-
1.
Irritable Bowel Syndrome Is Not Associated with an Increased Risk of Polyps and Colorectal Cancer: A Systematic Review and Meta-Analysis.
Vichos, T, Rezaie, A, Vichos, P, Cash, B, Pimentel, M
Digestive diseases and sciences. 2023;68(6):2585-2596
-
-
-
Free full text
-
Plain language summary
Colorectal cancer (CRC) is one of the most common cancers and adenomatous colorectal polyps (CRP) are a risk factor for developing CRC. The potential role of functional disturbances seen in irritable bowel syndrome (IBS) for the development of CRC are not yet clear. The aim of this systematic review and meta-analysis was to evaluate the occurrence of CRC and CRP in IBS patients. 14 cohort studies with a total of 654,764 IBS patients and 2,277,195 controls and six cross-sectional studies with 26,641 IBS patients and 87,803 controls were included in the review. Based on the pooled data from 5 cross-sectional studies, IBS patients had a significantly lower occurrence of CRP (by 71%). CRC risk was also reduced but this did not reach statistical significance. Only four of the 14 cohort studies were included in the meta-analysis and, again, CRC risk was lower in IBS patients but this was not statistically significant.
Abstract
OBJECTIVES Colorectal cancer (CRC) is the third most common malignancy in the US. Several factors are associated with increased/decreased CRC risk and often linked to adenomatous colorectal polyps (CRP). Recent studies suggest a lower risk of neoplastic lesions among irritable bowel syndrome (IBS) patients. We aimed to systematically assess the occurrence of CRC and CRP in IBS patients. METHODS Searches of the Medline, Cochrane, and EMBASE databases were performed, blindly and independently, by two investigators. Studies of CRC or CRP incidence in IBS patients (diagnosed by Rome or other symptom-based criteria) were eligible for inclusion. CRC and CRP effect estimates were pooled in meta-analyses using random models. RESULTS Of 4941 non-duplicate studies, 14 were included, comprising 654,764 IBS patients and 2,277,195 controls in 8 cohort studies, and 26,641 IBS patients and 87,803 controls in 6 cross-sectional studies. Pooled analysis revealed a significantly decreased prevalence of CRP in IBS subjects vs. controls, with a pooled odds ratio (OR) of 0.29 (95% CI (0.15, 0.54)). There was significant heterogeneity between studies (I2 = 96%, p < 0.01). This finding persisted when studies which did not report pre-cancerous polyps separately were excluded (OR 0.23, 95% CI (0.15, 0.35), I2 = 85%, p < 0.01). CRC prevalence was lower in IBS subjects, but this did not reach statistical significance (OR 0.40, 95% CI (0.09, 1.77]). CONCLUSION Our analyses reveal a decreased incidence of colorectal polyps in IBS, although CRC did not reach significance. Mechanistic studies with detailed genotypic analysis and clinical phenotyping are needed to better elucidate the potentially protective effect of IBS on CRC development.
-
2.
Prognostic and clinicopathological significance of prognostic nutritional index (PNI) in patients with oral cancer: a meta-analysis.
Dai, M, Sun, Q
Aging. 2023;15(5):1615-1627
-
-
-
Free full text
Plain language summary
Parameters derived from the peripheral blood are important sources of biomarkers for oral cancer including prognostic nutritional index (PNI). PNI is computed from the overall quantity of peripheral blood lymphocytes and serum albumin. The aim of this study was to investigate how prognostically significant PNI is in oral carcinoma. This study was a systematic review and meta-analysis of ten studies with a total of 3,130 patients. Results showed that a low PNI acted as a significant predictor for disease-free survival and overall survival, but not for cancer-specific survival among the oral carcinoma population. Besides, a low PNI was also linked to advanced stage of tumour-node-metastasis and ≥65 years of age. Authors conclude that PNI acted as a significant biomarker for predicting clinical outcomes of oral carcinoma patients.
