Table 5.
Summary of the individual results, the strength of evidence, and the conclusion of the SR*
| Food group | Outcome | Effect | Quality of included studies | Grade of evidence (high, moderate, low, insufficient) |
Conclusion |
|---|---|---|---|---|---|
| Potatoes | CVD/CHD | No studies | - | Insufficient | No conclusion on the association between potato consumption and risk of CVD/CHD |
| Type 2 diabetes | Halton et al., 2006 (8), US women. 60–120-Item FFQ (updated five times after baseline). Potatoes RR 1.14 (1.02–1.26) French fries RR 1.21 (1.09–1.33) comparing highest and lowest quintiles, corresponding to 0.63 and 0.07 serv/d and 0.14 and 0 serv/d, respectively, for potatoes (one baked or 1 cup mashed/serving) and French fries (113 g/serving). RR 1.18 (1.03–1.35) per continuous 1 cup mashed or baked. Associations persisted in obese but not in lean women. B | B=1 | Insufficient | No conclusion on the association between potato consumption and risk of type 2 diabetes | |
| Inflammatory factors | No studies | Insufficient | No conclusion on the association between potato consumption and inflammatory markers | ||
| Berries | CVD/CHD |
Mink et al., 2000 (9), US women. 127-Item FFQ. Blueberries and strawberries 0 servings/week compared with >0 servings/week. Lower incidence of CHD (blueberries RR 0.81 [0.69–0.95], strawberries 0.84 [0.74–0.95]) and CVD (blueberries RR 0.85 [0.75–0.96], strawberries 0.82 [0.74–0.89]) when age and energy adjusted. Strawberries lower incidence of CVD (RR 0.91 (0.82–1.00) also in multivariate adjusted model (adjusted for age, energy intake, marital status, education, blood pressure, diabetes, BMI, waist-to-hip ratio, physical activity, smoking, and oestrogen use). B Sesso et al., 2007 (10), US women. 131-Item semi-quantitative FFQ. Strawberry intake was not associated with the risk of incident CVD. Strawberries ≥2 servings/week compared with none. Total CVD RR=1.27 (0.94–1.72). Adjusted for age, treatment, lifestyle factors, dietary factors, and total energy intake. B |
B=2 | Insufficient | No conclusion on the association between berry consumption and risk of CVD/CHD |
| Type 2 diabetes | No studies | Insufficient | No conclusion on the association between berry consumption and risk of type 2 diabetes | ||
| Inflammatory markers |
Larmo et al., 2008 (11), Finnish men and women. Serum CRP decreased significantly (median change –0.059 mg/L) after 8-wk intervention (28 g/day sea buckthorn). B Larmo et al., 2009 (12), Finnish men and women. There was no correlation between changes of plasma flavonols and changes of serum CRP in the intervention group (28 g/day sea buckthorn). B Basu et al., 2010 (13), US men and women. 3-Day food records at three time points, i.e. baseline, week 4, and week 8. No effect of intervention (a daily dose of 50 g freeze-dried blueberries ∼350 g fresh blueberries) on inflammatory factors, CRP, adiponectin, IL-6, soluble intercellular adhesion molecule-1, and vascular adhesion molecule-1. B Karlsen et al., 2010 (14), Norwegian men and women. 7-Day registration of fluid intake before inclusion and during last week of intervention. Among adults at increased risk of CVD, supplementation with bilberry juice (330 mL/d diluted with tap water to 1 L) reduced plasma concentrations of several NF-κB-regulated inflammatory mediators, i.e. CRP, IL-6, IL-15, and monokine induced by INF-γ (MIG). Unexpected increase in plasma TNF-α. B Lehtonen et al., 2010 (15), Finnish women. 3-Day food records in the middle of the intervention. No effect of intervention (daily intake of 163 g of various berries) on plasma CRP, TNF-α, or ORAC. Plasma adiponectin increased in intervention group. B |
B=5 | Insufficient | No conclusion on the association between berry consumption and risk of inflammatory markers | |
