Impact of nutrition on ageing and disease

PURPOSE OF REVIEW: The globe is suffering a tsunami of chronic diseases, affecting especially the elderly and those with a dysfunctioning immune system. The fundamental principles of optimal health and optimal ageing are abstaining from smoking, modest alcohol consumption, regular physical exercise and a diet rich in fish and plants and low in condensed calories, sugar and dairy products. RECENT FINDINGS: Dietary supply and production of advanced glycation end products leads to the accumulation of these products in the tissues and is strongly associated with ageing of the vascular endothelium, nervous system, eyes and other vital organs. Telomeres, which are not involved in DNA repair, remain unrepaired and loose with time. A decline in innate and acquired immunity is seen with increasing age and maintenance of low basal immune activity (degree of inflammation) seems important for health and longevity: 'people who are predisposed to weak inflammatory activity may live longer'. SUMMARY: Supplementation with vitamins has little effect on ageing/prevention of chronic diseases, but antiinflammatory molecules like polyphenols are more effective, especially when combined with reduced intake of calorie-condensed foods. The effect of probiotics on ageing needs further exploration. The effects of caloric restriction, proven effective in other species to control aging and prolong lifespan, have not been fully explored in humans.     

Possible role of milk-derived bioactive peptides in the treatment and prevention of metabolic syndrome

The growing prevalence of metabolic syndrome as well as its impact on public health has garnered increased attention in recent years. As a result, metabolic syndrome is now considered one of the world's leading public health problems. Bioactive peptides deriving from milk proteins may play an important role in the prevention and treatment of metabolic syndrome and its complications via several mechanisms, such as the satiety response, the regulation of insulinemia levels and blood pressure, the uptake of free radicals, and alteration of the lipid profile. These peptides can be incorporated into functional foods or administered via nutraceuticals to decrease the risk of obesity, atherogenesis, arterial hypertension, and type 2 diabetes. Recent findings have generated considerable scientific and commercial interest in milk-derived bioactive peptides, leading to numerous publications on the effectiveness of these substances. This review summarizes the current knowledge on bioactive peptides derived from milk proteins and examines the potential value of these peptides in the treatment and prevention of metabolic syndrome and its complications.     

Probiotic-enriched milk and dairy products increase gut microbiota diversity: a comparative study

Targeting gut microbiota with probiotics has emerged as a promising nutritional approach for the prevention of obesity and metabolic syndrome. Cultured dairy products can be effectively employed for the delivery of probiotics to the gut as well as for the support of growth and survival of probiotic bacteria. The purpose of this study was to characterize the effects of probiotic-enriched pasteurized milk and dairy products (Greek-style yogurt and cottage cheese) of different origins (cow, goat, and camel) on taxonomic composition of the mouse gut microbiota. We hypothesized that cultured dairy products can be an effective vector for the delivery of probiotics to the gut because of its nutritional value, acidic nature, and long shelf-life. Mice were fed a standard low fat, plant polysaccharide-rich (LF/PP) diet supplemented with the probiotic-enriched milk and dairy products for 5 weeks. Next generation sequencing of DNA from mouse fecal samples was used to characterize the bacterial relative abundance. Mice fed a diet supplemented with camel milk demonstrated characteristic changes in the gut microbiota, which included an increase in relative abundance of order Clostridiales and genus Anaerostipes. Mice fed a diet supplemented with the probiotic-enriched cow cheese exhibited an increase in the relative abundance of order Clostridiales, family Ruminococcaceae, and family Lachnospiraceae. The results obtained and their bioinformatics analysis support the conclusion that camel milk and the probiotic cow cheese induce changes in the mouse gut microbiota, which can be characterized as potentially beneficial to health compared to the changes associated with a standard diet. These findings imply that probiotic-enriched milk and dairy products can be highly effective for the delivery and support of probiotic bacteria of the gut.     

