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Effect of supplementation with Chlorella vulgaris on lipid profile in adults: A systematic review and dose-response meta-analysis of randomized controlled trials.
Sherafati, N, Bideshki, MV, Behzadi, M, Mobarak, S, Asadi, M, Sadeghi, O
Complementary therapies in medicine. 2022;66:102822
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Dyslipidaemia is a chronic metabolic disorder that is characterized by increased levels of triglyceride (TG), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), and reduced levels of high-density lipoprotein cholesterol (HDL-C). Patients with dyslipidaemia have an increased risk of coronary heart disease, stroke, non-alcoholic fatty liver disease, diabetes and even mortality. The aim of this study was to investigate the effect of Chlorella vulgaris supplementation on lipid profile in adults. This study is a systematic review and meta-analysis of ten randomised controlled trial studies. The studies included a total of 539 individuals (n= 264 in the Chlorella vulgaris group and n= 275 in the control group). Results show that Chlorella vulgaris supplementation resulted in a significant reduction in TC and LDL-C levels, while it had no significant effect on TG and HDL-C levels either in the overall analysis or in the subgroup analysis. Furthermore, the reducing effect of Chlorella vulgaris supplementation on LDL-C levels was significant between zero and 1500 mg/d and it was not significant at higher dosages. Authors conclude that future studies should examine the effect of Chlorella vulgaris supplementation on other biochemical parameters such as glycaemic measures and inflammatory biomarkers.
Abstract
OBJECTIVE To summarize available findings on the effect of Chlorella vulgaris supplementation on lipid profile in adults. DESIGN Systematic review and meta-analysis of randomized controlled trials (RCTs). SETTING This study followed 2020 PRISMA guideline. We performed a systematic search in the online databases to identify relevant articles and then, extracted required data from each paper for the meta-analysis. Random-effects models were used to obtain overall mean difference (MD) comparing Chlorella vulgaris supplementation with a control group. MAIN OUTCOME MEASURES Blood lipids including triglyceride (TG), total cholesterol (TC), LDL-C, and HDL-C. RESULTS In total, 10 RCTs with a total sample size of 539 adults (264 in the Chlorella vulgaris group and 275 in the control group) were included. Of the 10 RCTs, four had a low risk of bias for all aspects of the Cochrane risk of bias tool. Also, only two studies determined the chlorella content, purity, potency, and contamination of the supplements used in the intervention. Combining results from these studies showed a summary MD of -2.11 mg/dL (95% CI: -7.28 to 3.06) for TG, -7.47 mg/dL (95% CI: -12.98 to -1.96) for TC, -7.71 mg/dL (95% CI: -14.05 to -1.37) for LDL-C, and -0.45 mg/dL (95% CI: -0.67 to 1.57) for HDL-C, indicating a beneficial effect of Chlorella vulgaris supplementation on TC and LDL-C levels. Based on the dose-response analysis, the reducing effect of Chlorella vulgaris supplementation on LDL-C levels was seen at the dosages between zero and 1500 mg/d (P for non-linearity= 0.01), whereas in higher amounts, this effect was not significant. CONCLUSION We found that Chlorella vulgaris supplementation had a beneficial effect on TC and LDL-C levels with no significant effect on TG and HDL-C levels.
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Do B Vitamins Enhance the Effect of Omega-3 Polyunsaturated Fatty Acids on Cardiovascular Diseases? A Systematic Review of Clinical Trials.
