Nutrition and health

Objectives:
With the increasing incidence of osteoporosis, vitamin K and calcium have been linked to bone mineral density (BMD) and undercarboxylated osteocalcin (UcOC) in many studies, but the results of studies of the combined effect of vitamin K and calcium on BMD and UcOC in humans have been inconsistent. Therefore, this review article has been conducted.

Do vitamin K and calcium supplements used in combination increase bone mineral density and decrease undercarboxylated osteocalcin level?

Study design:
This review article included 10 randomized controlled trials (RCTs) with a total of 1,346 patients.

Results and conclusions:
The investigators found that the combination of vitamin K and calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.20, 95% CI = 0.07 to 0.32, I2 = 46.9%, p = 0.049].
However, after applying trim and fill method (where correction was made for publication bias), the results were not statistically significant [estimate = 0.067, 95% CI = -0.044 to 0.178].

The investigators found that vitamin K and calcium supplementation led to a significant decrease in undercarboxylated osteocalcin [SMD = -1.71, 95% CI = - 2.45 to -0.96, I2 = 95.7%, p  0.01].
The results did not change after correcting publication bias [estimate = - 0.947, 95% CI = -1.211 to - 0.687].
The SMD in the sensitivity analysis was -0.82 [95% CI = - 1.10 to -0.55, I2 = 65.4%, p  0.01].

The investigators found in subgroup analysis that the combination of vitamin K2 and calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.30, 95% CI = 0.10 to 0.51, I2 = 0%].

The investigators found in subgroup analysis that the combination of vitamin K and  ≤ 1000 mg/d calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.19, 95% CI = 0.05 to 0.32, I2 = 62.3%].

The investigators found in subgroup analysis that the combination of  ≤100 µg/d vitamin K and calcium supplements was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.40, 95% CI = 0.20 to 0.61, I2 = 49.9%].

The investigators found in subgroup analysis that the combination of vitamin K and calcium supplements during ≤1 year was significantly associated with a higher lumbar spine bone mineral density [SMD = 0.38, 95% CI = 0.19 to 0.57, I2 = 40%].

The investigators concluded that ≤100 µg/d vitamin K2 and ≤1000 mg/d calcium supplements used in combination are associated with a higher lumbar spine bone mineral density and a lower undercarboxylated osteocalcin level.

Original title:
The combined effect of vitamin K and calcium on bone mineral density in humans: a meta-analysis of randomized controlled trials by Hu L, Ji J, [...], Yu B.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8515712/

Additional information of El Mondo:
Find more information/studies on review article/RCTs/publication bias, vitamin K, calcium and increasing bone mineral density right here.

Objectives:
Whether mushroom consumption, which is a rich source of potent antioxidants ergothioneine and glutathione, vitamins and minerals (e.g., selenium & copper), is associated with a lower mortality risk is not well understood. Therefore, this review article (meta-analysis) has been conducted.

Does mushroom consumption reduce all-cause mortality?

Study design:
This review article included 5 prospective cohort studies with a total of 50,787 cases of deaths accrued in 601,893 men and women.

Results and conclusions:
The investigators found in a meta-analysis that mushroom consumption was significantly associated with an 6% decrease of the risk of all-cause mortality [pooled risk ratio = 0.94, 95% CI = 0.91 to 0.98].  

The investigators concluded that a meta-analysis of prospective cohort studies shows mushroom consumption reduces all-cause mortality. These findings can be used to support public health recommendations and increase awareness about the health-promoting effects of mushrooms. Large prospective cohort studies with repeated dietary data measurements are needed to replicate these findings and clarify the potential protective role of mushrooms against premature mortality.

Original title:
Prospective study of dietary mushroom intake and risk of mortality: results from continuous National Health and Nutrition Examination Survey (NHANES) 2003-2014 and a meta-analysis by Ba DM, Gao X, [...], Richie Jr JP.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8454070/

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

Objectives:
Does fruits and vegetables (FVs) consumption reduce risk of frailty?

Study design:
This review article included 10 cohort studies and 4 cross-sectional studies with 18,616 subjects with frailty and 101,969 controls (persons without frailty).

Based on the NutriGrade score, the quality of evidence for a protective effect of fruits and vegetables consumption on frailty was "moderate".

Results and conclusions:
The investigators found in 7 cohort studies for the highest versus lowest category of fruits and vegetables consumption a significantly reduced risk of 35% for frailty [RR = 0.65, 95% CI = 0.50 to 0.84, I2 = 81%].

The investigators found that every 200g per day increment in fruits and vegetables consumption was significantly associated with a 14% lower risk of frailty.
The risk of frailty decreased linearly up to fruits and vegetables consumption of 700 g/d, with flattening the curve at higher intake.

The investigators found that pooled analysis regarding fruits and vegetables separately did not indicate a significant association with the risk of frailty.

The investigators concluded that 200-700 g/d fruits and vegetables consumption decreases risk of frailty. Further large-scale prospective cohort studies are needed to reach more confident conclusions.

Original title:
Fruit and vegetable intake and risk of frailty: A systematic review and dose response meta-analysis by Ghoreishy SM, Asoudeh F, […], Mohammadi H.

Link:
https://pubmed.ncbi.nlm.nih.gov/34534684/

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

Objectives:
Findings on the link between dietary intakes of monounsaturated fatty acids (MUFA) and risk of mortality are conflicting. Therefore, this review article has been conducted.

Does monounsaturated fatty acids dietary intake reduce risk of mortality?

Study design:
This review article included 17 prospective cohort studies with a total of 1022,321 participants aged ≥ 20 years, of which 191,283 all-cause deaths, 55,437 cardiovascular diseases (CVD) deaths and 64,448 cancer deaths.

