Correlations of dietary patterns with prostate health

Both genetic and environmental influences may be involved in etiology of prostate health and prostate cancer. These include ethnic origin, family history, smoking, and diet. Adiposity and excess energy intake are potentially distinct risk factors and positive associations with prostate cancer risk for both were observed among case-control and cohort studies. Some epidemiological studies support an association between dietary fat, particularly saturated or animal fats, and prostate cancer risk. Of these, several suggest reduced risk with low-fat diets high in n-3 fatty acids and increased risk with high-fat diets rich in n-6 fatty acids. Others suggested association with higher meat intake, possibly due to heterocyclic amines and polycyclic aromatic hydrocarbons, produced during grilling or frying. Positive association of prostate cancer risk with dairy intake could involve alpha-methylacyl-CoA racemase activity (required for beta-oxidation of phytanic acid present in dairy products and red meat) or the suppression of vitamin D activity by calcium. Inverse associations were observed with dietary intake of plant foods. These include cereals, soy products, and fruit and vegetable sources of carotenoids. Numerous plant constituents may act synergistically in the prevention and inhibition of prostate disorders. These diet-risk associations may lead to future individualized diet recommendations based upon genetic polymorphisms.     

支链脂肪酸的来源与功能研究进展

支链脂肪酸主要包括单支链脂肪酸和多支链脂肪酸,多存在于人体皮肤及其分泌物、微生物细胞膜、乳制品及肉制品中。近年来的研究表明,支链脂肪酸对乳腺癌细胞、前列腺癌细胞和膀胱癌细胞等具有潜在抑制作用,此外,支链脂肪酸还有抑制新生儿坏死性小肠结肠炎发病率等抗炎作用。进一步对各种食物以及人体各组织中的支链脂肪酸进行检测分析,并对支链脂肪酸结构功能与作用机理进行深入研究,是目前支链脂肪酸研究的重要方向。     

Impact of cows’ milk estrogen on cancer risk

Estrogens have been implicated in cancer at hormone-responsive sites, such as the breast, ovaries, endometrium and prostate. Because cows’ milk contains estrogens, some authors have suggested that its consumption may contribute to the risk of cancer at these sites. However, these reports do not recognize the complex mechanisms these cells possess to regulate estradiol levels. Hormone-responsive and many peripheral cells contain all the necessary steroidogenic enzymes necessary for in situ synthesis of bioactive estradiol from abundant androgenic precursors and for inactivation of unwanted estrogens. Estradiol from dairy products is extensively inactivated in the gastrointestinal tract and only about 5% survives the first pass to the liver. Thus daily dairy product intake would supply only about 0.25% of the FAO/WHO upper acceptable daily intake of estradiol. Available epidemiological evidence does not suggest an association between dairy product consumption and risk of cancer of the breast, ovaries and endometrium.     

Mechanisms Linking Colorectal Cancer to the Consumption of (Processed) Red Meat: A Review

Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the world. The vast majority of CRC cases have been linked to environmental causes rather than to heritable genetic changes. Over the last decades, epidemiological evidence linking the consumption of red and, more convincingly, of processed red meat to CRC has accumulated. In parallel, hypotheses on carcinogenic mechanisms underlying an association between CRC and the intake of red and processed red meat have been proposed and investigated in biological studies. The hypotheses that have received most attention until now include (1) the presence of polycyclic aromatic hydrocarbons and heterocyclic aromatic amines, two groups of compounds recognized as carcinogenic, (2) the enhancing effect of (nitrosyl)heme on the formation of carcinogenic N-nitroso compounds and lipid peroxidation. However, none of these hypotheses completely explains the link between red and processed red meat intake and the CRC risk. Consequently, scientists have proposed additional mechanisms or refined their hypotheses. This review first briefly summarizes the development of CRC followed by an in-depth overview and critical discussion of the different potential carcinogenic mechanisms underlying the increased CRC risk associated with the consumption of red and processed red meat.     

Soy, isoflavones, and prostate cancer

Prostate cancer has marked geographic variations between countries. Genetic, epigenetic, and environmental factors co-contribute to the development of the cancer. The association between dietary factors and prostate cancer has been investigated and one explanation for the low incidence of the cancer in Asia might be high consumption of fresh vegetables including soybean and its products. Soybean is a species of legume contain high amount of isoflavones including genistein, daidzein, glycitein, and equol, which have a prophylactic effect on prostate cancer. In this article, epidemiological and laboratory studies on the relationship between soybeans, isoflavones and prostate cancer are reviewed and large scale multiethnic epidemiological studies are recommended.     

