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The effects of time-restricted eating on sleep, cognitive decline, and Alzheimer's disease.
Ezzati, A, Pak, VM
Experimental gerontology. 2023;171:112033
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The ageing population is expected to double, with one in four people being over 65 years in Western countries by 2050. As a consequence, the presentation of age-related disorders like Alzheimer's disease (AD) and mild cognitive impairment (MCI) is likely to increase. MCI, a pre-stage of dementia, is considered reversible. However, there are no known cures for AD so far. Hence interventions such as lifestyle modifications that can delay the onset and progression of the disease are of great interest. Previous research demonstrated that calorie restriction (CR) and time-restricted eating (TRE) have beneficial effects on brain function. The authors of this article sought to summarize the current evidence of such eating patterns, as well as their underlying mechanisms and potential benefits concerning MCI and AD. The review also looked at sleep - as sleep disturbances are a risk factor and are associated with both conditions - and the effects of sleep on cognitive decline and neuroinflammatory markers. TRE presents itself as a promising intervention as it can restore the integrity of the blood-brain barrier and support healthy brain function whilst reducing oxidative stress and inflammation. Furthermore, it can be leveraged for weight and glucose management. Preliminary results also indicate a positive impact on sleep, with adequate sleep benefiting cognitive health. As this is a relatively new field, there is still much more to be understood about the underlying mechanisms, with the optimal time window for fasting needing to be determined. The authors advocate for more research on how TRE and sleep relates to neurodegenerative disease.
Expert Review
Conflicts of interest:
None
Take Home Message:
- To highlight the potential benefits of time-restricted eating (TRE) as a potential preventative approach to delay the onset and progression of neurodegenerative disease such as AD
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
- The authors highlight Alzheimer's disease (AD) is the most prevalent neurodegenerative disease affecting over 50 million aging people worldwide. While no cure is known for AD, this review proposes lifestyle interventions such as time-restricted eating (TRE) as a potential approach to delay the onset and progression of a neurodegenerative disease and could hint at autophagic mechanisms
- TRE involves strategically limiting the eating window to 8- to 12-h with fasting—drinking only water and calorie-free coffee/tea—for 12 to 16 h within a 24-h cycle.
Objectives
- To investigate the effects of TRE on sleep and cognitive decline in healthy individuals
Results
- Nine RCTs with varied length between one and sixteen weeks were examined
- A 5-week randomised controlled trial (RCT) showed no significant change in sleep quality between early TRE (fasting between 6 a.m.–3 p.m.), mid-day TRE (11 a.m.–8 p. m.) and control (ad lib intake) in 82 healthy subjects without obesity but the sleep quality improvement was greater in early TRE group (PSQI:Δ=−1.08±1.78vs.Δ=−0.22±2.19andΔ=−0.36±1.73, respectively).
- Sleep quality using the myCircadianClock app reported significant improvement in sleep quality (23 %) following a 12-week single arm intervention of 10-h TRE.
- Following a 16-week TRE intervention sleep duration was reported to be improved from a subjective score of 6 at base line to 8 after 36 weeks in eight overweight and obese subjects; however, the study used a subjective self-assessment survey for measuring sleep duration.
- The Pittsburgh Sleep Quality Index (PSQI) was carried out to assess sleep quality and disturbances in six trials but no trial reported significant improvement in sleep quality using the PSQI survey with TRE
Conclusion
- Authors highlight TRE as promising for its potential to reduce the markers of aging and neurodegenerative disease.
Clinical practice applications:
- To inform practitioners of the potential benefits of TRE that involves limiting the eating window to 8- to 12-h with fasting—drinking only water and calorie-free coffee/tea—for 12 to 16 h within a 24-h cycle.
- TRE may improve regulation of circadian rhythm and autophagy through aligning food intake with circadian rhythm, which coordinates metabolism and physiological functions including glucose, insulin sensitivity, lipid levels, energy expenditure, inflammation, sleep and cognitive function.
- TRE activates a metabolic switch which occurs 12–36 h after fasting is initiated and free fatty acids are released into the blood.
- TRE improved sleep quality and sleep duration, where a longer fasting period in TRE approach (≥12 h fasting) was associated with significantly higher sleep duration.
Considerations for future research:
- The potential benefits of TRE in neurodegenerative diseases such as AD should be further investigated clinically.
- The optimal time to initiate fasting needs to be identified in future trials.
- The potential benefits of TRE in neurodegenerative diseases such as AD in the context of sleep should be further investigated.
