Schwingshackl et al., 2017b
Schwingshackl, L., Hoffmann, G., Lampousi, A. M., Knüppel, S., Iqbal, K., Schwedhelm, C., ... & Boeing, H. (2017). Food groups and risk of type 2 diabetes mellitus: a systematic review and meta-analysis of prospective studies. European journal of epidemiology, 32, 363-375
Abstract
The aim of this systematic review and meta-analysis was to synthesize the knowledge about the relation between intake of 12 major food groups and risk of type 2 diabetes (T2D). We conducted a systematic search in PubMed, Embase, Medline (Ovid), Cochrane Central, and Google Scholar for prospective studies investigating the association between whole grains, refined grains, vegetables, fruits, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSB) on risk of T2D. Summary relative risks were estimated using a random effects model by contrasting categories, and for linear and non-linear dose–response relationships. Six out of the 12 food-groups showed a significant relation with risk of T2D, three of them a decrease of risk with increasing consumption (whole grains, fruits, and dairy), and 4 an increase of risk with increasing consumption (red meat, processed meat, eggs and SSB) in the linear dose–response meta-analysis. There was evidence of a non-linear relationship between fruits, vegetables, processed meat, whole grains, and SSB and T2D risk. Optimal consumption of risk-decreasing foods resulted in a 42% reduction, and consumption of risk-increasing foods was associated with a threefold T2D risk, compared to non-consumption. The meta-evidence was graded “low” for legumes and nuts; “moderate” for refined grains, vegetables, fruit, eggs, dairy, and fish; and “high” for processed meat, red meat, whole grains, and SSB. Among the investigated food groups, selecting specific optimal intakes can lead to a considerable change in risk of T2D.
| Food group | Risk ratio (RR), 95% CI | |||||||
|---|---|---|---|---|---|---|---|---|
| Inverse association | ||||||||
| Servings per day | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| Whole grains (1 serving = 30 g/day) | 1.00 | 0.78 (0.76–0.81) | 0.75 (0.71–0.79) | 0.76 (0.70–0.82) | NA | NA | NA | NA |
| Vegetables (1 serving = 80 g/day) | 1.00 | 0.96 (0.94–0.98) | 0.93 (0.90–0.96) | 0.92 (0.89–0.95) | 0.92 (0.88–0.95) | 0.92 (0.89–0.96) | 0.94 (0.90–0.97) | 0.95 (0.90–0.99) |
| Fruits (1 serving = 80 g/day) | 1.00 | 0.95 (0.94–0.96) | 0.92 (0.89–0.94) | 0.90 (0.88–0.93) | 0.90 (0.88–0.93) | 0.91 (0.89–0.94) | 0.92 (0.90–0.95) | 0.93 (0.90–0.96) |
| Dairy (1 serving = 200 g/day) | 1.00 | 0.97 (0.95–0.99) | 0.95 (0.92–0.98) | 0.94 (0.91–0.97) | 0.94 (0.91–0.97) | 0.94 (0.90–0.97) | NA | NA |
| Positive association | ||||||||
| Refined grains (1 serving = 30 g/day) | 1.00 | 1.01 (0.99–1.02) | 1.01 (0.98–1.05) | 1.02 (0.98–1.06) | 1.03 (0.98–1.08) | 1.04 (0.99–1.09) | 1.05 (0.99–1.10) | 1.06 (1.00–1.12) |
| Eggs (1 serving = 55 g/day) | 1.00 | 1.16 (1.09–1.23) | NA | NA | NA | NA | NA | NA |
| Red meat (1 serving = 85 g/day) | 1.00 | 1.18 (1.14–1.21) | 1.37 (1.30–1.43) | NA | NA | NA | NA | NA |
| Processed meat (1 serving = 35 g/day) | 1.00 | 1.29 (1.25–1.33) | 1.35 (1.28–1.42) | 1.39 (1.27–1.54) | 1.43 (1.26–1.63) | NA | NA | NA |
| Sugar sweetened beverages (1 serving = 250 ml/day) | 1.00 | 1.19 (1.14–1.23) | 1.28 (1.20–1.38) | 1.37 (1.23–1.53) | NA | NA | NA | NA |
| No association | ||||||||
| Nuts (1 serving = 28 g/day) | 1.00 | 1.01 (0.92–1.12) | NA | NA | NA | NA | NA | NA |
| Legumes (1 serving = 100 g/day) | 1.00 | 1.00 (0.95–1.05) | 0.97 (0.90–1.03) | NA | NA | NA | NA | NA |
| Fish (1 serving = 100 g/day) | 1.00 | 1.03 (0.98–1.09) | 1.03 (0.89–1.20) | NA | NA | NA | NA | NA |
Selected bits
Increasing the daily consumption of foods with inverse relation to risk of T2D beyond 2 servings of whole grains (60 g/day), 2–3 servings of vegetables and fruits (160–240 g/day respectively), and 3 servings of dairy (400–600 g/day) will not further reduce the risk.
Giving up red and processed meat, sugar sweetened beverages and eggs reduces diabetes risk by 70%
The NutriGrade meta-evidence grading was rated “low” for legumes and nuts; “moderate” for refined grains, vegetables, fruit, eggs, dairy and fish; and “high” for processed meat, red meat, whole grains, and SSB.
Eggs
Thirteen studies with 17,629 T2D cases were included