| Whole grains | CVD/CHD CAD, HF, Stroke |
Liu et al., 2000 (16), US women. 126-Item semi-quantitative FFQ. Ischemic stroke RR 0.69 (0.50–0.98) comparing highest quintile (median 2.7 servings/day) with lowest (median 0.13 servings/day). Adjusted for age and known CVD risk factors including total energy intake. B Liu et al., 2003 (17), US men. Simple semi-quantitative FFQ. CVD specific mortality RR 0.80 (CI 0.66–0.97) when comparing ≥1 servings/day to rare whole-grain cereal consumption. Adjusted for age, lifestyle factors, BMI, history of type 2 diabetes, high cholesterol, hypertension, and use of multivitamins. B Steffen et al., 2003 (18), US men and women. 66-Item semi-quantitative FFQ at baseline and 6 years later. Coronary artery disease incidence HR 0.72 (CI 0.53–0.97) comparing highest quintile (2.0–10.5 servings/day) with lowest quintile (0–0.2 servings/day). Ischemic stroke incidence HR 0.75 (0.46–1.22), comparing highest quintile (2.0–10.5 servings/day) with lowest quintile (0–0.2 servings/day). Adjusted for age and known CVD risk factors including energy intake. B Jensen et al., 2004 (19), US men. 131-Item semi-quantitative FFQ. CHD HR 0.82 (95% CI: 0.70–0.96) comparing highest quintile (median 42.4 g/day) with lowest quintile (median 3.5 g/day). Adjusted for age and known CVD risk factors, including energy intake. B Sahyoun et al, 2006 (20), US men and women. 3-Day food record. CVD mortality. A significant inverse trend was observed between whole-grain consumption and mortality from CVD (p=0.04), RR 0.48 (95% CI: 0.25–0.96), when comparing highest quartile (median 2.90 servings/day) with lowest quartile (median 0.31 servings/day). Adjusted for demographic and lifestyle factors. B Nettleton et al., 2008 (21), US men and women. 66-Item semi-quantitative FFQ. Heart failure risk was lower with greater whole-grain intake RR 0.93 (95% CI: 0.87–0.99) per 1 serving/day. Adjusted for age, energy, demographic factors, lifestyle, and prevalent disease. B |
B=6 | Moderate | Probable protective association between whole-grain consumption and risk of CVD/CHD For specific endpoints (e.g. stroke) the evidence is insufficient |
| Type 2 diabetes |
Prospective studies Liu et al., 2000 (22), US women. 126-Item semi-quantitative FFQ. Highest quintile (1.77–15.93 servings/day) compared with lowest quintile (0–0.26 servings/day) RR 0.73 (0.63–0.85) p <0.0001. Adjusted for age, lifestyle, and known type 2 diabetes risk factors including total energy intake. B Meyer et al., 2000 (23), US women. 127-Item FFQ. Highest quintile (median 20.5 servings/week) compared with lowest quintile (median 1 servings/week) RR 0.79 (0.65–0.96) p=0.0089. Adjusted for age and known risk factors for type 2 diabetes, including total energy intake. B Fung et al., 2002 (24), US men. 131-Item semi-quantitative FFQ. Highest quintile (3.2–21.5 servings/day) compared with lowest quintile (0.0–0.4 servings/day) RR 0.70 (0.57–0.85) p<0.0006. Adjusted for age and known risk factors for type 2 diabetes, including energy intake. B De Munter et al., 2007 (25), US women. Semi-quantitative FFQ used 1984, 1986, 1990, 1994, and 1998 for NHSI study and 1991, 1995, and 1999 for NHSII. NHSI study highest quintile (36.9 g/day) compared with lowest quintile (3.2 g/day) RR 0.75 (0.68–0.83); p <0.001, NHSII study highest quintile (45.6 g/day) compared with lowest quintile (5.5 g/day) RR 0.86 (0.72–1.02), fourth quintile (26.3 g/day) compared with lowest quintile (5.5 g/day) RR 0.74 (0.63–0.86), p=0.03. Adjusted for age and known risk factors for type 2 diabetes, including total energy intake. B Montonen et al., 2003 (26), Finnish men and women. Dietary history of previous year. Highest whole-grain quartile (238–1321 g/day) compared with lowest quartile (0–109 g/day) RR 0.65 (0.36–1.18), third quartile (163–237 g/day) compared with lowest quartile (0–109 g/day) RR 0.52 (0.31–0.88) p=0.02. Adjusted for age, sex, geographic area, lifestyle, and intakes of energy, fruit and berries, and vegetables. B Intervention study: glucose/insulin factors Juntunen et al., 2003 (27), Finnish women. 