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1.
Food for Mood: Relevance of Nutritional Omega-3 Fatty Acids for Depression and Anxiety.
Larrieu, T, Layé, S
Frontiers in physiology. 2018;9:1047
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The human brain contains high levels of polyunsaturated fatty acids (PUFAs). Of these PUFAs, omega-3s have been widely studied in relation to many brain diseases, including anxiety and depression. This review focuses on the clinical and experimental data linking dietary intake of omega-3s with depression or anxiety. People diagnosed with anxiety and depressive disorders have lower omega-3s and a higher ratio of omega-6s to omega-3s in their blood and brains compared to healthy subjects. Experiments on omega-3 supplementation for depression and post-traumatic stress have had promising results. Numerous mechanisms have been proposed for the effects of omega-3s. These include direct effects on specific receptors in the brain, regulation of the endocannabinoid system, effects on the hypothalamic-pituitary-adrenal (HPA) axis, and reduction of inflammation in the brain. The authors conclude that more research is needed into the potential of omega-3s as treatment for mood-related diseases.
Abstract
The central nervous system (CNS) has the highest concentration of lipids in the organism after adipose tissue. Among these lipids, the brain is particularly enriched with polyunsaturated fatty acids (PUFAs) represented by the omega-6 (ω6) and omega-3 (ω3) series. These PUFAs include arachidonic acid (AA) and docosahexaenoic acid (DHA), respectively. PUFAs have received substantial attention as being relevant to many brain diseases, including anxiety and depression. This review addresses an important question in the area of nutritional neuroscience regarding the importance of ω3 PUFAs in the prevention and/or treatment of neuropsychiatric diseases, mainly depression and anxiety. In particular, it focuses on clinical and experimental data linking dietary intake of ω3 PUFAs and depression or anxiety. In particular, we will discuss recent experimental data highlighting how ω3 PUFAs can modulate neurobiological processes involved in the pathophysiology of anxiety and depression. Potential mechanisms involved in the neuroprotective and corrective activity of ω3 PUFAs in the brain are discussed, in particular the sensing activity of free fatty acid receptors and the activity of the PUFAs-derived endocannabinoid system and the hypothalamic-pituitary-adrenal axis.
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2.
Recognizing Depression from the Microbiota⁻Gut⁻Brain Axis.
Liang, S, Wu, X, Hu, X, Wang, T, Jin, F
International journal of molecular sciences. 2018;19(6)
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Emerging research indicates that major depression is not just a mental disorder but also a systemic disease. In depression, the brain-gut axis, the bidirectional pathway that connects the brain and gut, is thought to be disturbed. This disruption is hypothesised to be a major pathological basis of depression. The aim of this paper is to explore this hypothesis by reviewing the current literature. According to the current literature, the authors found research stating the gut microbiota of depressed patients is significantly different from that of healthy controls. Additionally, disturbances or abnormalities in the gut can influence the susceptibility of onset of depression, while restoration of the gut will alleviate depression. Based on these findings, the authors conclude depression is closely related with the condition of the brain-gut axis, and that restoring the normal condition of gut microbiota may aid in the therapy of depression. The authors expect therapies that target gut microbiota will play an important role in the treatment and prevention of depression in the future.
Abstract
Major depression is one of the leading causes of disability, morbidity, and mortality worldwide. The brain⁻gut axis functions are disturbed, revealed by a dysfunction of the brain, immune system, endocrine system, and gut. Traditional depression treatments all target the brain, with different drugs and/or psychotherapy. Unfortunately, most of the patients have never received any treatment. Studies indicate that gut microbiota could be a direct cause for the disorder. Abnormal microbiota and the microbiota⁻gut⁻brain dysfunction may cause mental disorders, while correcting these disturbance could alleviate depression. Nowadays, the gut microbiota modulation has become a hot topic in treatment research of mental disorders. Depression is closely related with the health condition of the brain⁻gut axis, and maintaining/restoring the normal condition of gut microbiota helps in the prevention/therapy of mental disorders.
