Alzheimer's disease (AD) is a devastating disorder that strikes 1 in 10 Americans over the age of 65, and almost half of all Americans over 85 years old. The odds of an individual developing AD double every five years after the age of 65. While it has become increasingly common to meet heart attack or cancer survivors, there are no AD survivors. There is mounting evidence that dietary polyphenols, including resveratrol, may beneficially influence AD. Based on this consideration, several studies reported in the last few years were designed to validate sensitive and reliable translational tools to mechanistically characterize brain bioavailable polyphenols as disease-modifying agents to help prevent the onset of AD dementia and other neurodegenerative disorders. Several research groups worldwide with expertise in AD, plant biology, nutritional sciences, and botanical sciences have reported very high quality studies that ultimately provided the necessary information showing that polyphenols and their metabolites, which come from several dietary sources, including grapes, cocoa etc., are capable of preventing AD. The ultimate goal of these studies was to provide novel strategies to prevent the disease even before the onset of clinical symptoms. The studies discussed in this review article provide support that the information gathered in the last few years of research will have a major impact on AD prevention by providing vital knowledge on the protective roles of polyphenols, including resveratrol. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.
BACKGROUND: Mediterranean-style diet has been considered for its important beneficial effects on the progression of CV disease. Wine is an important component of the Mediterranean diet, and moderate wine drinkers have lower mortality rates than nondrinkers and heavy drinkers in epidemiologic studies. The beneficial effects of red wine are thought to be dependent on the polyphenol compounds such as resveratrol that exhibit potent antioxidant activity. However, white wine, although lacking polyphenols, contains simple phenols, such as tyrosol (Tyr) and hydroxytyrosol (OH-Tyr), characteristic also of extra-virgin olive oil, which may share similar antioxidant and inflammatory properties.
PATIENTS AND METHODS: The effect of white wine and extra-virgin olive oil on inflammatory markers was evaluated in 10 healthy volunteers and in 10 patients with CKD (chronic kidney disease) K-DOQI stage III-IV in a prospective, single blind, randomized, cross-over trial. After two weeks of wash-out from alcoholic beverages, subjects were randomized to a cross-over design A-B or B-A of a 2-week treatment with white wine (4 ml/kg body weight, 0.48 g/kg of alcohol 12%, corresponding to 2-3 glasses/daily) and extra-virgin olive oil (treatment A) or extra-virgin olive oil alone (treatment B). The two study periods were separated by a two-week wash-out period. At baseline and at the end of each treatment, plasma levels of inflammatory markers C-reactive protein (CRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-8 (IL-8) concentration were determined. Urinary levels of Tyr, OH-Tyr, and their metabolites were measured at the same time.
RESULTS: During combined consumption of white wine and extra-virgin olive oil (treatment A), plasma levels of CRP and IL-6 decreased from 4.1 +/- 1.8 to 2.4 +/- 1.9 mg/l (p < 0.05) and from 5.3 +/- 3.2 to 3.4 +/- 2.3 mg/l (p < 0.05) in CKD patients. CRP decreased from 2.6 +/- 1.2 to 1.9 +/- 0.9 mg/l (p < 0.05), and IL-6 decreased from 2.2 +/- 1.8 to 1.7 +/- 1.3 mg/l (p = ns) in healthy volunteers. No significant variation versus baseline was observed during treatment B. A significant increase in urinary Tyr and OH-Tyr was observed during treatment A (white wine and extra-virgin olive oil).
CONCLUSIONS: Plasma markers of chronic inflammation were significantly reduced in CKD patients during the combined consumption of white wine and olive oil, suggesting a possible anti-inflammatory effect of this nutritional intervention.
Alzheimer's disease (AD) is a devastating disorder that strikes 1 in 10 Americans over the age of 65, and almost half of all Americans over 85years old. The odds of an individual developing AD double every five years after the age of 65. While it has become increasingly common to meet heart attack or cancer survivors, there are no AD survivors. There is mounting evidence that dietary polyphenols, including resveratrol, may beneficially influence AD. Based on this consideration, several studies reported in the last few years were designed to validate sensitive and reliable translational tools to mechanistically characterize brain bioavailable polyphenols as disease-modifying agents to help prevent the onset of AD dementia and other neurodegenerative disorders. Several research groups worldwide with expertise in AD, plant biology, nutritional sciences, and botanical sciences have reported very high quality studies that ultimately provided the necessary information showing that polyphenols and their metabolites, which come from several dietary sources, including grapes, cocoa etc., are capable of preventing AD. The ultimate goal of these studies was to provide novel strategies to prevent the disease even before the onset of clinical symptoms. The studies discussed in this review article provide support that the information gathered in the last few years of research will have a major impact on AD prevention by providing vital knowledge on the protective roles of polyphenols, including resveratrol. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.
Wine is a traditional beverage that has been associated with both healthy and harmful effects. Conceptions like the so-called "French paradox" or the beneficial impact of the Mediterranean diet suggest benefit. Wine has a complex composition, which is affected by whether it is red or white or by other variables, like the variety of grapes or others. Alcohol and phenolic compounds have been attributed a participation in the benefits ascribed to wine. The case of alcohol has been extensively studied, but the key question is whether wine offers additional benefits. Resveratrol, a non-flavonoid compound, and quercetin, a flavonol, have received particular attention. There is much experimental work confirming a beneficial balance for both substances, particularly resveratrol, in various organs and systems. The pharmacological dosages used in many of those experiments have shed doubt, however, on the clinical translation of those findings. Clinical studies are limited by their observational nature as well as for the difficulties to abstract the benefits of wine from other confounders. Notwithstanding the doubts, there is reasonable unanimity in beneficial effects of moderate wine consumption in cardiovascular disease, diabetes, osteoporosis, maybe neurological diseases, and longevity. Observations are less enthusiastic in what refers to cancer. While considering these limitations, clinicians may spread the message that the balance of moderate wine consumption seems beneficial.