HR 0.65, 95% CI 0.43 to 0.994) and all cause dementia but only among ApoE epsilon 4 noncarriers (HR 0.60, 95% CI 0.40 to 0.90). Regular use of omega-3 rich oils was associated with a decreased risk of borderline significance for all cause dementia (HR 0.46, 95% CI 0.19 to 1.11). Regular consumption of omega-6 rich oils not compensated by consumption of omega-3 rich oils or fish was associated with an increased risk of dementia (HR 2.12, 95% CI 1.30 to 3.46) among ApoE epsilon 4 noncarriers. CONCLUSION: Frequent consumption of fruits and vegetables, fish, and omega-3 rich oils may decrease the risk of dementia and Alzheimer disease, especially among ApoE epsilon 4 noncarriers.

IANA task force on nutrition and cognitive decline with aging.

Cognitive impairment can be influenced by a number of factors. The potential effect of nutrition has become a topic of increasing scientific and public interest. In particular, there are arguments that nutrients (food and/or supplements) such as vitamins, trace minerals, lipids, can affect the risk of cognitive decline and dementia, especially in frail elderly people at risk of deficiencies. Our objective in this paper is to review data relating diet to risk of cognitive decline and dementia, especially Alzheimer's disease (AD). We chose to focus our statements on homocysteine-related vitamins (B-vitamins), antioxidant nutrients (vitamins E and C, carotenoids, flavonoids, enzymatic cofactors) and dietary lipids. Results of epidemiological studies may sometimes appeared conflicting; however, certain associations are frequently found. High intake of saturated and trans-unsaturated (hydrogenated) fats were positively associated with increased risk of AD, whereas intake of polyunsaturated and monounsaturated fats were protective against cognitive decline in the elderly in prospective studies. Fish consumption has been associated with lower risk of AD in longitudinal cohort studies. Moreover, epidemiologic data suggest a protective role of the B-vitamins, especially vitamins B9 and B12, on cognitive decline and dementia. Finally, the results on antioxidant nutrients may suggest the importance of having a balanced combination of several antioxidant nutrients to exert a significant effect on the prevention of cognitive decline and dementia, while taking into account the potential adverse effects of these nutrients. There is no lack of attractive hypotheses to support research on the relationships between nutrition and cognitive decline. It is important to stress the need to develop further prospective studies of sufficiently long duration, including subjects whose diet is monitored at a sufficiently early stage or at least before disease or cognitive decline exist. Meta analyses should be developed, and on the basis of their results the most appropriate interventional studies can be planned. These studies must control for the greatest number of known confounding factors and take into account the impact of the standard social determinants of food habits, such as the regional cultures, social status, and educational level.

Cognitive decline is associated with systemic oxidative stress: the EVA study. Etude du Vieillissement Artériel.

OBJECTIVE: To determine whether systemic oxidative stress status is associated with cognitive decline. DESIGN: A longitudinal population-based study. SETTING: A cohort study of older subjects in Nantes, France. PARTICIPANTS: A total of 1166 high cognitive functioning subjects aged 60 to 70 in the Etude du Vieillissement Arteriel (EVA) cohort with a 4 year follow-up. MEASUREMENTS: Subjects completed a baseline interview and a global cognitive test (Mini-Mental Status Examination (MMSE)). Blood samples were obtained at baseline to determine plasma levels of selenium, carotenoids, thiobarbituric acid reactant substances (TBARS), an indicator of lipoperoxidation, and red blood cell vitamin E. Risk of cognitive decline, defined as a loss of 3 points in MMSE score between baseline and the 4 year follow-up, was assessed by oxidative stress level. RESULTS: Subjects with the highest levels of TBARS show an increased risk of cognitive decline (adjusted odds ratio (OR) = 2.25; confidence interval (CI) 95% = 1.26-4.02). This result is reinforced in the lower antioxidant status subgroup. Subjects with low levels of selenium have an increased risk of cognitive decline (OR = 1.58; CI 95% = 1.08-2.31) after adjustment for various confounding factors. CONCLUSIONS: These results suggest that increased levels of oxidative stress and/or antioxidant deficiencies may pose risk factors for cognitive decline. The direct implication of oxidative stress in vascular and neurodegenerative mechanisms that lead to cognitive impairment should be further explored.

Systemic oxidative stress and cognitive performance in the population-based EVA study. Etude du Vieillissement Artériel.