Abstract
Accumulating literature has explored how prognostically significant the prognostic nutritional index (PNI) was for the oral carcinoma population, but with inconsistent findings. Therefore, we retrieved the most recent data and carried out this meta-analysis to comprehensively analyze the prognostic performance of pretreatment PNI in oral cancer. The electronic databases of PubMed, Embase, China National Knowledge Infrastructure (CNKI), Cochrane Library and Web of Science were fully retrieved. PNI's prognostic value for survival outcomes in oral carcinoma was assessed by estimating pooled hazard ratios (HRs) plus 95% confidence intervals (CIs). We examined the correlation of PNI with clinicopathological traits of oral carcinoma by utilizing the pooled odds ratios (ORs) plus 95% CIs. According to the pooled results of the present meta-analysis, which enrolled 10 studies involving 3,130 patients, for oral carcinoma suffers whose PNI was low, their disease-free survival (DFS) (HR=1.92, 95%CI=1.53-2.42, p<0.001) and overall survival (OS) (HR=2.44, 95%CI=1.45-4.12, p=0.001) would be inferior. Nonetheless, cancer-specific survival (CSS) was not linked significantly to PNI for the oral carcinoma population (HR=1.89, 95%CI=0.61-5.84, p=0.267). Significant associations of low PNI with TNM stages III-IV (OR=2.16, 95%CI=1.60-2.91, p<0.001) and age ≥ 65 years (OR=2.29, 95%CI=1.76-2.98, p<0.001) were found. As suggested by the present meta-analysis, a low PNI was linked to inferior DFS and OS among oral carcinoma patients. Oral cancer patients with low PNI may have high-risk of tumor progression. PNI could be served as a promising and effective index to predict prognosis in patients with oral cancer.
-
3.
Mycotoxin-Linked Mutations and Cancer Risk: A Global Health Issue.
Ekwomadu, T, Mwanza, M, Musekiwa, A
International journal of environmental research and public health. 2022;19(13)
-
-
-
Free full text
Plain language summary
Mycotoxins are toxic substances produced by fungi, which can be found in common foods like maize, wheat, nuts, and foods containing them. Mycotoxins such as aflatoxins, ochratoxin, fumonisins, zearalenone, and some Penicillium toxins can alter genetic material. According to previous studies, they can damage genetic material and affect cell growth. Usage of chemicals such as fertilizers and fungicides is a common practice in the agricultural industry to protect plants from fungus and to feed them. However, fungicides can accelerate mycotoxin production. 16 studies were included in this Systematic Review and 11 in Meta-Analysis. This research looked at the harmful effects of mycotoxins such as aflatoxins, fumonisins, ochratoxin, T2, zearalenone, and some Penicillium toxins in causing cancers. The researchers evaluated the link between aflatoxin exposure and liver cancer, fumonisin B1 exposure and liver cancer, zearalenone exposure and breast cancer, zearalenone exposure and cervical cancer, citrinine and patulin exposure and colorectal cancer, and NEO, HT-2, and T-2 exposure and Oesophageal cancer. This research did not show significant associations between various mycotoxins and cancer risk. As currently, most studies are primarily focused on aflatoxin; more robust studies are needed to assess the cancer risk associated with different mycotoxin exposure. Using the results of this study, healthcare professionals can gain a better understanding of how mycotoxins affect our bodies.
Abstract
Humans continue to be constantly exposed to mycotoxins, mainly through oral exposure (dietary), inhalation, or dermal contact. Recently, it has been of increasing interest to investigate mycotoxin-linked carcinogenicity. This systematic review was conducted to synthesize evidence of the association between mycotoxin-linked mutations and the risk of cancer, to provide an overview of the data linking exposure to different mycotoxins with human cancer risk, and to provide an update on current research on the risk of cancer associated with human exposure to mycotoxins. PRISMA guidelines were used when conducting the systematic review. PubMed, MEDLINE, and CINAHL electronic databases were comprehensively searched to extract the relevant studies published from inception to May 2022. A total of sixteen relevant studies (4907 participants) were identified and included in this review. Of these, twelve studies were from Asia, while four of the studies were conducted in Africa. The overall meta-analysis result found no significant association, although some of the studies confirmed an association between mycotoxin-linked mutations and primary liver cancer risk. Mainly, the experimental studies have shown associations between mycotoxin-linked mutations and cancer risk, and there is a need for researchers to confirm these links in epidemiological studies in order to guide public health policies and interventions.
