Antioxidants in cardiovascular disease: randomized trials

Unlocking the biochemical secrets of longevity: balancing healthspan and lifespan

In an era of rising global life expectancies, research focuses on enhancing the quality of extended years. This review examines the link between mitochondrial function and aging, highlighting the importance of healthspan alongside lifespan. This involves significant human and economic challenges, with longer lifespans often accompanied by reduced well-being. Addressing mitochondrial decline, exploring targeted interventions, and understanding the complexities of research models are vital for advancing our knowledge in this field. Additionally, promoting physical exercise and adopting personalized supplementation strategies based on individual needs can contribute to healthy aging. The insights from this Perspective article offer a hopeful outlook for future advances in extending both lifespan and healthspan, aiming to improve the overall quality of life in aging populations.

Nutritional determinants of frailty in older adults: A systematic review

BACKGROUND

Frailty is a geriatric syndrome that affects multiple domains of human functioning. A variety of problems contributes to the development of this syndrome; poor nutritional status is an important determinant of this condition. The purpose of this systematic review was to examine recent evidence regarding the association between nutritional status and frailty syndrome in older adults.

METHODS

PubMed, Web of Science, and Scopus electronic databases were searched using specific key words, for observational papers that were published during the period from 2005 to February 2017 and that studied the association or relationship between nutritional status and frailty in older adults. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Statement was followed to assess the quality of the included articles.

RESULTS

Of the 2042 studies found, nineteen met the inclusion criteria. Of these studies, five provided data on micronutrients and frailty, and reported that frailty syndrome is associated with low intakes of specific micronutrients. Five studies provided data on macronutrients and frailty, and among those studies, four revealed that a higher protein intake was associated with a lower risk of frailty. Three studies examined the relationship between diet quality and frailty, and showed that the quality of the diet is inversely associated with the risk of being frail. Two studies provided data on the antioxidant capacity of the diet and frailty, and reported that a high dietary antioxidant capacity is associated with a lower risk of developing frailty. Finally, seven studies evaluated the relationship between scores on both the Mini Nutritional Assessment (MNA) and the MNA-SF (Short Form) and frailty, and revealed an association between malnutrition and/or the risk of malnutrition and frailty.

CONCLUSIONS

This systematic review confirms the importance of both quantitative (energy intake) and qualitative (nutrient quality) factors of nutrition in the development of frailty syndrome in older adults. However, more longitudinal studies on this topic are required to further understand the potential role of nutrition in the prevention, postponement, or even reversion of frailty syndrome.

Antioxidants and cardiovascular disease: Still a topic of interest

Cardiovascular disease constitutes a major public health concern in industrialised nations. Over recent decades, a large body of evidence has accumulated indicating that free radicals play a critical role in cellular processes implicated in atherosclerosis. Herein, we present a mechanism of oxidative stress, focusing mainly on the development of an oxidised low density lipoprotein, and the results of a clinical trial of antioxidant therapy and epidemiological studies on the relationships between nutrient antioxidants, such as vitamin E, vitamin C, β-carotene, coenzyme Q, flavonoids and L-arginine, and coronary events. These studies indicated that a diet high in antioxidants is associated with a reduced risk of cardiovascular disease, but did not confirm a strong causality link. With regard to vitamin E, observational studies suggested that the daily use of at least 400 International Units of vitamin E is associated with beneficial effects on coronary events. However, it is apparently too early to define the clinical benefits of vitamin E for cardiovascular disease. From the results of several randomised interventional trials, it appears that no single antioxidant given to subjects at high doses has substantial benefits, and the question of whether nutrient antioxidants truly protect against cardiovascular disease remains open. This article provides an overview of the epidemiological and clinical studies related to antioxidants and cardiovascular disease.

Vitamin and carotenoid status in older women: associations with the frailty syndrome

OBJECTIVE

We investigated the relationship of micronutrient deficiencies with the frailty syndrome in older women living in the community.

METHODS

Frailty status and serum micronutrients were assessed in a cross-sectional study of 754 women, 70-80 years old, from the Women's Health and Aging Studies I and II.

RESULTS

Among nonfrail, prefrail, and frail women, respectively, geometric mean serum concentrations were 1.842, 1.593, and 1.376 micromol/L for total carotenoids (p <.001); 2.66, 2.51, and 2.43 micromol/L for retinol (p =.04); 50.9, 47.4, and 43.8 nmol/L for 25-hydroxyvitamin D (p =.019); 43.0, 35.8, and 30.9 nmol/L for vitamin B(6) (p =.002); and 10.2, 9.3, and 8.7 ng/mL for folate (p =.03). Frail women were more likely to have at least two or more micronutrient deficiencies (p =.05). The age-adjusted odds ratios of being frail were significantly higher for those participants whose micronutrient concentrations were in the lowest quartile compared to the top three quartiles for total carotenoids, alpha-tocopherol, 25-hydroxyvitamin D, and vitamin B(6). The association between nutrients and frailty was strongest for beta-carotene, lutein/zeaxanthin, and total carotenoids (odds ratio ranging from 1.82 to 2.45, p =.05), after adjusting for age, sociodemographic status, smoking status, and body mass index.

