Nutrition and health

Objectives:
Several studies have been conducted on the relationship between tea intake and the risk of osteoporosis. The results from these studies are, however, inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does tea intake reduce risk of osteoporosis?

Study design:
This review article included 2 prospective cohort studies, 4 cross-sectional studies and 11 case-control studies with 107,819 cases (people with osteoporosis). In the present study, the main symptom of osteoporosis was hip fracture.
10 studies - case-control and cohort studies were all of high quality - were in relative high quality (over 6 stars) with an average NOS score of 7.23.

The heterogeneity in the present review article mainly came from Asia group, female group, prospective cohort study group and case-control study group.

There was no publication bias of the meta-analysis about tea consumption and osteoporosis.

Results and conclusions:
The investigators found for the highest versus the lowest categories of tea consumption a significantly reduced risk of 38% [total OR = 0.62, 95% CI = 0.46-0.83, I2  =  94%, p   0 .01] for osteoporosis. However, when reducing heterogeneity, the overall OR [95% CI = 0.57-0.74, I2 = 30%] was still significant.
Subgroup analysis showed that tea consumption significantly reduced the risk of osteoporosis in all examined subgroups.

The investigators found stratified by categories of osteoporosis, a significantly reduced risk of 26% [OR  =  0.74, 95% BI = 0.63-0.88] for hip fracture.

The investigators found among women a significantly reduced risk of 27% [OR  =  0.73, 95% CI = 0.54-0.99] for osteoporosis.

The investigators concluded that high tea consumption reduces risk of osteoporosis, particularly hip fracture and particularly among women. However, the exact mechanism of the relationship between tea consumption and osteoporosis still needs further research.

Original title:
Association between tea consumption and osteoporosis: A meta-analysis by Sun K, Wang L, [...], Li X.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5728912/

Additional information of El Mondo:
Find more information/studies on tea consumption and elderly right here.
 

Objectives:
Previous studies have shown that fish consumption and dietary intake of n-3 polyunsaturated fatty acids (n-3 PUFAs) are associated with hip fracture; however, findings were conflicting. Therefore, this review article (meta-analysis) has been conducted.

Do both dietary intake of fish and n-3 polyunsaturated fatty acids decrease hip fracture risk?

Study design:
This review article included 7 prospective cohort studies and 3 case-control studies with a total sample size of 29,2657 participants. The age of participants was 20 years or older.

Results and conclusions:
The investigators found combining 8 effect sizes from 4 prospective cohort studies and 2 case-control studies revealed a significant inverse association between fish consumption and risk of hip fracture [pooled effect size = 0.88, 95% CI = 0.79-0.98, p = 0.02].
Although this relationship became non-significant in prospective cohort studies, a significant inverse association was found in prospective cohort studies with sample size of 10,000 individuals or more and studies that considered body mass index as a covariate.

The investigators also found dietary intake of n-3 PUFAs significantly reduced risk of hip fracture with 12% [pooled effect size = 0.88, 95% CI = 0.80-0.98, p = 0.02].

The investigators concluded that both fish consumption and dietary intake of n-3 PUFAs have protective effects on bone health and decline the risk of hip fracture.

Original title:
Dietary intake of fish, n-3 polyunsaturated fatty acids and risk of hip fracture: A systematic review and meta-analysis on observational studies by Sadeghi O, Djafarian K, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29244536

Additional information of El Mondo:
Find more information/studies on fish consumption, n-3 PUFAs and elderly right here.

Fatty acids in fish are all n-3 PUFAs.
 

Objectives:
Randomised controlled trials comparing low- versus high-fat diets on cardiometabolic risk factors in people with overweight or obesity have shown inconsistent results, which may be due to the mixed metabolic status of people with excess adiposity. The role of dietary fat manipulation in modifying cardiometabolic indicators in people with overweight or obese without metabolic disturbance is unclear. Therefore, this review article (meta-analysis) has been conducted.

Does a low-fat diet modify cardiometabolic indicators in people who are overweight (BMI>25) or obese (BMI>30) without metabolic disturbance?

Study design:
This review article included 20 RCTs with 2,106 participants.

Results and conclusions:
The investigators found total cholesterol levels in people who are overweight or obese without metabolic disturbance were significantly lower following low-fat diet compared with high-fat diet [WMD = -7.05 mg/dL, 95% CI = -11.30 to -2.80, p = 0.001].  

The investigators found LDL-cholesterol levels (bad cholesterol) in people who are overweight or obese without metabolic disturbance were significantly lower following low-fat diet compared with high-fat diet [WMD = -4.41 mg/dL, 95% CI = -7.81 to -1.00, p = 0.011].  

The investigators found HDL-cholesterol levels (good cholesterol) in people who are overweight or obese without metabolic disturbance were significantly lower following low-fat diet compared with high-fat diet [WMD = -2.57 mg/dL, 95% CI = -3.85 to -1.28, p 0.001].  

The investigators found TAG levels (blood fat levels) in people who are overweight or obese without metabolic disturbance were significantly higher following low-fat diet compared with high-fat diet [WMD = -11.68 mg/dL, 95% CI = 5.90 to 17.45, p 0.001].  

The investigators concluded a low-fat diet reduces cholesterol and TAG levels in people with overweight or obesity without metabolic disturbances.