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Zinc, Magnesium, Selenium and Depression: A Review of the Evidence, Potential Mechanisms and Implications.
Wang, J, Um, P, Dickerman, BA, Liu, J
Nutrients. 2018;10(5)
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Adequate micronutrient consumption and mental health are of major public health importance. Recent findings suggest micronutrient deficiencies may play a role in the development and progression of depression, yet the findings remain unclear. The aim of this review is to present the recent evidence on the association between several micronutrients and depression and discuss the potential mechanisms and clinical implications. Based on the current literature, evidence shows an association between both zinc and magnesium deficiency and the risk of depression, with stronger evidence supporting zinc. Studies on selenium are limited or inconclusive. According to these findings, the authors support the importance of adequate micronutrient consumption for promoting mental health. They suggest future research should investigate the safety and efficacy of micronutrient supplementation as an adjunct treatment for depression to better inform current prevention and treatment strategies.
Abstract
Micronutrient deficiency and depression are major global health problems. Here, we first review recent empirical evidence of the association between several micronutrients—zinc, magnesium, selenium—and depression. We then present potential mechanisms of action and discuss the clinical implications for each micronutrient. Collectively, empirical evidence most strongly supports a positive association between zinc deficiency and the risk of depression and an inverse association between zinc supplementation and depressive symptoms. Less evidence is available regarding the relationship between magnesium and selenium deficiency and depression, and studies have been inconclusive. Potential mechanisms of action involve the HPA axis, glutamate homeostasis and inflammatory pathways. Findings support the importance of adequate consumption of micronutrients in the promotion of mental health, and the most common dietary sources for zinc and other micronutrients are provided. Future research is needed to prospectively investigate the association between micronutrient levels and depression as well as the safety and efficacy of micronutrient supplementation as an adjunct treatment for depression.
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Microbiome-Gut-Brain Axis and Toll-Like Receptors in Parkinson's Disease.
Caputi, V, Giron, MC
International journal of molecular sciences. 2018;19(6)
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Parkinson’s disease (PD) is a progressively debilitating neurodegenerative disease and recently the role of the microbiota-gut-brain axis has gained attention in patients with PD. Research shows that an altered gut microbiota can activate Toll-like receptors (TLRs), receptors involved in the innate immune response, causing an inflammatory cascade in the gut and brain. Based on this knowledge, gut microbiota and TLRs may be potential therapeutic targets for PD. This review sheds light on the current knowledge regarding the association between the microbiota-gut-brain axis and innate immunity via TLR signalling in PD. Increased understanding of this relationship should lead to insights on the pathophysiology of PD, as well as improved dietary and pharmaceutical therapeutic approaches in PD patients. Based on the existing evidence, the authors conclude that through modulating the gut, thus balancing the immune response in PD patients, it may be possible to influence early phases of the neurodegenerative cascade.
Abstract
Parkinson’s disease (PD) is a progressively debilitating neurodegenerative disease characterized by α-synucleinopathy, which involves all districts of the brain-gut axis, including the central, autonomic and enteric nervous systems. The highly bidirectional communication between the brain and the gut is markedly influenced by the microbiome through integrated immunological, neuroendocrine and neurological processes. The gut microbiota and its relevant metabolites interact with the host via a series of biochemical and functional inputs, thereby affecting host homeostasis and health. Indeed, a dysregulated microbiota-gut-brain axis in PD might lie at the basis of gastrointestinal dysfunctions which predominantly emerge many years prior to the diagnosis, corroborating the theory that the pathological process is spread from the gut to the brain. Toll-like receptors (TLRs) play a crucial role in innate immunity by recognizing conserved motifs primarily found in microorganisms and a dysregulation in their signaling may be implicated in α-synucleinopathy, such as PD. An overstimulation of the innate immune system due to gut dysbiosis and/or small intestinal bacterial overgrowth, together with higher intestinal barrier permeability, may provoke local and systemic inflammation as well as enteric neuroglial activation, ultimately triggering the development of alpha-synuclein pathology. In this review, we provide the current knowledge regarding the relationship between the microbiota-gut⁻brain axis and TLRs in PD. A better understanding of the dialogue sustained by the microbiota-gut-brain axis and innate immunity via TLR signaling should bring interesting insights in the pathophysiology of PD and provide novel dietary and/or therapeutic measures aimed at shaping the gut microbiota composition, improving the intestinal epithelial barrier function and balancing the innate immune response in PD patients, in order to influence the early phases of the following neurodegenerative cascade.