-
4.
The Dose-Response Associations of Sugar-Sweetened Beverage Intake with the Risk of Stroke, Depression, Cancer, and Cause-Specific Mortality: A Systematic Review and Meta-Analysis of Prospective Studies.
Wang, Y, Zhao, R, Wang, B, Zhao, C, Zhu, B, Tian, X
Nutrients. 2022;14(4)
-
-
-
Free full text
Plain language summary
The consumption of sugar-sweetened beverages is high in today's society, which may lead to weight gain, inflammation, and a number of obesity-associated diseases. The objective of this systematic review and meta-analysis was to investigate the associations and causal links between the consumption of sugar-sweetened beverages and cancer, stroke, depression, and cause-specific mortality. Consumption of sugar-sweetened beverages significantly increased the risk of cancer, strokes, depression, and cause-specific mortality when compared with the consumption of low or no-sugar-sweetened beverages. As little as a 250ml increment of sugar-sweetened beverages was associated with an increase in risk. Consumption of sugar-sweetened beverages increases the risk of ischemic stroke by 10%, CVD-caused mortality by 13%, and cancer-caused mortality by 6.0% compared to those who consume less or no sugar-sweetened beverages. These findings can be used by healthcare professionals to understand the clinical significance of intervention strategies that reduce the consumption of sugar-sweetened beverages. It is imperative to conduct additional robust studies as there is an insufficient amount of evidence at present to establish a causal connection between the consumption of sugary beverages and the risk of depression, stroke, cancer, and cause-specific mortality.
Abstract
The associations between sugar-sweetened beverage (SSB) consumption and the risk of stroke, depression, cancer, and cause-specific mortality have not been determined, and the quantitative aspects of this link remain unclear. This meta-analysis therefore conducted a systematic review and dose-response analysis to determine their causal links. The database searches were conducted in PubMed, Cochrane library, Embase, Web of Science up to 10 November 2021. The intervention effects were evaluated by relative risk (RR) with 95% confidences (CI). Thirty-two articles met the inclusion criteria. Higher levels of SSB consumption significantly increased the risk of stroke (RR 1.12, 95% CI 1.03-1.23), depression (1.25, 1.11-1.41), cancer (1.10, 1.03-1.17), and all-cause mortality (1.08, 1.05-1.11) compared with none or lower SSB intake. The associations were dose-dependent, with per 250 mL increment of SSB intake daily increasing the risk of stroke, depression, cancer, and all-cause mortality by RR 1.09 (1.03-1.15), 1.08 (1.06-1.10), 1.17 (1.04-1.32), and 1.07 (1.03-1.11), respectively. The link was curved for depression and cancer risk (pnon-linear < 0.05). Subgroup analysis suggested that higher SSB intake increased ischemic stroke by 10%, CVD-caused mortality by 13%, and cancer-caused mortality by 6.0% than none or lower SSB consumption. It is suggested that SSB accounts for a leading risk factor of stroke, depression, cancer, and mortality, and that the risk rises in parallel with the increment of SSB intake (and is affected by participant characteristics).
-
5.
Sedentary behavior and cancer-an umbrella review and meta-analysis.
Hermelink, R, Leitzmann, MF, Markozannes, G, Tsilidis, K, Pukrop, T, Berger, F, Baurecht, H, Jochem, C
European journal of epidemiology. 2022;37(5):447-460
-
-
-
Free full text
-
Plain language summary
Globally, cancer is one of the leading causes of death. In modern day-to-day life, sedentary behaviour is prevalent, with adults spending an average of 8.2 hours without any physical activity. It is believed that sedentary behaviour plays a significant role in the increase in all-cause mortality, obesity, chronic diseases, and cancer risk. The purpose of this review and meta-analysis was to examine previous studies that reported associations between sedentary behaviour and cancer incidence and all-cancer mortality. A total of 14 meta-analyses were included in the study, and the strength of the evidence for each association was rated. A significant association was found between sedentary behaviour and cancer incidence across various cancer sites, including ovarian, endometrial, colon, breast, rectal, and prostate cancers. All-cancer mortality also showed positively significant associations with sedentary behaviour. There is a need for further research to evaluate the mechanisms associated with sedentary behaviour and the development of cancer at various sites. However, the results of this study can be used by healthcare professionals to better understand the importance of recommending physical activity and other therapeutic strategies.