Zhu, J, Xun, PC, Kolencik, M, Yang, KF, Fly, AD, Kahe, K
Nutrients. 2022;14(8)
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Dietary intake of B-vitamins or omega-3 polyunsaturated fatty acids (PUFAs) has been found to be inversely related to cardiovascular disease (CVD). The aim of this study was to examine whether the combined supplementation of B-vitamins and omega-3 PUFAs could provide additional beneficial effects on improving risk factors to prevent CVD beyond the effects of either of them alone. This study is a systematic review of fifteen studies. The sample sizes ranged from 12 to 2501 participants with study duration ranging from 4 weeks to 4.7 years. Results show that the combined supplementation with B-vitamins and omega-3 PUFAs may be promising and more effective at reducing plasma homocysteine, triglycerides and low-density lipoprotein cholesterol than each supplementation alone. Authors conclude that: - there is no solid evidence that the joint supplementation of B-vitamins and omega-3 PUFAs can offer a synergistic effect on preventing CVD and decreasing the relevant morbidity and/or mortality in susceptible populations. - dietetic strategies for preventing CVD need to focus more on the importance of considering effects at the whole food and dietary patterns level. - further well-designed high-quality trials that will use the combined supplementation of B vitamins and omega-3 PUFAs or dietary patterns rich in these two types of nutrients are required.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Combined vitamin B and n3 PUFA supplementation might have favourable health effects
- Combined vitamin B and n3 PUFA supplementation could help in the primary and secondary prevention of cardiovascular disease
- The suggested favourable dose ranges are vitamin B6: 2.5–80 mg/day, vitamin B12: 20–1000 μg/day, folic acid: 150–10000 μg/day, and n3 PUFA 0.2–2) g/day.
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 paper reviews whether combined supplementation of vitamin B (B2, B6, B9, and B12) and omega-3 polyunsaturated fatty acids (n3 PUFA) outweighs the individual cardiovascular benefits of each supplement. Registered in PROSPERO under CRD42018085993
- A total of 15 clinical studies including 8,263 individuals published from December 2021, that investigated the combined effects of the supplements met inclusion criteria and were included in the review
- Although the results indicate the beneficial effects of combined supplementation in primary and secondary cardiovascular prevention, firm conclusions cannot be drawn from the existing data, and more studies are needed in this area.
Clinical practice applications:
In comparison with a single supplement alone, the combined administration of vitamin B and n3 PUFA might have:
- Hypolipidemic effects, by reducing triglycerides and LDL-cholesterol. Some of the studies indicate a lowering of LDL-c up to 13% and triglycerides up to 24%
- Anti-inflammatory effects, by reducing homocysteine. Based on some of the studies, the lowering effects might go up to 39%.
Dietary practice might benefit from the following:
- The authors highlighted food-based and healthy dietary pattern-based strategies should include food sources rich in these nutrients such as fish, vegetables, fruit, legumes, nuts, and eggs
- The authors conclude that intake of whole foods and whole diets rich in desirable foods (such as MedDiet) should be encouraged
- The supplementation dose ranges in the studies covered by the review were the following: vitamin B6: 2.5–80 mg/day, vitamin B12: 20–1000 μg/day, folic acid: 150–10000 μg/day and n3 PUFA 0.2–2) g/day
- Limitations of the systematic review include different supplementation regimens, variability of study designs in terms of duration of the intervention, existence of placebo group, dosages and the inability to monitor study subjects’ habitual diet.
Considerations for future research:
- Future studies should be designed regarding the need for a uniform methodological approach in testing the combined effects of vitamin B complex and n3 PUFA supplements
- The studies should investigate supplementation strategies and dietary patterns rich in both nutrients.
Abstract
Studies have suggested that B vitamins or omega-3 polyunsaturated fatty acids (PUFAs) may deter the development of cardiovascular disease (CVD). This systematic review aims to examine whether the combined supplementation of both B vitamins and omega-3 PUFAs could provide additional beneficial effects to prevent CVD beyond the effect of each supplement based on clinical trials published up to December 2021. The overall findings are inconsistent and inconclusive, yet the combined supplementation of these two nutrients may be more effective at reducing plasma homocysteine, triglyceride, and low-density lipoprotein-cholesterol than the individual components. The underlying mechanisms mainly include alleviating endothelial dysfunction, inhibiting atherosclerosis and lesion initiation, reducing oxidative stress, suppressing activation of pro-inflammatory cytokines, regulating endothelial nitric oxide synthase, and interfering with methylation of genes that promote atherogenesis. Although biologically plausible, the existing literature is insufficient to draw any firm conclusion regarding whether B vitamins can further enhance the potential beneficial effects of omega-3 PUFA intake on either primary or secondary prevention of CVD. The inconsistent findings may be largely explained by the methodological challenges. Therefore, well-designed high-quality trials that will use the combined supplementation of B vitamins and omega-3 PUFAs or dietary patterns rich in these two types of nutrients are warranted.