Original title:
Effects of low-fat compared with high-fat diet on cardiometabolic indicators in people with overweight and obesity without overt metabolic disturbance: a systematic review and meta-analysis of randomised controlled trials by Lu M, Wan Y, [...], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29212558

Additional information of El Mondo:
Find more information/studies on fat, cholesterol and overweight right here.

A triglyceride (TG, triacylglycerol, TAG or triacylglyceride) is an ester derived from glycerol and three fatty acids. Triglycerides are the main constituents of body fat in humans.

Those with overweight or obesity are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Objectives:
There is considerable evidence of the favourable role of more physical activity (PA) in fighting against dementia. However, the shape of the dose-response relationship is still unclear. Therefore, this review article (meta-analysis) has been conducted.

Does leisure time physical activity reduce risk of all-cause dementia (ACD), Alzheimer’s disease (AD) and vascular dementia (VD) in dose-response manner?

Study design:
This review article included 15 cohort studies with 37,436 participants for all-cause dementia, with 25,031 participants for Alzheimer’s disease and with 16,797 participants for vascular dementia.
During follow-up (3-31.6 years for all-cause dementia, 3.9-31.6 years for Alzheimer’s disease and 4-11.9 years for vascular dementia), at least 2,665, 1,337 and 343 participants who were not suffering from dementia at baseline (=at the beginning of the study) were diagnosed with all-cause dementia, Alzheimer’s disease and vascular dementia, respectively.

There was no publication bias.

Results and conclusions:
The investigators found in the dose-response analysis, either all-cause dementia [p trend 0.005 and p non-linearity = 0.87] or Alzheimer’s disease [p trend 0.005 and p non-linearity = 0.10] exhibited a linear relationship with leisure time physical activity over the observed range (0-2000 kcal/week or 0-45 metabolic equivalent of task hours per week (MET-h/week)).

The investigators found for every 500 kcal or 10 MET-h increase per week, a significantly 10% [95% CI = 0.85-0.97] and 13% [95% CI = 0.79-0.96] decrease in the risk of all-cause dementia and Alzheimer’s disease, respectively.

The investigators concluded leisure time physical activity over a specific range (0-2000 kcal/week or 0-45 MET-h/week) is associated with a risk of dementia and Alzheimer’s disease in an inverse linear dose-response manner; with for every 500 kcal (calories) or 10 MET-h increase per week, a 10% and 13% decrease in the risk of all-cause dementia and Alzheimer’s disease, respectively.

Original title:
Leisure time physical activity and dementia risk: a dose-response meta-analysis of prospective studies by Xu W, Wang HF, [...], Tan L.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5665289/

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Find more information/studies on physical activities and dementia here.

If you do a 4 MET activity for 30 minutes, you have done 4 x 30 = 120 MET-minutes or 2.0 MET-hours of physical activity.
 

Objectives:
The aim of this meta-analysis (review article) is to evaluate the influence of dietary intake and blood level of vitamin A (total vitamin A, retinol or β-carotene) on total and hip fracture risk?

Study design:
This review article included 11 prospective cohort studies and 2 nested case-control studies, involving a total of 319,077 participants over the age of 20 years (109,056 post-menopausal women).

Results and conclusions:
The investigators found higher dietary intake of retinol significantly decreased total fracture risk with 5% [RR = 0.95, 95% CI = 0.91 to 1.00, I2 = 64.64%, p = 0.04].

The investigators found higher dietary intake of retinol significantly increased hip fracture risk with 40% [RR = 1.40, 95% CI = 1.02 to 1.91, I2 = 30.01%, p = 0.40].

The investigators found higher dietary intake of vitamin A significantly decreased total fracture risk with 6% [RR = 0.94, 95% CI = 0.88 to 0.99, I2 = 35.18%, p = 0.20].

The investigators found higher dietary intake of vitamin A significantly increased hip fracture risk with 29% [RR = 1.29, 95% CI = 1.06 to 1.57, I2 = 0.00%, p = 0.60].

The investigators found lower blood level of retinol significantly increased hip fracture risk with 27% [RR = 1.27, 95% CI = 1.05 to 1.53, I2 = 0.00%, p = 0.62].

The investigators concluded that higher dietary intake of total vitamin A or retinol increases the risk of hip fracture but decreases total fracture risk. Clinical trials are warranted to confirm these results and assess the clinical applicability.

Original title:
The Effect of Vitamin A on Fracture Risk: A Meta-Analysis of Cohort Studies by Zhang X, Zhang R, [...], Chen G.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5615580/

Additional information of El Mondo:
Find more information/studies on vitamin A and elderly right here.

Vitamin A is a generic term for compounds with the biological activity of retinol. Preformed vitamin A (mainly retinol and retinyl esters) is usually found in foods derived from animal products and provitamin A (mainly β-carotene and carotenoids) is usually found in foods derived from plant products.
 

Objectives:
Dietary fiber intake may provide beneficial effects on the components of metabolic syndrome (MetS); however, observational studies reported inconsistent results for the relationship between dietary fiber intake and metabolic syndrome risk. Therefore, this review article (meta-analysis) has been conducted.

Does dietary fiber intake reduce risk of metabolic syndrome?

Study design:
This review article included 11 cross-sectional studies and 3 cohort studies.
There was evidence of publication bias in cross-sectional studies.