Vascular risk factors, cognitive decline, and dementia

Dementia is one of the most important neurological disorders in the elderly. Aging is associated with a large increase in the prevalence and incidence of degenerative (Alzheimer's disease) and vascular dementia, leading to a devastating loss of autonomy. In view of the increasing longevity of populations worldwide, prevention of dementia has turned into a major public health challenge. In the past decade, several vascular risk factors have been found to be associated with vascular dementia but also Alzheimer's disease. Some longitudinal studies, have found significant associations between hypertension, diabetus mellitus, and metabolic syndrome, assessed at middle age, and dementia. Studies assessing the link between hypercholesterolemia, atrial fibrillation, smoking, and dementia have given more conflicting results. Furthermore, some studies have highlighted the possible protective effect of antihypertensive therapy on cognition and some trials are evaluating the effects of statins and treatments for insulin resistance. Vascular risk factors and their treatments are a promising avenue of research for prevention of dementia, and further long-term, placebo-controlled, randomized studies, need to be performed.     

Metabolic,Affective and Neurocognitive Characterization of Metabolic Syndrome Patients with and without Food Addiction. Implications for Weight Progression

According to the food addiction (FA) model, the consumption of certain types of food could be potentially addictive and can lead to changes in intake regulation. We aimed to describe metabolic parameters, dietary characteristics, and affective and neurocognitive vulnerabilities of individuals with and without FA, and to explore its influences on weight loss progression. The sample included 448 adults (55–75 years) with overweight/obesity and metabolic syndrome from the PREDIMED-Plus cognition sub-study. Cognitive and psychopathological assessments, as well as dietary, biochemical, and metabolic measurements, were assessed at baseline. Weight progression was evaluated after a 3-year follow up. The presence of FA was associated with higher depressive symptomatology, neurocognitive decline, low quality of life, high body mass index (BMI), and high waist circumference, but not with metabolic comorbidities. No differences were observed in the dietary characteristics except for the saturated and monounsaturated fatty acids consumption. After three years, the presence of FA at baseline resulted in a significantly higher weight regain. FA is associated with worse psychological and neurocognitive state and higher weight regain in adults with metabolic syndrome. This condition could be an indicator of bad prognosis in the search for a successful weight loss process.     

Nondairy Probiotic Products: Functional Foods That Require More Attention

The potential health benefits of probiotics have been illustrated by many studies. However, most functional foods containing probiotics are from dairy sources. This review provides an overview of potential strains and raw materials for nondairy probiotic products together with the role of its in vitro assessment. Probiotic-containing products from raw nondairy materials are known both in terms of quality and nutritional values. The sensory properties of raw plant-based materials are generally improved as a result of fermentation with probiotics. Increased market shares for plant-based probiotic products may also help to curb environmental challenges. The sustainability of this food results from reductions in land use, greenhouse gas emissions, and water use during production. Consuming nondairy probiotic food can be a personal step to contribute to climate change mitigation. Since some people cannot or do not want to eat dairy products, this creates a market gap in the supply of nutritious food. Therefore, the promotion and broader development of these foods are needed. Expanding our knowledge on how to best produce these functional foods and increasing our understanding of their in vivo behaviours are crucial. The latter may be efficiently achieved by utilizing available in vitro digestion systems that reliably recapitulate the in vivo situation without introducing any ethical concerns.     