Abstract
According to the United Nations, by 2050, one in six individuals will be over age 65 globally, and one in four people would be aged 65 and older in western countries. The unprecedented growth of the aging population is associated with increased age-related disorders like Alzheimer's disease (AD) and Mild cognitive impairment (MCI). To date, no cure is known for AD, thus lifestyle interventions including calorie restriction (CR) and time-restricted eating (TRE) are proposed as potential approach to delay the onset and progression of the disease. Sleep disturbances are common in people with MCI and AD. Moreover, accumulating data indicates that pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), IL-6, IL-8 and IL-10 increase in individuals with AD and MCI versus healthy subjects. Thus, the purpose of the present review is to describe the potential effects of TRE on sleep, cognition decline, and neuroinflammatory markers in humans. Preliminary evidence suggests that TRE may produce neuroprotective effects on cognition and reduce neuroinflammatory markers related to AD in humans. To date, no studies investigated the effects of TRE on sleep disturbances and patients with AD. Thereby, the impact of TRE on cognition in individuals with cognitive decline and AD needs to be investigated further in randomized controlled trials (RCTs).
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Effects of whey and soy protein supplementation on inflammatory cytokines in older adults: a systematic review and meta-analysis.
Prokopidis, K, Mazidi, M, Sankaranarayanan, R, Tajik, B, McArdle, A, Isanejad, M
The British journal of nutrition. 2023;129(5):759-770
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Reduced muscle mass and reduction in physical activity may lead to sarcopenia in older people. Age-related sarcopenia is associated with increased systemic low-grade inflammation and obesity. Protein supplementation is found to be beneficial in reducing circulating pro-inflammatory cytokines in old people. Previous research has shown that supplementation with isolated whey and soy protein reduces the levels of inflammatory cytokines in older adults. However, there is limited research on intact whey and soy protein supplementation in reducing age-related inflammation. This systematic review and meta-analysis investigated the effect of intact whey and soy protein on serum inflammatory markers such as C-reactive protein (CRP), Interleukin-6 (IL6) and TNF-α in older adults. The results of this meta-analysis show a significant reduction in circulating IL-6 and TNF-α levels after the supplementation with whey and soy protein. The addition of soy isoflavones resulted in a further decline in serum CRP levels. Subgroup analysis showed that the whey protein supplementation significantly improved sarcopenia and pre-frailty. Healthcare professionals can use the result of this systematic review and meta-analysis to understand the anti-inflammatory properties of intact whey and soy protein and soy isoflavones. However, further robust studies are required to assess the anti-inflammatory properties of whey and soy protein due to the high heterogeneity of included studies in this review.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Nutritional strategies such as whey and soy protein supplementation may be regarded as safe and effective to attenuate adverse changes in muscle mass with ageing, however need to be considered alongside individual dietary intake and health status.
- Consider optimising protein intake and quality of protein through diet as an alternative or first line strategy.
Evidence Category:
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A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
- A decline in muscle mass and physical capacity, known as sarcopenia, may start in the fourth decade with accumulation of adiposity, resulting in elevated circulating proinflammatory cytokines.
- Systematic and local elevation of oxidative stress and reactive oxygen species accumulation may accelerate age-related muscle wasting, however may be mitigated with antioxidant nutrients.
- This SR and MA evaluated whey and soy proteins effects on interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-α) and C-reactive protein (CRP) in older adults.
Methods
SR followed PRISMA guidelines, was registered on PROSPERO and included 31 RCT studies published in English between 2004-21. Intervention group received soy/whey supplements and comparator group received a placebo; circulating levels of CRP, IL-6 and/or TNF-α were assessed. MA used random-effects to calculate the pooled effects. Overall quality of evidence was rated as moderate.
Results
Males and females with a mean age 50 - 80 years were included.
Whey protein:
- IL-6 levels were reduced significantly (Number of studies (k) = 12, Mean Difference (MD): −0·79, 95 % Confidence Interval (CI): −1·15, −0·42, p< 0.01), however, high heterogeneity was observed (I2 = 96 %).
- Treatment duration ≤ 8 weeks showed a significant reduction in serum CRP (k = 4, MD: –0·30, 95 % CI: –0·39, –0·21, I2 = 0 %) compared with > 8 weeks (k = 6, MD: 0·13, 95 % CI: –0·13, 0·40, I2 = 9 %), whereas TNF-α and IL-6 remained unaltered.
- Individuals with sarcopenia and pre-frailty displayed a significant reduction of IL-6 (k = 3, MD: –0·98, 95 % CI: –1·56, –0·39, I2 = 0 %) but no benefits were observed for CRP or TNF.
Soy protein:
- There was a significant reduction in TNF-α (k = 6, MD: −0·16, 95 % CI: −0·26, p<0·05).
- The addition of isoflavones demonstrated a significant decrease in TNF-α (k = 5, MD: –0·20, 95 % CI: –0·31, –0·08, I2 = 34 %) but an increase in CRP (k = 7, MD: 0·53, 95 % CI: 0·12, 0·94), however high heterogeneity was observed in the latter (I2 = 91 %).