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Low-carbohydrate diets and men's cortisol and testosterone: Systematic review and meta-analysis.
Whittaker, J, Harris, M
Nutrition and health. 2022;28(4):543-554
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Testosterone is the primary male sex hormone, and vital for reproductive development and function. Moreover, low endogenous testosterone is associated with an increased risk of chronic disease, including type 2 diabetes and cardiovascular disease. The aim of this study was to investigate the effects of low- versus high-carbohydrate diets on mens' testosterone and cortisol. This study is a systematic review and meta-analysis of twenty-seven studies with a total of 309 participants. Twelve of these studies were randomised trials whilst the rest were non-randomised. Results show an increase in resting and post-exercise cortisol on short-term low-carbohydrate diets (<3 weeks). In fact, resting cortisol levels return to baseline after <3 weeks on a LC diet, whilst post-exercise cortisol remains elevated. Furthermore, high-protein diets cause a large decrease in resting total testosterone. Authors conclude that further research is required in order to warrant their findings.
Expert Review
Conflicts of interest:
None
Take Home Message:
- Short-term LC-diets diets cause a moderate increase in resting and post-exercise cortisol however this effect is not seen in LC-diets followed for great than 3 weeks
- HP-LC diets caused a statistically significant decrease in resting TT, suggesting caution in relation to endocrine effects of LC diets
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 systematic review and network meta-analysis was conducted on the effects of low-carbohydrate (LC) versus high-carbohydrate (HC) diets on men’s testosterone and cortisol.
The review was registered with PROSPERO and reported using PRISMA 2020 checklists.
Methods:
A comprehensive search strategy was used to find intervention studies looking at healthy adult males and LC diets of <35% carbohydrate. Studies were assessed for quality using the Cochrane Risk of Bias tool. Sub-group analyses was conducted for diet duration, protein intake and exercise duration.
Results:
The literature search resulted in 27 studies with a total of 309 healthy adult male participants, age: 27.3 ± 4.7 (to minimise variation in steroid hormone metabolism), body mass: 78.6± 7.1kg and BMI: 24.8 ±1.6. 12 randomised and 15 non-randomised controlled trials were analysed. 21 studies were considered low risk bias, 5 medium and 1 high risk.
- Short-term (<3 weeks) LC diets moderately increased resting cortisol (0.41 [0.16, 0.66], p < 0.01) when compared to HC diets.
- Long-term (≥3 weeks) LC diets had no consistent effect on resting cortisol
- LC diets resulted in higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], p < 0.01), 1 h (0.81 [0.31, 1.31], p < 0.01), and 2 h (0.82 [0.33, 1.3], p < 0.01).
- The overall results for resting total testosterone (TT) showed a significant decrease on LC versus HC diets (SMD = −0.48, p = 0.01. However, subgroup analyses revealed this effect to be limited to high-protein (HP) LC diets, which yielded a very large decrease in TT (SMD = −1.08, p < 0.01; ∼5.23 nmol/L), albeit in a small sample (n = 26).
- Moderate protein (MP) (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (−1.08 [−1.67, −0.48], p < 0.01) and post-exercise total testosterone (−1.01 [−2, −0.01] p = 0.05).