Results and conclusions:
The investigators found in cross-sectional studies when comparing the highest with lowest categories of dietary fiber intake, a significantly reduced risk of 33% [OR = 0.67, 95% CI = 0.58-0.78, I2 = 32.4%, p = 0.181] for metabolic syndrome. However, this reduced risk was not significant in cohort studies [pooled RR = 0.86, 95% CI = 0.70-1.06]. Not significant because RR of 1 was found in the 95% CI of 0.70 to 1.06. RR of 1 means no risk/association.

The investigators concluded that a high dietary intake of fiber may reduce risk of metabolic syndrome. May reduce because there was evidence of publication bias in cross-sectional studies and the reduced risk was not significant in cohort studies. Therefore, more prospective cohort studies are needed to further verify the association between dietary fiber intake and the risk of metabolic syndrome.

Original title:
Fruit and vegetable consumption and risk of the metabolic syndrome: a meta-analysis by Tian Y, Su L, [...], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29151369

Additional information of El Mondo:
Find more information/studies on publication bias/cohort studies/significant, fiber consumption and overweight right here.  

Find out whether you are overweight or not right here.

Those with metabolic syndrome are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Objectives:
Several epidemiological studies have been performed to evaluate the association of fruit and vegetable consumption with risk of the metabolic syndrome (MetS), but the results remain controversial. Therefore, this review article (meta-analysis) has been conducted.

Does consumption of vegetables or fruit reduce risk of metabolic syndrome?

Study design:
This review article included a total of 9 studies for fruit consumption, 9 studies for vegetable consumption and 7 studies for fruit and vegetable consumption.

There was no evidence of small-study effect (publication bias)

Results and conclusions:
The investigators found a significantly reduced risk of 13% [pooled RR = 0.87, 95% CI = 0.82-0.92, I2 = 46.7%] for metabolic syndrome when comparing the highest fruit consumption versus the lowest consumption.

The investigators found a significantly reduced risk of 15% [pooled RR = 0.85, 95% CI = 0.80-0.91, I2 = 0.0%] for metabolic syndrome when comparing the highest vegetable consumption versus the lowest consumption.

The investigators found a significantly reduced risk of 24% [pooled RR = 0.76, 95% CI = 0.62-0.93, I2 = 83.5%] for metabolic syndrome when comparing the highest fruit and vegetable consumption versus the lowest consumption.

The investigators found in subgroup analyses stratified by continent, the inverse association of fruit consumption [RR = 0.86, 95% CI = 0.77-0.96] and vegetable consumption [RR = 0.86, 95% CI = 0.80-0.92] with risk of metabolic syndrome remained significant in Asia.

The investigators concluded that a high fruit or/and vegetable consumption reduce risk of metabolic syndrome, particularly among Asian. Therefore, people should consume more fruits and vegetables to reduce risk of metabolic syndrome.

Original title:
Fruit and vegetable consumption and risk of the metabolic syndrome: a meta-analysis by Tian Y, Su L, [...], Jiang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29151369

Additional information of El Mondo:
Find more information/studies on fruit and vegetables consumption and overweight right here.  

Find out whether you are overweight or not right here.

Those with metabolic syndrome are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Objectives:
Vitamin D is involved in musculoskeletal health. There is no consensus on a possible association between circulating 25-hydroxyvitamin D (25OHD) concentrations and walking speed, a “vital sign” in older adults. Therefore, this meta-analysis (review article) has been conducted.

Does a high vitamin D level (expressed as circulating 25-hydroxyvitamin D (25OHD) concentrations) increase walking speed in older adults?

Study design:
This review article included 22 observational studies (17 cross-sectional and 5 longitudinal). The number of participants ranged between 54 and 4,100 (0-100% female).

Results and conclusions:
The investigators found usual walking speed was slower among participants with hypovitaminosis D, with a clinically relevant difference compared with normal vitamin D (>75 nmol/L) of -0.18m/s for severe vitamin D deficiency (≤25 nmol/L), -0.08m/s for vitamin D deficiency (≤50 nmol/L) and -0.12m/s for vitamin D insufficiency (≤75 nmol/L).

The investigators found similar results regarding the fast walking speed [mean differences = -0.04m/s for vitamin D deficiency (≤50 nmol/L) and vitamin D insufficiency (≤75 nmol/L) compared with normal vitamin D (>75 nmol/L) and Timed Up and Go test (TUG) [mean difference = 0.48s for severe vitamin D deficiency (≤25 nmol/L) compared with normal vitamin D (>75 nmol/L).

The investigators found a slow usual walking speed was positively associated with:
-severe vitamin D deficiency (≤25 nmol/L) [summary OR = 2.17, 95% CI = 1.52-3.10];
-vitamin D deficiency (≤50 nmol/L) [OR = 1.38, 95% CI = 1.01-1.89] and;
-vitamin D insufficiency (≤75nmol/L) [OR = 1.38, 95% CI = 1.04-1.83], using normal vitamin D (>75 nmol/L) as the reference.

The investigators concluded that robust evidence shows a high 25OHD concentration (vitamin D level of >75 nmol/L) increases walking speed among older adults.

Original title:
Vitamin D and walking speed in older adults: Systematic review and meta-analysis by Annweiler C, Henni S, [...], Duval GT.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29150169

Additional information of El Mondo:
Find more information/studies on review article/observational studies, vitamin D and elderly right here.

A vitamin D level of >75 nmol/L can be achieved by taking 800-1200 IU/d (800-1200 mcg/d) vitamin D3 supplements.
 