Bioactive proteins and peptides in foods

Increasing amounts of data demonstrate a bioactive role of proteins and peptides above and beyond their nutritional impact. The focus of the investigations has mainly been on vitamin- and mineral-binding proteins, on antimicrobial, immunosuppressing/-modulatory proteins, and on proteins with enzyme inhibitory activity as well as on hormones and growth factors from different food proteins; most research has been performed on milk proteins. Because of their molecular size, intact absorption of proteins in the human gastrointestinal tract is limited. Therefore, most of the proteins with biological functions show physiological activity in the gastrointestinal tract by enhancing nutrient absorption, inhibiting enzymes, and modulating the immune system to defend against pathogens. Peptides are released during fermentation or digestion from food proteins by proteolytic enzymes; such peptides have been found mainly in milk. Some of these released peptides exert biological activities such as opiate-like, antihypertensive, mineral-binding, antioxidative, antimicrobial, immuno-, and cytomodulating activity. Intact absorption of these smaller peptides is more likely than that of the larger proteins. Consequently, other organs than the gastrointestinal tract are possible targets for their biological functions. Bioactive proteins as well as bioactive peptides are part of a balanced diet. It is possible to accumulate bioactive peptides in food, for example by using specific microorganisms in fermented dairy products. Although bioactive peptides have been the subject of several studies in vitro and in vivo, their health potential is still under investigation. Up to now, the Commission of European Communities has not (yet) authorized any health claims for bioactive proteins and peptides from food.     

Role of Fluid Milk in Attenuating Postprandial Hyperglycemia and Hypertriglyceridemia

Postprandial plasma glucose and triglyceride concentrations are predictive of relative cardiovascular disease (CVD) risk, and the pathogenesis of both insulin resistance and atherosclerosis has been attributed to acute states of hyperglycemia and hypertriglyceridemia. Postprandial lipemia and hyperglycemia suppress vascular reactivity and induce endothelial dysfunction. Epidemiological studies suggest that chronically-high consumption of milk and milk products is associated with a reduced risk of type 2 diabetes, metabolic syndrome, and CVD. The addition of dairy products to meals high in carbohydrates and fat may lessen these risks through reductions in postprandial glucose and triglyceride responses. Purported mechanisms include dairy proteins and bioactive compounds, which may explain the inverse relationship between dairy consumption and cardiometabolic diseases. The current review evaluates the available literature describing the relationships between metabolic dysfunction, postprandial metabolism, and vascular dysfunction and discusses the potential role of milk and dairy products in attenuating these impairments.     

Vascular risk factors, alcohol intake, and cognitive decline

Since the therapeutic options currently available have demonstrated limited efficacy, the search for preventive strategies for cognitive decline and dementia is mandatory. A possible role of vascular and lifestyle-related factors was recently proposed for age-related changes of cognitive function, predementia syndromes, and cognitive decline of degenerative (Alzheimer’s disease, AD) or vascular origin. At present, cumulative evidence suggested that vascular risk factors may be important in the development of mild cognitive impairment (MCI), dementia, and AD. Among vascular-related factors, metabolic syndrome has been associated with the risk of cognitive decline and overall dementia. Moderate alcohol drinking has been proposed as a protective factor against MCI and dementia in several longitudinal studies, but contrasting findings also exist. However, in most cases, these were only observational studies, and results are awaited from large multicenter randomized clinical trials in older persons. At present, vascular risk factor management, lifestyle changes, and drugs could be employed together to delay the onset of dementia syndromes.     

Diosgenin, 4-Hydroxyisoleucine,and Fiber from Fenugreek: Mechanisms of Actions and Potential Effects on Metabolic Syndrome

Metabolic syndrome and its complications continue to rise in prevalence and show no signs of abating in the immediate future. Therefore, the search for effective treatments is a high priority in biomedical research. Products derived from botanicals have a time-honored history of use in the treatment of metabolic diseases including type 2 diabetes. Trigonella foenum-graecum, commonly known as fenugreek, is an annual herbaceous plant that has been a staple of traditional herbal medicine in many cultures. Although fenugreek has been studied in both clinical and basic research settings, questions remain about its efficacy and biologic mechanisms of action. Diosgenin, 4-hydroxyisoleucine, and the fiber component of the plant are the most intensively studied bioactive constituents present in fenugreek. These compounds have been demonstrated to exert beneficial effects on several physiologic markers including glucose tolerance, inflammation, insulin action, liver function, blood lipids, and cardiovascular health. Although insights into the molecular mechanisms underlying the favorable effects of fenugreek have been gained, we still do not have definitive evidence establishing its role as a therapeutic agent in metabolic disease. This review aims to summarize the currently available evidence on the physiologic effects of the 3 best-characterized bioactive compounds of fenugreek, with particular emphasis on biologic mechanisms of action relevant in the context of metabolic syndrome.     