Abstract
Several systematic reviews and meta-analyses have summarized the association between sedentary behavior (SB) and cancer. However, the level of evidence and the potential for risk of bias remains unclear. This umbrella review summarized the current data on SB in relation to cancer incidence and mortality, with a particular emphasis on assessing the risk of bias. We searched PubMed, Web of Science and Cochrane Database for systematic reviews and meta-analyses on the association between SB and cancer incidence and mortality. We also searched for recent observational studies not yet included in existing meta-analyses. We re-calculated summary risk estimates for cancer incidence and mortality using random effects models. We included 14 meta-analyses covering 17 different cancer sites from 77 original studies. We found that high SB levels increase the risk for developing ovarian, endometrial, colon, breast, prostate, and rectal cancers, with relative risks of 1.29 (95% confidence interval (CI) = 1.08-1.56), 1.29 (95% CI = 1.16-1.45), 1.25 (95% CI = 1.16-1.33), 1.08 (95% CI = 1.04-1.11), 1.08 (95% CI = 1.00-1.17), and 1.07 (95% CI = 1.01-1.12), respectively. Also, we found an increased risk of cancer mortality of 1.18 (95% CI = 1.09-1.26). Most associations between SB and specific cancer sites were supported by a "suggestive" level of evidence. High levels of SB are associated with increased risk of several types of cancer and increased cancer mortality risk.
-
6.
Association between SARS-CoV-2 infection and disease severity among prostate cancer patients on androgen deprivation therapy: a systematic review and meta-analysis.
Sari Motlagh, R, Abufaraj, M, Karakiewicz, PI, Rajwa, P, Mori, K, Mun, DH, Shariat, SF
World journal of urology. 2022;40(4):907-914
-
-
-
Free full text
-
Plain language summary
The incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is equal in both sexes; however, disease severity and progression rates are approximately three times higher in the male gender. Androgen deprivation therapy (ADT) and the second-generation androgen receptor targeting therapy were developed to suppress the androgen-activated intracellular cascade that leads to tumour progression and aggressive tumour growth. The aim of this study was to assess the risk of SARS-CoV-2 infection and the severity of disease in prostate cancer (PCa) patients treated with ADT. This study is a systematic review and meta-analysis of six cohort studies. The study results show that there is not a significant association between ADT use and the severity of SARS-CoV-2 infection or coronavirus disease 2019 (COVID-19) in PCa patients. However, results also show that ADT does not worsen COVID-19 risk and trajectory. Authors conclude that ADT, as a cancer treatment, might be safely administered to patients during the COVID-19 pandemic.
Abstract
PURPOSE Androgen-regulated enzymes such as the angiotensin-converting enzyme 2 (ACE2) and the transmembrane serine protease 2 (TMPRSS2) are involved in the SARS-CoV-2 infection process. The expression of TMPRSS2 and its fusion gene, which are increased in the epithelium of the human prostate gland during prostate carcinogenesis, are regulated by androgens. Our goal was to assess the risk of the SARS-CoV-2 infection and the severity of the disease in PCa patients treated with androgen deprivation therapy (ADT). METHODS We conducted a systematic review and meta-analysis according to PRISMA guidelines. We queried PubMed and Web of Science databases on 1 July 2021. We used random- and/or fixed-effects meta-analytic models in the presence or absence of heterogeneity according to Cochrane's Q test and I2 statistic, respectively. RESULTS Six retrospective studies (n = 50,220 patients) were selected after considering inclusion and exclusion criteria for qualitative evidence synthesis. Four retrospective studies were included to assess the SARS-CoV-2 infection risk in PCa patients under ADT vs. no ADT and the summarized risk ratio (RR) was 0.8 (95% confidence intervals (CI) 0.44-1.47). Five retrospective studies were included to assess the severity of coronavirus disease 2019 (COVID-19) in PCa patients under ADT versus no ADT and the summarized RR was 1.23 (95% CI 0.9-1.68). CONCLUSION We found a non-significant association between the risk of SARS-CoV-2 infection and COVID-19 severity in PCa patients treated with ADT. However, our results suggest that during the COVID-19 pandemic PCa patients can safely undergo ADT as a cancer therapy without worsening COVID-19 risk and trajectory.