4-d food records and daily records of the intake of bread. Acute insulin response increased significantly (p=0.047) during the rye bread period (mean intake 208 g ± 38.3 g) compared with wheat bread period (mean intake 170 ± 36.4 g). Plasma glucose did not change. B |
B=5 | Moderate | Probable protective association between whole-grain consumption and risk of type 2 diabetes | |
| Inflammatory markers |
Intervention studies: Andersson et al., 2007 (28), Sweden. 3-Day dietary records. Cross-over intervention. No effect of adding 112 g of whole grains to the habitual diet. B Brownlee et al., 2010 (29), UK. 149-Item FFQ during the preceding 7 day. Intervention 60–120 g whole-grain products daily. No effect. B |
B=2 | Insufficient | No conclusion on the association between whole-grain consumption and inflammatory markers | |
| Colorectal cancer |
Larsson et al., 2005 (30), Swedish women. 67-Item FFQ at baseline. High consumption of whole grains was associated with lower risk of colon but not rectal cancer. Highest (≥4.5 servings/day) vs. lowest (<1.5 servings/day) RR 0.65 (0.45–0.94) p=0.04. Adjusted for age, BMI, education, total energy intake, and intakes of saturated fat, calcium, red meat, fruits, and vegetables. B Egeberg et al., 2010 (31), Danish men and women. 192-Item FFQ. Higher whole-grain product intake (median in total cohort 130 g/day, 5th–95th percentile 42–267 g/day) was associated with lower risk of colon cancer in men. The adjusted IRR was 0.85 (0.77–0.94) per every 50 g/day increment. By quartile categories RR was 0.61 (0.43–0.86) when comparing highest quartile (>160 g/day) with lowest quartile (≤75 g/day). No association among women. Adjusted for BMI, alcohol intake, education, intake of red and processed meat, use of hormone replacement therapy (women only), and leisure time physical activity. B McCullough et al., 2003 (32), US men and women. 68-Item semi-quantitative FFQ. Multivariate RR: no association when comparing highest quintile (14.5 servings/week) with lowest quintile (0.8 servings/week). Adjusted for age, METS, aspirin, smoking, family history of colorectal cancer, BMI, education, energy, multivitamin use, total calcium, and red meat intake. B Schatzkin et al., 2007 (33), US men and women. 124-Item FFQ. Whole-grain intake was inversely associated with colorectal cancer risk RR 0.79 (0.70–0.89). The association was stronger with rectal cancer RR 0.64 (0.51–0.81) than colon cancer RR 0.86 (0.75–0.99) comparing highest quintile (1.3 servings/1,000 kcal) with lowest (0.3 servings/1,000 kcal). Adjusted for sex, physical activity, smoking, menopausal hormone therapy in women, intakes of red meat, dietary calcium, and dietary folate, and total energy intake. B |
B=4 | Low | Suggestive protective association between whole-grain consumption and risk of colorectal cancer | |
| Milk and milk products | CVD/CHD. Stroke (haemorrhage and infarction) Heart failure |