Objectives:
No quantitative assessment has been performed to specifically link the consumption of fruit and vegetables with the incident risk of cognitive disorders. Therefore, this meta-analysis (review article) has been conducted.

Does consumption of fruit and vegetables reduce risk of cognitive disorders?

Study design:
This review article included 6 cohort studies involving a total of 21,175 participants.

Results and conclusions:
The investigators found in pooled analysis that consumption of fruit and vegetables significantly reduced risk of cognitive disorders with 26% [pooled RR = 0.74, 95% BI = 0.62-0.88, I2 = 68%; the significant heterogeneity might be attributed to the ethnic difference].

The investigators concluded that consumption of fruit and vegetables reduces risk of cognitive disorders. However, further large prospective studies should be performed to quantify the potential dose-response patterns of fruit and/or vegetables intake and to explore the role of fruit or vegetables consumption separately on cognitive disorders in different populations.

Original title:
Intake of Fruit and Vegetables and the Incident Risk of Cognitive Disorders: A Systematic Review and Meta-Analysis of Cohort Studies by Wu L, Sun D and Tan Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29188891

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

Objectives:
Currently, dementia is considered untreatable and there are many factors that cause dementia. However, previous studies were unable to identify the factors that affect directly. Therefore, this meta-analysis (review article) has been conducted.

What are the risk factors for prognostic dementia in stroke patients?

Study design:
This review article included 7 hospital-based cohorts of consecutive patients with stroke and 1 population-based cross-sectional study.

Results and conclusions:
The investigators found:
a significantly increased risk of 68% [pooled relative ratio = 1.68, 95% CI = 1.28 to 2.22, I2 = 72%] for atrial fibrillation;
a significantly increased risk of 59% [pooled relative ratio = 1.59, 95% CI = 1.33 to 1.91] for previous stroke;
a significantly increased risk of 40% [pooled relative ratio = 1.40, 95% CI = 1.23 to 1.59, I2% = 14%] for myocardial infarction;
a significantly increased risk of 36% [pooled relative ratio = 1.36, 95% CI = 1.20 to 1.53, I2 = 46%] for hypertension;
a significantly increased risk of 25% [pooled relative ratio = 1.25, 95% CI = 1.11 to 1.41, I2 = 0%] for diabetes mellitus and;
a significantly increased risk of 25% [pooled relative ratio = 1.25, 95% CI = 1.08 to 1.45, I2 = 16%] for previous transient ischemic attack (TIA).

The investigators concluded that strongly risk factors associated with increased risk of post-stroke dementia are atrial fibrillation, previous stroke, myocardial infarction, hypertension, diabetes and previous TIA. However, there are other risk factors related to dementia. Therefore, further studies are needed to investigate and develop the risk score value to forecast the dementia incident in stroke patients.

Original title:
Risk factors associated with post-stroke dementia: a systematic review and meta-analysis by Surawan J, Areemit S, […], Saensak S.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5641826/

Additional information of El Mondo:
Find more information/studies on stroke, diabetes, hypertension, dementia and elderly right here.
 

Objectives:
The scientific literature shows conflicting evidence about the relationship between adiposity and bone mass in overweight and obese populations. Therefore, this review article (meta-analysis) has been conducted.

Does a high adipose mass reduce bone mineral density in overweight and obese populations?

Study design:
This review article included a total of 16 studies, comprising 2587 participants and 75 correlation coefficients.

Results and conclusions:
The investigators found strong evidence supported a negative relationship between relative (%) adipose mass and bone mineral density (BMD) in men [R = -0.37, 95% CI = -0.57 to -0.12] and in those aged less than 25 years [R = -0.28, 95% CI = -0.45 to -0.08].

The investigators concluded that a high relative (%) adipose mass reduces bone mineral density in overweight (BMI = 25-30) and obese populations (BMI > 30), particularly in men and those aged less than 25 years. Therefore, to prevent bone loss in overweight and obese populations, nutrition- and exercise-based interventions that focus on a controlled reduction of adipose mass with concomitant preservation of lean mass are recommended.

Original title:
Influence of adipose tissue mass on bone mass in an overweight or obese population: systematic review and meta-analysis by Dolan E, Swinton PA, […], O'Reilly J.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29028271

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

Find out whether you are overweight or not right here.

Those with overweight (BMI = 25-30) or obesity (BMI > 30) are advised to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
The most easy way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is to choose meals/products with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.
However, the most practical way to follow a diet with maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal is all meals/products that you eat on a daily basis should on average contain maximum 30 En% fat, of which maximum 7 En% saturated fat and minimum 1.5 grams fiber per 100 kcal.

Strength exercise is the best way to reduce adipose mass while preserving lean mass.

Objectives:
Whole grains are rich source of nutrients and have shown beneficial effects on human health. Therefore, this meta-analysis (review article) has been conducted.

Do taking whole grains reduce mortality risk?

Study design:
This review article included 19 cohort studies with in total 1,041,692 participants and 96,710 deaths.

Results and conclusions:
The investigators found when comparing the highest versus the lowest categories of whole grain, a significantly reduced risk of 16% [RR = 0.84, 95% CI = 0.81-0.88, n = 9] for total mortality.

The investigators found when comparing the highest versus the lowest categories of whole grain, a significantly reduced risk of 17% [RR = 0.83, 95% CI = 0.79-0.86, n = 8] for cardiovascular mortality.