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Harnessing the Power of Microbiome Assessment Tools as Part of Neuroprotective Nutrition and Lifestyle Medicine Interventions.
Toribio-Mateas, M
Microorganisms. 2018;6(2)
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This is a practical review written by a clinician for other clinicians. It draws from an extensive body of evidence on the links between the gut microbes (bacteria amongst them), called the microbiota, both in health and in a variety of human diseases. The author, who is also a researcher in the communication between the gut and the brain (the gut-brain axis), focuses on the translation of science into simple clinical applications that result in measurable health outcomes, and in particular in neurodegenerative conditions such as Alzheimer's and Parkinson's, but also other less well studied such as Chronic Fatigue Syndrome (CFS). The paper also covers mental health / mood conditions such as anxiety, and depression. Practitioners who work in the area of gut health and use stool tests to assess various imbalances their patients may be experiencing will get the most out this paper. The author takes a look at the physiological processes that influence gastrointestinal as well as brain health and discusses how tools such as the characterisation or "mapping" of commensal bacteria (the bacteria that lives inside our guts normally), along with the identification of potential opportunistic and pathogenic bacteria and parasites, together with knowledge of molecules such as short chain fatty acids or zonulin can enable better clinical decision making by nutrition and lifestyle medicine practitioners. The paper also includes a valuable discussion on patient-reported outcome measures (PROMs), and particularly on the use of MYMOP by practitioners as a validated tool to collect insight from exposure to real world data in clinical practice.
Abstract
An extensive body of evidence documents the importance of the gut microbiome both in health and in a variety of human diseases. Cell and animal studies describing this relationship abound, whilst clinical studies exploring the associations between changes in gut microbiota and the corresponding metabolites with neurodegeneration in the human brain have only begun to emerge more recently. Further, the findings of such studies are often difficult to translate into simple clinical applications that result in measurable health outcomes. The purpose of this paper is to appraise the literature on a select set of faecal biomarkers from a clinician’s perspective. This practical review aims to examine key physiological processes that influence both gastrointestinal, as well as brain health, and to discuss how tools such as the characterisation of commensal bacteria, the identification of potential opportunistic, pathogenic and parasitic organisms and the quantification of gut microbiome biomarkers and metabolites can help inform clinical decisions of nutrition and lifestyle medicine practitioners.
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Movement Disorders Related to Gluten Sensitivity: A Systematic Review.
Vinagre-Aragón, A, Zis, P, Grunewald, RA, Hadjivassiliou, M
Nutrients. 2018;10(8)
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Gluten related disorders (GRDs) is an umbrella term for diseases triggered by gluten, including coeliac disease and gluten sensitivity. People with GRDs may experience a wide range of symptoms including digestive and nervous system issues. Movement Disorders (MDs) refers to a group of nervous system conditions that cause abnormal movements, which may be voluntary or involuntary. This literature review looked at the current research on GRDs and MDs such as epilepsy, Parkinson’s disease, restless leg syndrome and tremors. 48 papers were used for the review. Most papers looked at MDs in those diagnosed with coeliac disease, rather than other GRDs. The authors found many examples where the symptoms of MDs, including chorea, restless leg syndrome, stiff person syndrome and tics, improved on a gluten free diet. The authors concluded that gluten-related MDs may be more common than previously thought, and that following a gluten free diet can be beneficial in many cases. They recommended that gluten sensitivity and coeliac disease should be considered in patients with MDs of unknown cause.
