Nutrition and health

Objectives:
Is fish or omega-3 fatty acids consumption associated with a lower risk of venous thromboembolism (VTE)?

Study design:
This review article included 8 prospective cohort studies.
The follow-up duration ranged from 0.5 to 19 years.
The sample size ranged from 595 to 80,263.
The fish and omega-3 fatty acids consumption was assessed by food-frequency questionnaire (FFQ) in all studies.
The diagnosis of venous thromboembolism was obtained in registered medical record (imaging or autopsy) and food was considered as the source of omega-3 fatty acids in all included studies.
Begg's rank-correlation test showed no evidence of publication bias.

Results and conclusions:
The investigators found the overall multi-variable adjusted RR showed no significant relationship between fish consumption and the risk of venous thromboembolism [RR = 1.02, 95% CI = 0.93 to 1.11, p = 0.709, I2 = 33%, p = 0.176].
The sensitivity analysis showed only minimal changes in magnitude of the pooled RR when any study was excluded from the meta-analysis, suggesting that no individual study had excessive influence on these robust aggregate results.

The investigators found the overall multi-variable adjusted RR showed that omega-3 fatty acids consumption was associated with a lower risk of 11% for venous thromboembolism [RR = 0.89, 95% CI = 0.80 to 0.98, p = 0.024, I2 = 0%, p = 0.469].
The sensitivity analysis showed only minimal changes in magnitude of the pooled RR when any study was excluded from the meta-analysis, suggesting that no individual study had excessive influence on these robust aggregate results.

The investigators found the overall multi-variable adjusted RR showed that omega-3 fatty acids consumption was associated with a lower risk of 55% for recurrent venous thromboembolism [RR = 0.45, 95% CI = 0.25 to 0.81, p = 0.008, I2 = 26.4%, p = 0.244].
Significant because RR of 1 was not found in the 95% CI of 0.25 to 0.81. RR of 1 means no risk/association.

The investigators concluded omega-3 fatty acids consumption is associated with a lower risk of both venous thromboembolism and recurrent venous thromboembolism.

Original title:
Associations of Fish and Omega-3 Fatty Acids Consumption With the Risk of Venous Thromboembolism. A Meta-Analysis of Prospective Cohort Studies by Zhang Y, Ding J, [...],Li Y.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7793732/

Additional information of El Mondo:
Find more information/studies on omega-3 and fish consumption and cardiovascular diseases right here.

Venous thromboembolism (VTE) is a condition in which a blood clot forms most often in the deep veins of the leg, groin or arm (known as deep vein thrombosis, DVT) and travels in the circulation, lodging in the lungs (known as pulmonary embolism, PE).

Objectives:
Do melatonin supplements improve sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) in adults with various diseases?

Study design:
This review article included a total of 23 RCTs.

Results and conclusions:
The investigators found that melatonin supplements had significant effects on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) [WMD = -1.24, 95% CI = -1.77 to -0.71, p = 0.000, I2 = 80.7%, p = 0.000].

The investigators found subgroup analysis based on health status revealed melatonin supplements in subjects with respiratory diseases [WMD = -2.20, 95% CI = -2.97 to -1.44, p = 0.000], metabolic disorders [WMD = -2.74, 95% CI = -3.48 to -2.00, p = 0.000] and sleep disorders [WMD = -0.67, 95% CI = -0.98 to -0.37, p = 0.000] had significant effects on sleep quality.

The investigators concluded the treatment with exogenous melatonin (melatonin supplements) has positive effects on sleep quality as assessed by the Pittsburgh Sleep Quality Index (PSQI) in adults, particularly with respiratory diseases, metabolic disorders, primary sleep disorders; however, not with mental disorders, neurodegenerative diseases and other diseases.

Original title:
Effect of melatonin supplementation on sleep quality: a systematic review and meta-analysis of randomized controlled trials by Fatemeh G, Sajjad M, […], Khadijeh M.