The investigators found when comparing the highest versus the lowest categories of whole grain, a non-significantly reduced risk of 6% [RR = 0.94, 95% CI = 0.87-1.01, n = 14] for cancer mortality.

The investigators found a nonlinear relationship of whole grain intake with risk of total, cardiovascular and cancer mortality.

The investigators found each 28 g/d intake of whole grains was associated with a 9% [pooled RR = 0.91, 95% CI = 0.90-0.93] lower risk for total mortality.

The investigators found each 28 g/d intake of whole grains was associated with a 14% [pooled RR = 0.86, 95% CI = 0.83-0.89] lower risk for cardiovascular mortality.

The investigators found each 28 g/d intake of whole grains was associated with a 3% [pooled RR = 0.97, 95% CI = 0.95-0.99] lower risk for cancer mortality.

The investigators concluded that a higher whole grain intake (at least 28 g/d) reduces risk of total, cardiovascular and cancer mortality. These findings support current dietary guidelines to increase the intake of whole grains. Government officials, scientists and medical staff should take actions to promote whole grains intake.
 
Original title:
Association of whole grain intake with all-cause, cardiovascular, and cancer mortality: a systematic review and dose-response meta-analysis from prospective cohort studies by Zhang B, Zhao Q, [...], Wang X.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29091078

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Find more information/studies on cardiovascular disease and cancer right here.
 

Objectives:
Previous studies had inconsistent findings regarding the association between vitamin C intake and the risk of hip fracture. Therefore, this meta-analysis (review article) has been conducted.

Does taking dietary vitamin C reduce risk of hip fracture?

Study design:
This review article included 6 articles, containing 7908 controls and 2899 cases of hip fracture.

Results and conclusions:
The investigators found when comparing the highest versus the lowest categories of vitamin C, that dietary vitamin C was statistically correlated with a lower risk of 27% for hip fracture [overall OR = 0.73, 95% CI = 0.55-0.97, I2 = 69.1%].

The investigators found that every increment of 50 mg/day dietary vitamin C intake significantly reduced risk of hip fracture with 5% [OR = 0.95, 95% CI = 0.91-1.00, p = 0.05].

The investigators concluded that increasing dietary vitamin C (at least 50 mg/day) intake decreases the risk of hip fracture. In order to verify the association of vitamin C intake and hip fracture risk, further well-designed largely randomized controlled trials (RCTs) are needed.

Original title:
Dietary vitamin C intake and the risk of hip fracture: a dose-response meta-analysis by Sun Y, Liu C, […], Lu Q.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29101410

Additional information of El Mondo:
Find more information/studies on vitamin C and elderly right here.
 

Objectives:
Fish are a primary source of long-chain omega-3 fatty acids, which may help delay cognitive aging. Therefore, this meta-analysis (review article) has been conducted.

Does a higher fish intake reduce cognitive decline?

Study design:
This review article included 5 cohort studies (23,688 Caucasians aged ≥65 years, 88% female and median follow-up range of 3.9-9.1 years).

Results and conclusions:
The investigators found in multivariate analyses, higher fish intake was associated with slower decline in both global cognition and memory [p-trend ≤ 0.031].

The investigators found consuming ≥4 versus 1 fish serving/week was associated with 0.018 [95% CI = 0.004-0.032] standard units lower rate of memory decline; an effect estimate equivalent to that found for 4 years of age.

The investigators found for global cognition, no comparisons of higher versus low fish intake reached statistical significance.

The investigators found no evidence of effect modification by Alzheimer's.

The investigators concluded that increasing fish intake (at least 4 servings/week) is associated with decreasing memory decline of older persons.

Original title:
Fish intake, genetic predisposition to alzheimer's disease and decline in global cognition and memory in five cohorts of older persons by Samieri C, Morris MC,[…], Grodstein F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29053784

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Find more information/studies on fish consumption and elderly right here.

A typical serving size of fish can range from 3 to 6 oz., depending on the type of fish and its preparation. The American Heart Association considers 3.5 oz. of cooked fish, or about 3/4 cup, to be a single serving.
 

Objectives:
With an aging population and no cure for dementia on the horizon, risk factor modification prior to disease onset is an urgent health priority. Therefore, this meta-analysis (review article) has been conducted.

What is the effect of low vitamin D status or vitamin D supplementation on cognition in midlife and older adults without a diagnosis of dementia?

Study design:
This review article included 26 observational (cross-sectional and longitudinal cohort) studies and 3 intervention studies (n = 19-9,556).

Results and conclusions:
The investigators found in 26 observational studies that low vitamin D status was associated with worse cognitive performance [OR = 1.24, CI = 1.14-1.35] and cognitive decline [OR = 1.26, CI = 1.09-1.23] in midlife and older adults without a diagnosis of dementia; with cross-sectional yielding a stronger effect compared to longitudinal studies.

However, the investigators found in 3 intervention studies that vitamin D supplementation showed no significant benefit on cognition compared with control [SMD = 0.21, CI = -0.05 to 0.46].

The investigators concluded that observational evidence demonstrates low vitamin D is related to poorer cognition in midlife and older adults without a diagnosis of dementia; however, interventional studies are yet to show a clear benefit from vitamin D supplementation. From the evidence to date, there is likely a therapeutic age window relevant to the development of disease and therefore vitamin D therapy. Longitudinal lifespan studies are necessary to depict the optimal timing and duration in which repletion of vitamin D may protect against cognitive decline and dementia in aging, to better inform trials and practice towards a successful therapy.