Abstract
Gluten related disorders (GRD) represent a wide spectrum of clinical manifestations that are triggered by the ingestion of gluten. Coeliac disease (CD) or gluten sensitive enteropathy is the most widely recognised, but extra-intestinal manifestations have also been increasingly identified and reported. Such manifestations may exist in the absence of enteropathy. Gluten sensitivity (GS) is another term that has been used to include all GRD, including those where there is serological positivity for GS related antibodies in the absence of an enteropathy. Gluten ataxia (GA) is the commonest extraintestinal neurological manifestation and it has been the subject of many publications. Other movement disorders (MDs) have also been reported in the context of GS. The aim of this review was to assess the current available medical literature concerning MDs and GS with and without enteropathy. A systematic search was performed while using PubMed database. A total of 48 articles met the inclusion criteria and were included in the present review. This review highlights that the phenomenology of gluten related MDs is broader than GA and demonstrates that gluten-free diet (GFD) is beneficial in a great percentage of such cases.
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Dietary Neurotransmitters: A Narrative Review on Current Knowledge.
Briguglio, M, Dell'Osso, B, Panzica, G, Malgaroli, A, Banfi, G, Zanaboni Dina, C, Galentino, R, Porta, M
Nutrients. 2018;10(5)
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Neurotransmitters (NTs) are chemical messengers, found mainly within the nervous system. Common NTs are acetylcholine (ACh), glutamate, γ-aminobutyric acid (GABA), dopamine, serotonin (5-HT), and histamine. Many foods are natural sources of NTs that may influence the nervous system, and therefore mood and mental health. This review paper looked at books and studies and discusses the NT content of foods and the possible implications for human health. Acetylcholine is a NT involved in muscle movement, learning and memory. Its presence is documented in more than 50 plant species, including squash, aubergine spinach and nettles. Glutamate is the most abundant excitatory NT in the brain. Glutamic acid naturally occurs in foods with high protein content. Seaweeds, cheeses, fish sauces, soy sauces, fermented beans, and tomato showed high levels of free glutamic acid. Dried cod, salami, caviar, and instant coffee powder are other sources of this amino acid. Salts of glutamic acid, such as monosodium glutamate, are added to certain foods as flavour enhancers. GABA is a calming NT. Studies have found the highest contents of GABA in raw spinach, potato, sweet potato and cruciferous vegetables such as kale and broccoli. Shiitake mushrooms and chestnuts also contained a significant amount of GABA. Dopamine plays an essential role in the coordination of body movements, motivation, and reward. Information on the content of dopamine foods is very limited. Bananas, plantains and avocado were reported to contain high levels of dopamine. 5-HT pathways modulate behaviours, eating, and sleep, and in the gut are involved in the regulation of gastrointestinal motility. In recent years, the number of studies on the content of 5-HT in plants has increased. 5-HT appeared to be prevalent in the green bananas, with higher concentrations found in the peel compared with the flesh. 5-HT was also found in peppers, paprika, hazelnut, tomatoes, pineapple, plum, passion fruit, papaya and kiwi fruit. Histamine is involved in arousal, attention, and reactivity, as well as in local immune responses. The presence of histamine in processed foods, such as aged cheeses, contributes to characteristic flavours and textures. Wine and beer may contain a significant amount of histamine. Fermented foods contain histamine. The food industry generally aims to maintain the levels of amines in foods as low as possible; consumption of fish, cured meat products, sauerkraut, and cheese varieties such as Cheddar, Swiss, Gruyère, and Gouda have been associated with amine poisoning. The significance of dietary NTs intake needs to be further investigated, as there is little data about their bioavailability or clinical implications. New studies should consider if dietary NTs can be transported across the blood-brain barriers or act on the central nervous system via other organs. The authors suggest that in future, including or excluding particular foods containing NTs could be beneficial for patients suffering from Alzheimer’s disease or dementia (an ACh diet), epilepsy or migraines (a glutamate-free diet), anxiety or insomnia (a GABA diet), Parkinson’s disease (a dopamine diet), depressive disorders (a serotonin diet), and vascular headaches (a histamine-free diet).
