1
|
Jensen DEA, Leoni V, Klein-Flügge MC, Ebmeier KP, Suri S. Associations of dietary markers with brain volume and connectivity: A systematic review of MRI studies. Ageing Res Rev 2021; 70:101360. [PMID: 33991658 DOI: 10.1016/j.arr.2021.101360] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 04/22/2021] [Accepted: 05/08/2021] [Indexed: 11/20/2022]
Abstract
The high prevalence of unhealthy dietary patterns and related brain disorders, such as dementia, emphasizes the importance of research that examines the effect of dietary factors on brain health. Identifying markers of brain health, such as volume and connectivity, that relate to diet is an important first step towards understanding the lifestyle determinants of healthy brain ageing. We conducted a systematic review of 52 studies (total n = 21,221 healthy participants aged 26-80 years, 55 % female) that assessed with a range of MRI measurements, which brain areas, connections, and cerebrovascular factors were associated with dietary markers. We report associations between regional brain measures and dietary health. Collectively, lower diet quality was related to reduced brain volume and connectivity, especially in white and grey matter of the frontal, temporal and parietal lobe, cingulate, entorhinal cortex and the hippocampus. Associations were also observed in connecting fibre pathways and in particular the default-mode, sensorimotor and attention networks. However, there were also some inconsistencies in research methods and findings. We recommend that future research use more comprehensive and consistent dietary measures, more representative samples, and examine the role of key subcortical regions previously highlighted in relevant animal work.
Collapse
Affiliation(s)
- Daria E A Jensen
- Department of Psychiatry, University of Oxford, OX3 7JX, UK; Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX37JX, UK.
| | - Virginia Leoni
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Italy
| | - Miriam C Klein-Flügge
- Department of Experimental Psychology, Wellcome Centre for Integrative Neuroimaging, University of Oxford, Tinsley building, OX1 3SR, UK
| | | | - Sana Suri
- Department of Psychiatry, University of Oxford, OX3 7JX, UK; Oxford Centre for Human Brain Activity, Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX37JX, UK
| |
Collapse
|
2
|
Allaf M, Elghazaly H, Mohamed OG, Fareen MFK, Zaman S, Salmasi AM, Tsilidis K, Dehghan A. Intermittent fasting for the prevention of cardiovascular disease. Cochrane Database Syst Rev 2021; 1:CD013496. [PMID: 33512717 PMCID: PMC8092432 DOI: 10.1002/14651858.cd013496.pub2] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND Cardiovascular disease (CVD) is the leading cause of death worldwide. Lifestyle changes are at the forefront of preventing the disease. This includes advice such as increasing physical activity and having a healthy balanced diet to reduce risk factors. Intermittent fasting (IF) is a popular dietary plan involving restricting caloric intake to certain days in the week such as alternate day fasting and periodic fasting, and restricting intake to a number of hours in a given day, otherwise known as time-restricted feeding. IF is being researched for its benefits and many randomised controlled trials have looked at its benefits in preventing CVD. OBJECTIVES To determine the role of IF in preventing and reducing the risk of CVD in people with or without prior documented CVD. SEARCH METHODS We conducted our search on 12 December 2019; we searched CENTRAL, MEDLINE and Embase. We also searched three trials registers and searched the reference lists of included papers. Systematic reviews were also viewed for additional studies. There was no language restriction applied. SELECTION CRITERIA We included randomised controlled trials comparing IF to ad libitum feeding (eating at any time with no specific caloric restriction) or continuous energy restriction (CER). Participants had to be over the age of 18 and included those with and without cardiometabolic risk factors. Intermittent fasting was categorised into alternate-day fasting, modified alternate-day fasting, periodic fasting and time-restricted feeding. DATA COLLECTION AND ANALYSIS Five review authors independently selected studies for inclusion and extraction. Primary outcomes included all-cause mortality, cardiovascular mortality, stroke, myocardial infarction, and heart failure. Secondary outcomes include the absolute change in body weight, and glucose. Furthermore, side effects such as headaches and changes to the quality of life were also noted. For continuous data, pooled mean differences (MD) (with 95% confidence intervals (CIs)) were calculated. We contacted trial authors to obtain missing data. We used GRADE to assess the certainty of the evidence. MAIN RESULTS: Our search yielded 39,165 records after the removal of duplicates. From this, 26 studies met our criteria, and 18 were included in the pooled analysis. The 18 studies included 1125 participants and observed outcomes ranging from four weeks to six months. No studies included data on all-cause mortality, cardiovascular mortality, stroke, myocardial infarction, and heart failure at any point during follow-up. Of quantitatively analysed data, seven studies compared IF with ab libitum feeding, eight studies compared IF with CER, and three studies compared IF with both ad libitum feeding and CER. Outcomes were reported at short term (≤ 3 months) and medium term (> 3 months to 12 months) follow-up. Body weight was reduced with IF compared to ad libitum feeding in the short term (MD -2.88 kg, 95% CI -3.96 to -1.80; 224 participants; 