Table 1.

Summary of epidemiological studies investigating the association between dietary intake of heme iron and/or red meat with various diseases.

Disease	Diet Intake	HR/OR/RR (95% CI) Highest vs. Lowest	Reported Association	Number of Pzarticipants	Age (Years)	Years of Follow Up	Diet Assessment Method	Reference
Colorectal cancer	Red Meat	HR = 1.24 (1.12–1.36)	+	567,169	50–71	8.2	124-item FFQ	[40]
Colon cancer	High heme and low chlorophyll	RR = 1.58 (0.99–2.54)	+	58,279 Men	55–69	9.3	150-item semi quantitative FFQ	[50]
Colorectal cancer with KRAS mutation	Heme Iron	HR = 1.71 (1.15–2.57)	+	4026	55–69	7.3	150-item FFQ	[54]
Esophageal squamous cell carcinoma	Red Meat	HR = 1.79 (1.07–3.01)	+	494,979	50–71	10	124-item FFQ	[42]
	Heme Iron	HR = 1.47 (0.99–2.20)
Esophageal cancer	Red Meat	HR = 1.51 (1.09–2.08)	+	567,169	50–71	8.2	124-item FFQ	[40]
	Heme Iron	OR = 3.04 (1.20–7.72)	+	124 esophageal, 154 stomach cancer and 449 controls	≥21		100-item Short health habit and history questionnaire	[57]
Gastric cancer	Heme Iron	HR = 1.13 (1.01–1.26)	+	481,419	35–70	8.7	Validated country specific questionnaires	[56]
Stomach cancer	Heme Iron	OR = 1.99 (1.00–3.95)	+	124 esophageal, 154 stomach cancer and 449 controls	≥21		100-item Short health habbit and history questionnaire	[57]
Liver cancer	Red Meat	HR = 1.61 (1.12–2.31)	+	567,169	50–71	8.2	124-item FFQ	[40]
Pancreatic cancer	Red Meat	HRMen = 1.43 (1.11–1.83)	+	567,169	50–71	8.2	124-item FFQ	[40]
Endometrial cancer	Red Meat	HR = 0.75 (0.62–0.91)	inverse association	567,169	50–71	8.2	124-item FFQ	[40]
	Heme Iron	RR = 1.24 (1.01–1.53)	moderate	60,895	Women born between 1914 and 1948	21	67-item FFQ in 1987 and 96-item FFQ in 1997	[62]
Lung cancer	Red Meat	HRMen = 1.11 (0.79–1.56)	No Association	99,579	55–74	8	124-item FFQ	[46]
		HRWomen = 1.30 (0.87–1.95)
	Red Meat	HR = 1.2 (1.10–1.31)	+	567,169		8.2	124-item FFQ	[40]
	Red Meat	HRMen = 1.22 (1.09–1.38)	+	278,380 men and 189,596 women	50–71	8	124-item FFQ	[63]
		HRWomen = 1.13 (0.97–1.32)
	Heme Iron	HRMen = 1.25 (1.07–1.45)
		HRWomen = 1.18 (0.99–1.42)
Type 2 Diabetes	Red Meat	RR = 1.44 (0.92–2.24)	moderate, non-significant	91,246 U.S women	26–46	8	133-item semiquantitative FFQ	[64]
	Red Meat	RR = 1.63 (1.26–2.10)	+	38,394 Men	40–75	12	131-item semiquantitative FFQ	[65]
	Heme Iron	RR = 1.28 (1.04–1.58)	+	35,698 postmenopausal women	55–69	11	127-item FFQ	[66]
	Heme Iron	RR = 1.28 (1.14–1.45)	+	85,031 women	34–59	20	131-item expanded FFQ	[67]
Gestational Diabetes Mellitus	Heme Iron	RR = 1.51 (0.99–2.36)	+	3158 pregnant women	≥18		121-item FFQ	[68]
Myocardial Infarction	Heme Iron	RR = 1.86 (1.14–3.09)	+	4802	≥55	3–7	170-item semiquantitative FFQ	[69]

HR, hazard ratio; OR, odds ratio; RR, relative risk; +, positive association; FFQ, food frequency questionnaire.