The associations of red/processed meat consumption and cancer-related health outcomes have been well discussed. The umbrella review aimed to summarise the associations of red/processed meat consumption and various non-cancer-related outcomes in humans. We systematically searched the systematic reviews and meta-analyses of associations between red/processed meat intake and health outcomes from PubMed, Embase, Web of Science and the Cochrane Library databases. The umbrella review has been registered in PROSPERO (CRD 42021218568). A total of 40 meta-analyses were included. High consumption of red meat, particularly processed meat, was associated with a higher risk of all-cause mortality, CVD and metabolic outcomes. Dose–response analysis revealed that an additional 100 g/d red meat intake was positively associated with a 17 % increased risk of type 2 diabetes mellitus (T2DM), 15 % increased risk of CHD, 14 % of hypertension and 12 % of stroke. The highest dose–response/50 g increase in processed meat consumption at 95 % confident levels was 1·37, 95 % CI (1·22, 1·55) for T2DM, 1·27, 95 % CI (1·09, 1·49) for CHD, 1·17, 95 % CI (1·02, 1·34) for stroke, 1·15, 95 % CI (1·11, 1·19) for all-cause mortality and 1·08, 95 % CI (1·02, 1·14) for heart failure. In addition, red/processed meat intake was associated with several other health-related outcomes. Red and processed meat consumption seems to be more harmful than beneficial to human health in this umbrella review. It is necessary to take the impacts of red/processed meat consumption on non-cancer-related outcomes into consideration when developing new dietary guidelines, which will be of great public health importance. However, more additional randomised controlled trials are warranted to clarify the causality.

Limited data exist regarding the role of meat consumption in early-stage colorectal carcinogenesis. We examined associations of red and processed meat intake with screen-detected colorectal lesions in immunochemical fecal occult blood test (FIT)-positive participants, enrolled in the Norwegian CRCbiome study during 2017–2021, aged 55–77 years. Absolute and energy-adjusted intakes of red and processed meat (combined and individually) were assessed using a validated, semi-quantitative FFQ. Associations between meat intake and screen-detected colorectal lesions were examined using multinomial logistic regression analyses with adjustment for key covariates. Of 1162 participants, 319 presented with advanced colorectal lesions at colonoscopy. High v. low energy-adjusted intakes of red and processed meat combined, as well as red meat alone, were borderline to significantly positively associated with advanced colorectal lesions (OR of 1·24 (95 % CI 0·98, 1·57) and 1·34 (95 % CI 1·07, 1·69), respectively). A significant dose–response relationship was also observed for absolute intake levels (OR of 1·32 (95 % CI 1·09, 1·60) per 100 g/d increase in red and processed meat). For processed meat, no association was observed between energy-adjusted intakes and advanced colorectal lesions. A significant positive association was, however, observed for participants with absolute intake levels ≥ 100 v. < 50 g/d (OR of 1·19 (95 % CI 1·09, 1·31)). In summary, high intakes of red and processed meat were associated with presence of advanced colorectal lesions at colonoscopy in FIT-positive participants. The study demonstrates a potential role of dietary data to improve the performance of FIT-based screening.

In October 2015, the International Agency for Research on Cancer (IARC) released a report classifying processed meat as a type 1 carcinogen. The report prompted headlines and attracted immediate public attention, but the economic impacts remain unknown. In this paper, we investigate the impacts of the IARC report on selected processed meat prices and purchases using retail scanner data from US grocery stores. We compare changes in prices and sales of selected processed meat products to a constructed synthetic control group (using a convex combination of nonmeat food products). We find a significant decrease in bacon prices in the wake of the IARC report release, but we find no evidence of a sales reduction. We find no significant changes in price and sales for ham and sausage. The pattern of price and quantity changes are consistent with downward shifts in demand and outward shifts in supply for bacon and sausage following the release of the IARC report.

Current cancer prevention recommendations advise limiting red meat intake to <500 g/week and avoiding consumption of processed meat, but do not differentiate the source of processed meat. We examined the associations of processed meat derived from red v. non-red meats with cancer risk in a prospective cohort of 26 218 adults who reported dietary intake using the Canadian Diet History Questionnaire. Incidence of cancer was obtained through data linkage with Alberta Cancer Registry with median follow-up of 13·3 (interquartile range (IQR) 5·1) years. Multivariable Cox proportional hazards regression models were adjusted for covariates and stratified by age and sex. The median consumption (g/week) of red meat, processed meat from red meat and processed meat from non-red meat was 267·9 (IQR 269·9), 53·6 (IQR 83·3) and 11·9 (IQR 31·8), respectively. High intakes (4th Quartile) of processed meat from red meat were associated with increased risk of gastrointestinal cancer adjusted hazard ratio (AHR): 1·68 (95 % CI 1·09, 2·57) and colorectal cancers AHR: 1·90 (95 % CI 1·12, 3·22), respectively, in women. No statistically significant associations were observed for intakes of red meat or processed meat from non-red meat. Results suggest that the carcinogenic effect associated with processed meat intake may be limited to processed meat derived from red meats. The findings provide preliminary evidence towards refining cancer prevention recommendations for red and processed meat intake.