Conclusion
- The study found a significant reduction in IL-6 following whey protein with effects augmented in those with frailty and sarcopenia and a significant reduction in TNF-α following soy protein with effects augmented by additional soy isoflavones, possibly due to antioxidant effects.
Clinical practice applications:
- Consider whey and/or soy protein supplementation in older adults particularly those reported with pre-frailty and sarcopenia as an effective and safe strategy to attenuate low-grade inflammation and associated risks.
- Soy isoflavones may have additional antioxidant benefits for older adults although further research is needed to confirm this due to high heterogeneity found.
Considerations for future research:
Future research could:
- Evaluate other factors which influence the inflammatory profile such as nutrient density, vitamins and minerals supplementation and exercise.
- Include those with co-morbidities and healthy populations with placebo comparator groups.
- Evaluate dose and type of soy isoflavones on circulating inflammatory markers and the effect of combined whey and soy protein.
Abstract
BACKGROUND AND AIMS Low-grade inflammation is a mediator of muscle proteostasis. This study aimed to investigate the effects of isolated whey and soy proteins on inflammatory markers. METHODS We conducted a systematic literature search of randomised controlled trials (RCT) through MEDLINE, Web of Science, Scopus and Cochrane Library databases from inception until September 2021. To determine the effectiveness of isolated proteins on circulating levels of C-reactive protein (CRP), IL-6 and TNF-α, a meta-analysis using a random-effects model was used to calculate the pooled effects (CRD42021252603). RESULTS Thirty-one RCT met the inclusion criteria and were included in the systematic review and meta-analysis. A significant reduction of circulating IL-6 levels following whey protein [Mean Difference (MD): -0·79, 95 % CI: -1·15, -0·42, I2 = 96 %] and TNF-α levels following soy protein supplementation (MD: -0·16, 95 % CI: -0·26, -0·05, I2 = 68 %) was observed. The addition of soy isoflavones exerted a further decline in circulating TNF-α levels (MD: -0·20, 95 % CI: -0·31, -0·08, I2 = 34 %). According to subgroup analysis, whey protein led to a statistically significant decrease in circulating IL-6 levels in individuals with sarcopenia and pre-frailty (MD: -0·98, 95 % CI: -1·56, -0·39, I2 = 0 %). These findings may be dependent on participant characteristics and treatment duration. CONCLUSIONS These data support that whey and soy protein supplementation elicit anti-inflammatory effects by reducing circulating IL-6 and TNF-α levels, respectively. This effect may be enhanced by soy isoflavones and may be more prominent in individuals with sarcopenia.
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The Impact of Vitamin D Supplementation on the IFNγ-IP10 Axis in Women with Hashimoto's Thyroiditis Treated with Levothyroxine: A Double-blind Randomized Placebo-controlled Trial.
Robat-Jazi, B, Mobini, S, Chahardoli, R, Mansouri, F, Nodehi, M, Esfahanian, F, Saboor Yaraghi, AA
Iranian journal of allergy, asthma, and immunology. 2022;21(4):407-417
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Hashimoto’s thyroiditis is an autoimmune disease characterized by the presence of antibodies against thyroid proteins such as thyroperoxidase (TPO) and thyroglobulin (TG), the local accumulation of inflammatory cells and immune-mediated destruction of the thyroid gland. Disease manifestation is due to a genetic disposition but is also influenced by several environmental factors, including stress, smoking, infections, and levels of nutrients like iodine, selenium and vitamin D. Many cells of the immune system have receptors for Vitamin D and thus have the potential to be influenced by Vitamin D. Indeed, numerous findings demonstrated that vitamin D can exert anti-inflammatory effects on the immune system. This double-blind, randomized, placebo-controlled trial investigated 40 Hashimoto's thyroiditis subjects and the effect of Vitamin D supplementation on various markers of the immune system that mediate the inflammatory response as part of the interferon-gamma-induced protein 10 (IFNγ-IP10) axis. 20 of the enrolled candidates received 50000 IU of Vitamin D (cholecalciferol) once a week – an equivalent to about 7140 IU per day - over three months. The other half received a placebo. All candidates had a fixed dose of thyroid hormone replacement levothyroxine for the duration of the trial. Before and after the intervention several blood biomarkers were investigated relating to Vitamin D levels, D-receptors, immune activity and inflammation. Upon completion of the trial, the intervention group who supplemented Vitamin D had significantly higher Vitamin D levels, which had increased from an average of 25.29 ng/ml to 50.65ng/ml. In addition, several inflammatory factors were significantly decreased. These findings affirmed Vitamin D’s ability to favourably regulate the IFNγ-IP10 axis, which could slow disease progression. This effect may also be useful for the management of other autoimmune disorders involving IP10 overproduction, which attracts other inflammatory cells. More studies in larger groups would help to get more information on other variables not considered in this trial.