-
7.
Exposure to glyphosate and risk of non-Hodgkin lymphoma: an updated meta-analysis.
Boffetta, P, Ciocan, C, Zunarelli, C, Pira, E
La Medicina del lavoro. 2021;112(3):194-199
-
-
-
Free full text
Plain language summary
Glyphosate is an herbicide and crop desiccant widely used by professional applicators and consumers. The aim of this study was to update a recent systematic review and meta-analysis of epidemiologic studies to help clarify the association between exposure to glyphosate and risk of non-Hodgkin lymphoma (NHL). Results confirmed the conclusions drawn on the previous systematic review and meta-analysis i.e. that there was no association between exposure to glyphosate and the risk of NHL even though larger better-designed studies were analysed. Authors conclude that an association with risk of diffuse large B-cell lymphoma [happens when healthy B-cells change into fast-growing cancer cells that do not die] cannot be ruled out.
Abstract
OBJECTIVE We updated a recent systematic review and meta-analysis of epidemiologic studies to help clarifying the association between exposure to glyphosate and risk of non-Hodgkin lymphoma (NHL). METHODS We conducted an updated search of the literature, and identified a total of 15 relevant publications, from which we extracted results from six non-overlapping studies. We performed random-effects meta-analyses for ever-exposure to glyphosate, dose-response, and risk of specific NHL subtypes Results: The meta-RR for ever-exposure to glyphosate was 1.05 (95% confidence interval [CI] 0.90-1.24; I2 = 0%). The meta-RR for the highest category of exposure was 1.15 (95% CI 0.72-1.83; 3 studies). The meta-RR for diffuse large B-cell lymphoma (DLBCL) was 1.29 (95% CI 1.02-1.63; 4 studies), that for follicular lymphoma was 0.84 (95% CI 0.61-1.17), and that for chronic lymphocytic leukemia/small lymphocytic lymphoma was 1.33 (95% CI 0.65-2.70). There was indication of publication bias. CONCLUSIONS This updated meta-analysis reinforces our previous conclusion of a lack of an association between exposure to glyphosate and risk of NHL overall, although an association with DLBCL cannot be ruled out.
-
8.
An updated systematic review and meta-analysis on adherence to mediterranean diet and risk of cancer.
Morze, J, Danielewicz, A, Przybyłowicz, K, Zeng, H, Hoffmann, G, Schwingshackl, L
European journal of nutrition. 2021;60(3):1561-1586
-
-
-
Free full text
-
Plain language summary
The development of cancer is associated with a number of risk factors, including smoking, obesity, sedentary lifestyles, alcohol consumption, infections, pollution, and dietary imbalances. Based on previous research, optimal consumption of fruits, vegetables, and whole grains, along with reduced consumption of red and processed meat, reduces cancer risk. According to this systematic review and meta-analysis, adherence to the Mediterranean diet is associated with lower cancer mortality and site-specific cancer development. A Mediterranean diet includes fruits, vegetables, nuts, legumes, fish, whole grains, extra virgin olive oil, and low amounts of red meat, processed meat, egg, and dairy, along with moderate amounts of red wine. According to this systematic review and meta-analysis, adherence to the Mediterranean diet reduces the risk of cancer mortality and the risk of developing cancers specific to the site, such as colorectal cancer, bladder cancer, gastric cancer, and lung cancer. Among the components of the Mediterranean diet, fruits, vegetables, and whole grains have been shown to reduce cancer risk. Bioactive substances found in Mediterranean diet components require additional robust studies to evaluate their benefits. A healthcare professional can use the results of this study to make clinical decisions and recommend therapeutic interventions to cancer patients.