We aimed to investigate the associations of poor oral health cross-sectionally with diet quality and intake in older people. We also examined whether change in diet quality is associated with oral health problems. Data from the British Regional Heart Study (BRHS) comprising British males aged 71–92 years and the Health, Aging and Body Composition (HABC) Study comprising American males and females aged 71–80 years were used. Dental data included tooth loss, periodontal disease, dry mouth and self-rated oral health. Dietary data included diet quality (based on Elderly Dietary Index (BRHS) and Healthy Eating Score (HABC Study)) and several nutrients. In the BRHS, change in diet quality over 10 years (1998–2000 to 2010–2012) was also assessed. In the BRHS, tooth loss, fair/poor self-rated oral health and accumulation of oral health problems were associated with poor diet quality, after adjustment. Similar associations were reported for high intake of processed meat. Poor oral health was associated with the top quartile of percentage of energy content from saturated fat (self-rated oral health, OR 1·34, 95 % CI 1·02, 1·77). In the HABC Study, no significant associations were observed for diet quality after adjustment. Periodontal disease was associated with the top quartile of percentage of energy content from saturated fat (OR 1·48, 95 % CI 1·09, 2·01). In the BRHS, persistent low diet quality was associated with higher risk of tooth loss and accumulation of oral health problems. Older individuals with oral health problems had poorer diets and consumed fewer nutrient-rich foods. Persistent poor diet quality was associated with oral health problems later in life.

The adverse effect of red meat consumption on the risk for CVD is a major population health concern, especially in developing Hispanic/Latino countries in which there are clear trends towards increased consumption. This population-based case–control study examined the associations between total, processed and unprocessed red meat intakes and non-fatal acute myocardial infarction (MI) in Costa Rica. The study included 2131 survivors of a first non-fatal acute MI and 2131 controls individually matched by age, sex and area of residence. Dietary intake was assessed with a FFQ. OR were estimated by using conditional logistic regression. Higher intakes of total and processed red meat were associated with increased odds of acute MI. The OR were 1·31 (95 % CI 1·04, 1·65) and 1·29 (95 % CI 1·01, 1·65) for the highest quintiles of total red meat (median: 110·8 g or 1 serving/d) and processed red meat intake (median: 36·1 g or 5 servings/week), respectively. There were increasing trends in the odds of acute MI with higher total (P trend=0·01) and processed (P trend=0·02) red meat intakes. Unprocessed red meat intake was not associated with increased odds of acute MI. Substitutions of 50 g of alternative foods (fish, milk, chicken without skin and chicken without fat) for 50 g of total, processed and unprocessed red meat were associated with lower odds of acute MI. The positive association between red meat intake and acute MI in Costa Rica highlights the importance of reducing red meat consumption in middle-income Hispanic/Latino populations.

A sample selection system is used to examine factors associated with likelihoods of purchase and amounts spent on fresh, frozen, and processed meats in Malaysia based on data from the 2009/10 Malaysian Household Expenditure Survey. Statistical tests support use of the sample selection system estimator over more conventional estimation procedures. Results indicate that household size, location of residence, ethnicity, age, education, and income are closely associated with patterns of household expenditures for fresh, frozen, and processed meats. Several observations are noted regarding determinants of purchase likelihoods and expenditure patterns for meat in Malaysia.