Abstract
Hashimoto's thyroiditis (HT) results from chemoattraction of inflammatory cells toward the thyroid gland by inducing the production of interferon-gamma (IFNγ)-induced protein 10 (IP10) by T helper (Th) 1 cells. Vitamin D may suppress the IFNγ-IP10 axis, but this new function of vitamin D has not yet been investigated in HT patients. In an intervention and control group, patients received 50000 IU cholecalciferol or placebo every week for three months, respectively. The CD4+ T cells of 40 patients were isolated, and the mRNA expression levels of vitamin D receptor (VDR), peroxisome proliferator-activated receptors (PPAR)-α, and PPAR-γ genes were determined by real-time PCR. ELISA method was used to determine serum levels of vitamin D, tumor necrosis factor-alpha (TNF-α), IFN-γ, and IP10. Vitamin D levels in the intervention group were significantly higher than in the placebo group after supplementation. PPAR-α and PPAR-γ gene expression levels did not differ significantly between the two groups. The serum levels of IP10, IFNγ, and TNF-α decreased significantly in the vitamin D group, as well as in the placebo group. During this study, vitamin D levels significantly increased in the intervention group and inflammatory factors decreased. Based on the similar results obtained in the placebo group, further studies with larger sample sizes and longer intervention times are recommended.
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Efficacy and Safety of Curcumin and Curcuma longa Extract in the Treatment of Arthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trial.
Zeng, L, Yang, T, Yang, K, Yu, G, Li, J, Xiang, W, Chen, H
Frontiers in immunology. 2022;13:891822
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Arthritic disease is a chronic inflammatory condition affecting one or more joints. Over 100 different forms of arthritis have been identified. Despite their different causes (i.e. degenerative, autoimmune), they share common symptoms such as joint pain, swelling, stiffness, and reduced mobility, which can be disabling in many cases. Drug treatment focuses mainly on limiting the progression of the disease, reducing joint inflammation and managing pain. However, these drugs are associated with many side effects. The rhizome of Curcuma longa (CL), also known as turmeric, has longstanding use as an anti-inflammatory in traditional Asian medicines. Research has affirmed its anti-inflammatory and immunosuppressive properties. Evidence from multiple clinical trials suggests that curcumin, one of the active compounds of CL, can reduce the subjective experience of pain in some conditions and can also improve the symptoms and inflammation associated with arthritis. Hence this systematic review sought to evaluate the efficacy and safety of CL-extract in 5 types of arthritis (including Ankylosing Spondylitis, Rheumatoid Arthritis, Osteoarthritis, Juvenile idiopathic arthritis and gout). The review included 29 randomized controlled trials involving 2396 participants, with dosages ranging from 120 mg to 1500 mg for a period of 4-36 weeks. Overall, curcumin and CL extract appeared to improve inflammation and pain levels in arthritic subjects whilst demonstrating safety with no increases in adverse effects. CL and its active constituents appeared to favourably change immune and inflammatory responses, as well as serum uric acid levels in the reviewed forms of arthritis. However, due to the small sample numbers in the trials and some lower quality studies, the authors advocate to interpret the results with caution until more solid evidence is available.
Abstract
Background: Modern pharmacological research found that the chemical components of Curcuma longa L. are mainly curcumin and turmeric volatile oil. Several recent randomized controlled trials (RCT) have shown that curcumin improves symptoms and inflammation in patients with arthritis. Methods: Pubmed, Cochran Library, CNKI, and other databases were searched to collect the randomized controlled trials (RCTs). Then, the risk of bias of RCTs were assessed and data of RCTs were extracted. Finally, RevMan 5.3 was utilized for meta-analysis. Results: Twenty-nine (29) RCTs involving 2396 participants and 5 types of arthritis were included. The arthritis included Ankylosing Spondylitis (AS), Rheumatoid Arthritis (RA), Osteoarthritis (OA), Juvenile idiopathic arthritis (JIA) and gout/hyperuricemia. Curcumin and Curcuma longa Extract were administered in doses ranging from 120 mg to 1500 mg for a duration of 4-36 weeks. In general, Curcumin and Curcuma longa Extract showed safety in all studies and improved the severity of inflammation and pain levels in these arthritis patients. However, more RCTs are needed in the future to elucidate the effect of Curcumin and Curcuma longa Extract supplementation in patients with arthritis, including RA, OA, AS and JIA. Conclusion: Curcumin and Curcuma longa Extract may improve symptoms and inflammation levels in people with arthritis. However, due to the low quality and small quantity of RCTs, the conclusions need to be interpreted carefully.