Dietary fatty acids, age-related cognitive decline, and mild cognitive impairment

Currently available epidemiological evidence suggested that an increase of saturated fatty acids (SFA) could have negative effects on cognitive functions, while increased polyunsaturated fatty acids (PUFA) and monounsaturated fatty acids (MUFA) may be protective against cognitive decline. In a Southern Italian elderly population from the Italian Longitudinal Study on Aging (ILSA), a clear reduction of risk of age-related cognitive decline (ARCD) has been found with elevated intake of PUFA and MUFA. Furthermore, in the ILSA, while dietary fatty acids intakes were not associated with incident mild cognitive impairment (MCI), high PUFA intake appeared to have borderline non-significant trend for a protective effect against the development of MCI. These epidemiological findings on predementia syndromes, i.e. MCI or ARCD, together with a recent randomised controlled trial on a possible effect on cognitive and depressive symptoms of ω-3 PUFA supplementation in patients with very mild AD, suggested a possible role of fatty acids intake in maintaining adequate cognitive functioning and possibly in preventing or delaying the onset of dementia.     

A berry thought-provoking idea: the potential role of plant polyphenols in the treatment of age-related cognitive disorders

Today, tens of millions of elderly individuals worldwide suffer from dementia. While the pathogenesis of dementia is complex and incompletely understood, it may be, at least to a certain extent, the consequence of systemic vascular pathology. The metabolic syndrome and its individual components induce a proinflammatory state that damages blood vessels. This condition of chronic inflammation may damage the vasculature of the brain or be directly neurotoxic. Associations have been established between the metabolic syndrome, its constituents and dementia. A relationship has also been observed between certain dietary factors, such as constituents of the 'Mediterranean diet', and the metabolic syndrome; similar associations have been noted between these dietary factors and dementia. Fruit juices and extracts are under investigation as treatments for cognitive impairment. Blueberry, strawberry, blackberry, grape and plum juices or extracts have been successfully tested in cognitively impaired rodents. Published trials of the benefits of grape and blueberry juice in the treatment of small numbers of cognitively impaired persons have recently appeared. The benefits of fruit products are thought to be a result of its polyphenol content. A grape polyphenol found in grapes, resveratrol, now being studied in humans, and one in grapes and blueberries, pterostilbene, have been found to improve cognition in rodents. In the design of future human trials, one ought to consider the poor bioavailability of these products, the possible need to initiate the experimental therapy long before the onset of symptoms, and currently limited knowledge about the appropriate form (e.g. juice, powder or individual polyphenol) of treatment.     

Milk and Dairy Products and Their Impact on Carbohydrate Metabolism and Fertility—A Potential Role in the Diet of Women with Polycystic Ovary Syndrome

Milk and dairy products are considered an important component of healthy and balanced diet and are deemed to exert a positive effect on human health. They appear to play a role in the prevention and treatment of carbohydrate balance disturbances. The products include numerous valuable components with a potential hypoglycemic activity, such as calcium, vitamin D, magnesium and probiotics. Multiple authors suggested that the consumption of dairy products was negatively associated with the risk of type 2 diabetes mellitus, insulin resistance and ovulation disorders. However, there are still numerous ambiguities concerning both the presumed protective role of dairy products in carbohydrate metabolism disorders, and the advantage of consuming low-fat dairy products over high-fat ones, especially in women with the risk of ovulation disorders. Therefore, this literature review aims at the presentation of the current state of knowledge concerning the relationship between dairy product consumption and the risk of insulin resistance, type 2 diabetes mellitus in women, and the potential effect on the course of polycystic ovary syndrome.     