CONCLUSION

Frail women are more likely to have relatively low serum carotenoid and micronutrient concentrations and are more likely to have multiple micronutrient deficiencies. Future longitudinal studies are needed to examine the relationships between micronutrient concentrations and frailty in older women.

Enteral administration of soybean phosphatidylcholine enhances the lymphatic absorption of lycopene, but reduces that of alpha-tocopherol in rats

Dietary phosphatidylcholine (PC) increases the lymphatic absorption of triglyceride (TG). This result suggests that dietary PC might also enhance the absorption of other fat-soluble nutrients. We examined the effects of PC on lycopene and alpha-tocopherol absorption in male rats fitted with a thoracic lymph cannula. The lymphatic output was collected after administration of 1 mL of emulsified test oils containing lycopene and/or alpha-tocopherol in 3 separate experiments. The sodium taurocholate-emulsified test oils contained soybean oil (SO; 113 micromol triglyceride), SO containing soybean PC (SPC; 82.5 micromol SO plus 30.5 micromol purified soybean PC) or SO containing egg PC (EPC; 82.5 micromol SO plus 30.5 micromol purified egg PC) with both lycopene and alpha-tocopherol (Expt. 1) or SO, SPC, or EPC with lycopene (Expt. 2) or alpha-tocopherol alone (Expt. 3). In rats administered SPC or EPC, the lymphatic outputs of TG and lycopene were higher, and that of alpha-tocopherol was lower compared with rats administered SO (Expt. 1). The absorption rate for lycopene increased from 0.59% (SO group) to 2.16 and 1.28% in the SPC and EPC groups (P < 0.05), respectively, whereas the corresponding rates for tocopherol were 21.5% for the SO, 14.8% for the SPC, and 12.9% for the EPC groups. The increase in lycopene, but not in triglyceride absorption, was higher in the SPC than in the EPC groups. The promotive effects of SPC and EPC were decreased when lycopene alone was added to the test lipids (Expt. 2), and the inhibitory effects of PC were reduced when alpha-tocopherol alone was added to the test lipids (Expt. 3). Dietary PC increased the lymphatic output of lycopene and TG and decreased that of alpha-tocopherol, suggesting that differences exist between lycopene and alpha-tocopherol in the absorptive mechanisms. The present results also show that the promotive effects of PC on lycopene absorption are influenced by the type of fatty acids in PC.

Dietary glycemic load and breast cancer risk in the Women's Health Study

A diet with a high glycemic load (GL) may contribute to a metabolic environment that enhances tumorigenesis. Little is known, however, about whether high glycemic diets increase breast cancer risk in women. We examined the associations between baseline measurements of dietary GL and overall glycemic index (GI) and subsequent breast cancer in a cohort of 39,876 women, ages 45 years or older, participating in the Women's Health Study. During a mean of 6.8 years of follow-up there were 946 confirmed cases of breast cancer. We found no association between dietary GL [multivariable-adjusted relative risk (RR), 1.01; confidence interval (CI), 0.76-1.35, comparing extreme quintiles; P for trend = 0.96] or overall GI (corresponding RR, 1.03; CI, 0.84-1.28; P for trend = 0.66) and breast cancer risk in the cohort as a whole. Exploratory analyses stratified by baseline measurements of menopausal status, physical activity, smoking history, alcohol use, and history of diabetes mellitus, hypertension, or hypercholesterolemia showed no significant associations, except in the subgroup of women who were premenopausal and reported low levels of physical activity (GL multivariable-adjusted RR, 2.35; CI, 1.03-5.37; P for trend = 0.07; GI multivariable-adjusted RR, 1.56; CI, 0.88-2.78; P for trend = 0.02, comparing extreme quintiles). Although we did not find evidence that a high glycemic diet increases overall breast cancer risk, the increase in risk in premenopausal women with low levels of physical activity suggests the possibility that the effects of a high glycemic diet may be modified by lifestyle and hormonal factors. Prospective studies of a larger sample size and longer duration are warranted to confirm our findings.

The diet-induced proinflammatory state: a cause of chronic pain and other degenerative diseases?