Link:
https://pubmed.ncbi.nlm.nih.gov/33417003/

Additional information of El Mondo:
Find here more information/studies about RCTs/significant and chronic diseases.

Objectives:
Undernutrition is one of the most common problems among people living with Human Immunodeficiency Virus (HIV), contributing to premature death and the development of comorbidities within this population. In Sub-Saharan Africa (SSA), the impacts of these often inter-related conditions appear in a series of fragmented and inconclusive studies. Therefore, this review article has been conducted.

Does undernutrition increase the risk of mortality and morbidity among adults living with HIV in Sub-Saharan Africa (SSA)?

Study design:
This review article included 53 studies (cohort and cross-sectional studies) with a total of 367,680 adults living with HIV (76.2% females).
Publication year of the included studies ranged from 2006 to 2019.
The sample size of the included studies ranged from 71 in Kenya to 68,378 in Tanzania. Most were cohort studies (n = 47, 88.7%). About 63.8% of the included cohort studies had a follow-up period of less than 5 years for mortality and/or less than 2 years for morbidities.
NOS quality scores ranged from 5 to 9 for cohort studies and 8 to 10 for cross-sectional studies.
The mean quality score of the included studies was 7.34 [SD = 0.14].
There was no publication bias.

Results and conclusions:
The investigators found a meta-analysis of 23 cohort studies (involving 125,790 individuals) indicated that undernutrition significantly [AHR = 2.1, 95% CI = 1.8 to 2.4, I2 = 66.4%, p  0.001] increased the risk of mortality among adults living with HIV, while severely undernourished adults living with HIV were at higher risk of death [AHR = 2.3, 95% CI = 1.9 to 2.8) as compared to mildly undernourished adults living with HIV.

The investigators found, furthermore, the pooled estimates of 10 cohort studies (involving 104,387 adults living with HIV) revealed that undernutrition significantly increased the risk of developing tuberculosis [AHR = 2.1, 95% CI = 1.6 to 2.7, I2 = 75.2%, p  0.001] among adults living with HIV.

The investigators concluded that undernutrition has significant effects on mortality and morbidity among adults living with HIV. As the degree of undernutrition became more severe, mortality rate also increased. Therefore, these findings may be used to update the nutritional guidelines used for the management of people living with HIV (PLHIV), by different stakeholders, especially in limited-resource settings.

Original title:
Effects of undernutrition on mortality and morbidity among adults living with HIV in sub-Saharan Africa: a systematic review and meta-analysis by Alebel A, Demant D, […], Sibbritt D.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7780691/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition right here.

Objectives:
Although several epidemiological studies have investigated associations between poultry and fish consumption and pancreatic cancer (PC) risk, these findings have been inconsistent. Therefore, this review article has been conducted.

Do high dietary poultry or fish intakes increase risk of pancreatic cancer?

Study design:
This review article included 25 studies (cohort studies and case-control studies).

Results and conclusions:
The investigators found for the highest vs. lowest poultry intake category a significantly increased risk of 14% for pancreatic cancer [pooled RR = 1.14, 95% CI = 1.02 to 1.26] in cohort studies.
Significant because RR of 1 was not found in the 95% CI of 1.02 to 1.26. RR of 1 means no risk/association.

The investigators found there was no association between fish intake and pancreatic cancer risk [RR = 1.00, 95% CI = 0.93 to 1.07].
No association because RR of 1 was found in the 95% CI of 0.93 to 1.07. RR of 1 means no risk/association.

The investigators concluded that large amount of poultry intake increases pancreatic cancer risk, while fish intake is unlikely to be linked to pancreatic cancer risk. These findings require further investigation, particularly between poultry and pancreatic cancer.

Original title:
Poultry and Fish Intake and Pancreatic Cancer Risk: A Systematic Review and Meta-Analysis by Gao Y, Ma Y, […], Wang X.

Link:
https://pubmed.ncbi.nlm.nih.gov/33432844/

Additional information of El Mondo:
Find more information/studies on poultry and fish consumption and cancer right here.

