- How did this page pass the Good Article review? Many of the so-called "studies" cited here are unscientific, as they fail to account for confounding factors and rely on correlation-causation fallacies.
- Associations of unprocessed and processed meat intake with mortality and cardiovascular disease in 21 countries [Prospective Urban Rural Epidemiology (PURE) Study]: a prospective cohort study
- https://www.sciencedirect.com/science/article/pii/S0002916522004282
- Red Meat and Processed Meat Consumption and All-Cause Mortality: A Meta-Analysis
- https://academic.oup.com/aje/article/179/3/282/103471
- Red and processed meat consumption and mortality: dose–response meta-analysis of prospective cohort studies
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10270853/
- Processed and Unprocessed Red Meat and Risk of Colorectal Cancer: Analysis by Tumor Location and Modification by Time
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4549221/
- Health effects associated with consumption of unprocessed red meat: a Burden of Proof study
- https://www.nature.com/articles/s41591-022-01968-z
- Associations of unprocessed and processed meat intake with mortality and cardiovascular disease in 21 countries [Prospective Urban Rural Epidemiology (PURE) Study]: a prospective cohort study
- https://www.sciencedirect.com/science/article/pii/S0002916522004282
- "Results: In the PURE study, during 9.5 y of follow-up, we recorded 7789 deaths and 6976 CVD events. Higher unprocessed red meat intake (≥250 g/wk vs. <50 g/wk) was not significantly associated with total mortality (HR: 0.93; 95% CI: 0.85, 1.02; P-trend = 0.14) or major CVD (HR: 1.01; 95% CI: 0.92, 1.11; P-trend = 0.72). Similarly, no association was observed between poultry intake and health outcomes. Higher intake of processed meat (≥150 g/wk vs. 0 g/wk) was associated with higher risk of total mortality (HR: 1.51; 95% CI: 1.08, 2.10; P-trend = 0.009) and major CVD (HR: 1.46; 95% CI: 1.08, 1.98; P-trend = 0.004).
- Conclusions: In a large multinational prospective study, we did not find significant associations between unprocessed red meat and poultry intake and mortality or major CVD. Conversely, a higher intake of processed meat was associated with a higher risk of mortality and major CVD."
- The risk associated with different types of meat consumption in this study was as follows:
- Unprocessed red meat: Consuming 250 grams or more per week compared to less than 50 grams per week was not significantly associated with total mortality or major cardiovascular disease (CVD). The hazard ratio (HR) for mortality was 0.93 (95% confidence interval (CI): 0.85, 1.02), indicating a non-significant 7% reduction in risk, which statistically isn’t different from no effect. The HR for major CVD was 1.01 (95% CI: 0.92, 1.11), showing virtually no association.
- Processed meat: Consuming 150 grams or more per week compared to none at all was associated with a significantly higher risk of both total mortality and major CVD. The HR for mortality was 1.51 (95% CI: 1.08, 2.10), suggesting a 51% increased risk of death. The HR for major CVD was 1.46 (95% CI: 1.08, 1.98), indicating a 46% increased risk of major cardiovascular events.
- Red Meat and Processed Meat Consumption and All-Cause Mortality: A Meta-Analysis
- Study: https://academic.oup.com/aje/article/179/3/282/103471
- "For total red meat consumption, the corresponding relative risk for 120 g/day (∼1.5 servings/day) versus 20 g/day (∼1.5–2 servings/week) was 1.29 (95% CI: 1.20, 1.38). Unprocessed red meat consumption (5 studies) showed a statistically nonsignificant linear association with all-cause mortality (for a 100-g/day increase in consumption, RR = 1.09, 95% CI: 0.997, 1.20)."
- Red and processed meat consumption and mortality: dose–response meta-analysis of prospective cohort studies
- Study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10270853/
- "Nine articles with seventeen prospective cohorts were eligible in this meta-analysis, including a total of 150 328 deaths. There was evidence of a non-linear association between processed meat consumption and risk of all-cause and cardiovascular mortality, but not for cancer mortality. For processed meat, the pooled relative risk with an increase of one serving per day was 1·15 (95 % CI 1·11, 1·19) for all-cause mortality (five studies; P<0·001 for linear trend), 1·15 (95 % CI 1·07, 1·24) for cardiovascular mortality (six studies; P<0·001) and 1·08 (95 % CI 1·06, 1·11) for cancer mortality (five studies; P<0·001). Similar associations were found with total meat intake. The association between unprocessed red meat consumption and mortality risk was found in the US populations, but not in European or Asian populations."