Abstract
PURPOSE The aim of current systematic review was to update the body of evidence on associations between adherence to the Mediterranean diet (MedDiet) and risk of cancer mortality, site-specific cancer in the general population; all-cause, and cancer mortality as well as cancer reoccurrence among cancer survivors. METHODS A literature search for randomized controlled trials (RCTs), case-control and cohort studies published up to April 2020 was performed using PubMed and Scopus. Study-specific risk estimates for the highest versus lowest adherence to the MedDiet category were pooled using random-effects meta-analyses. Certainty of evidence from cohort studies and RCTs was evaluated using the NutriGrade scoring system. RESULTS The updated search revealed 44 studies not identified in the previous review. Altogether, 117 studies including 3,202,496 participants were enclosed for meta-analysis. The highest adherence to MedDiet was inversely associated with cancer mortality (RRcohort: 0.87, 95% CI 0.82, 0.92; N = 18 studies), all-cause mortality among cancer survivors (RRcohort: 0.75, 95% CI 0.66, 0.86; N = 8), breast (RRobservational: 0.94, 95% CI 0.90, 0.97; N = 23), colorectal (RRobservational: 0.83, 95% CI 0.76, 0.90; N = 17), head and neck (RRobservational: 0.56, 95% CI 0.44, 0.72; N = 9), respiratory (RRcohort: 0.84, 95% CI 0.76, 0.94; N = 5), gastric (RRobservational: 0.70, 95% CI 0.61, 0.80; N = 7), bladder (RRobservational: 0.87, 95% CI 0.76, 0.98; N = 4), and liver cancer (RRobservational: 0.64, 95% CI 0.54, 0.75; N = 4). Adhering to MedDiet did not modify risk of blood, esophageal, pancreatic and prostate cancer risk. CONCLUSION In conclusion, our results suggest that highest adherence to the MedDiet was related to lower risk of cancer mortality in the general population, and all-cause mortality among cancer survivors as well as colorectal, head and neck, respiratory, gastric, liver and bladder cancer risks. Moderate certainty of evidence from cohort studies suggest an inverse association for cancer mortality and colorectal cancer, but most of the comparisons were rated as low or very low certainty of evidence.
-
9.
Coffee Consumption and Cancer Risk: An Assessment of the Health Implications Based on Recent Knowledge.
Pauwels, EKJ, Volterrani, D
Medical principles and practice : international journal of the Kuwait University, Health Science Centre. 2021;30(5):401-411
-
-
-
Free full text
Plain language summary
Coffee is one of the most consumed beverages worldwide. Coffee is a good source of polyphenolic antioxidant and anti-inflammatory compounds such as caffeine, cafestol, kahweol, and chlorogenic acids. This review included one hundred and five cohort studies and meta-analyses to evaluate the relationship between coffee consumption and cancer of the breast, liver, oesophagus, stomach, pancreas, colorectum, kidney, bladder, prostate, and ovaries. The results of this review found an inverse association between coffee consumption and reduced risk of hepatocellular cancer. A slight risk reduction is observed against breast cancer in postmenopausal women. This review found no considerable association between coffee consumption and decreased cancer risk in other organs. Further robust studies are required to investigate the benefits of coffee consumption on cancer risk reduction due to the high heterogeneity of included studies. However, healthcare professionals can use the results of this study to understand the benefits of coffee consumption.