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An oleuropein-based dietary supplement may improve joint functional capacity in older people with high knee joint pain: findings from a multicentre-RCT and post hoc analysis.
Horcajada, MN, Beaumont, M, Sauvageot, N, Poquet, L, Saboundjian, M, Costes, B, Verdonk, P, Brands, G, Brasseur, J, Urbin-Choffray, D, et al
Therapeutic advances in musculoskeletal disease. 2022;14:1759720X211070205
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Mobility is an important factor for the quality of life and healthy ageing. Yet, most people as they age will experience some degree of mobility issue, typically linked to problems with joints, bones or muscles. Current medical treatments focus on the management of pain and discomfort with anti-inflammatory drugs and pain relief. However, chronic use of these medications is associated with many side effects. Olive leaf extract (OLE) is a rich source of anti-inflammatory and antioxidant compounds such as oleuropein. Animal studies of OLE showed it had promising effects on inflammation and age-related joint degeneration, and in clinical studies, it was demonstrated to preserve bone mineral density. This 6-month randomized placebo-controlled trial investigated the use of 125mg OLE on knee pain, discomfort and loss of mobility in 124 elderly subjects over 55 who experienced mild to moderate pain during or after physical activity in the absence of diagnosed underlying conditions such as osteoarthritis. The outcome was tracked by scoring questionnaires and blood samples to monitor inflammatory markers, as well as urinary samples to assess compliance. At the end of the trial, there was no significant difference in pain or inflammatory markers, apart from a decline in Prostaglandin E2 in the OLE takers. An adjusted analysis showed that whereby people with mild to moderate pain did not experience any benefits, a significant effect was seen in people who had higher levels of baseline pain to begin with. Due to the good safety profile of OLE, it may be a suitable intervention for those candidates. Larger scale trials may help to enhance these findings.
Abstract
OBJECTIVES To investigate a 6-month intervention with an olive leaf extract (OLE) on knee functionality and biomarkers of bone/cartilage metabolism and inflammation. DESIGN This randomized, double-blind, placebo-controlled, multi-centric trial included 124 subjects with knee pain or mobility issues. Subjects received twice a day one capsule of placebo or 125 mg OLE (Bonolive™, an OLE containing 50 mg of oleuropein) for 6 months. The co-primary endpoints were Knee injury and Osteoarthritis Outcome Score (KOOS) and serum Coll2-1NO2. The secondary endpoints were the subscales of the KOOS, knee pain VAS at rest and at walking, OARSI core set of performance-based tests and multiple inflammatory and bone or cartilage remodeling serum biomarkers and concentration of oleuropein's metabolites in urine. RESULTS At 6 months, OLE group was not efficient on global KOOS score, changes of inflammatory and cartilage remodeling biomarkers compared to placebo. Post hoc analyses demonstrated a large and significant treatment effect of OLE in a sub-group of subjects with high walking pain at baseline (p = 0.03). This was observed at 6 months for the global KOOS score, and each different subscale and for pain at walking (p = 0.02). OLE treatment was well tolerated. CONCLUSION OLE was not effective on joint discomfort excepted in a sub-group of subjects with high pain at treatment initiation. As oleuropein is well tolerated, OLE can be used to relieve knee joint pain and enhance mobility in subjects with articular pain.
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The effects of saffron supplementation on cardiovascular risk factors in adults: A systematic review and dose-response meta-analysis.
Zamani, M, Zarei, M, Nikbaf-Shandiz, M, Gholami, F, Hosseini, AM, Nadery, M, Shiraseb, F, Asbaghi, O
Frontiers in nutrition. 2022;9:1055517
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Cardiovascular disease (CVD) is a leading cause of death and disability around the world and presents a significant burden for healthcare systems. CVD has many risk factors, including diet and lifestyle habits. Hence, favourable interventions in those areas can help prevent and manage CVD. This systematic review examined the effects of saffron crocus on cardiovascular risk factors. Saffron is derived from the flowering plant Saffron Crocus (Crocus sativus). It contains many active compounds such as crocetin, crocin, picrocrocin, and safrana, which in various studies demonstrated positive effects on blood glucose levels, insulin resistance and sensitivity and blood fats, besides also having antioxidant and anti-inflammatory qualities. Yet, results were not always consistent, and hence this meta-analysis gathered evidence from 32 randomised controlled trials (RCTs) which included a total of 1674 subjects and investigated the effect of saffron supplements on cardiovascular risk factors such as blood fats, blood glucose control, blood pressure, anthropometric measures, and inflammatory markers. In conclusion, the analysis showed that saffron supplementation aided the reduction of some inflammatory markers (CRP, TNF-α), had favourable effects on antioxidant capacity, reduced blood fats except high-density lipoprotein (HDL), enhanced blood control and insulin sensitivity, reduced blood pressure and was linked to a reduction in waist circumference but with no significant effect on weight itself, BMI or fat mass. The authors discussed how their results relate to previous research and what underlying mechanisms can explain the effects or discrepancies. Given the positive results, saffron presents itself as a promising supplement and adjunct therapy for managing CVD and its risk factors.