Milk and dairy consumption, diabetes and the metabolic syndrome: the Caerphilly prospective study

OBJECTIVES: To report a negative association between milk or dairy consumption and the metabolic syndrome and to examine associations within the Caerphilly cohort. SETTING: A representative sample of men aged 45-59 years in Caerphilly, UK. PARTICIPANTS AND DATA: Data on fasting blood glucose and plasma insulin, fasting plasma triglycerides and high-density lipoprotein cholesterol, body mass index, and blood pressure were used to define the metabolic syndrome in terms of levels of two or more variates within the top 10%. The clinical importance of the syndrome was assessed from 20-year incidence of diabetes, vascular events and deaths. The relationships between the syndrome and the consumption of milk and dairy products was examined using data from both a semiquantitative food frequence questionnaire, and from a 7-day weighed intake record which had been kept by a 1:3 subsample of the men. MAIN RESULTS: There were 2,375 men without diabetes in the cohort. The prevalence of the metabolic syndrome was 15%. Men with the syndrome had significantly increased risks of a subsequent ischaemic heart disease event, death or diabetes. Negative relationships were shown between both the consumption of milk and dairy produce, and the syndrome. Adjusted odds ratio in men who regularly drank a pint of milk or more daily was 0.38 (0.18 to 0.78) and that for dairy food consumption was 0.44 (0.21 to 0.91). Milk intake showed no significant trend with incident diabetes. CONCLUSIONS: The consumption of milk and dairy products is associated with a markedly reduced prevalence of the metabolic syndrome, and these items therefore fit well into a healthy eating pattern.     

Dairy components and risk factors for cardiometabolic syndrome: recent evidence and opportunities for future research

Cardiometabolic syndrome (CMS), a cluster of metabolic abnormalities that increases the risk of cardiovascular disease (CVD) and type 2 diabetes, affects over one-third of American adults and accounts for billions of dollars in health care costs annually. Current evidence indicates an inverse association between consumption of dairy foods and risk of CMS and its related disease outcomes. Although the specific mechanism(s) underlying the beneficial effects of dairy consumption on the development of CMS, CVD, and type 2 diabetes have not been fully elucidated, there is evidence that specific components within dairy such as milkfat, vitamin D, calcium, magnesium, potassium, and whey proteins may be individually or collectively involved. Specifically, each of these dairy components has been implicated as having a neutral or beneficial effect on one or more elements of CMS, including the serum lipid profile, blood pressure, fasting glucose, and body composition. Although several mechanisms have been identified by which components in dairy may beneficially affect symptoms associated with CMS, further research is required to better understand how dairy and its components may contribute to metabolic health. The purpose of this review is to present the mechanisms by which specific dairy components modulate risk factors for CMS and identify opportunities for future research.     

HRT and dementia

The role of HRT and/or oestrogens in the aetiology, progression and prevention of neurodegenerative disorders is unclear. Various studies have been conducted in cells, animals and humans to better define these relationships. The following is a presentation of data on the role of oestrogens in the two most common dementia syndromes Alzheimer's Disease and vascular dementia. This review examines whether there is support for the hypothesis that the use of oestrogens reduces the risk for dementia and cognitive decline in a variety of experimental models. A literature search was performed using the following key words: oestrogen and dementia, oestrogen and Alzheimer, oestrogen and cognition, oestrogen and learning, and oestrogen and memory. The reference lists for the articles identified using these search strategies were examined. The strongest evidence for a beneficial effect comes from cell and animal studies. These suggest that treatment with oestrogens may influence the pathogenetic processes of AD, mainly by affecting the beta-amyloid metabolism, by promoting the activity of the cholinergic system, by reducing oxidative stress or cardiovascular risk. Observational studies give some support to the hypothesis that HRT may be protective for cognitive decline and dementia in the elderly, but the inherited methodological problems in these studies preclude any conclusions. The treatment trials published thus far have methodological problems that prohibit definite conclusions on the relationship between HRT and cognitive decline and dementia.     

