Red meat,diseases, and healthy alternatives: A critical review

Meat is an important food for human nutrition, by especially providing high-quality protein and also some essential micronutrients, in front iron, zinc, and vitamin B₁₂. However, a high intake of red and processed meat is associated with an increased risk for diseases, especially type 2 diabetes and colorectal cancer, as several epidemiological studies and meta-analyses have shown. This review summarizes meta-analyses of publications studying the association between red and processed meat intake and type 2 diabetes, cardiovascular diseases, colorectal and other cancers, and all-cause mortality. Various potential mechanisms involved in the increased disease risk are discussed. Furthermore, the beneficial effects of healthy alternatives for meat, like fish, nuts, vegetables and fruits, pulses and legumes, whole grains, and dairy products are reviewed by including selected papers and recent meta-analyses.     

Controversy on the correlation of red and processed meat consumption with colorectal cancer risk: an Asian perspective

Abstract

This study aimed to investigate the relationship between meat intake and colorectal cancer risk from an Asian, particularly Korean, perspective. A report by the International Agency for Research on Cancer (IARC) published in 2015 concluded that intake of processed and red meat increases the risk of developing colorectal cancer. We conducted an in-depth analysis of prospective, retrospective, case-control and cohort studies, systematic review articles, and IARC monograph reports, which revealed that the IARC/WHO report weighted the results of studies based in Western countries more and that the correlation between intake of processed meat products and colorectal cancer incidence in Asians is not clearly supported. Among 73 epidemiological studies, approximately 76% were conducted in Western countries, whereas only 15% of studies were conducted in Asia. Furthermore, most studies conducted in Asia showed that processed meat consumption is not related to the onset of cancer. Moreover, there have been no reports showing significant correlation between various factors that directly or indirectly affect colorectal cancer incidence, including processed meat products types, raw meat types, or cooking methods. Further epidemiological studies taking each country’s food culture into consideration are required to reliably elucidate the effects of processed meat product intake, especially on cancer incidence.     

Potential applications of plant based derivatives as fat replacers,antioxidants and antimicrobials in fresh and processed meat products

Growing concern about diet and health has led to development of healthier food products. In general consumer perception towards the intake of meat and meat products is unhealthy because it may increase the risk of diseases like cardiovascular diseases, obesity and cancer, because of its high fat content (especially saturated fat) and added synthetic antioxidants and antimicrobials. Addition of plant derivatives having antioxidant components including vitamins A, C and E, minerals, polyphenols, flavanoids and terpenoids in meat products may decrease the risk of several degenerative diseases. To change consumer attitudes towards meat consumption, the meat industry is undergoing major transformations by addition of nonmeat ingredients as animal fat replacers, natural antioxidants and antimicrobials, preferably derived from plant sources.     

Effect of Dietary Red Meat on Colorectal Cancer Risk—A Review

Heme iron overload has been implicated as the main cause of the increased risk of cancer due to the consumption of red meat. However, fish and shellfish, teas, and spices contain up to five times more iron than red meat. There is insufficient evidence that iron intake in dietary red meat is the primary causal factor for colorectal cancer. In addition, harmful substances produced during the preparation of red meat, including heterocyclic amines (HCAs), polycyclic aromatic hydrocarbons (PAHs), N‐nitroso compounds, and acrylamide, are extrinsic factors that increase carcinogenicity. HCAs are produced during the cooking of red meat, poultry meat, and fish. PAHs may also be produced during the cooking of diverse food groups, such as dairy products, fruits, vegetables, and cereals. The average daily intake of red meat among Korean individuals is 62 g; the amount of PAHs entering the body via red meat is less than the average amount of PAHs the body is exposed to in the air. Therefore, it is difficult to conclude that dietary red meat is the main cause of colorectal cancer. Rather, there may be an intricate influence of multiple factors, including fruit and vegetable intake, alcohol consumption, smoking, overweight, obesity, and stress.     

Oxidation During Digestion of Meat: Interactions with the Diet and Helicobacter pylori Gastritis,and Implications on Human Health

The last decade has seen epidemiological evidence of a positive association between high consumption of red meat and processed meat and the risk of developing a range of chronic diseases, such as colorectal cancer, cardiovascular disease, and type 2 diabetes. Oxidative stress is potentially involved in this association; however, oxidative stress is likely limited if red meat and processed meat are consumed in moderation, and combined with high intake of fruits and vegetables and low intake of refined sugars. In addition, it appears that some subgroups of the population are more prone to developing oxidative stress‐related diseases as a consequence of high red and processed meat consumption. For example, the gastric juice in the inflamed stomach of individuals infected with Helicobacter pylori may be an excellent site for enhanced oxidation following meat consumption. Similarly, patients with inflammatory bowel disease may be at increased risk. Oxidative stress resulting from red or processed meat consumption may mediate the onset and/or progression of a wide range of diseases through various mechanisms, which are discussed in this review.     