- There was no overall effect of LC versus HC diets on 0 h post-exercise TT (SMD = −0.03, p = 0.95). However, subgroup analysis showed 0 h post-exercise was non-significantly higher on long-term LC versus HC diets (SMD = 0.44, p = 0.18), and much lower on short-term LC versus HC diets (SMD = −1.01, p = 0.05)
Conclusion:
This systematic review and metanalysis found an increase in resting and post-exercise cortisol on short-term LC diets. Cortisol does return to baseline in the first 3 weeks of a low-carbohydrate (LC) diet. The same response is, however, not seen in post-exercise cortisol, which remains elevated. In addition, the review showed that compared to moderate-protein diets, HP diets were found to cause a large decrease in resting and post-exercise TT (∼5.23 nmol/L).
Clinical practice applications:
The results of this review suggest that exercising whilst following a LC diet can increase cortisol in the short term, but not long-term. This suggests a period of diet adaptation. The effects of long-term LC diets on cardiovascular disease risk is uncertain and healthcare practitioners should monitor client responses and keep up-to-date with new research in this area
Since HP-LC diets were found to significantly decrease resting testosterone it highlights the need to ensure that protein intake does not exceed the urea cycle’s capacity due to potential adverse endocrine effects.
For clients where there is a desire to increase strength, power and hypertrophy, a MP-LC diet could be of benefit, as it showed potential to signal an increased anabolic state post exercise..
NB: Since the review only included a low number of studies and saw within these some heterogeneity that could not be explained, more research is needed before the paper’s findings can be conclusive. The above potential practice applications should therefore be seen as something to be mindful of when working with clients where cortisol and testosterone levels are relevant to their protocol.
Considerations for future research:
Future research should consider:
- Since LC diets have been shown to have a positive effect on health – decreased triglycerides, increased high density lipoprotein cholesterol and weight loss - future studies would benefit from including these markers so any positive and negative impacts can be monitored directly.
- Despite extensive analysis including sensitivity analysis to reduce bias and heterogeneity of the results, the paper highlights a need for further research to ensure consistency in key parameters e.g., exercise duration and intensity, carbohydrate supplements inclusion and period of dietary intervention. Since it was identified that HP-LP diets impact post exercise and resting TT, follow up studies would benefit from consistency in participants diets. This would help to reduce any potential confounding results.
Abstract
Background: Low-carbohydrate diets may have endocrine effects, although individual studies are conflicting. Therefore, a review was conducted on the effects of low- versus high-carbohydrate diets on men's testosterone and cortisol. Methods: The review was registered on PROSPERO (CRD42021255957). The inclusion criteria were: intervention study, healthy adult males, and low-carbohydrate diet: ≤35% carbohydrate. Eight databases were searched from conception to May 2021. Cochrane's risk of bias tool was used for quality assessment. Random-effects, meta-analyses using standardized mean differences and 95% confidence intervals, were performed with Review Manager. Subgroup analyses were conducted for diet duration, protein intake, and exercise duration. Results: Twenty-seven studies were included, with a total of 309 participants. Short-term (<3 weeks), low- versus high-carbohydrate diets moderately increased resting cortisol (0.41 [0.16, 0.66], p < 0.01). Whereas, long-term (≥3 weeks), low-carbohydrate diets had no consistent effect on resting cortisol. Low- versus high-carbohydrate diets resulted in much higher post-exercise cortisol, after long-duration exercise (≥20 min): 0 h (0.78 [0.47, 1.1], p < 0.01), 1 h (0.81 [0.31, 1.31], p < 0.01), and 2 h (0.82 [0.33, 1.3], p < 0.01). Moderate-protein (<35%), low-carbohydrate diets had no consistent effect on resting total testosterone, however high-protein (≥35%), low-carbohydrate diets greatly decreased resting (-1.08 [-1.67, -0.48], p < 0.01) and post-exercise total testosterone (-1.01 [-2, -0.01] p = 0.05). Conclusions: Resting and post-exercise cortisol increase during the first 3 weeks of a low-carbohydrate diet. Afterwards, resting cortisol appears to return to baseline, whilst post-exercise cortisol remains elevated. High-protein diets cause a large decrease in resting total testosterone (∼5.23 nmol/L).