Meat is a food rich in protein, minerals such as iron and zinc as well as a variety of vitamins, in particular B vitamins. However, the content of cholesterol and saturated fat is higher than in some other food groups. Processed meat is defined as products usually made of red meat that are cured, salted or smoked (e.g. ham or bacon) in order to improve the durability of the food and/or to improve colour and taste, and often contain a high amount of minced fatty tissue (e.g. sausages). Hence, high consumption of processed foods may lead to an increased intake of saturated fats, cholesterol, salt, nitrite, haem iron, polycyclic aromatic hydrocarbons, and, depending upon the chosen food preparation method, also heterocyclic amines. Several large cohort studies have shown that a high consumption of processed (red) meat is related to increased overall and cause-specific mortality. A meta-analysis of nine cohort studies observed a higher mortality among high consumers of processed red meat (relative risk (RR) = 1·23; 95 % CI 1·17, 1·28, top v. bottom consumption category), but not unprocessed red meat (RR = 1·10; 95 % CI 0·98, 1·22). Similar associations were reported in a second meta-analysis. All studies argue that plausible mechanisms are available linking processed meat consumption and risk of chronic diseases such as CVD, diabetes mellitus or some types of cancer. However, the results of meta-analyses do show some degree of heterogeneity between studies, and it has to be taken into account that individuals with low red or processed meat consumption tend to have a healthier lifestyle in general. Hence, substantial residual confounding cannot be excluded. Information from other types of studies in man is needed to support a causal role of processed meat in the aetiology of chronic diseases, e.g. studies using the Mendelian randomisation approach.

Contamination of locally produced, ready-to-eat meats by Listeria spp. has been previously reported at one processing plant in Trinidad. However, the status of this pathogen in locally produced products sold at retail outlets is unknown. This study was conducted to establish whether there is a risk to consumers of locally processed meats caused by the presence of Listeria spp., and whether a link exists between the presence of the pathogen in retail products and the manufacturing plant of one brand (B). Four hundred and eighty ready-to-eat meat products of two popular local brands (A and B) were collected from retail outlets and analysed for the presence of Listeria spp. together with food samples and surfaces from one manufacturing plant (B). Eighty-eight of the retail products (18·3%) were contaminated with Listeria spp., of which, 52·3% were L. innocua, 44·3% were L. monocytogenes and 3·4% belonged to the L. seeligeri–L. welshimeri–L. ivanovii (Siwi) group. L. innocua was found in 15 in-process food samples and on three surfaces of equipment at plant B. Four in-process food samples were also contaminated with Siwi isolates. Repetitive extragenic palindromic PCR DNA fingerprinting showed a possible association between strains of different Listeria spp. and brand as well as with manufacturing plant B.

Relatively small lifestyle modifications related to weight reduction, physical activity and diet have been shown to decrease the risk of type 2 diabetes. Connected with diet, low consumption of meat has been suggested as a protective factor of diabetes. The aim of the present study was to examine the association between the consumption of total meat or the specific types of meats and the risk of type 2 diabetes. The Alpha-Tocopherol, Beta-Carotene Cancer Prevention cohort included middle-aged male smokers. Up to 12 years of follow-up, 1098 incident cases of diabetes were diagnosed from 24 845 participants through the nationwide register. Food consumption was assessed by a validated FFQ. In the age- and intervention group-adjusted model, high total meat consumption was a risk factor of type 2 diabetes (relative risk (RR) 1·50, 95 % CI 1·23, 1·82, highest v. lowest quintile). The result was similar after adjustment for environmental factors and foods related to diabetes and meat consumption. The RR of type 2 diabetes was 1·37 for processed meat (95 % CI 1·11, 1·71) in the multivariate model. The results were explained more by intakes of Na than by intakes of SFA, protein, cholesterol, haeme Fe, Mg and nitrate, and were not modified by obesity. No association was found between red meat, poultry and the risk of type 2 diabetes. In conclusion, reduction of the consumption of processed meat may help prevent the global epidemic of type 2 diabetes. It seems like Na of processed meat may explain the association.

The aim of the present study was to examine the association of red meat, white meat and processed meat consumption in Irish adults with dietary quality. A cross-sectional study of subjects, randomly selected using the electoral register, estimated habitual food intakes using a 7 d food diary in a nationally representative sample of 662 men and 717 women (not pregnant or lactating) aged 18–64 years. Consumers were classified into thirds, based on the distribution of mean daily intakes for red meat, white meat and processed meat. The mean intakes of red meat, white meat and processed meat were 51, 33 and 26 g/d respectively, and men consumed significantly more (P<0·001) than women for all meat types. In men, red meat consumption was associated with lower (P<0·001) prevalence of inadequacy for Zn, riboflavin and vitamin C intakes. Increasing processed meat intake was associated with a lower (P<0·01) level of compliance with dietary recommendations for fat, carbohydrate and fibre in men. Increasing processed meat consumption was associated with lower (P<0·01) wholemeal bread, vegetables, fruit and fish intakes in men and women. Managerial occupations were associated with lower processed meat intakes. It is important to distinguish between meat groups, as there was a large variation between the dietary quality in consumers of red meat, white meat and processed meat. Processed meat consumption is negatively associated with dietary quality and might therefore be a dietary indicator of poor dietary quality. This has important implications in nutritional epidemiological studies and for the development of food-based dietary guidelines.