Abstract
INTRODUCTION Cardiovascular disease (CVD) is one of the leading causes of death and disability in the world and is estimated to involve more people in the next years. It is said that alternative remedies such as herbs can be used to manage the complications of this disease. For this reason, we aimed to conduct this meta-analysis to systematically assess and summarize the effects of saffron supplementation as an important herb on cardiovascular risk factors in adults. METHODS A systematic search was done in PubMed, Scopus, and Web of Science to find eligible articles up to September 2022. Randomized controlled trials (RCTs) that evaluated the effects of saffron on lipid profiles, glycemic control, blood pressure, anthropometric measures, and inflammatory markers were included. In the meta-analysis, 32 studies were taken into account (n = 1674). RESULTS Consumption of saffron significantly decreased triglyceride (TG) (WMD = -8.81 mg/dl, 95%CI: -14.33, -3.28; P = 0.002), total cholesterol (TC) (WMD = -6.87 mg/dl, 95%CI: -11.19, -2.56; P = 0.002), low density lipoprotein (LDL) (WMD = -6.71 mg/dl, 95%CI: -10.51, -2.91; P = 0.001), (P = 0.660), fasting blood glucose (FBG) level (WMD = -7.59 mg/dl, 95%CI: -11.88, -3.30; P = 0.001), HbA1c (WMD = -0.18%, 95%CI: -0.21, -0.07; P < 0.001), homeostasis model assessment-insulin resistance (HOMA-IR) (WMD = -0.49, 95%CI: -0.89, -0.09; P = 0.016), systolic blood pressure (SBP) (WMD = -3.42 mmHg, 95%CI: -5.80, -1.04; P = 0.005), tumor necrosis factor α (TNF-α) (WMD = -2.54 pg/ml, 95%CI: -4.43, -0.65; P = 0.008), waist circumference (WC) (WMD = -1.50 cm; 95%CI: -2.83, -0.18; P = 0.026), malondialdehyde (MDA) (WMD = -1.50 uM/L, 95%CI: -2.42, -0.57; P = 0.001), and alanine transferase (ALT) (WMD = -2.16 U/L, 95%CI: -4.10, -0.23; P = 0.028). Also, we observed that saffron had an increasing effect on total antioxidant capacity (TAC) (WMD = 0.07 mM/L, 95%CI: 0.01, 0.13; P = 0.032). There was linear regression between FBG and the duration of saffron intake. Additionally, the non-linear dose-response analysis has shown a significant association of saffron intervention with HDL (P = 0.049), HOMA-IR (P = 0.002), weight (P = 0.036), ALP (P = 0.016), FBG (P = 0.011), HbA1c (P = 0.002), and TNF-α (P = 0.042). A non-linear association between the length of the intervention and the level of HDL and DBP was also found. DISCUSSION That seems saffron could effectively improve TG, TC, LDL, FBG, HbA1c, HOMA-IR, SBP, CRP, TNF-α, WC, MDA, TAC, and ALT.
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Effects of the Treatment with Flavonoids on Metabolic Syndrome Components in Humans: A Systematic Review Focusing on Mechanisms of Action.
Gouveia, HJCB, Urquiza-Martínez, MV, Manhães-de-Castro, R, Costa-de-Santana, BJR, Villarreal, JP, Mercado-Camargo, R, Torner, L, de Souza Aquino, J, Toscano, AE, Guzmán-Quevedo, O
International journal of molecular sciences. 2022;23(15)
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Metabolic syndrome is a condition characterised by at least three of the five risk factors, such as abdominal obesity, elevated fasting glucose, blood pressure and triglycerides and reduced high-density lipoprotein cholesterol (HDL-c). There is a strong link between metabolic syndrome and the development of cardiovascular disease and Type 2 diabetes. Research suggests that increasing consumption of flavonoid-rich foods can be beneficial in reducing cardiovascular morbidity and mortality. Flavonoids are bioactive compounds that possess antioxidative, anti-inflammatory, anti-cancerous, anti-mutagenic, and enzymatic properties. This systematic review of 29 randomised controlled trials evaluated the beneficial effects of long-term flavonoid supplementation in reducing the risk factors of metabolic syndrome. This review included a variety of flavonoid supplements, such as anthocyanin, hesperidin, quercetin, epigallocatechin gallate (egcg), genistein, theaflavin, catechin, and eriocitrin. Additionally, this research investigated the mechanisms behind the beneficial effects of flavonoid supplementation. Results showed that flavonoid supplementation for at least three weeks improved metabolic parameters and inflammatory markers, with hesperidin showing the greatest improvements in metabolic parameters. Healthcare professionals can use these findings to understand the potential benefits of long-term flavonoid supplementation in improving metabolic parameters. However, more robust studies are needed to determine the therapeutic dosages of different flavonoids.