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Cinnamon as a Complementary Therapeutic Approach for Dysglycemia and Dyslipidemia Control in Type 2 Diabetes Mellitus and Its Molecular Mechanism of Action: A Review.
Silva, ML, Bernardo, MA, Singh, J, de Mesquita, MF
Nutrients. 2022;14(13)
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Diabetes is a metabolic disorder resulting from defects in insulin secretion and/or action, leading to chronic hyperglycaemia, which has an adverse impact on health. The aim of this study was to provide an overview of the beneficial effects of cinnamon in exerting dysglycemia and dyslipidaemia control in type 2 diabetic patients and a summary of its mechanisms of action. This study is a narrative review of twenty-three articles. Results showed that: - in diabetic patients with dyslipidaemia, the lipid profile could be modulated with cinnamon supplementation as it seems to decrease serum triglycerides, total cholesterol and low-density lipoprotein levels. - cinnamon seems to exert beneficial and protective anti-inflammatory and antioxidant effects. - cinnamon seems to be effective as an antihyperlipidemic agent – through the regulation of lipid metabolism in enterocyte [a cell of the intestinal lining]. Authors conclude that targeted cinnamon-based therapy can provide an opportunity to modulate glucose and lipid dysregulation to avoid the progression of T2DM. Thus, future research studies should investigate the effect of cinnamon by employing a larger number of standardized randomized clinical trials to provide a comprehensive impact of cinnamon on diabetic patients.
Abstract
The scientific evidence that cinnamon may exert beneficial effects on type 2 diabetes mellitus due to the biological activity of its bioactive compounds has been increasing in recent years. This review provides an overview of the effects of cinnamon on clinical parameters of diabetes and summarizes the molecular mechanisms of action of cinnamon on glucose and lipid metabolism. Search criteria include an electronic search using PubMed, Medline, and Cochrane Library databases. English literature references from 2000 up to 2022 were included. Following title and abstract review, full articles that met the inclusion criteria were included. The results from the available evidence revealed that cinnamon improved glycemic and lipidemic indicators. Clinical trials clarified that cinnamon also possesses an anti-inflammatory effect, which may act beneficially in diabetes. Based on in vitro and in vivo studies, cinnamon seems to elicit the regulation of glucose metabolism in tissues by insulin-mimetic effect and enzyme activity improvement. Furthermore, cinnamon seems to decrease cholesterol and fatty acid absorption in the gut. The current literature search showed a considerable number of studies on diabetic subjects. Some limitations in comparing published data should be highlighted, including variability in doses, extracts and species of cinnamon, administration forms, and antidiabetic therapy.
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Menopause-Associated Lipid Metabolic Disorders and Foods Beneficial for Postmenopausal Women.
Ko, SH, Kim, HS
Nutrients. 2020;12(1)
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Menopause is the absence of menstruation due to the loss of ovarian activity with ageing. During this transition period, changes in hormones, primarily the decline in the oestrogen estradiol, give rise to altered lipid metabolism. An unfavourable lipid profile presents a risk for metabolic disorders, such as cardiovascular diseases and type 2 diabetes. Post-menopausal changes also lead to shifts in body fat and fat distribution, resulting in an increased tendency for central fat accumulation and obesity. Obesity is associated with insulin resistance. This susceptibility for weight accumulation is possibly also driven by the age-associated decline in skeletal muscle, which reduces metabolic energy expenditure. This review summarizes the physiology of menopause and postmenopause and the consequential impact on lipid metabolism. In addition, there is a discussion of dietary recommendations, nutritional and plant-derived compounds that could support the management of menopause associated changes in lipid levels, metabolic risk factors and obesity. The recommendations discussed include traditional healthy diets and low-calorie diets, with attention drawn to adequate protein intake. Furthermore, the role of probiotics, nutritional and plant-sourced constituents are considered, including Vitamin D, Omega-3 fatty acids, antioxidants like Vitamin A, β-carotene, Vitamin C and E, genistein, resveratrol, flavonoids, indoles and capsaicin. The authors advocate sourcing these compounds from a varied whole-foods diet, which would minimize nutrient interactions and absorption issues that can occur with supplementation. This review may be of interest to those supporting the nutritional needs of menopausal and post-menopausal women, that are experiencing or are at risk of experiencing metabolic disorders.