NuBrain: UK consortium for optimal nutrition for healthy brain ageing

With an ageing global population, there is an urgent need to identify effective strategies to maintain brain health across the life course and therein minimise the risk of age‐related neurodegenerative disorders reaching a severe stage which may manifest as dementia. An increasing body of evidence indicates that nutrition is a modifiable lifestyle factor that can promote healthy brain ageing and reduce dementia risk. However, at present, little is known about which dietary patterns, foods and food bioactives influence brain function during ageing, and more research is required to identify at‐risk individuals and population subgroups who are most likely to benefit from future nutritional intervention intended to promote healthier brain ageing. This article introduces the newly established Medical Research Council‐funded NuBrain consortium, the vision of which is to provide a step change in research in the area by developing novel approaches and techniques to further understand the complex interactions between diet and brain health and how we can support appropriate behaviour changes in the population. NuBrain will form a new, sustainable and internationally field‐leading research consortium with multidisciplinary and complementary areas of expertise to address the fundamental research challenges in this area.     

Certain dietary patterns are beneficial for the metabolic syndrome: reviewing the evidence

The metabolic syndrome (MetS) is a global public health issue of increasing magnitude. The Asia-Pacific region is expected to be hardest hit due to large population numbers, rising obesity, and insulin resistance (IR). This review assessed the protective effects of dietary patterns and their components on MetS. A literature search was conducted using prominent electronic databases and search terms that included in combination: diet, dietary components, dietary patterns, and metabolic syndrome. Articles were restricted to prospective studies and high quality randomized controlled trials that were conducted on humans, reported in the English language, and within the time period of 2000 to 2012. Traditional factors such as age, gender, physical activity, and obesity were associated with risk of MetS; however, these potential confounders were not always accounted for in study outcomes. Three dietary patterns emerged from the review; a Mediterranean dietary pattern, dietary approaches to stop hypertension diet, and the Nordic Diet. Potential contributors to their beneficial effects on prevalence of MetS or reduction in MetS components included increases in fruits, vegetables, whole grains, dairy and dairy components, calcium, vitamin D, and whey protein, as well as monounsaturated fatty acids, and omega-3 fatty acids. Additional prospective and high quality randomized controlled trial studies that investigate Mediterranean dietary pattern, the dietary approaches to stop hypertension diet, and the Nordic Diet would cement the protective benefits of these diets against the MetS.     

Nutrient reference values for bioactives: new approaches needed? A conference report

Purpose

To comprehensively review the data on the relationship between the consumption of dairy fat and high-fat dairy foods, obesity, and cardiometabolic disease.

Methods

We have conducted a systematic literature review of observational studies on the relationship between dairy fat and high-fat dairy foods, obesity, and cardiometabolic disease. We have integrated these findings with data from controlled studies showing effects of several minor dairy fatty acids on adiposity and cardiometabolic risk factors, and data on how bovine feeding practices influence the composition of dairy fat.

Results

In 11 of 16 studies, high-fat dairy intake was inversely associated with measures of adiposity. Studies examining the relationship between high-fat dairy consumption and metabolic health reported either an inverse or no association. Studies investigating the connection between high-fat dairy intake and diabetes or cardiovascular disease incidence were inconsistent. We discuss factors that may have contributed to the variability between studies, including differences in (1) the potential for residual confounding; (2) the types of high-fat dairy foods consumed; and (3) bovine feeding practices (pasture- vs. grain-based) known to influence the composition of dairy fat.

Conclusions

The observational evidence does not support the hypothesis that dairy fat or high-fat dairy foods contribute to obesity or cardiometabolic risk, and suggests that high-fat dairy consumption within typical dietary patterns is inversely associated with obesity risk. Although not conclusive, these findings may provide a rationale for future research into the bioactive properties of dairy fat and the impact of bovine feeding practices on the health effects of dairy fat.