Al-Delaimy et al., 2003 (34), US men. 131-Item FFQ. IHD (fatal and non-fatal). No association between total dairy (RR 1.01, 0.83–1.23) comparing highest quintile with lowest. No separate assessment was performed for specific dairy foods. B Warensjö et al., 2010 (35), Swedish men and women. 84-Item FFQ. Nested case-control study of incident myocardial infarction with biomarkers of milk fat intake and FFQ data. FFQ: Comparing highest quartile with lowest (>580 vs. 230 g/day): Men: total dairy, OR 1.36 (0.71–2.6) fermented dairy, OR 0.49 (0.26–0.93) cheese, OR 0.60 (0.30–1.20) Women: total dairy, OR 0.45 (0.09–2.32) fermented dairy, OR 0.34 (missing–1.64) cheese, OR 0.38 (0.07–2.22). Biomarker concentrations for milk fat: Lower in cases, especially in women, than in controls and inversely associated with risk markers of metabolic syndrome. B Bonthuis et al., 2010 (36), Australian men and women. 129-Item FFQ. CVD mortality: no association between total dairy or low-fat dairy, milk, yoghurt, or full-fat cheese and CVD mortality comparing highest tertile (599 g/day) with lowest (174 g/day); however, full-fat dairy associated with CVD mortality RR 0.33 (0.13–0.81). B Elwood et al., 2004 (37), and Elwood et al., 2005 (38), British men. (Note that the men in the 2005 study were part of the 2004 study). FFQ (2004 study) plus 7-d weighted record in 30% of men (2005 study). No significant associations between milk drinking and ischemic heart disease (IHD) or stroke (or combined) (although RR below 1.0 in all) comparing ≥1 pint/day with no milk consumption. Above median milk 187 mL/day compared with below associated with reduced risk of stroke (OR 0.52; 0.27–0.91) IHD OR 0.88 (0.56–1.40). B Larsson et al., 2009 (39), Finnish men, smokers only. 276-Item FFQ. Stroke: Comparing extreme quintiles (1,296 vs. 287 g/day) of total dairy RR 1.14 (0.99–1.32) for cerebral infarction and 1.32 (0.89–1.94) for intracerebral haemorrhage. No association for separate dairy products except for: whole milk and intracerebral haemorrhage RR 1.41 (1.02–1.96) and cream and cerebral infarction RR 0.81 (0.72–0.92). B |
B=6 2 SRs |
Insufficient Moderate |
No conclusion on the specific direction of the association between dairy/milk consumption and risk of CVD. Altogether (including the SRs), there was no consistent evidence that dairy food consumption in general is associated with increased risk of CVD/CHD (moderate–grade evidence) However, dairy products are a heterogenic group of foods that may have different effects on CVD/CHD. In addition, the studies may have had limited ability to detect the effect of a single food in a mixed diet on complex clinical outcomes |
| Type 2 diabetes and biomarkers (insulin resistance,* insulin sensitivity, and glucose tolerance) *IRS=insulin resistance=presence of 2 or more of 4 signs: 1) fasting plasma insulin >20 pU/mL fasting glucose >6.1 mmol/L or medications; 2) obesity >BMI 30 or WHR >0.85 F and 0.90 M; 3) blood pressure >130/80 or medications; and 4) dyslip HDL<0.90 mmol/ or high Tg ≥2.26 mmol/L |
Insulin resistance IRS 1 study Pereira et al., 2002 (40), US men and women (18–30 years at baseline). 700-Item FFQ. Prospective, longitudinal. Dairy consumption inversely associated with incidence of all components of IRS at BMI ≥25 at baseline but not among leaner; multivariable-adjusted OR of developing IRS were 0.28; (0.14–0.58) among overweight in the highest (≥35 times/week. 24/102 individuals) compared with the lowest (<10 times/week. 85/190 individuals) category of dairy consumption. Per each daily increase in dairy consumption a 21% lower odds of IRS: OR. 0.79 (0.70–0.88). Other dietary factors, including macronutrients and micronutrients, did not explain the association. Significant inverse associations observed for most of separate dairy products except butter/cream and yoghurt. B Diabetes incidence 3 Prospective cohort studies: Choi et al., 2005 (41), US men (HPF). 130-Item FFQ. Dairy consumption (quintile 5 vs. 1), multivariable-adjusted RR 0.77 (0.62–0.95). 9% lower risk per 1 serving/day increase RR=0.91 (0.85–0.97). Stronger for low-fat dairy vs. high-fat dairy p-trend 0.001 vs. 0.12. Among individual dairy products, significant inverse association only for skimmed milk. Borderline statistically significant positive associations for whole milk consumption. B Liu et al., 2006 (42), US women (WHS). 