BACKGROUND

It is the rare physician who includes diet therapy and nutritional supplements in patient care. Perhaps this is because chiropractic and medical schools devote very few classroom hours to nutrition. It is also possible that physicians are under the misconception that a detailed biochemical understanding of each individual disease is required before nutritional interventions can be used.

OBJECTIVE

The purpose of this article is two-fold: (1) to demonstrate that chronic pain and other degenerative conditions encountered in clinical practice have similar biochemical etiologies, such as a diet-induced proinflammatory state, and (2) to outline a basic nutritional program that can be used by all practitioners.

DATA SOURCES

The data were accumulated over a period of years by reviewing contemporary articles and books and subsequently by retrieving relevant articles. Articles were also selected through MEDLINE and manual library searches.

RESULTS

The typical American diet is deficient in fruits and vegetables and contains excessive amounts of meat, refined grain products, and dessert foods. Such a diet can have numerous adverse biochemical effects, all of which create a proinflammatory state and predispose the body to degenerative diseases. It appears that an inadequate intake of fruits and vegetables can result in a suboptimal intake of antioxidants and phytochemicals and an imbalanced intake of essential fatty acids. Through different mechanisms, each nutritional alteration can promote inflammation and disease.

CONCLUSION

We can no longer view different diseases as distinct biochemical entities. Nearly all degenerative diseases have the same underlying biochemical etiology, that is, a diet-induced proinflammatory state. Although specific diseases may require specific treatments, such as adjustments for hypomobile joints, beta-blockers for hypertension, and chemotherapy for cancer, the treatment program must also include nutritional protocols to reduce the proinflammatory state.

Intake of antioxidant vitamins and risk of death from stroke in postmenopausal women

BACKGROUND

Antioxidant vitamins may play a role in the prevention of stroke because they scavenge free radicals and prevent LDL oxidation. Epidemiologic studies that have examined this relation produced conflicting results.

OBJECTIVE

We examined the association between antioxidant vitamin intakes and death from stroke.

DESIGN

This was a prospective cohort study of 34492 postmenopausal women.

RESULTS

During follow-up, 215 deaths from stroke were documented. Total vitamin A, carotenoid, and vitamin E intakes were not associated with death from stroke after multivariate adjustment. Relative risks (RRs) and 95% CIs of the highest compared with the lowest category were 0.79 (0.45, 1.38; P for trend = 0.33) for vitamin A, 0.80 (0.45, 1.40; P for trend = 0.40) for carotenoids, and 0.91 (0.55, 1.52; P for trend = 0.86) for vitamin E. The test for trend for total vitamin C intake was significant, although the association appeared somewhat U-shaped, not monotonic. An inverse association was seen between death from stroke and vitamin E intake from food. RRs (and 95% CIs) of death from stroke from the lowest to highest intake categories were 1.0, 0.80 (0.51, 1.26), 0.93 (0.58, 1. 49), 0.67 (0.39, 1.14), 0.40 (0.20, 0.80); P for trend = 0.008. The results suggest inverse associations between death from stroke and intakes of the most concentrated vitamin E food sources consumed by this cohort: mayonnaise, nuts, and margarine.

CONCLUSIONS

Our results suggest a protective effect of vitamin E from foods on death from stroke but do not support a protective role for supplemental vitamin E or other antioxidant vitamins. However, given the number of deaths from stroke in the present cohort, a small-to-moderate association could not be ruled out.

Dietary and pharmacological antioxidants in atherosclerosis

Antioxidants that inhibit LDL oxidation are thought to be potential anti-atherogenic compounds. The results of major human randomized trials with antioxidants have, however, been disappointing, except for probucol, which consistently inhibits restenosis. Similarly, animal intervention studies show that antioxidants do not generally inhibit atherosclerosis, although some compounds provide protection. Direct evidence for the oxidation of LDL causing atherosclerosis is needed. This article summarizes results from antioxidant intervention studies, and highlights some of the key issues that need to be addressed to link biochemical changes in the arterial wall more directly to the oxidation theory of atherosclerosis.

Fruit and vegetable consumption and prevention of cancer: the Black Churches United for Better Health project

OBJECTIVES

This study assessed the effects of the Black Churches United for Better Health project on increasing fruit and vegetable consumption among rural African American church members in North Carolina.

METHODS

Ten counties comprising 50 churches were pair matched and randomly assigned to either intervention or delayed intervention (no program until after the follow-up survey) conditions. A multicomponent intervention was conducted over approximately 20 months. A total of 2519 adults (77.3% response rate) completed both the baseline and 2-year follow-up interviews.