Abstract
Foods are natural sources of substances that may exert crucial effects on the nervous system in humans. Some of these substances are the neurotransmitters (NTs) acetylcholine (ACh), the modified amino acids glutamate and γ-aminobutyric acid (GABA), and the biogenic amines dopamine, serotonin (5-HT), and histamine. In neuropsychiatry, progressive integration of dietary approaches in clinical routine made it necessary to discern the more about some of these dietary NTs. Relevant books and literature from PubMed and Scopus databases were searched for data on food sources of Ach, glutamate, GABA, dopamine, 5-HT, and histamine. Different animal foods, fruits, edible plants, roots, and botanicals were reported to contain NTs. These substances can either be naturally present, as part of essential metabolic processes and ecological interactions, or derive from controlled/uncontrolled food technology processes. Ripening time, methods of preservation and cooking, and microbial activity further contributes to NTs. Moreover, gut microbiota are considerable sources of NTs. However, the significance of dietary NTs intake needs to be further investigated as there are no significant data on their bioavailability, neuronal/non neuronal effects, or clinical implications. Evidence-based interventions studies should be encouraged.
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Neurohealth Properties of Hericium erinaceus Mycelia Enriched with Erinacines.
Li, IC, Lee, LY, Tzeng, TT, Chen, WP, Chen, YP, Shiao, YJ, Chen, CC
Behavioural neurology. 2018;2018:5802634
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The individual compounds within culinary mushrooms has gained much interest and enthusiasm due to their potential health benefits when applied to specific illness or ailments. This particular paper reviews the effects of erinacine compound found in a particular mushroom named Hericium erinaceus (known as Lion’s Mane) and its health properties with regards to aging associated diseases of the nervous system, such as Parkinson’s disease, depression and Alzheimer’s disease. Animal studies reportedly show that erinacines stimulate the synthesis of nerve growth factor, which can prolongs the survival of neurons and reduce the consequence of neurodegenerative diseases. The studies discussed are encouraging to read and offer hope to those with a predisposition to or suffering from such diseases. However, more research in this field is required.
Abstract
Hericium erinaceus, an ideal culinary-medicinal mushroom, has become a well-established candidate in promoting positive brain and nerve health-related activities by inducing the nerve growth factor from its bioactive ingredient. Among its active compounds, only erinacine A has confirmed pharmacological actions in the central nervous system in rats. Hence, this review has summarized the available information on the neurohealth properties of H. erinaceus mycelia enriched with erinacines, which may contribute to further research on the therapeutic roles of these mycelia. The safety of this mushroom has also been discussed. Although it has been difficult to extrapolate the in vivo studies to clinical situations, preclinical studies have shown that there can be improvements in ischemic stroke, Parkinson's disease, Alzheimer's disease, and depression if H. erinaceus mycelia enriched with erinacines are included in daily meals.
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The Effects of Magnesium Supplementation on Subjective Anxiety and Stress-A Systematic Review.
Boyle, NB, Lawton, C, Dye, L
Nutrients. 2017;9(5)
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15% of the population experience anxiety-related conditions at some point in their lives. Several studies have found a relationship between low magnesium (Mg) and an increased likelihood of stress and anxiety. This systematic review examined the available evidence for the effectiveness of Mg supplementation in reducing anxiety and stress. 18 studies were included in the review. Of the eight studies looking at Mg supplementation and anxiety, four reported positive results. Four of seven studies on premenstrual syndrome and one of two studies in people with high blood pressure reported positive effects of Mg on anxiety. Mg had no effect on postpartum anxiety in the study reviewed. The authors concluded that existing evidence is suggestive of a beneficial effect of Mg on anxiety. However, the quality of the existing evidence is poor. Well-designed randomised controlled trials are required to further confirm the effect of Mg supplementation on anxiety and stress.