131-Item FFQ. Dairy consumption (quintile 5 vs. 1; >2.9 vs. 0.85 serving/day) associated with RR 0.68 (0.52–0.89) (p-trend=0.006) per serving increase RR 0.96 (0.90.1.02). For low-fat dairy RR 0.69 (0.52–0.91) and for high-fat dairy 0.99 (0.82–1.20) comparing quintile 5 with 1. For individual dairy products, inverse association mainly for yoghurt. B Kirii et al., 2009 (43), Japanese men and women. 147-Item FFQ. Total dairy OR=0.71(0.51–0.98) in women, no association in men, comparing >300 with <50 g/day. No association for milk, cheese, or yoghurt. B Intervention (1 study) |
B=7 | Low | Suggestive protective association between dairy consumption and type 2 diabetes incidence Total dairy consistently associated with decreased risk in three prospective cohort studies rated B; varying results for specific dairy products but seemed stronger for low-fat than high-fat dairy Less support for the above finding in studies using intermediate biomarkers of type 2 diabetes |
|
|
Barr et al., 2000 (44), US men and women. Adding three 8-ounce servings of skimmed or 1% fluid milk to usual consumption of dairy for 12 weeks: no difference in insulin or HbA1c between intervention group and controls; a slight increase (∼2%) in fasting glucose in intervention group and 1% decrease in control group. B Insulin sensitivity, fasting glucose, and post-load glucose (2 prospective studies) |
|||||
|
Ma et al., 2006 (45), US men and women. 114-Item FFQ. Total dairy (average 1 serving/day) not associated with insulin sensitivity. B Snijder et al., 2008 (46), US men and women. 92-Item FFQ. Dairy consumption (continuous, 0–17 serving/day) at baseline not associated with delta fasting glucose or post-load glucose. Similar for individual dairy products after 6 years. B |
|||||
| Inflammatory markers |
Intervention study Wennersberg et al., 2009 (47), Finnish, Norwegian, and Swedish men and women. Middle-aged overweight men and women with traits of the metabolic syndrome. Advised to consume 3–5 servings of dairy/day. No effect on inflammatory markers. A |
A=1 | Insufficient | No conclusion on the association between dairy consumption and inflammatory markers | |
| Prostate cancer |
Michaud et al., 2001 (48), US men. 130-Item FFQ. Metastatic prostate cancer risk (stage D and fatal), multivariate model (not adjusting for calcium intake) Dairy >69 g/day vs. <19 g/day; RR 1.43 (0.91–2.3) Skim milk >2 serving/week vs. 0 serving/week; RR 1.25 (0.83–1.9) Whole milk >4 serving/week vs. 0 serving/week; RR 1.25 (0.80–1.9) Cottage cheese ≥2 serving/week vs. 0 serving/week; RR 1.06 (0.75–1.5) Other cheese ≥5 serving/week vs. ≤3 serving/month; RR 1.29 (0.88–1.9) Cream cheese ≥1 serving/week vs. 0 serving/week; RR 1.20 (0.81–1.8) B Tseng et al., 2005 (49), US men. 105-Item FFQ. Total prostate cancer, multivariate model (not adjusting for calcium intake) Dairy 21 serving/week vs. 5 serving/week; RR 2.2 (1.2–3.9) Total milk 14 serving/week vs. 0.5 serving/week; RR 1.8 (1.1–2.9) Low-fat milk 7 serving/week vs. 0 serving/week; RR 1.5 (1.1–2.2) Whole milk 7 serving/week vs. 0 serving/week; RR 0.8 (0.5–1.3) Cheese 4 pint/week vs. 0.25 serving/week; RR 1.1 (0.6–1.9) Cottage cheese 1 serving/week vs. 0 serving/week; RR 1.2 (0.8–1.8) Cream yes/no; RR 0.9 (0.6–1.3) Yoghurt yes/no; RR 1.0 (0.6–1.9) B Rohrman et al., 2005 (50), US men. 60-Item FFQ. Total prostate cancer, multivariate model (not adjusting for calcium intake) Dairy >1.9 serving/day vs. <0.9 serving/day; HR 1.08 (0.78–1.54) Cheese >5 serving/week vs. <1 serving/week; HR 1.43 (1.01–2.03) Milk >5 serving/week vs. <1 serving/week; HR 1.26 (0.91–1.74) B Mitrou et al., 2007 (51), Finnish men, smokers only. 276-Item FFQ. Total prostate cancer, multivariate model (not adjusting for calcium intake) Dairy 