Abstract
A significant number of studies suggest that coffee consumption reduces cancer risk. This beneficial effect is usually ascribed to the presence of polyphenolic antioxidants and anti-inflammatory agents, including caffeine, cafestol, kahweol, and chlorogenic acids. To summarize recent literature on this subject, we performed a bibliographic search in PubMed and Embase over the period January 2005 to December 2020 to identify cohort studies and meta-analysis (with data collection ensuring quality of selected reports) that could provide quantitative data on the relationship between coffee consumption and common cancers. The totality of eligible scientific articles supports the evidence that coffee intake is inversely associated with risk of hepatocellular cancer and, to a slight extent, risk of breast cancer among postmenopausal women. As to the association with other organs, including the esophagus, pancreas, colorectum, kidneys, bladder, ovaries, and prostate, the results are less clear as reports reveal conflicting results or statistically nonsignificant data. Therefore, this overview does not provide broad-based conclusions. Important uncertainties include general study design, inhomogeneous patient sampling, different statistical analysis (deliberate), misreporting of socioeconomic status, education, coffee-brewing methods, consumption of caffeinated or decaffeinated coffee, smoking habits, and alcohol intake. Clearly, more epidemiologic research needs to be conducted before solid science-based recommendations can be made with regard to coffee consumption.
-
10.
Dietary intake of total, animal, and plant proteins and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of prospective cohort studies.
Naghshi, S, Sadeghi, O, Willett, WC, Esmaillzadeh, A
BMJ (Clinical research ed.). 2020;370:m2412
-
-
-
Free full text
Plain language summary
Eating a diet high in protein, particularly from plants, has been linked to improvements in indicators for heart disease. However, links to reduction in heart disease, cancer and death remain controversial. This systematic review and meta-analysis of 32 cohort papers aimed to investigate the associations between dietary protein intake and the risk of death, death due to heart disease and death due to cancer. The results showed that total protein and animal protein intake did not affect the risk of death due to heart disease. However, increased plant protein intake decreased the risk of death from heart disease, and this was apparent from as little as an additional 3% of energy from plant proteins per day. Death from any cause decreased as protein and plant protein intake increased, but animal protein alone had no effect. Death due to cancer was not affected by the amount of dietary protein, animal protein, or plant protein. It was concluded that this study supports the recommendation of higher dietary plant protein in the general population to reduce the risk of death by any cause and death due to heart disease and healthcare professionals could use this study to justify this decision.
Abstract
OBJECTIVE To examine and quantify the potential dose-response relation between intake of total, animal, and plant protein and the risk of mortality from all causes, cardiovascular disease, and cancer. DESIGN Systematic review and meta-analysis of prospective cohort studies. DATA SOURCES PubMed, Scopus, and ISI Web of Science until December 2019, and references of retrieved relevant articles. STUDY SELECTION Prospective cohort studies that reported the risk estimates for all cause, cardiovascular, and cancer mortality in adults aged 18 or older. DATA SYNTHESIS Random effects models were used to calculate pooled effect sizes and 95% confidence intervals for the highest versus lowest categories of protein intake and to incorporate variation between studies. Linear and non-linear dose-response analyses were done to evaluate the dose-response relations between protein intake and mortality. RESULTS 32 prospective cohort studies were included in the systematic review and 31 in the meta-analysis. During the follow-up period of 3.5 to 32 years, 113 039 deaths (16 429 from cardiovascular disease and 22 303 from cancer) occurred among 715 128 participants. Intake of total protein was associated with a lower risk of all cause mortality (pooled effect size 0.94, 95% confidence interval 0.89 to 0.99, I2=58.4%, P<0.001). Intake of plant protein was significantly associated with a lower risk of all cause mortality (pooled effect size 0.92, 95% confidence interval 0.87 to 0.97, I2=57.5%, P=0.003) and cardiovascular disease mortality (pooled hazard ratio 0.88, 95% confidence interval 0.80 to 0.96, I2=63.7%, P=0.001), but not with cancer mortality. Intake of total and animal protein was not significantly associated with risk of cardiovascular disease and cancer mortality. A dose-response analysis showed a significant inverse dose-response association between intake of plant protein and all cause mortality (P=0.05 for non-linearity). An additional 3% energy from plant proteins a day was associated with a 5% lower risk of death from all causes. CONCLUSIONS Higher intake of total protein was associated with a lower risk of all cause mortality, and intake of plant protein was associated with a lower risk of all cause and cardiovascular disease mortality. Replacement of foods high in animal protein with plant protein sources could be associated with longevity.