Khalid Iqbal

Mr. Khalid Iqbal

orcid

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
10 April 2017 in European Journal of Epidemiology
Verified
Journal Article
Open access
PDF file
LSLukas Schwingshackl
Lukas Schwingshackl
GHGeorg Hoffmann
Georg Hoffmann
ALAnna-Maria Lampousi
Anna-Maria Lampousi
SKSven Knüppel
Sven Knüppel
KIKhalid Iqbal
Khalid Iqbal
HBHeiner Boeing
Heiner Boeing
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 three an increase of risk with increasing consumption (red meat, processed meat, 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.

1 June 2017 in The American Journal of Clinical Nutrition
Verified
Journal Article
Closed access
PDF file
LSLukas Schwingshackl
Lukas Schwingshackl
CSCarolina Schwedhelm
Carolina Schwedhelm
GHGeorg Hoffmann
Georg Hoffmann
ALAnna-Maria Lampousi
Anna-Maria Lampousi
SKSven Knüppel
Sven Knüppel
HBHeiner Boeing
Heiner Boeing
Background: Suboptimal diet is one of the most important factors in preventing early death and disability worldwide.

1 November 2016 in Advances in Nutrition
Verified
Journal Article
Open access
PDF file
LSLukas Schwingshackl
Lukas Schwingshackl
SKSven Knüppel
Sven Knüppel
CSCarolina Schwedhelm
Carolina Schwedhelm
GHGeorg Hoffmann
Georg Hoffmann
BMBenjamin Missbach
Benjamin Missbach
HBHeiner Boeing
Heiner Boeing
The objective of this study was to develop a scoring system (NutriGrade) to evaluate the quality of evidence of randomized controlled trial (RCT) and

1 November 2017 in Advances in Nutrition
Verified
Journal Article
Closed access
PDF file
LSLukas Schwingshackl
Lukas Schwingshackl
CSCarolina Schwedhelm
Carolina Schwedhelm
GHGeorg Hoffmann
Georg Hoffmann
SKSven Knüppel
Sven Knüppel
KIKhalid Iqbal
Khalid Iqbal
HBHeiner Boeing
Heiner Boeing
The aim of this systematic review and meta-analysis was to summarize the evidence on the relation of the intakes of 12 major food groups, including w

1 June 2017 in Carcinogenesis
Verified
Journal Article
Open access
PDF file
MSMagdalena Stepien
Magdalena Stepien
MJMazda Jenab
Mazda Jenab
HFHeinz Freisling
Heinz Freisling
NBNiels-Peter Becker
Niels-Peter Becker
MCMagdalena Czuban
Magdalena Czuban
DHDavid J. Hughes
David J. Hughes
Adequate intake of copper and zinc, two essential micronutrients, are important for antioxidant functions. Their imbalance may have implications for development of diseases like colorectal cancer (CRC), where oxidative stress is thought to be etiologically involved. As evidence from prospective epidemiologic studies is lacking, we conducted a case-control study nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort to investigate the association between circulating levels of copper and zinc, and their calculated ratio, with risk of CRC development. Copper and zinc levels were measured by reflection X-ray fluorescence spectrometer in 966 cases and 966 matched controls. Multivariable adjusted odds ratios (OR) and 95% confidence intervals (CI) were calculated using conditional logistic regression and are presented for the fifth versus first quintile. Higher circulating concentration of copper was associated with a raised CRC risk (OR = 1.50; 95% CI: 1.06, 2.13; P-trend = 0.02) whereas an inverse association with cancer risk was observed for higher zinc levels (OR = 0.65; 95% CI: 0.43, 0.97; P-trend = 0.07). Consequently, the ratio of copper/zinc was positively associated with CRC (OR = 1.70; 95% CI: 1.20, 2.40; P-trend = 0.0005). In subgroup analyses by follow-up time, the associations remained statistically significant only in those diagnosed within 2 years of blood collection. In conclusion, these data suggest that copper or copper levels in relation to zinc (copper to zinc ratio) become imbalanced in the process of CRC development. Mechanistic studies into the underlying mechanisms of regulation and action are required to further examine a possible role for higher copper and copper/zinc ratio levels in CRC development and progression.

1 September 2018 in The American Journal of Clinical Nutrition
Verified
Journal Article
Open access
LSLukas Schwingshackl
Lukas Schwingshackl
GHGeorg Hoffmann
Georg Hoffmann
KIKhalid Iqbal
Khalid Iqbal
CSCarolina Schwedhelm
Carolina Schwedhelm
HBHeiner Boeing
Heiner Boeing
In previous meta-analyses of prospective observational studies, we investigated the association between food groups and risk of chronic disease. The aim of the present network meta-analysis (NMA) was to assess the effects of these food groups on intermediate-disease markers across randomized intervention trials. Literature searches were performed until January 2018. The following inclusion criteria were defined a priori: 1) randomized trial (≥4 wk duration) comparing ≥2 of the following food groups: refined grains, whole grains, nuts, legumes, fruits and vegetables, eggs, dairy, fish, red meat, and sugar-sweetened beverages (SSBs); 2) LDL cholesterol and triacylglycerol (TG) were defined as primary outcomes; total cholesterol, HDL cholesterol, fasting glucose, glycated hemoglobin, homeostasis model assessment insulin resistance, systolic and diastolic blood pressure, and C-reactive protein were defined as secondary outcomes. For each outcome, a random NMA was performed, and for the ranking, the surface under the cumulative ranking curves (SUCRA) was determined. A total of 66 randomized trials (86 reports) comparing 10 food groups and enrolling 3595 participants was identified. Nuts were ranked as the best food group at reducing LDL cholesterol (SUCRA: 93%), followed by legumes (85%) and whole grains (70%). For reducing TG, fish (97%) was ranked best, followed by nuts (78%) and red meat (72%). However, these findings are limited by the low quality of the evidence. When combining all 10 outcomes, the highest SUCRA values were found for nuts (66%), legumes (62%), and whole grains (62%), whereas SSBs performed worst (29%). The present NMA provides evidence that increased intake of nuts, legumes, and whole grains is more effective at improving metabolic health than other food groups. For the credibility of diet-disease relations, high-quality randomized trials focusing on well-established intermediate-disease markers could play an important role. This systematic review was registered at PROSPERO (www.crd.york.ac.uk/PROSPERO) as CRD42018086753.