Original title:
A Systematic Review and Meta-Analysis of The Effect of Low Vitamin D on Cognition by Goodwill AM and Szoeke C.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28758188

Additional information of El Mondo:
Find more information/studies on vitamin D, review article/significant, elderly and dementia right here.
 

Objectives:
Many publications have investigated the association between metal ions and the risk of Alzheimer's disease (AD), but the results were ambiguous. Therefore, this meta-analysis (review article) has been conducted.

What is the association between serum copper/zinc/iron levels and Alzheimer's disease risk?

Study design:
This review article included 44 case-control studies.

Results and conclusions:
The investigators found in 35 case-control studies (2,128 Alzheimer's disease patients and 2,889 healthy controls. The mean age of the patient groups was >54), that serum copper levels were significant higher in Alzheimer's disease patients [MD = 9.13, 95% CI = 6.17 to 12.09, p 0.00001].

The investigators found in 22 case-control studies (1,027 Alzheimer's disease patients and 1,949 healthy controls. The mean age of the patient groups was >54), that serum zinc levels were significant lower in Alzheimer's disease patients [MD = -7.80, 95% CI = -11.61 to -3.99, p 0.0001].

The investigators found in 25 case-control studies (1,379 Alzheimer's disease patients and 1,664 healthy controls. The mean age of the patient groups was >62.74), that serum iron levels were significant lower in Alzheimer's disease patients [MD = -13.01, 95% CI = -20.75 to -5.27, p = 0.001].

The investigators concluded that serum copper levels are significantly increased, while serum zinc/iron levels are significantly decreased in Alzheimer's disease patients.

Original title:
Serum Copper, Zinc, and Iron Levels in Patients with Alzheimer's Disease: A Meta-Analysis of Case-Control Studies by Li DD, Zhang W, [...], Zhao P.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5605551/

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Objectives:
The prevalence of metabolic syndrome (MetS) has been greatly increased, worldwide. In recent years, investigators have proposed that sodium might contribute to the development of metabolic syndrome; however, the published data were conflicting. Therefore, this review article (meta-analysis) has been conducted.

Does sodium contribute to the development of metabolic syndrome?

Study design:
This review article included 17 observational studies with 66,274 participants.

Results and conclusions:
The investigators found that subjects with metabolic syndrome had significantly higher levels of sodium compared to healthy controls [Hedges' g = 0.21, 95% CI = 0.12-0.29, I2 = 68.6%]. Subgroup analyses revealed that the difference was significant when the sodium status was assessed using urinary sodium levels.

The investigators found that random effects meta-regression analysis also revealed that body sodium level increases with the number of metabolic syndrome components.

The investigators found that participants with highest dietary/urinary or serum sodium levels had a significantly 37% higher chance of developing metabolic syndrome when compared with participants with the lowest sodium levels [OR = 1.37, 95% CI = 1.31-1.42, I2 = 86.9%].

The investigators concluded that higher sodium input into the body is directly associated with the likelihood of metabolic syndrome. Prospective cohort studies and well-designed randomized clinical trials considering the effect of sodium restricted diets on the risk of metabolic syndrome as an outcome are necessary to represent the causal association.

Original title:
Sodium status and the metabolic syndrome: A systematic review and meta-analysis of observational studies by Soltani S, Kolahdouz Mohammadi R, […], Salehi-Abargouei A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28846446

Additional information of El Mondo:
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Those with metabolic syndrome are advised to select the following food items.

Sodium is part of table salt or sodium choride.

High-sodium or high-salt products are products with more than 0.3 gram salt per 100 kcal. These products are rich in salt.
A high-salt diet is a diet with many products with more than 0.3 gram salt per 100 kcal.

Objectives:
The relationships between metabolic syndrome (MetS) and risk of incident stroke are inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does metabolic syndrome increase risk of stroke?

Study design:
This review article included a total of 16 prospective cohort studies, including 116,496 participants who were initially free of cardiovascular diseases.

Results and conclusions:
The investigators found comparing the persons without metabolic syndrome, those with metabolic syndrome had a significantly higher risk of 70% for incident stroke [pooled relative risk (RR) = 1.70, 95% CI = 1.49-1.95]. Significant means that there is an association with a 95% confidence.

The investigators found in subgroup analyses that women with metabolic syndrome had a significantly higher risk of 83% for incident stroke [pooled relative risk (RR) = 1.83, 95% CI = 1.31-2.56]. Significant because RR of 1 was not found in the 95% CI of 1.31 to 2.56. RR of 1 means no risk/association.

The investigators found in subgroup analyses that men with metabolic syndrome had a significantly higher risk of 47% for incident stroke [pooled relative risk (RR) = 1.47, 95% CI = 1.22-1.78].

The investigators found in subgroup analyses that those with metabolic syndrome had a significantly higher risk of 112% for ischemic stroke [pooled relative risk (RR) = 2.12, 95% CI = 1.46-3.08].

The investigators found in subgroup analyses that those with metabolic syndrome had a non-significantly higher risk of 48% for hemorrhagic stroke [pooled relative risk (RR) = 1.48, 95% CI = 0.98-2.24].

The investigators concluded metabolic syndrome increases risk of stroke, particularly among women and those with ischemic stroke.