The aim of this study was to examine the relationships between cognitive functioning and blood levels of antioxidants and lipoperoxidation products in an elderly population. In 1991-1992, 1389 volunteers (574 men and 815 women aged 59 to 71 years) were recruited from the general population. Levels of selenium, carotenoids, and thiobarbituric-reactive substances in plasma and of vitamin E, glutathione peroxidase, and Cu-Zn superoxide dismutase in red blood cells were measured. Cognitive functioning was assessed with various psychometric tests. We used logistic regression to estimate the risk of poor cognitive functioning (< 25th percentile of the score distribution) associated with low values of each antioxidants (< 25th percentile) including potential confounding factors. A low level of total carotenoids (< 1.86 mumol/l) was associated with poor cognitive performance in two tests assessing visual attention and logical reasoning: the Trail-Making Test part B [OR = 1.34 IC95% (0.99-1.81), p = .055] and the Digit Symbol Substitution from the WAIS-R [OR = 1.38 IC95% (1.02-1.89), p = .04]. Low levels of other antioxidants and high levels of thiobarbituric-reactive substances were not related to poor cognitive functioning. Results observed with plasma carotenoids are in accordance with previous data obtained mostly from dietary records.

Demographic and cardiovascular risk factors in relation to antioxidant status: the EVA Study.

The aim of the study was to examine the determinants of blood antioxidant indicators on a large sample. Levels of plasma selenium and carotenoids, vitamin E in red blood cells, and thiobarbituric acid reactive substances (TBARS) were determined. The cross-sectional relationships between these markers and demographic and cardiovascular risk factors were examined in participants of the EVA study, a cohort of 1389 men and women, aged 59-71 years. Multivariable regression models including demographic (age, sex, socio-economic level), lifestyle (alcohol, tobacco), clinical and metabolic (lipids, glycemia) factors were used. Women had higher levels of plasma carotenoids, TBARS and red blood cell vitamin E. Cholesterol levels were positively associated to lipid-soluble vitamins, selenium and TBARS. Use of lipid-lowering drugs was positively associated with selenium and vitamin E and negatively with carotenoids. Body mass index was the strongest determinant of plasma carotenoids. Education and income levels were positively associated with selenium and total carotenoids. Tobacco consumption was negatively associated with red blood cell vitamin E, whereas alcohol consumption was positively associated with TBARS. This study emphasizes the respective place of the various determinants of antioxidant status. When considering tissue antioxidant indicators, analyses should take into account not only the metabolic parameters but also socio-economic factors and the subject's life style.

Combined effects of lipid peroxidation and antioxidant status on carotid atherosclerosis in a population aged 59-71 y: The EVA Study. Etude sur le Vieillisement Artériel.

There are few epidemiologic studies of the effects of lipid peroxidation and antioxidant status on atherosclerosis. The relation of lipid peroxidation evaluated by thiobarbituric acid-reactive substances (TBARS) and biological markers of antioxidant status to ultrasonographically assessed carotid atherosclerosis was examined from baseline data of a longitudinal study on cognitive and vascular aging (Etude sur le Vieillisement Artériel, the EVA Study). The study sample was composed of 1187 mean and women aged 59-71 y without any history of coronary artery disease or stroke. Ultrasound examination included measurements of intima-media thickness (IMT) on the common carotid arteries (CCAs) and at the site of plaques. After adjustment for conventional cardiovascular risk factors, erythrocyte vitamin E was significantly and negatively associated with CCA-IMT in both men and women whereas plasma selenium and carotenoids were not. No association was found between TBARS and CCA-IMT in either sex. However, TBARS were significantly higher in men with carotid plaques than in those without. This association was strengthened in men with concentrations of erythrocyte vitamin E, plasma selenium, and carotenoids below the lowest quartile. Our findings give some epidemiologic support to the hypothesis that lipid peroxidation and low antioxidant status are involved in the early phases of atherosclerosis.

Selenium and oxygen-metabolizing enzymes in elderly community residents: a pilot epidemiological study.

OBJECTIVE: To investigate the relationship of selenium and oxygen-deactivating enzymes with age in the elderly. SAMPLE: The study sample consisted of volunteers recruited from the PAQUID study. This study is conducted in a representative sample of non-institutionalized individuals aged > or = 65 years living in Southwestern France; its main objective is to study longitudinally the incidence and risk factors of dementia. METHODS: Plasma and erythrocyte selenium and activities of oxygen metabolizing enzymes in erythrocytes (GSH-Px, CuZn-SOD, and GSSG-RD) were measured in 239 volunteers (108 males and 131 females; mean age 73.7 years). RESULTS: Plasma selenium (PSe) decreased significantly with age; a similar but non-significant trend was found for erythrocyte selenium (ESe). None of the enzyme activities showed a clear relationship with age. Women had significantly higher GSH-Px activities than men. For PSe levels lower than 77 ng/mL, there was a strong correlation between PSe and GSH-Px; above this value, the correlation decreased, suggesting that the selenium requirement for GSH-Px production had been satisfied. In this sample, CuZn-SOD was correlated negatively with GSH-Px (r = -0.18; P < or = 0.01) and positively with GSSG-RD (r = +0.20; P < or = 0.01). CONCLUSIONS: In individuals aged > or = 65 years, we found that blood selenium levels were negatively correlated with age. Our analysis of the relationship between selenium and GSH-Px activity suggests that low selenium values are associated with decreased GSH-Px activity.