Abstract
Menopause is clinically diagnosed as a condition when a woman has not menstruated for one year. During the menopausal transition period, there is an emergence of various lipid metabolic disorders due to hormonal changes, such as decreased levels of estrogens and increased levels of circulating androgens; these may lead to the development of metabolic syndromes including cardiovascular diseases and type 2 diabetes. Dysregulation of lipid metabolism affects the body fat mass, fat-free mass, fatty acid metabolism, and various aspects of energy metabolism, such as basal metabolic ratio, adiposity, and obesity. Moreover, menopause is also associated with alterations in the levels of various lipids circulating in the blood, such as lipoproteins, apolipoproteins, low-density lipoproteins (LDLs), high-density lipoproteins (HDL) and triacylglycerol (TG). Alterations in lipid metabolism and excessive adipose tissue play a key role in the synthesis of excess fatty acids, adipocytokines, proinflammatory cytokines, and reactive oxygen species, which cause lipid peroxidation and result in the development of insulin resistance, abdominal adiposity, and dyslipidemia. This review discusses dietary recommendations and beneficial compounds, such as vitamin D, omega-3 fatty acids, antioxidants, phytochemicals-and their food sources-to aid the management of abnormal lipid metabolism in postmenopausal women.
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Metabolic Syndrome Features: Is There a Modulation Role by Mineral Water Consumption? A Review.
Costa-Vieira, D, Monteiro, R, Martins, MJ
Nutrients. 2019;11(5)
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Metabolic syndrome, defined as having high blood pressure, triglycerides, blood glucose and being obese, is becoming an increasing worldwide health problem. It’s considered to be a result of modern-day life styles and there is no effective cure other than diet and life style interventions. This review paper looks at the mineral content and the alkalising effects of mineral water when consumed by participants with metabolic syndrome. The minerals within mineral water are thought to be more readily absorbed in the body than when consumed in foods and since Westernised diets are low in mineral content and high in acidity, consuming mineral water could help counteract mineral deficiencies and help to balance pH in those with metabolic syndrome. 20 studies, both animal and human, were selected for evaluation of the effect of mineral water on blood pressure, lipid profile, blood glucose and waist circumference. The authors conclude that mineral water is indeed beneficial to those with metabolic syndrome and can help counteract mineral deficiencies and balance pH. However, it is unclear whether mineral water in high quantities would be detrimental to a person with adequate mineral status and a pH within optimal range. Further studies are needed.
Abstract
Metabolic syndrome (MetSyn) promotes, among others, the development of atherosclerotic cardiovascular disease and diabetes. Its prevalence increases with age, highlighting the relevance of promoting precocious MetSyn primary prevention and treatment with easy-to-implement lifestyle interventions. MetSyn features modulation through mineral water consumption was reviewed on Pubmed, Scopus and Google Scholar databases, using the following keywords: metabolic syndrome, hypertension, blood pressure (BP), cholesterol, triglycerides, apolipoprotein, chylomicron, very low-density lipoprotein, low-density lipoprotein, high-density lipoprotein (HDL), glucose, insulin, body weight, body mass index, waist circumference (WC), obesity and mineral(-rich) water. Twenty studies were selected: 12 evaluated BP, 13 assessed total-triglycerides and/or HDL-cholesterol, 10 analysed glucose and/or 3 measured WC. Mineral waters were tested in diverse protocols regarding type and composition of water, amount consumed, diet and type and duration of the study. Human and animal studies were performed in populations with different sizes and characteristics. Distinct sets of five studies showed beneficial effects upon BP, total-triglycerides, HDL-cholesterol and glucose. WC modulation was not reported. Minerals/elements and active ions/molecules present in mineral waters (and their pH) are crucial to counterbalance their inadequate intake and body status as well as metabolic dysfunction and increased diet-induced acid-load observed in MetSyn. Study characteristics and molecular/physiologic mechanisms that could explain the different effects observed are discussed. Further studies are warranted for determining the mechanisms involved in the putative protective action of mineral water consumption against MetSyn features.