1,220 g/day vs. 381 g/day; RR 1.26 (1.04–1.51) Total milk 994 g/day vs. 153 g/day; RR 1.08 (0.91–1.30) Whole milk 668 g/day vs. 0 g/day; RR 1.05 (0.86–1.29) Low-fat milk 773 g/day vs. 76 g/day; RR 1.18 (0.97–1.44) Cheese 55 g/day vs. 3 g/day; RR 1.13 (0.95–1.36) Sour milk 423 g/day vs. 0 g/day; RR 1.07 (0.90–1.28) Similar findings for different stages of prostate cancer B Allen et al., 2008 (52), men in 8 European countries. Total prostate cancer, multivariate model (not adjusting for calcium intake) Milk and milk beverages 466 g/day vs. 34 g/day; HR 1.01 (0.89–1.16) Yoghurt 135 g/day vs. 12 g/day; HR 1.17 (1.04–1.31) Cheese 57 g/day vs. 15 g/day; HR 1.04 (0.90–1.20) B Rodriguez et al., 2003 (53), US men. 68-Item FFQ. Total prostate cancer, multivariate model (not adjusting for calcium intake) Dairy ≥4 serving/day vs. <3 serving/week; RR 1.1 (0.9–1.3) B Park et al., 2007 (54), US men. 180-Item FFQ. Total prostate cancer, multivariate model (not adjusting for calcium intake) Dairy ≥332 g/day vs. <49 g/day; RR 1.03 (0.92–1.16) Total milk ≥256 g/day vs. <17 g/day; RR 1.07 (0.95–1.19) Low/no-fat milk ≥243 g/day vs. 0 g/day; RR 1.16 (1.04–1.29) Whole milk ≥163 g/day vs. 0 g/day; RR 0.88 (0.77–1.00) Yoghurt ≥40 g/day vs. 0 g/day; RR 0.96 (0.84–1.09) Cheese ≥14 g/day vs. 0 g/day; RR 1.01 (0.91–1.12) After stratification, effects of low/non-fat milk were limited to localised or low-grade tumours. B Kurahashi et al., 2008 (55), Japanese men. 138-Item FFQ. Total prostate cancer, multivariate model (not adjusting for calcium intake) Dairy 339.8 g/day vs. 12.8 g/day; RR 1.63 (1.14–2.32) Milk 290.5 g/day vs. 2.3 g/day; RR 1.53 (1.07–2.19) Yoghurt 31.5 g/day vs. 1.9 g/day; RR 1.52 (1.10–2.12) Cheese 6.2 g/day vs. 1.9 g/day; RR 1.32 (0.93–1.89) B |
B=8 | Low | Suggestive increased risk of prostate cancer with increased total dairy consumption based mainly on two prospective cohorts (graded B) with sufficient exposure range and comparatively high intakes in the highest exposure category. In cohort studies with lower intakes and narrower intake ranges, null associations were observed | |
| Breast cancer |
McCullough et al., 2005 (56), US women. 68-Item FFQ. Total postmenopausal breast cancer. Dairy products ≥2 serving/day vs. <0.5 serving/day; RR 0.81 (0.69–0.95) reduced risk of postmenopausal breast cancer. The association was slightly stronger in women with oestrogen receptor-positive tumours, comparing highest to lowest intake. B Pala et al., 2008 (57), women in 8 European countries. Pre- and postmenopausal breast cancer, multivariate model (not adjusting for calcium intake) Total milk 439 g/day vs. 0 g/day; HR 1.05 (0.97–1.14) Whole milk 150 g/day vs. 0 g/day; HR 1.06 (0.97–1.15) Semiskim 293 g/day vs. 0 g/day; HR 1.05 (0.97–1.12) Skim 210 g/day vs. 0 g/day; HR 0.93 (0.87–1.01) Cheese 82 g/day vs. 6 g/day; HR 0.97 (0.89–1.06) No consistent association with total breast cancer risk. B Shin et al., 2002 (58), US women. 61–130-Item FFQ updated. Premenopausal diet for premenopausal breast cancer, multivariate model (not adjusting for calcium intake) Total dairy foods >3 serving/day vs. ≤1 serving/day; RR 0.73 (0.55–0.86) Skim/low-fat milk >1 serving/day vs. never; RR 0.72 (0.56–0.91) No association was found between pre/postmenopausal intake of dairy products and postmenopausal breast cancer. Among premenopausal women, high intake of low-fat dairy foods, especially skim/low-fat milk, was associated with reduced risk of breast cancer. B |
B=3 | Insufficient | No conclusion on the association between dairy consumption and risk of breast cancer | |
| Bone health | Feskanich, 2003 (59), US women. FFQ. No association between milk consumption (5 categories ranging from <1/week to >1.5/day) and risk of hip fractures (p-trend=0.21 for continuous intakes). B | B=1 | Insufficient | No conclusion on the association between dairy consumption and bone health | |