Abstract
Diets high in bioactive compounds, such as polyphenols, have been used to mitigate metabolic syndrome (MetS). Polyphenols are a large group of naturally occurring bioactive compounds, classified into two main classes: non-flavonoids and flavonoids. Flavonoids are distributed in foods, such as fruits, vegetables, tea, red wine, and cocoa. Studies have already demonstrated the benefits of flavonoids on the cardiovascular and nervous systems, as well as cancer cells. The present review summarizes the results of clinical studies that evaluated the effects of flavonoids on the components of the MetS and associated complications when offered as supplements over the long term. The results show that flavonoids can significantly modulate several metabolic parameters, such as lipid profile, blood pressure, and blood glucose. Only theaflavin and catechin were unable to affect metabolic parameters. Moreover, only body weight and body mass index were unaltered. Thus, the evidence presented in this systematic review offers bases in support of a flavonoid supplementation, held for at least 3 weeks, as a strategy to improve several metabolic parameters and, consequently, reduce the risk of diseases associated with MetS. This fact becomes stronger due to the rare side effects reported with flavonoids.
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Effect of Vitamin D Supplementation on Inflammatory Biomarkers in School-Aged Children with Attention Deficit Hyperactivity Disorder.
Samadi, M, Gholami, F, Seyedi, M, Jalali, M, Effatpanah, M, Yekaninejad, MS, Abdolahi, M, Chamari, M, Mohammadzadeh Honarvar, N
International journal of clinical practice. 2022;2022:1256408
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Attention deficit hyperactivity disorder (ADHD) is one of the most prevalent psychiatric and developmental disorders among children and adolescents. Besides clinical impairments, these children have challenges with school performance and independent socioeconomic factors. The aim of this study was to assess the possible effects of vitamin D on inflammatory cytokines (tumour necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6)) levels in children with ADHD. This study is a randomised, double-blind, placebo-controlled clinical trial which was conducted on 86 children aged 6–12. Patients were randomly assigned to two groups to receive vitamin D3 or a placebo. Results show children with ADHD taking vitamin D supplementation for 3 months demonstrated a significant increase in serum levels of Vitamin D3. However, serum levels of IL-6 and TNF-α were not significantly influenced by vitamin D administration. Authors conclude that their findings failed to find a favourable effect of 3 months of supplementation with vitamin D on inflammatory cytokines. Thus, they highly recommend conducting further studies with different doses of vitamin D and various designs in addition to differences in the characteristics of participants.
Abstract
METHOD This randomized double-blind, placebo-controlled trial was conducted on 75 school-aged children with a diagnosis of ADHD based on DSM-V criteria. Children were randomly allocated to receive either vitamin D3 (2000 IU/day) or a placebo for 3 months. Serum IL-6, TNF-α, and 25(OH) D were assessed before and after the intervention to determine the effects of vitamin D on the highlighted parameters. RESULTS Serum levels of 25(OH) D increased significantly in the vitamin D group (P=0.01). However, no significant differences in serum IL-6 and TNF-α were found between both groups at the baseline and at the end of the intervention. CONCLUSION The findings revealed that vitamin D supplementation for 3 months is not efficacious in reducing inflammatory cytokines in children with ADHD. Further studies are required to confirm these results.
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The Effects of Dairy Product and Dairy Protein Intake on Inflammation: A Systematic Review of the Literature.
Nieman, KM, Anderson, BD, Cifelli, CJ
Journal of the American College of Nutrition. 2021;40(6):571-582
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Plain language summary
Systemic inflammation contributes to the risk and progression of chronic disease, which is in turn influenced by several factors including diet. The aim of this study was to conduct a systematic review to evaluate the effect of dairy products and dairy protein on markers of inflammation in adults that do not have inflammatory-related disorders. The authors analysed 27 previous randomised controlled trial, of which 19 looked at dairy products, and eight looked at dairy protein (casein or whey). In the trials which evaluated dairy products, 10 reported no effect of the intervention, while eight reported a reduction in at least one biomarker of inflammation. All eight trials that investigated dairy protein intake on markers of inflammation reported no effect. The researchers concluded that the available literature suggests that dairy products and dairy proteins have neutral to beneficial effects on biomarkers of inflammation. Additional clinical studies designed using inflammatory biomarkers as the primary outcome are needed to fully understand the effects of dairy intake on inflammation.