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Dietary carbohydrates: role of quality and quantity in chronic disease.
Ludwig, DS, Hu, FB, Tappy, L, Brand-Miller, J
BMJ (Clinical research ed.). 2018;361:k2340
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Human populations have thrived on diets with widely varying carbohydrate content. Dietary carbohydrates comprise compounds that can be digested or metabolically transformed directly into glucose, or that undergo oxidation into pyruvate, including some sugar alcohols. This study is a review that examines the links between different types of carbohydrates and health, with special focus on obesity, diabetes, cardiovascular disease, cancer and early death. Evidence suggests that the type of carbohydrates may have a greater effect on health outcomes than total amount for the general population. A strong case can be made for consumption of high glycaemic load grains, potato products, and added sugars namely sugary drinks, being causally related to obesity, diabetes, cardiovascular disease, and some cancers. Whereas non-starchy vegetables, whole fruits, legumes, and whole kernel grains appear to protective. Authors conclude that the recent influx of rapidly digestible, high glycaemic index carbohydrates in developed nations has contributed to the epidemics of obesity and cardiometabolic disease.
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Adiponectin-leptin ratio: A promising index to estimate adipose tissue dysfunction. Relation with obesity-associated cardiometabolic risk.
Frühbeck, G, Catalán, V, Rodríguez, A, Gómez-Ambrosi, J
Adipocyte. 2018;7(1):57-62
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Obesity is medically defined as a condition of abnormal or excessive fat accumulation in adipose tissue, of sufficient extent to produce adverse health consequences. Presently, adipose tissue has emerged as an extremely active endocrine organ, based on its ability to secrete a plethora of biologically active adipokines [a class of cytokine mediators that are predominantly secreted by adipose cells] such as leptin and adiponectin. Furthermore, obesity is characterized by an increase in circulating leptin concentrations, in parallel to a decrease in blood levels of adiponectin. Thus, the adiponectin/leptin ratio has been suggested as a marker of adipose tissue dysfunction. A dysfunctional adipose tissue, evidenced by a lower adiponectin/ leptin ratio, is a clear contributor to the low-grade chronic inflammation associated with metabolic syndrome. Authors conclude that this ratio is highly and negatively correlated with markers of low-grade chronic inflammation emerging as a useful estimator of obesity- and metabolic syndrome- associated cardiometabolic risk.
Abstract
Obesity is currently the most extended metabolic disturbance worldwide favoring the development of cardiometabolic alterations such as type 2 diabetes, hypertension, and dyslipidemia. Obesity and the metabolic syndrome (MS) are characterized by an increase in circulating leptin concentrations, in parallel to a decrease in blood levels of adiponectin. Consequently, the adiponectin/leptin ratio has been suggested as a maker of adipose tissue dysfunction. This emerging biomarker correlates with insulin resistance better than adiponectin or leptin alone, or even HOMA and is decreased with increasing number of metabolic risk factors having been proposed as a predictive marker for the MS. Moreover, the adiponectin/leptin ratio is negatively correlated with markers of low-grade chronic inflammation. In this sense, an increase in this ratio has been related with reduced atherosclerosis risk as well as with a decreased risk of some types of cancer in epidemiological studies. In this commentary we propose new cutoffs to estimate obesity- and MS-associated cardiometabolic risk according to the adiponectin/leptin ratio and discuss different therapeutic strategies to increase this promising biomarker of metabolic risk.