Objectives:
Does dietary acrylamide intake increase risk of breast, endometrial and ovarian cancer?

Study design:
This review article included 14 prospective cohort studies.

Results and conclusions:
The investigators found no significant association between dietary acrylamide intake and the risk of breast [RR = 0.95, 95% CI = 0.90 to 1.01], endometrial [RR = 1.03, 95% CI = 0.89 to 1.19] and ovarian cancers [RR = 1.02, 95% CI = 0.84 to 1.24].
In addition, no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers in different subgroup analyses by smoking status, menopausal status, BMI status and different types of breast cancer.

The investigators concluded there is no significant association between dietary acrylamide intake and the risk of breast, endometrial and ovarian cancers.

Original title:
Dietary acrylamide intake and risk of women's cancers: a systematic review and meta-analysis of prospective cohort studies by Benisi-Kohansal S, Salari-Moghaddam A, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33413725/

Additional information of El Mondo:
Find more information/studies on breast cancer right here.

Acrylamide is a chemical that naturally forms in starchy food products during high-temperature cooking processes, such as frying, roasting and baking. Acrylamide in food forms from sugars and an amino acid that are naturally present in food.
 

Objectives:
There is an ongoing debate on the involvement of systemic copper (Cu) dysfunctions in Alzheimer's disease (AD) and clinical studies comparing Cu levels in serum, plasma and cerebrospinal fluid (CSF) of AD patients with those of healthy controls have delivered non-univocal and often conflicting results. Therefore, this review article has been conducted.

Does blood level of copper increase in Alzheimer’s disease?

Study design:
This review article included 26 studies including a pooled total of 761 AD subjects and 664 controls for serum Cu studies, 205 AD subjects and 167 controls for plasma Cu and of 116 AD subjects and 129 controls for CSF Cu.

Results and conclusions:
The investigators found Alzheimer's disease patients have higher levels of serum copper than healthy controls. Plasma data did not allow conclusions, due to their high heterogeneity, but the meta-analysis of the combined serum and plasma studies confirmed higher copper levels in Alzheimer's disease patients. 

The investigators found the analysis of CSF data revealed no difference between Alzheimer's disease patients and controls.

The investigators concluded Alzheimer's disease patients have higher levels of serum and plasma copper than healthy controls.

Original title:
Copper in Alzheimer's disease: a meta-analysis of serum, plasma, and cerebrospinal fluid studies by Bucossi S, Ventriglia M, […], Squitti R.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/21187586

Additional information of El Mondo:
Find more information/studies on copper and dementia right here.

Objectives:
The aim of this review article was to assess the relation between the level of habitual potassium intake and the incidence of cardiovascular disease (CVD).

Study design:
This review article included 15 cohort studies involving a total of 247510 male and female participants, 7,066 strokes, 3,058 coronary heart disease (CHD) events and 2,497 total CVD events.
The weighted average follow-up time was 12.2 years (range 5 to 19 years).
There was significant heterogeneity among studies in terms of sample size, duration of observation, number of events and difference in dietary potassium intake between the groups being compared. This heterogeneity led to a reduced statistical power in detecting a possible association between dietary potassium and coronary heart disease and cardiovascular disease.

There was no evidence of publication bias by the Egger test.

Potassium intake was assessed by 24-h dietary recall (n = 2), food frequency questionnaire (n = 6) or 24-h urinary excretion (n = 3).

Results and conclusions:
The investigators found in a pooled analysis, a dietary intake of 1.64g (42 mmol) potassium per day was significantly associated with a 21% lower risk of stroke [RR = 0.79, 95% CI = 0.68 to 0.90, p = 0.0007]. Significant means it can be said with a 95% confidence that a daily intake of 1.64g potassium really decreased the risk of having a stroke.

The investigators found a trend toward an inverse association between higher potassium intake (average weighted difference = 1.38g or 35.3 mmol/day) and risk of coronary heart disease [RR = 0.92, 95% CI = 0.81 to 1.04], which was not statistically significant [p = 0.18].
Not significant means it cannot be said with a 95% confidence that a daily intake of 1.38g potassium really decreased the risk of coronary heart disease with 8%. 