RESULTS

The 2 study groups consumed similar amounts of fruits and vegetables at baseline. AT the 2-year follow-up, the intervention group consumed 0.85 (SE = 0.12) servings more than the delayed intervention group (P < .0001). The largest increases were observed among people 66 years or older (1 serving), those with education beyond high school (0.92 servings), those widowed or divorced (0.96 servings), and those attending church frequently (1.3 servings). The last improvement occurred among those aged 18 to 37 years and those who were single.

CONCLUSIONS

The project was a successful model for achieving dietary change among rural African Americans.

The ambivalence of vitamin E in atherogenesis

The early events in atherogenesis might be due to the oxidation of low- density lipoprotein. The antioxidant vitamin E, therefore, has received much attention as a potential anti-atherogenic agent. Recent mechanistic studies of the early stage of lipoprotein-lipid oxidation show that the role of vitamin E in this process is not simply that of a classical antioxidant. Unless additional compounds are present, vitamin E can have antioxidant, neutral or pro-oxidant activity. This more complex function is reflected in the results of vitamin-E-intervention studies of atherosclerosis in animals and of controlled prospective trials on the incidence of cardiovascular disease in humans, which, overall, are inconclusive.

Establishing the significance and optimal intake of dietary antioxidants: the biomarker concept

Diets rich in fruits and vegetables are associated with decreased risk of cardiovascular disease and cancer. Biomarkers of oxidative DNA damage and lipid peroxidation can be used to establish the role of antioxidants in this protection and the optimal intake of those antioxidants. This concept is based on the presumptions that oxidative DNA damage is a significant contributor to the age-related development of some cancers and that lipid peroxidation plays a key role in the development of cardiovascular disease. Mass spectrometric measurements of various families of isoprostanes (F2-, F3-, and F4-isoprostanes) and of multiple DNA base oxidation products are probably the most promising biomarkers for use in human nutritional intervention studies. Biomarker studies should precede, as well as accompany, major intervention trials that measure disease incidence. The use of biomarkers provides a logical scientific basis for major intervention trials of antioxidants; such trials will, in turn, eventually validate or disprove the biomarker concept.

[Anthropometric and dietary determinants of blood levels of HDL cholesterol in a population-based study. The REGICOR study. Researchers of the REGICOR study]

OBJECTIVES

The aim of the present study was to identify dietary and anthropometric factors influencing HDL cholesterol levels in the region of Girona. POBLATION AND METHODS: A cross-sectional study was designed with random recruitment and 798 men and 862 women were included. Anthropometric variables were collected, the energy expenditure in physical activity was calculated and a dietary questionnaire was supplied in order to obtain nutritional data. Furthermore, lipid levels and lipoprotein concentrations were determined.

RESULTS

Significant differences were found in serum triglycerides, body mass index, glucose levels and alcohol intake between the upper and the lower tertils of HDL cholesterol in both men and women. In men, energy expenditure in physical activity was significantly associated with HDL cholesterol levels, as well as total fat and monounsaturated fat. In women, together with the waist-to-hip ratio and fasted glycemia, vitamin C was the dietary factor positively associated with HDL cholesterol levels.

CONCLUSIONS

Moderate alcohol intake, physical activity, vitamin C consumption and optimizing body weight strongly contribute to increased HDL cholesterol levels in our region.

Effect of antioxidant in endothelial cells exposed to oxidized low-density lipoproteins

Antioxidants such as probucol and alpha-tocopherol have been shown to attenuate the oxidation of low-density lipoproteins (LDL) and atherosclerotic lesions in animal models of atherosclerosis. The purpose of this study is to determine the protection effect of antioxidants on endothelial cells when exposed to oxidized and native LDL. In a cell-free system, we found that probucol, alpha-tocopherol, and ascorbic acid inhibited copper-induced LDL oxidation by a dose-dependent fashion (from 1 microM to 10 mM). In porcine aortic endothelial cells, antioxidants alone did not change basal endothelin-1 (ET-1) secretion. When porcine aortic endothelial cells were exposed to LDL and oxidized-LDL, both of them stimulated ET-1 secretion dose-dependently, whereas oxidized-LDL elicited higher ET-1 secretion. However, probucol, alpha-tocopherol, and ascorbic acid did not prevent LDL or oxidized-LDL induced ET-1 secretion. Furthermore, nimodipine inhibited both of native and oxidized LDL induced ET-1 secretion. Since Ca2+ channel blocker reduced the elevation of induced ET-1 secretion, the [Ca2+]i is possibly involved for the regulation of ET-1 secretion. Our results suggest that antioxidants can only prevent the oxidation of LDL rather than oxidized and native LDL-induced ET-1 secretion in vascular endothelial cells. The increase in the [Ca2+]i of endothelial cells through the opening of voltage-dependent Ca2+ channels may be involved in the LDL-induced ET-1 release.