Original title:
Metabolic syndrome and stroke: A meta-analysis of prospective cohort studies by Li X, Li X, […], Gao Q.

Link:
http://www.sciencedirect.com/science/article/pii/S0967586816311079

Additional information of El Mondo:
Find more information/studies on overweight and cardiovascular disease right here. 

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Those with metabolic syndrome are advised to select the following food items.

Objectives:
Available studies in the literature on the selenium levels in Alzheimer's disease (AD) are inconsistent with some studies reporting its decrease in the circulation, while others reported an increase or no change as compared to controls. Therefore, this meta-analysis (review article) has been conducted.

Do lower circulatory (plasma/serum and blood), erythrocyte and cerebrospinal fluid (CSF) selenium levels increase Alzheimer's disease risk?

Study design:
This review article included 12 case-control/observational studies reporting selenium concentrations in Alzheimer's disease and controls.

Results and conclusions:
The investigators found random-effects meta-analysis indicated a decrease in circulatory [SMD = -0.44], erythrocellular [SMD = -0.52] and cerebrospinal fluid [SMD = -0.14] selenium levels in Alzheimer's disease patients compared to controls

The investigators found stratified meta-analysis demonstrated that the selenium levels were decreased in both the subgroups with [SMD = -0.55] and without [SMD = -0.37] age matching between Alzheimer's disease and controls.

The investigators also found a direct association between decreased selenium levels and glutathione peroxidase (GPx) in Alzheimer's disease.

The investigators concluded that circulatory selenium concentration is significantly lower in Alzheimer's disease patients compared to controls and this decrease in selenium is directly correlated with an important antioxidant enzyme, the glutathione peroxidase, in Alzheimer's disease.

Original title:
A systematic review and meta-analysis of the circulatory, erythrocellular and CSF selenium levels in Alzheimer's disease: A metal meta-analysis (AMMA study-I) by Reddya VS, Bukkeb S, […], Pandeye AK.

Link:
http://www.sciencedirect.com/science/article/pii/S0946672X1630205X%20

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

Objectives:
Does higher protein intake increase bone mineral density?

Study design:
This review article included 6 RCTs and 20 prospective cohort studies.
There were no adverse effects of higher protein intakes.
Studies were heterogeneous and confounding could not be excluded.

Results and conclusions:
The investigators found moderate evidence suggested that higher protein intake may have a protective effect on lumbar spine bone mineral density compared with lower protein intake [net percentage change = 0.52%, 95% CI = 0.06%-0.97%, I2 = 0%, n = 5] but had no effect on total hip, femoral neck, or total body bone mineral density or bone biomarkers.

The investigators concluded that higher protein intake may have a protective effect on lumbar spine bone mineral density. May have because studies were heterogeneous and confounding could not be excluded. Therefore, high-quality, long-term studies are needed to clarify dietary protein's role in bone health.

Original title:
Dietary protein and bone health: a systematic review and meta-analysis from the National Osteoporosis Foundation by Shams-White MM, Chung M, […], Weaver CM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28404575

Additional information of El Mondo:
Find more information/studies on protein and elderly right here.

A higher protein diet is a diet with 20-35 En% protein. The easiest way to meet a diet with 20-35 En% protein is to choose food items/meals with also 20-35 En% protein. Check here which products contain 20-35 En% protein.
 

Objectives:
The associations between n-3 polyunsaturated fatty acids (PUFAs) and metabolic syndrome (MetS) risk have demonstrated inconsistent results. Therefore, this review article (meta-analysis) has been conducted.

Do higher circulating n-3 PUFA levels associate with a lower metabolic syndrome risk?

Study design:
This review article included a total of 7 case-control studies and 20 cross-sectional studies.
There was no publication bias.
Results and conclusions:
The investigators found a higher plasma/serum n-3 PUFAs was associated with a lower metabolic syndrome risk of 37% [pooled OR = 0.63, 95% CI = 0.49-0.81, I2 = 72.4%].

The investigators found the plasma/serum n-3 PUFAs in controls was significantly higher than cases [WMD = 0.24, 95% CI = 0.04-0.43], especially docosapentaenoic acid (DPA) and docosahexaenoic acid (DHA).

The investigators found, however, no significant association between dietary intake of n-3 PUFAs or fish and metabolic syndrome risk.

The investigators found in sensitivity analysis by omitting one study at a time and re-calculated the remaining data, that exclusion of anyone study did not substantially influence the pooled effects.

The investigators concluded a higher circulating n-3 PUFAs is associated with a lower metabolic syndrome risk. The circulating n-3 PUFAs can be regarded as biomarkers indicating metabolic syndrome risk, especially DPA and DHA. The evidence of this review article will have important public implications in preventing metabolic syndrome through supplemental long-chain n-3 PUFAs of marine-origin. Furthermore, added RCTs and epidemiological studies with large sample-size are warranted to confirm these findings.

Original title:
n-3 Polyunsaturated Fatty Acids and Metabolic Syndrome Risk: A Meta-Analysis by Guo XF, Li X, […], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5537818/

Additional information of El Mondo:
Find more information/studies on overweight and n-3 PUFA right here.  
Docosapentaenoic acid (DPA) is a dietary omega-3 fatty acid mainly found in fish, fish oil, seal oil and red meat.

Find out whether you are overweight or not right here.

Objectives:
Have flaxseed supplementation positive effects on body composition?