Consumption of processed red meat and its impact on human health: A review

Meat is an important component of the human diet, and the consumption of processed meat is high, despite the increasing popularity of the vegetarian model of nutrition. Both meat and meat product consumption contribute to delivering many vitamins and minerals, such as iron, zinc, selenium and vitamin B12; moreover, meat products are a significant source of high biological value protein, providing essential amino acids. Processed meat should be eaten in moderation. Excessive consumption of processed red meat (cured and smoked) carries the risk of developing new diseases or intensifying existing ones. This review aims to present scientific reports on the role and safety of the consumption of processed red meat in the diet of healthy individuals. The impact of meat consumption on the risk of cancer, cardiovascular diseases, diabetes, obesity, inflammatory bowel diseases, non-alcoholic fatty liver and infertility was described.     

Red meat consumption: An overview of the risks and benefits

Red meat is long established as an important dietary source of protein and essential nutrients including iron, zinc and vitamin B12, yet recent reports that its consumption may increase the risk of cardiovascular disease (CVD) and colon cancer have led to a negative perception of the role of red meat in health. The aim of this paper is to review existing literature for both the risks and benefits of red meat consumption, focusing on case–control and prospective studies. Despite many studies reporting an association between red meat and the risk of CVD and colon cancer, several methodological limitations and inconsistencies were identified which may impact on the validity of their findings. Overall, there is no strong evidence to support the recent conclusion from the World Cancer Research Fund (WCRF) report that red meat has a convincing role to play in colon cancer. A substantial amount of evidence supports the role of lean red meat as a positive moderator of lipid profiles with recent studies identifying it as a dietary source of the anti-inflammatory long chain (LC) n−3 PUFAs and conjugated linoleic acid (CLA). In conclusion, moderate consumption of lean red meat as part of a balanced diet is unlikely to increase risk for CVD or colon cancer, but may positively influence nutrient intakes and fatty acid profiles, thereby impacting positively on long-term health.     

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.     

How meaty? Detection and quantification of adulterants,foreign proteins and food additives in meat products

The worldwide consumption of meat is increasing, especially in developing countries. Many studies have correlated a diet characterised by high intake of processed red meats with a risk of colorectal cancer, stroke, coronary heart diseases and diabetes. Moreover, the quality and safety of meat products may be compromised by several admitted and not admitted procedures (i.e. addition of food additives and/or foreign proteins). For these reasons, the topic ‘meat products’ quality and safety’ has gained much in importance during last few years. In this review, the recent advances in the field of analytical methods for the evaluation of meat adulteration due to the addition of foreign proteins and food additives are reported, compared and critically evaluated. Moreover, the most representative monitoring practices, developed worldwide, related to meats adulteration are described and discussed.     

Food properties and dietary habits in colorectal cancer prevention and development

Colorectal cancer (CRC) is a very common and lethal disease worldwide. The etiology of the disease includes genetic and environmental factors. Among environmental factors, the dietary habits are considered to be easily changeable regarding preventing the CRC. Although there is still a long road to cover the gaps in knowledge on nutritional determinants and the dietary pattern on the CRC risk, several dietary suggestions and goals could be summarized. Diets high in energy, consumption of red meat or processed meat, food with a high glycemic index (carbohydrates, snack food, frying fast food, and sugar-sweetened drinks, sweets), exceed intake of salt (NaCl), low daily water intake (<4 cups per day) have been linked to an increased CRC risk. In contrast, consumption of white meat, as well as plant and fish oils with a high omega-3 PUFA to omega-6 PUFA ratio might even reduce the occurrence of CRC. A fiber-rich diet can lower the CRC risk up to 50%. Diet rich in vitamin B6, C, D, E, folic acid, selenium, and magnesium has also been considered to reduce the CRC risk. General unhealthy lifestyle which results in overweight and obesity-related syndromes (chronic inflammation, type 2 diabetes) can promote CRC. However, in many cases, the results are inconsistent and depend on multiple interdependent factors, i.e., ethnic, anthropometric, gender, age, hormones, and environment. In addition to dietary habits, all these agents are suggested to modify the risk of CRC.