7 studies; low-certainty evidence). We are uncertain of the effect of IF when compared to CER in the short term (MD -0.88 kg, 95% CI -1.76 to 0.00; 719 participants; 10 studies; very low-certainty evidence) and there may be no effect in the medium term (MD -0.56 kg, 95% CI -1.68 to 0.56; 279 participants; 4 studies; low-certainty evidence). We are uncertain about the effect of IF on glucose when compared to ad libitum feeding in the short term (MD -0.03 mmol/L, 95% CI -0.26 to 0.19; 95 participants; 3 studies; very-low-certainty of evidence) and when compared to CER in the short term: MD -0.02 mmol/L, 95% CI -0.16 to 0.12; 582 participants; 9 studies; very low-certainty; medium term: MD 0.01, 95% CI -0.10 to 0.11; 279 participants; 4 studies; low-certainty evidence). The changes in body weight and glucose were not deemed to be clinically significant. Four studies reported data on side effects, with some participants complaining of mild headaches. One study reported on the quality of life using the RAND SF-36 score. There was a modest increase in the physical component summary score. AUTHORS' CONCLUSIONS Intermittent fasting was seen to be superior to ad libitum feeding in reducing weight. However, this was not clinically significant. There was no significant clinical difference between IF and CER in improving cardiometabolic risk factors to reduce the risk of CVD. Further research is needed to understand the safety and risk-benefit analysis of IF in specific patient groups (e.g. patients with diabetes or eating disorders) as well as the effect on longer-term outcomes such as all-cause mortality and myocardial infarction.
Collapse
Affiliation(s)
| | | | | | | | - Sadia Zaman
- School of Medicine, Imperial College London, London, UK
| | - Abdul-Majeed Salmasi
- Department of Cardiology, London North West University Healthcare NHS Trust, London, UK
| | - Kostas Tsilidis
- Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, UK
- Department of Hygiene and Epidemiology, University of Ioannina School of Medicine, Ioannina, Greece
| | - Abbas Dehghan
- School of Public Health, Imperial College London, London, UK
| |
Collapse
|
3
|
Orfanos S, Toygar T, Berthold-Losleben M, Chechko N, Durst A, Laoutidis ZG, Vocke S, Weidenfeld C, Schneider F, Karges W, Beckmann CF, Habel U, Kohn N. Investigating the impact of overnight fasting on intrinsic functional connectivity: a double-blind fMRI study. Brain Imaging Behav 2019; 12:1150-1159. [PMID: 29071464 PMCID: PMC6063348 DOI: 10.1007/s11682-017-9777-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The human brain depends mainly on glucose supply from circulating blood as an energy substrate for its metabolism. Most of the energy produced by glucose catabolism in the brain is used to support intrinsic communication purposes in the absence of goal-directed activity. This intrinsic brain function can be detected with fMRI as synchronized fluctuations of the BOLD signal forming functional networks. Here, we report results from a double-blind, placebo controlled, cross-over study addressing changes in intrinsic brain activity in the context of very low, yet physiological, blood glucose levels after overnight fasting. Comparison of four major resting state networks in a fasting state and a state of elevated blood glucose levels after glucagon infusion revealed altered patterns of functional connectivity only in a small region of the posterior default mode network, while the rest of the networks appeared unaffected. Furthermore, low blood glucose was associated with changes in the right frontoparietal network after cognitive effort. Our results suggest that fasting has only limited impact on intrinsic brain activity, while a detrimental impact on a network related to attention is only observable following cognitive effort, which is in line with ego depletion and its reliance on glucose.
Collapse
Affiliation(s)
- Stelios Orfanos
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany. .,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany.
| | - Timur Toygar
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Department of Biology, RWTH Aachen University, 52074, Aachen, Germany
| | - Mark Berthold-Losleben
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Natalya Chechko
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Annette Durst
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Zacharias G Laoutidis
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Department of Psychiatry and Psychotherapy, University of Düsseldorf, Bergische Landstrasse 2, 40629, Düsseldorf, Germany
| | - Sebastian Vocke
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Caren Weidenfeld
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Frank Schneider
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Wolfram Karges
- Division of Endocrinology and Diabetes, Medical Faculty, RWTH Aachen University, 52074, Aachen, Germany
| | - Christian F Beckmann
- Department of Cognitive Neuroscience, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands.,Centre for Functional MRI of the Brain (FMRIB), University of Oxford, Oxford, UK
| | - Ute Habel
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Jülich Aachen Research Alliance (JARA) - BRAIN Institute Brain Structure-Function Relationships: Decoding the Human Brain at systemic levels, Forschungszentrum Jülich GmbH and RWTH Aachen University, Jülich, Germany
| | - Nils Kohn
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, RWTH Aachen University, Aachen, Germany.,Department of Cognitive Neuroscience, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, The Netherlands
| |
Collapse
|