Study design:
This review article included a total of 45 RCTs.

Results and conclusions:
The investigators found a significant reduction in body weight [WMD = -0.99 kg, 95% CI = -1.67 to -0.31, p = 0.004], BMI [WMD = -0.30 kg m², 95% CI = -0.53 to -0.08, p = 0.008] and waist circumference [WMD = -0.80 cm, 95% CI = -1.40 to -0.20, p = 0.008] following flaxseed supplementation.

The investigators found subgroup analyses showed that using whole flaxseed in doses ≥30 g/d, longer-term interventions (≥12 weeks) and studies including participants with higher BMI (≥ 27 kg/m²) had positive effects on body composition.

The investigators concluded whole flaxseed supplementation in doses ≥30 g/d during ≥12 weeks has positive effects on body composition in overweight and obese participants (=participants with BMI ≥ 25 kg/m²).

Original title:
The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials by Mohammadi-Sartang M, Mazloom Z, […], Totosy de Zepetnek JO.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28635182

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

Find out whether you are overweight or not right here.

Objectives:
Have flaxseed supplementation positive effects on body composition?

Study design:
This review article included a total of 45 RCTs.

Results and conclusions:
The investigators found a significant reduction in body weight [WMD = -0.99 kg, 95% CI = -1.67 to -0.31, p = 0.004], BMI [WMD = -0.30 kg m², 95% CI = -0.53 to -0.08, p = 0.008] and waist circumference [WMD = -0.80 cm, 95% CI = -1.40 to -0.20, p = 0.008] following flaxseed supplementation.

The investigators found subgroup analyses showed that using whole flaxseed in doses ≥30 g/d, longer-term interventions (≥12 weeks) and studies including participants with higher BMI (≥ 27 kg/m²) had positive effects on body composition.

The investigators concluded whole flaxseed supplementation in doses ≥30 g/d during ≥12 weeks has positive effects on body composition in overweight and obese participants (=participants with BMI ≥ 25 kg/m²).

Original title:
The effect of flaxseed supplementation on body weight and body composition: a systematic review and meta-analysis of 45 randomized placebo-controlled trials by Mohammadi-Sartang M, Mazloom Z, […], Totosy de Zepetnek JO.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28635182

Additional information of El Mondo:
Find more information/studies on nuts&seeds and overweight right here. 

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Objectives:
Current studies evaluating the association of tea consumption and bone mineral density (BMD) have yielded inconsistent findings. Therefore, this meta-analysis (review article) has been conducted.

Does tea consumption increase bone mineral density?

Study design:
This review article included 4 cohort, 1 case-control and 8 cross-sectional studies including a total of 12,635 cases (6,059 in the tea consumption group and 6,576 individuals in non-tea consumption group).

Results and conclusions:
The investigators found tea consumption significantly reduced the occurrence of low bone mass with 34% [OR  =  0.66, 95% CI  =  0.47-0.94, p =  0.02].

The investigators found tea consumption significantly yielded higher mineral densities in several bones, including:
-the lumbar spine [standardized mean difference (SMD) = 0.19, 95% CI = 0.08-0.31, p  =  0.001];
-hip [SMD = 0.19, 95% CI = 0.05-0.34, p  =  0.01];
-femoral neck [mean difference (MD) = 0.01, 95% CI = 0.00-0.02, p  =  0.04];
-Ward triangle [MD = 0.02, 95% CI = 0.01-0.04, p  =  0.001] and;
-greater trochanter [MD = 0.03, 95% CI = 0.02-0.04, p  0.00001]
than the non-tea consumption group.

The investigators concluded that tea consumption increases bone mineral density, especially in the lumbar spine, hip, femoral neck, Ward triangle and greater trochanter, which can prevent bone loss.

Original title:
Updated association of tea consumption and bone mineral density: A meta-analysis by Zhang ZF, Yang JL, [...], Liu ZX.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5371490/

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Find more information/studies on tea consumption and elderly right here.
 

Objectives:
Do overweight and obese adults benefit from n-3 PUFA supplements?

Study design:
This review article included a total of 11 RCTs involving 617 participants.

Results and conclusions:
The investigators found a statistically non-significant difference in weight loss between n-3 PUFA supplements and placebo [WMD = 0.00, 95% CI = -0.42 to 0.43, p = 0.99].

The investigators found n-3 PUFA supplements was superior to placebo in reducing serum triglyceride levels [Std MD = -0.59, 95% CI = -0.93 to -0.25, p = 0.0007].

The investigators found a significant reduction in waist circumference for n-3 PUFA group [WMD = -0.53, 95% CI = -0.90 to -0.16, p = 0.005].

The investigators found no significant differences in body mass index, total serum levels of cholesterol, low density lipoprotein (LDL) cholesterol, high density lipoprotein (HDL) cholesterol and fasting glucose levels between n-3 PUFA supplements and placebo.

The investigators concluded that n-3 PUFA supplements reduce waist circumference and triglyceride levels in overweight and obese adults. However, large-scale, well-designed RCTs are needed to further address this issue.

Original title:
Efficacy of Omega-3 Polyunsaturated Fatty Acids Supplementation in Managing Overweight and Obesity: A Meta-Analysis of Randomized Clinical Trials by Zhang YY, Liu W, […], Tian HM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/28112774

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Find more information/studies on overweight, n-3 PUFA and cholesterol right here.  

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