Abstract
Systemic inflammation is associated with obesity and chronic disease risk. Intake of dairy foods is associated with reduced risk of type 2 diabetes and cardiovascular disease; however, the impact of dairy foods on inflammation is not well-established. The objective of this study was to conduct a systematic review to evaluate the effect of dairy product (milk, cheese, and yogurt) and dairy protein consumption on low-grade systemic inflammation in adults without severe inflammatory disorders. A literature search was completed in September 2019 using PubMed and CENTRAL as well as inspection of reference lists from relevant review articles. The search resulted in the identification of 27 randomized controlled trials which were included in this analysis. In the 19 trials which evaluated dairy products, 10 reported no effect of the intervention, while 8 reported a reduction in at least one biomarker of inflammation. All 8 trials that investigated dairy protein intake on markers of inflammation reported no effect of the intervention. The available literature suggests that dairy products and dairy proteins have neutral to beneficial effects on biomarkers of inflammation. Additional clinical studies designed using inflammatory biomarkers as the primary outcome are needed to fully elucidate the effects of dairy intake on inflammation.
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Effects of Fermented Milk Containing Lacticaseibacillus paracasei Strain Shirota on Constipation in Patients with Depression: A Randomized, Double-Blind, Placebo-Controlled Trial.
Zhang, X, Chen, S, Zhang, M, Ren, F, Ren, Y, Li, Y, Liu, N, Zhang, Y, Zhang, Q, Wang, R
Nutrients. 2021;13(7)
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Plain language summary
Constipation is a common complaint among people with depression and may negatively affect their quality of life. In association with this, previous studies have shown a correlation between the reduction of Lactobacillus or Bifidobacterium strains in the gut of patients with major depressive disorder. Thus, this two-arm, parallel-design, randomised, double-blinded, placebo-controlled trial examined the effects of supplementing fermented milk with Lacticaseibacillus paracasei Strain Shirota or LcS (previously known as Lactobacillus casei strain Shirota) on constipation in people with depression. Symptoms of constipation, stool problems, and depressive symptoms improved after 9 weeks of consuming fermented milk containing LcS. The abundance of Adlercreutzia, Megasphaera, and Veillonella increased significantly in the intervention group. In contrast, the abundance of bacteria related to mental disorders such as Rikenellaceae_RC9_gut_group, Sutterella and Oscillibacter significantly decreased after the intervention. After 9 weeks of intervention with LcS, a significant reduction in serum proinflammatory cytokines such as IL-1β, IL-6, and TNF-α was observed in patients with depression. The intervention group also showed a decrease in inflammation-causing bacteria, Surrerella, which correlated with a reduction in proinflammatory cytokines. The mechanisms driving the changes in gut microbial composition, depression, and gastrointestinal symptoms after LcS intervention need to be evaluated in more robust studies. Healthcare professionals can use the results of the study to better understand how probiotics can reduce constipation and depression and improve gut microbial composition.
Abstract
Probiotics have been shown to benefit patients with constipation and depression, but whether they specifically alleviate constipation in patients with depression remains unclear. The aim of this study was to investigate the effect of Lacticaseibacillus paracasei strain Shirota (LcS), formerly Lactobacillus casei strain Shirota, on constipation in patients with depression with specific etiology and gut microbiota and on depressive regimens. Eighty-two patients with constipation were recruited. The subjects consumed 100 mL of a LcS beverage (108 CFU/mL) or placebo every day for 9 weeks. After ingesting beverages for this period, we observed no significant differences in the total patient constipation-symptom (PAC-SYM) scores in the LcS group when compared with the placebo group. However, symptoms/scores in item 7 (rectal tearing or bleeding after a bowel movement) and items 8-12 (stool symptom subscale) were more alleviated in the LcS group than in the placebo group. The Beck Depression Index (BDI) and Hamilton Depression Rating Scale (HAMD) scores were all significantly decreased, and the degree of depression was significantly improved in both the placebo and LcS groups (p < 0.05), but there was no significant difference between the groups. The LcS intervention increased the beneficial Adlercreutzia, Megasphaera and Veillonella levels and decreased the bacterial levels related to mental illness, such as Rikenellaceae_RC9_gut_group, Sutterella and Oscillibacter. Additionally, the interleukin (IL)-1β, IL-6, and tumor necrosis factor-α (TNF-α) levels were significantly decreased in both the placebo and LcS groups (p < 0.05). In particular, the IL-6 levels were significantly lower in the LcS group than the placebo group after the ingestion period (p < 0.05). In conclusion, the daily consumption of LcS for 9 weeks appeared to relieve constipation and improve the potentially depressive symptoms in patients with depression and significantly decrease the IL-6 levels. In addition, the LcS supplementation also appeared to regulate the intestinal microbiota related to mental illness.