- In the US, eating unprocessed red meat is linked to mortality risk, but this connection isn't seen in European or Asian populations.
- The regional differences in the association between unprocessed red meat consumption and mortality risk could be influenced by variations in meat quality. Factors such as production practices, processing standards, and environmental factors may lead to differences in the nutritional composition and safety of meat products across regions. For example, variations in the use of hormones, antibiotics, and feed additives, as well as differences in livestock-raising practices (such as grass-fed vs. grain-fed), could contribute to differing health effects of red meat consumption between populations.
- Additionally, it is likely that compared with European habits, red meat in the USA may be often barbecued or grilled, thus contributing to higher contents of polycyclic hydrocarbons and heterocyclic amines.
- Processed and Unprocessed Red Meat and Risk of Colorectal Cancer: Analysis by Tumor Location and Modification by Time
- Study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4549221/
- According to the analysis from two large cohort studies, there is a modest increase in colorectal cancer (CRC) risk associated with the consumption of processed red meat, particularly affecting the distal colon. Processed red meat consumption was linked to a higher CRC risk with a hazard ratio (HR) of 1.15 for a 1 serving/day increase, and even more so for distal colon cancer (HR = 1.36). In contrast, the consumption of unprocessed red meat did not significantly increase the overall risk of CRC and was actually inversely associated with distal colon cancer risk (HR = 0.75 for a 1 serving/day increase).
- These findings highlight the importance of differentiating between processed and unprocessed meats when considering dietary recommendations for CRC prevention. The studies underline the need for further investigation into how meat processing and the timing of consumption influence CRC risk across different parts of the colon and rectum.
- Health effects associated with consumption of unprocessed red meat: a Burden of Proof study
- Study: https://www.nature.com/articles/s41591-022-01968-z
- Unprocessed red meat consumption and colorectal cancer
- "We found weak evidence of harmful associations between unprocessed red meat consumption and risk of colorectal cancer; the mean RR at 50 g d−1 relative to no intake was 1.30 (95% UI inclusive of between-study heterogeneity of 1.01–1.64), while the mean RR at 100 g d−1 was 1.37 (1.01–1.78) (Table 2 and Fig. 1), where the UIs account for between-study heterogeneity and other forms of uncertainty. We estimated the exposure-averaged burden of proof RR to be 1.06, indicating that consuming unprocessed red meat in the range of 15th to 85th percentiles of exposure (0 g d−1 to 98 g d−1) was associated with at least a 6% higher risk of colorectal cancer. This corresponds to an ROS of 0.06 and a two-star rating, consistent with weak evidence."
- Unprocessed red meat consumption and ischemic heart disease
- "We found weak evidence of a harmful association between unprocessed red meat consumption and risk of IHD. The RR was 1.09 (0.99–1.18) at 50 g d−1 and 1.12 (0.99–1.25) at 100 g d−1 (Table 2 and Fig. 3). The corresponding exposure-averaged BPRF was 1.01, which translates to a ROS of 0.01 and a two-star rating at the lower threshold of two-star pairs (at the boundary between weak evidence and no evidence of an association between consumption of unprocessed red meat and increased risk of IHD incidence and mortality)."
- Unprocessed red meat consumption and breast cancer
- "We found weak evidence of a harmful association between unprocessed red meat intake and risk of breast cancer. The BPRF value (averaged across the 15th to 85th percentiles of red meat consumption, 0–69 g d−1) was 1.03, which was substantially lower than the mean RR of 1.26 (0.98–1.56) and 1.26 (0.98–1.56) at 50 g d−1 and 100 g d−1, respectively. The corresponding ROS is 0.03 (Table 2 and Fig. 2), which translates to a two-star risk and means that unprocessed red meat intake is associated with at least a 3% higher risk of colorectal cancer. When accounting for between-study heterogeneity, the mean RR UI at different exposure levels spanned 1 (Table 2)."