The investigators found a trend toward an inverse relationship between higher potassium intake (average weighted difference = 1.30g or 33.4 mmol/day) and cardiovascular disease risk [RR = 0.85, 95% CI = 0.62 to 1.16], which was not statistically significant [p = 0.31].

The investigators found a trend toward lower risk of CHD [RR = 0.93, 95% CI = 0.87 to 0.99, p = 0.03] and total CVD [RR = 0.74, 95% CI = 0.60 to 0.91, p = 0.0037] that attained statistical significance after the exclusion of a single cohort, based on sensitivity analysis.

The results of meta-regression analyses indicated that potassium intake difference, length of follow-up, quality score, recruitment year and population potassium intake at baseline were not significant sources of heterogeneity in the relationship of the potassium intake effect on the risk of CHD.

The results of meta-regression analyses indicated that the length of follow-up (coefficient: -0.064, 95% CI = -0.112 to -0.015, p = 0.01) and quality score (coefficient: -0.165, 95% CI = -0.287 to -0.043, p = 0.01) were significant sources of heterogeneity.

The investigators concluded that 1.64g dietary potassium per day decreases the risk of having a stroke and might also reduce the risk of coronary heart disease and total cardiovascular disease. This result applies to the general population, not only to specific subgroups at higher risk.
The favorable effects of dietary potassium were documented at least to some extent independently of other factors.
The results of this meta-analysis support recommendations for higher consumption of potassium-rich foods to prevent vascular diseases.

Original title:
Potassium Intake, Stroke, and Cardiovascular Disease : A Meta-Analysis of Prospective Studies by D'Elia L, Barba G, [...], Strazzullo P.

Link:
http://www.sciencedirect.com/science/article/pii/S0735109710049764

Additional information of El Mondo:
Find more information/studies on potassium right here.
The protective effect of potassium against the risk of stroke may conceivably relate to its blood pressure lowering effect.

Objectives:
There is no published systematic review and meta-analysis regarding the effect of olive oil consumption on cancer occurrence. Therefore, this review article has been conducted.

Does olive oil consumption reduce cancer risk?

Study design:
This review article included 19 case-control studies (13800 cancer patients and 23340 controls).

Random effects meta-analysis was applied in order to evaluate the research hypothesis.
Heterogeneity of the effect-size measures was observed in studies performed in the Mediterranean region (n = 15, p = 0.0002), whereas no heterogeneity was observed in non-Mediterranean studies (n = 4, p = 0.12).

Results and conclusions:
The investigators found when comparing with the lowest, the highest category of olive oil consumption was significantly associated with lower odds of having any type of cancer [log odds ratio = -0.41, 95% CI = -0.53 to -0.29, Cohran's Q = 47.52, p = 0.0002, I2 = 62%].

The investigators found both Mediterranean and non-Mediterranean people reported olive oil intake were less likely to have developed any type of cancer.

The investigators found olive oil consumption was significantly associated with lower odds of developing breast cancer [logOR = -0.4,  95% CI = -0.78 to -0.12] and a cancer of the digestive system [logOR = -0.36, 95% CI = -0.50 to -0.21] compared with the lowest intake.

The investigators concluded olive oil consumption probably reduces risk of any type of cancer, especially breast cancer and cancer of the digestive system. Probably, because this review article only included case-control studies and there was heterogeneity.
The reduced risk is similar to studies performed in Mediterranean as well as non-Mediterranean countries. However, it is still unclear whether olive oil's monounsaturated fatty acid content or its antioxidant components are responsible for its beneficial effects.

Original title:
Olive oil intake is inversely related to cancer prevalence: a systematic review and a meta-analysis of 13800 patients and 23340 controls in 19 observational studies by Psaltopoulou T, Kosti RI, […], Panagiotakos DB.

Link:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199852/

Additional information of El Mondo:
Find more studies on olive oil consumption and fat.