| Meat | CVD/CHD |
He et al., 2003 (60), US men. Semiquantitative FFQ (3 times). Outcome: ischemic and haemorrhagic stroke Ischemic stroke: Red meat (in frequency) ≥1/d vs. <1/wk; RR 0.97 (0.60–1.55) Haemorrhagic stroke: Red meat (in frequency) ≥1/day vs. <1/week; RR 1.58 (0.55–4.55) No significant association between red meat and ischemic/haemorrhagic stroke. B Steffen et al., 2007 (61), US men and women. 66-Item semiquantitative FFQ (interview administered at baseline and 6 years later). Outcome: venous thromboembolism (VTE) Red and processed meat >1.5 serving/day vs. <0.5 serving/day; HR 2.01 (1.15–3.53) Red and processed meat intake was significantly associated with risk of VTE. B Nettleton et al., 2008 (21), US men and women. 66-Item semiquantitative FFQ (interview administered at baseline and 6 years later) Outcome: Incident heart failure (HF) RR for HF incidence according to intake of red or processed meat (RR representing expected changes in risk of HF per 1 serving/day difference in food group consumption): RR 1.27 (1.18–1.37) when adjusted only for energy intake. Red or processed meat was not significantly associated with HF risk after multivariable adjustment; RR 1.07 (0.97–1.17). B Sinha et al., 2009 (62), US men and women. 124-Item FFQ. Outcome: CVD mortality In men (5th vs. 1st quintile): Red meat: 68.1 g/1,000 kcal vs. 9.3 g/1,000 kcal, HR 1.27 (1.20–1.35); processed meat: 19.4 g/1,000 kcal vs. 5.1 g/1,000 kcal, HR 1.09 (1.03–1.15). In women (5th vs. 1st quintile): Red meat: 65.9 g/1,000 kcal vs. 9.1 g/1,000 kcal, HR 1.50 (1.37–1.65); processed meat 16.0 g/1,000 kcal vs. 3.8 g/1,000 kcal, HR 1.38 (1.26–1.51) Increased CVD mortality for both men and women with increased intake of red and processed meat. B |
B=4 | Insufficient | No conclusion on the association between red meat/processed meat and CVD/CHD The end-point diversity of these 4 studies contributes to the unclear conclusion |
| Inflammatory markers | No studies | Insufficient | No conclusion on the association between red or processed meat consumption and inflammatory markers | ||
| Iron status |
Szymlek-Gay et al., 2009 (66), New Zealand. 20-month RCT among 12–20-month-old toddlers; red meat group, milk group, and control group. Participants in the red meat group were encouraged to eat ≥2 portions of red meat/day (56 g). However, compliance was low and mean number of meat dishes consumed was only 0.7/day. No intervention effect on prevalence of suboptimal iron status. In the red meat group there was no change in serum ferritin during the intervention, but at week 20, serum ferritin was significantly higher in the meat than the control group (p=0.033). B |
B=1 | Insufficient | No conclusion on the association between red meat consumption and iron status | |
| Colorectal cancer |
WCRF/AICR: World Cancer Research Fund/American Institute for Cancer Research. Continuous Update Project Report Summary. Food, Nutrition, Physical Activity, and the Prevention of Colorectal Cancer (2011) (6). Nine of 12 studies of colorectal cancer demonstrated increased risk with higher intake of red meat. Meta-analysis: 17% increased risk of colorectal cancer per 100 g/day intake. Indication of increased risk of colon and rectal cancer but non-significant. Ten of 13 studies of colorectal cancer demonstrated increased risk with higher intake of processed meat. Meta-analysis: 18% increased risk of colorectal cancer and 24% increased risk of colon cancer per 50 g/day intake. Indication of increased risk of rectal cancer but non-significant. |
… | … | Red and processed meat are convincingly associated with increased risk of colorectal cancer |
*
Based on apparently healthy population.