Major scientific advances with dairy foods in nutrition and health

A large body of scientific evidence collected in recent decades demonstrates that an adequate intake of calcium and other nutrients from dairy foods reduces the risk of osteoporosis by increasing bone acquisition during growth, slowing age-related bone loss, and reducing osteoporotic fractures. These results have culminated in the new (2005) Dietary Guidelines for Americans that now recommend 3 servings of milk products per day to reduce the risk of low bone mass and contribute important amounts of many nutrients that may have additional health attributes beyond bone health. A number of animal, observational, and clinical studies have shown that dairy food consumption can help reduce the risk of hypertension. Clinical trials indicate that the consumption of recommended levels of dairy products, as part of a healthy diet, can contribute to lower blood pressure in individuals with normal and elevated blood pressure. Emerging data also indicate that specific peptides associated with casein and whey proteins can significantly lower blood pressure. In addition, a growing body of evidence has provided support for a beneficial effect of dairy foods on body weight and fat loss. Clinical studies have demonstrated that during caloric restriction, body weight and body fat loss occurs when adequate calcium is provided by supplements and that this effect is further augmented by an equivalent amount of calcium supplied from dairy foods. Several studies support a role for calcium, vitamin D, and dairy foods against colon cancer. Additionally, conjugated linoleic acid, a fatty acid found naturally in dairy fat, confers a wide range of anticarcinogenic benefits in experimental animal models and is especially consistent for protection against breast cancer.     

Milk and milk-derived peptides combat against hypertension and vascular dysfunction: a review

Epidemiological studies have revealed that consumption of milk and fermented dairy products is inversely associated with elevated blood pressure and with many of the risk factors of the metabolic syndrome. Previously, calcium was thought to be behind this phenomenon, but during the last 20 years, convincing evidence emerging from experimental, epidemiological and intervention studies has highlighted the important role of the small peptides formed during fermentation processes. This review provides an overview of the potential blood pressure lowering components present in dairy products with a special focus on casein-derived tripeptides.     

Dairy nutrients and their effect on inflammatory profile in molecular studies

Dairy products contain milk fat, proteins, minerals, vitamin D, and other bioactive nutrients that have the potential to contribute to the association observed between increased dairy intake and a decreased risk of inflammation. The objective of this paper is to review the role of dairy bioactive molecules including dairy fat, proteins, micronutrients, and vitamins on inflammation markers in adipose, macrophage, and vascular tissues, which play a key role in the regulation of inflammation. A review was conducted to identify current scientific literature on dairy nutrients and inflammation in cell studies published until November 2014. The majority of saturated fatty acids (FAs) activate proinflammatory markers. Therefore, other dairy FAs or components may offset these harmful effects. Protein and amino acid composition of dairy products may have anti‐inflammatory action. Magnesium may have beneficial effects on inflammatory profile; on the contrary, studies on vitamin D demonstrate conflicting results. In conclusion, numerous studies assessed the effects of individual or mixtures of FAs on inflammatory markers; yet, there is far less research on the effects of other dairy bioactive nutrients. The exact bioactive molecule or combination of these molecules in dairy products, which underlies the inverse association between dairy intake and inflammation remains to be elucidated.     

Coffee and cancer risk,epidemiological evidence,and molecular mechanisms

Although early studies suggested that coffee consumption might increase risk of some cancers, more comprehensive epidemiological and experimental data now generally indicate either neutral or beneficial effects. In this review, we summarize the current evidence for associations between breast, prostate, colorectal, and liver cancers and the consumption of coffee, and discuss the experimental evidence for potential chemopreventive mechanisms of coffee and coffee constituents. The epidemiological evidence consistently indicates that coffee protects against liver cancer, and also point toward protective effects for risk of colorectal cancers (with relative risks of 0.50 (95% CI: 0.42–0.59) and 0.83 (95% CI: 0.75–0.92), respectively, in the most recent meta‐analyses). There seems to be no association between the overall risk of breast and prostate cancer and coffee intake. However, for subgroups such as postmenopausal breast cancers, advanced prostate cancers, and breast and prostate cancer survivors, an inverse association with coffee intake is indicated. Potential mechanisms for chemopreventive effects of coffee phytochemicals includes inhibition of oxidative stress and oxidative damage, regulation of DNA repair, phase II enzymatic activity, apoptosis, inflammation, as well as having antiproliferative, antiangiogenetic effects and antimetastatic effects. The experimental evidence for effects of coffee and coffee constituents on each of these processes is discussed.     