Abstract
BACKGROUND Anxiety related conditions are the most common affective disorders present in the general population with a lifetime prevalence of over 15%. Magnesium (Mg) status is associated with subjective anxiety, leading to the proposition that Mg supplementation may attenuate anxiety symptoms. This systematic review examines the available evidence for the efficacy of Mg supplementation in the alleviation of subjective measures of anxiety and stress. METHODS A systematic search of interventions with Mg alone or in combination (up to 5 additional ingredients) was performed in May 2016. Ovid Medline, PsychInfo, Embase, CINAHL and Cochrane databases were searched using equivalent search terms. A grey literature review of relevant sources was also undertaken. RESULTS 18 studies were included in the review. All reviewed studies recruited samples based upon an existing vulnerability to anxiety: mildly anxious, premenstrual syndrome (PMS), postpartum status, and hypertension. Four/eight studies in anxious samples, four/seven studies in PMS samples, and one/two studies in hypertensive samples reported positive effects of Mg on subjective anxiety outcomes. Mg had no effect on postpartum anxiety. No study administered a validated measure of subjective stress as an outcome. CONCLUSIONS Existing evidence is suggestive of a beneficial effect of Mg on subjective anxiety in anxiety vulnerable samples. However, the quality of the existing evidence is poor. Well-designed randomised controlled trials are required to further confirm the efficacy of Mg supplementation.
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Vegetarian, vegan diets and multiple health outcomes: A systematic review with meta-analysis of observational studies.
Dinu, M, Abbate, R, Gensini, GF, Casini, A, Sofi, F
Critical reviews in food science and nutrition. 2017;57(17):3640-3649
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Vegetarian diet is experiencing a considerable popularity in the general population. The aim of this study was to obtain an estimate of the association between vegetarian, vegan diets, and multiple health outcomes, including risk factors for chronic diseases, risk of all-cause mortality, incidence and mortality from cardio-cerebrovascular diseases, total cancer and specific types of cancer. This study is a comprehensive systematic review with meta-analysis of all cross-sectional and cohort studies. A total of 108 articles were included in the meta-analysis with a total population of over 130,000 vegetarians and 15,000 vegans. Results indicate that: - vegetarians and vegans show significantly lower levels of the most relevant risk factor for chronic disease such as body mass index, lipid variables and fasting glucose, when compared to non-vegetarians and nonvegans. - a significant protection versus ischemic heart disease and cancer is present in vegetarian subjects, however this protection is not significant for overall mortality, cardio and cerebrovascular diseases. - vegan diet seems to be associated with a lower rate of cancer incidence (interpreted with caution due to the small sample size of the study). Authors conclude that their findings may be useful for helping to give correct information to subjects who want to adopt vegetarian or vegan dietary patterns.
Abstract
BACKGROUND Beneficial effects of vegetarian and vegan diets on health outcomes have been supposed in previous studies. OBJECTIVES Aim of this study was to clarify the association between vegetarian, vegan diets, risk factors for chronic diseases, risk of all-cause mortality, incidence, and mortality from cardio-cerebrovascular diseases, total cancer and specific type of cancer (colorectal, breast, prostate and lung), through meta-analysis. METHODS A comprehensive search of Medline, EMBASE, Scopus, The Cochrane Library, and Google Scholar was conducted. RESULTS Eighty-six cross-sectional and 10 cohort prospective studies were included. The overall analysis among cross-sectional studies reported significant reduced levels of body mass index, total cholesterol, LDL-cholesterol, and glucose levels in vegetarians and vegans versus omnivores. With regard to prospective cohort studies, the analysis showed a significant reduced risk of incidence and/or mortality from ischemic heart disease (RR 0.75; 95% CI, 0.68 to 0.82) and incidence of total cancer (RR 0.92; 95% CI 0.87 to 0.98) but not of total cardiovascular and cerebrovascular diseases, all-cause mortality and mortality from cancer. No significant association was evidenced when specific types of cancer were analyzed. The analysis conducted among vegans reported significant association with the risk of incidence from total cancer (RR 0.85; 95% CI, 0.75 to 0.95), despite obtained only in a limited number of studies. CONCLUSIONS This comprehensive meta-analysis reports a significant protective effect of a vegetarian diet versus the incidence and/or mortality from ischemic heart disease (-25%) and incidence from total cancer (-8%). Vegan diet conferred a significant reduced risk (-15%) of incidence from total cancer.