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Paleolithic nutrition for metabolic syndrome: systematic review and meta-analysis.
Manheimer, EW, van Zuuren, EJ, Fedorowicz, Z, Pijl, H
The American journal of clinical nutrition. 2015;102(4):922-32
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Metabolic syndrome is a cluster of 5 risk factors, including waist circumference, blood pressure, and serum concentrations of glucose, triglycerides, and high-density lipoprotein (HDL) cholesterol in the fasting condition. These often occur in concert and predispose people to type 2 diabetes and cardiovascular disease. The aim of this study was to evaluate whether current evidence supports the idea that Paleolithic nutrition improves risk factors for chronic disease more than do other dietary interventions in people with one or more components of the metabolic syndrome. The study is a systematic review and meta-analysis of 4 randomized controlled trials that compared Paleolithic nutrition with any other dietary intervention in participants with one or more of the 5 components of the metabolic syndrome. Results indicate that Paleolithic nutrition resulted in greater short-term pooled improvements on each of the 5 components of metabolic syndrome than did currently recommended guideline-based control diets. However, the greater pooled improvements did not reach significance for 2 of the 5 components (i.e., HDL cholesterol and fasting blood sugar). Authors conclude that the available data warrant additional evaluations of the health benefits of Paleolithic nutrition.
Abstract
BACKGROUND Paleolithic nutrition, which has attracted substantial public attention lately because of its putative health benefits, differs radically from dietary patterns currently recommended in guidelines, particularly in terms of its recommendation to exclude grains, dairy, and nutritional products of industry. OBJECTIVE We evaluated whether a Paleolithic nutritional pattern improves risk factors for chronic disease more than do other dietary interventions. DESIGN We conducted a systematic review of randomized controlled trials (RCTs) that compared the Paleolithic nutritional pattern with any other dietary pattern in participants with one or more of the 5 components of metabolic syndrome. Two reviewers independently extracted study data and assessed risk of bias. Outcome data were extracted from the first measurement time point (≤6 mo). A random-effects model was used to estimate the average intervention effect. The quality of the evidence was rated with the use of the Grading of Recommendations Assessment, Development and Evaluation approach. RESULTS Four RCTs that involved 159 participants were included. The 4 control diets were based on distinct national nutrition guidelines but were broadly similar. Paleolithic nutrition resulted in greater short-term improvements than did the control diets (random-effects model) for waist circumference (mean difference: -2.38 cm; 95% CI: -4.73, -0.04 cm), triglycerides (-0.40 mmol/L; 95% CI: -0.76, -0.04 mmol/L), systolic blood pressure (-3.64 mm Hg; 95% CI: -7.36, 0.08 mm Hg), diastolic blood pressure (-2.48 mm Hg; 95% CI: -4.98, 0.02 mm Hg), HDL cholesterol (0.12 mmol/L; 95% CI: -0.03, 0.28 mmol/L), and fasting blood sugar (-0.16 mmol/L; 95% CI: -0.44, 0.11 mmol/L). The quality of the evidence for each of the 5 metabolic components was moderate. The home-delivery (n = 1) and dietary recommendation (n = 3) RCTs showed similar effects with the exception of greater improvements in triglycerides relative to the control with the home delivery. None of the RCTs evaluated an improvement in quality of life. CONCLUSIONS The Paleolithic diet resulted in greater short-term improvements in metabolic syndrome components than did guideline-based control diets. The available data warrant additional evaluations of the health benefits of Paleolithic nutrition. This systematic review was registered at PROSPERO (www.crd.york.ac.uk/PROSPERO) as CRD42014015119.