Update on the relationship of fish intake with prostate, breast, and colorectal cancers

A systematic review of prospective cohort and case-control studies investigating relationships between the intake of fish and incidence of prostate, breast, or colorectal cancers was conducted. A total of 106 studies fulfilled the requirements stated in the "Search strategy and selection criteria." Among 273 estimates of association reported by these studies, 53 indicated decreased risk while 12 indicated increased risk associated with fish intake. The hypothesis linking fish consumption and low cancer incidence appears to be supported by little epidemiological data. However, there are several factors that may mask potential protective associations with fish intake. The type and the amount of fish eaten, the cooking method, the stage of the cancer and, amongst women, menopausal status may all be important factors that relate to whether fish is protective or not. Future epidemiologic studies with a clearer assessment of these factors are needed to know more about the effects of fish consumption on cancer risk. Therefore, until there are better measures of dietary exposure or biomarkers to correlate self-report, no conclusion can be drawn regarding the recommendation for increasing fish consumption in general to reduce the risk of developing the most common cancers in Western societies.     

Invited review: The anti-inflammatory properties of dairy lipids

Dairy product consumption is often associated with negative effects because of its naturally high levels of saturated fatty acids. However, recent research has shown that dairy lipids possess putative bioactivity against chronic inflammation. Inflammation triggers the onset of several chronic diseases, including cardiovascular disease, type 2 diabetes mellitus, obesity, and cancer. This review discusses the anti-inflammatory properties of dairy lipids found in milk, yogurt, and cheese, and it examines them in relation to their implications for human health: their protective effects and their role in pathology. We also consider the effect of lipid profile alteration in dairy products—by using ruminant dietary strategies to enrich the milk, or by lipid fortification in the products. We critically review the in vivo, in vitro, ex vivo, and epidemiological studies associated with these dairy lipids and their role in various inflammatory conditions. Finally, we discuss some suggestions for future research in the study of bioactive lipids and dairy products, with reference to the novel field of metabolomics and epidemiological studies.     

Acrylamide and 5-hydroxymethylfurfural (HMF): A review on metabolism, toxicity, occurrence in food and mitigation strategies

Neo-formed contaminants (NFCs) are compounds forming during heating or preservation processes and exhibiting possible harmful effects to humans. Among the several NFCs described in literature, Acrylamide and 5-hydroxymethylfurfural (HMF) have attracted the attention of the scientific community in recent years. Both acrylamide and HMF are considered as probably or potentially carcinogenic to humans or might be metabolized by humans to potentially carcinogenic compounds. Acrylamide and HMF are mainly formed through Maillard Reaction and can be regarded as the most important heat-induced contaminants occurring in bread and bakery products. Acrylamide is carcinogen in rodent and some recent epidemiological studies have highlighted the association between dietary acrylamide and an increased risk of some types of cancer. HMF has been recently shown to be converted in vivo to 5-sulfoxymethylfurfural (SMF) which is a genotoxic compound. Dietary intake of HMF is in the order of mg/kg far above that of other food toxicants. In this paper, the latest available data on acrylamide and HMF have been reviewed focusing on available mitigation strategies, metabolism, dietary exposure, and toxicity. The results from the epidemiological studies about acrylamide and cancer risk and their relevance have been discussed, the major gaps of knowledge have been identified and the perspective of ongoing and future research was established.     

Prebiotics as functional foods: A review

Prebiotics are short chain carbohydrates that are non-digestible by digestive enzymes in humans and selectively enhance the activity of some groups of beneficial bacteria. In the intestine, prebiotics are fermented by beneficial bacteria to produce short chain fatty acids. Prebiotics also render many other health benefits in the large intestine such as reduction of cancer risk and increase calcium and magnesium absorption. Prebiotics are found in several vegetables and fruits and are considered functional food components which present significant technological advantages. Their addition improves sensory characteristics such as taste and texture, and enhances the stability of foams, emulsions and mouthfeel in a large range of food applications like dairy products and bread. This contribution reviews bioactives from food sources with prebiotic properties. Additionally, food application of bioactive prebiotics, stimulation of the viability of probiotics, health benefits, epidemiological studies, and safety concerns of prebiotics are also reviewed.     