- Unprocessed red meat consumption and ischemic heart disease
- "We found weak evidence of a harmful association between unprocessed red meat consumption and risk of IHD. The RR was 1.09 (0.99–1.18) at 50 g d−1 and 1.12 (0.99–1.25) at 100 g d−1 (Table 2 and Fig. 3). The corresponding exposure-averaged BPRF was 1.01, which translates to a ROS of 0.01 and a two-star rating at the lower threshold of two-star pairs (at the boundary between weak evidence and no evidence of an association between consumption of unprocessed red meat and increased risk of IHD incidence and mortality)."
- Unprocessed red meat consumption and type 2 diabetes
- "We found evidence of weak harmful effects between unprocessed red meat consumption and risk of type 2 diabetes, with a mean RR of 1.14 (0.97–1.32) at 50 g d−1 relative to no intake and a mean RR of 1.23 (0.96–1.52) at 100 g d−1 relative to no intake (Table 2 and Extended Data Fig. 2). The BPRF value was 1.01 and the corresponding ROS was 0.01, equating to a two-star rating at the lower threshold of two-star pairs (at the boundary between weak evidence and no evidence of an association between consumption of unprocessed red meat and increased risk of type 2 diabetes)."
- Unprocessed red meat consumption and ischemic stroke "The exposure-averaged BPRF value for ischemic stroke (averaged between 15th and 85th percentiles of red meat exposure) was 0.98 (Table 2 and Extended Data Fig. 3), which put it opposite null from the mean RR of 1.15 (95% UI inclusive of between-study heterogeneity of 0.93–1.40) at 100 g d−1. The corresponding ROS of –0.02 resulted in a one-star rating, consistent with no evidence of an association between consumption of unprocessed red meat and increased risk of ischemic stroke."
- Unprocessed red meat consumption and hemorrhagic stroke
- "The exposure-averaged BPRF value for hemorrhagic stroke was 1.14 (Table 2 and Extended Data Fig. 4), which was opposite null from the mean RR of 0.87 (0.56–1.35) at 100 g d−1. The corresponding ROS of −0.13 resulted in a one-star rating, consistent with no evidence of an association between consumption of unprocessed red meat and decreased risk of hemorrhagic stroke."
- The Importance of Accounting for Confounding Factors
- When assessing the link between unprocessed meat consumption and colorectal cancer, it's essential to consider how earlier studies might have arrived at different conclusions due to not fully accounting for confounding factors. Confounding factors are variables that can influence both the exposure (in this case, unprocessed meat consumption) and the outcome (colorectal cancer), potentially skewing the results if not properly adjusted for in the analysis.
- For instance, some studies suggesting an association between unprocessed meat and colon cancer may not have adequately adjusted for a range of lifestyle and dietary behaviors, such as smoking, alcohol consumption, overall diet quality, physical activity, and other health-related behaviors. These factors are crucial as they can independently increase the risk of cancer and are often correlated with meat consumption habits. For example, individuals who eat significant amounts of unprocessed meat might also lead a less healthy lifestyle overall or engage in other behaviors that increase cancer risk.
- For example in this study:
- "We documented 1,735 CRCs (809 proximal colon, 514 distal colon, and 373 rectal cancers) in women during 2,439,732 person-years of follow-up in the NHS and 996 CRCs (342 proximal colon, 303 distal colon, and 216 rectal cancers) in men during 1,013,022 person-years of follow-up in the HPFS. Characteristics of study participants, averaged according to proportion of person-time in each category of intake, are shown in Table 1. Men and women with higher red meat consumption tended to have a higher BMI, lower physical activity, higher intake of alcohol, and lower intakes of fish, folate, calcium, and vitamin D compared to participants with lower red meat intake."
- By not controlling for these confounders, these studies could incorrectly attribute the cause of increased cancer risk to unprocessed meat alone, when it could be due to a combination of factors associated with a particular lifestyle. This is why the methodology used in more recent studies, which include adjusting for such variables to isolate the impact of unprocessed meat alone, is crucial. These adjustments help provide a clearer picture of whether unprocessed meat directly contributes to colorectal cancer risk or if the observed association is influenced by other confounding factors. This thorough approach aids in making more accurate public health recommendations based on sound scientific evidence.
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There is currently a discussion at Wikipedia:Administrators' noticeboard/Incidents regarding an issue with which you may have been involved. Thank you. Psychologist Guy (talk) 20:03, 22 May 2024 (UTC)