乳制品消费与癌症风险控制

乳制品是营养价值很高的食物,但近年来对于乳制品的健康意义有了质疑之声。本文综述了乳制品与结肠癌、乳腺癌、前列腺癌、卵巢癌4种癌症发生风险关系的营养流行病学研究,对近年"牛奶致癌论"作出客观评价。证据表明,乳制品与前列腺癌和卵巢癌可能有一定的正相关性,但研究结果并不一致;乳制品对结肠癌的预防具有益处,对乳腺癌的影响未有定论;尚无证据表明每日摄入200g以下会显著增加癌症的风险。     

乳制品与糖尿病的饮食防控

本文综述了乳制品与糖尿病之间关系的研究进展。流行病学研究表明,乳制品对糖尿病的发生风险无不良影响,甚至有一定降低风险的作用。乳制品中的乳糖不会快速升高血糖,其反式脂肪成分并不是糖尿病的风险因子,而其中的乳清蛋白对于糖尿病患者是有利的。因此,乳制品是糖尿病患者饮食的有益组成。     

Diet, nutrition, and cancer

Evidence pertaining to the role of dietary factors in carcinogenesis comes from both epidemiological studies and laboratory experiments. In 1982, the Committee on Diet, Nutrition, and Cancer of the National Research Council conducted a comprehensive evaluation of this evidence. That assessment as well as recent epidemiological and laboratory investigations suggest that a high fat diet is associated with increased susceptibility to cancer of different sites, particularly the breast and colon, and to a lesser extent, the prostate. Current data permit no definitive conclusions about other dietary macroconstituents including cholesterol, total caloric intake, protein, carbohydrates and total dietary fiber. Specific components of fiber, however, may have a protective effect against colon cancer. In epidemiological studies, frequent consumption of certain fruits and vegetables, especially citrus fruits and carotene-rich and cruciferous vegetables, is associated with a lower incidence of cancers at various sites. The specific components responsible for these effects are not clearly identified, although the epidemiological evidence appears to be most consistent for a protective effect of carotene on lung cancer and less so for vitamins A and C and various cancer sites. The laboratory evidence is most consistent for vitamin A deficiency and enhanced tumorigenesis, and for the ability of various nonnutritive components in cruciferous vegetables to block in-vivo carcinogenesis. The data for minerals and carcinogenesis are extremely limited, although preliminary evidence from both epidemiological and laboratory studies suggests that selenium may protect against overall cancer risk. Frequent consumption of cured, pickled, or smoked foods, possibly because they may contain nitrosamines or polycyclic aromatic hydrocarbons, appears to increase the risk of esophageal or stomach cancer, however, the specific causative agents in these foods are not clearly identified. Excessive alcohol consumption among smokers appears to be associated with an elevated risk of cancers of the oral cavity, esophagus, larynx, and respiratory tract. The mechanisms of action of dietary factors on carcinogenesis are poorly understood. The NRC committee, and more recently, the National Cancer Institute and the American Cancer Society have proposed interim dietary guidelines to lower the risk of cancer. These guidelines are consistent with general dietary recommendations proposed by U.S. government agencies for maintenance of good health.(ABSTRACT TRUNCATED AT 400 WORDS)     

Investigation of the Putative Associations Between Dairy Consumption and Incidence of Type 1 and Type 2 Diabetes

A growing body of evidence suggests a possible relationship between the consumption of dairy products and the incidence of diabetes. A positive correlation between the early introduction of dairy in infancy and the incidence of type 1 diabetes (T1D) in genetically predisposed infants has been suggested by studies on rodents and humans. However, the lines of evidence supporting this association, including epidemiological studies and the observation of antibodies to bovine serum albumin, β-casein and bovine insulin in the serum of patients with T1D, are not without controversy. On the other hand, an inverse relationship between the consumption of dairy foods and the development of metabolic syndrome and/or type 2 diabetes (T2D) has been implied by epidemiological studies. Several dairy components, especially milk proteins, are believed to play a role in the beneficial effect of dairy consumption on glucose regulation by modulation of incretin hormones. Other dietary factors have also been associated with the incidence of T1D and T2D, indicating that dairy foods might be only one among many dietary agents possibly implicated in the development of diabetes. The present paper critically reviews the evidence and plausible mechanisms for the putative associations between dairy food consumption and incidence of T1D and T2D.     

Colorectal Cancer and Nonfermented Milk,Solid Cheese,and Fermented Milk Consumption: A Systematic Review and Meta-Analysis of Prospective Studies

Colorectal cancer is the second most prevalent cancer worldwide. A systematic review and meta-analysis of prospective studies was conducted to examine the association between intake of different types of dairy foods during adulthood and the development of colorectal cancer, specifically comparing nonfermented milk, solid cheese, and fermented milk. Seven databases were systematically searched and 15 cohort studies selected for inclusion, involving over 900,000 subjects and over 5200 colorectal cancer cases. Meta-analysis resulted in an overall relative risk of colon cancer of 0.74 (95% confidence interval 0.60–0.91) in men consuming nonfermented milk (highest intake category averaging 525 g/day). No association was found between consumption of nonfermented milk and rectal cancer in men or nonfermented milk and colon or rectal cancer in women. No protective association was found between consumption of solid cheese or fermented milk and colorectal cancer. Reasons for the differences in the impact of nonfermented milk, solid cheese, and fermented milk in the colon are discussed. This meta-analysis supports the inverse association between nonfermented milk consumption and risk of colon cancer in men, and provides an evidence base to assist in the formulation of dietary guidelines involving dairy foods.     

Milk fatty acids and potential health benefits: An updated vision

BackgroundMilk fat intake is often associated with a high risk of suffering from cardiovascular disease (CVD) due to its high saturated fat content. However, not all saturated fatty acids (SFA) are equal and they present structural differences that promote distinct effects on the biological processes. In addition, there is a growing scientific consensus pointing to dairy fat as a natural source of bioactive components.Scope and approachThe present review provides the most recent knowledge on the bioactive properties of fatty acids detected in dairy products and their potential effects on consumer health. The metabolic processes that involve these fatty acids and serious chronic diseases such as CVD, obesity, diabetes or cancer are explained and discussed throughout the text based on in vitro, animal and human studies. Moreover, information gaps are highlighted to inspire further research in the field.Key findings and conclusionsRecent investigations support that milk SFA should no longer be considered as a single group in terms of metabolism or negative effects in case of excess. Even they suggest that individual SFA possess specific properties associated with important physiological functions. Whole dairy products would also promote human health due to the presence of certain bioactive fatty acids. Among them, it is worth mentioning the maintenance of gut microbiota and weight control from short and medium-chain SFA, the essential role of branched-chain SFA in gut health at birth and the prevention of chronic inflammatory diseases by vaccenic and rumenic acids.     

Milk minerals and the metabolic syndrome

The prevalence of the metabolic syndrome or single components of it has dramatically risen across continents in the recent past and shows a tendency to increase in the future. The increase of these metabolic disorders was accompanied by dramatic changes in people's lifestyles, mainly less physical activity and a change in dietary habits. The consumption of fast food, convenience food and soft drinks increased, while a decline in the consumption of milk and milk products occurred. Most epidemiological studies have demonstrated a negative association between calcium and dairy consumption, and the prevalence of components of the metabolic syndrome. Diets rich in calcium or dairy products facilitated weight loss and fat loss in obese subjects or rodents and reduced weight and the regaining of fat in rodents during re-feeding after dieting. A more pronounced effect was seen if calcium was derived from dairy products. From animal and cell culture experiments a mechanism was proposed that is based mainly on dietary calcium-stimulated reduction of circulating calcitriol levels, which consequently results in a lower influx of calcium into adipocytes, leading to a metabolic state that favors catabolic over anabolic pathways. Moreover, the direct effect of calcitriol on autocrine cortisol synthesis may contribute to the weight-regulating effect of calcium. Overall, human and animal experiments have shown that dietary calcium has a slight but significantly beneficial effect on blood pressure. This was more pronounced if the calcium intake was based on milk products, which may be due to the high magnesium and potassium, and low sodium content, and to angiotensin converting enzyme-inhibiting peptides in milk products. The threshold for the minimum calcium requirement with respect to weight regulation is considered to be 800–1000 mg per day. More controlled intervention studies are needed to confirm the findings and support this hypothesis. The diversity of results indicates a complex rather than a simplistic model.