Results and conclusions:
The investigators found combining 15 effect sizes from 11 studies, monounsaturated fatty acids dietary intake was significantly associated with a reduced risk of 6% for all-cause mortality [RR = 0.94, 95% CI = 0.90 to 0.98, I2 = 55.5%, p = 0.005].
Significantly because RR of 1 was not found in the 95% CI of 0.90 to 0.98. RR of 1 means no risk/association.

The investigators found based on 17 effect sizes from 11 studies, no significant association between monounsaturated fatty acids dietary intake and risk of cardiovascular diseases mortality [RR = 0.95, 95% CI = 0.89 to 1.01, I2 =37.0%, p = 0.06].
No significant means that there is no association with a 95% confidence.

The investigators found when combining 10 effect sizes from 6 studies, monounsaturated fatty acids dietary intake was not significantly associated with cancer mortality [RR = 0.99, 95% CI = 0.96 to 1.03, I2 = 13.3%, p = 0.32].  
Not significantly because RR of 1 was found in the 95% CI of 0.96 to 1.03. RR of 1 means no risk/association.

The investigators found an additional 5% of energy (5 En%) from monounsaturated fatty acids was significantly associated with a 3% reduced risk of all-cause mortality [RR = 0.97, 95% CI = 0.96 to 0.98], but not with cardiovascular diseases [RR = 0.98, 95% CI = 0.95 to 1.01] and cancer mortality [RR = 0.99, 95% CI = 0.97 to 1.01].

The investigators concluded that monounsaturated fatty acids dietary intake reduces risk of all-cause mortality.

Original title:
Dietary intakes of monounsaturated fatty acids and risk of mortality from all causes, cardiovascular disease and cancer: A systematic review and dose-response meta-analysis of prospective cohort studies by Lotfi K, Salari-Moghaddam A, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/34560281/

Additional information of El Mondo:
Find more information/studies on fatty acids, cardiovascular disease and elderly right here.

Objectives:
Despite growing evidence that type 2 diabetes is associated with dementia, the question of whether intensive glucose control can prevent or arrest cognitive decline remains unanswered. Therefore, this review articles (meta-analysis) has been conducted.

Does intensive glucose control slow down cognitive decline in persons with type 2 diabetes?

Study design:
This review article included 5 cohort studies with 16,584 participants.
The mean follow-up duration ranged from 3.5 to 10 years.
The mean age of participants in the studies included in the current meta-analysis was 65.6 years at the initiation of the studies and the proportion of women was 40.8%.
All quality assessment scores fell in the range of 8 or 9, indicating high quality.
There was no publication bias.

Results and conclusions:
The investigators found a significantly poorer decline in cognitive function in the intensive glucose control group [β = -0.03, 95% CI = -0.05 to -0.02] than in the conventional glucose control group.

The investigators found, subgroup analysis showed a significant difference in the change in cognitive performance in composite cognitive function [β = -0.03, 95% CI = -0.05 to -0.01] and memory [β = -0.13, 95% CI = -0.25 to -0.02].

The investigators concluded that intensive glucose control in persons with type 2 diabetes slows down cognitive decline, especially the decline in composite and memory function. The impact of intensive glucose control on the brain structural abnormalities and risk of dementia needs further rigorously designed studies to validate these findings. Also, replicating and validating these findings is warranted.

Original title:
Impact of Intensive Glucose Control on Brain Health: Meta-Analysis of Cumulative Data from 16,584 Patients with Type 2 Diabetes Mellitus by Tang X, Cardoso MA, […], Simó R.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7947088/

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

Objectives:
Magnesium supplementation is often purported to improve sleep; however, as both an over-the-counter sleep aid and a complementary and alternative medicine, there is limited evidence to support this assertion. Therefore, this review article (meta-analysis) has been conducted.

Does magnesium supplementation improve sleep in older adults with insomnia?

Study design:
This review article included 3 randomized control trials (RCTs), comparing oral magnesium to placebo in 151 older adults in 3 countries.

All 3 RCTs were at moderate-to-high risk of bias and outcomes were supported by low to very low quality of evidence.

Daily elemental magnesium intake ranged from 320 mg to 729 mg taken 2 to 3 times per day using 2 formulations (magnesium oxide and magnesium citrate tablets).
Duration of follow-up for outcome assessment ranged from 20 days to 8 weeks.

Results and conclusions:
The investigators found pooled analysis showed that post-intervention sleep onset latency time was significantly 17.36 min less [95% CI = -27.27 to -7.44, p = 0.0006] after magnesium supplementation compared to placebo.
Significantly because the calculated p-value of = 0.0006 was less than the p-value of 0.05.

The investigators found pooled analysis showed that total sleep time improved by 16.06 min in the magnesium supplementation group but was statistically insignificant [95% CI = - 5.99 to 38.12, p = 0.15].
Insignificant because the calculated p-value of 0.15 was larger than the p-value of 0.05.

The investigators concluded that RCT evidence may support oral magnesium supplements (less than 1 g quantities given up to 3 times a day) for insomnia symptoms in older adults. May support because all 3 RCTs are at moderate-to-high risk of bias and outcomes are supported by low to very low quality of evidence.

Original title:
Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis by Mah J and Pitre T.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8053283/

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

Magnesium oxide contains 60% elemental magnesium and magnesium citrate contains 16% elemental magnesium.
So if you want to get 320 mg elemental magnesium from magnesium supplements, you have to take 534 mg magnesium oxide supplements or 2000 mg magnesium citrate.

Objectives:
Lifestyle interventions are an important and viable approach for preventing cognitive deficits. However, the results of studies on alcohol, coffee and tea consumption in relation to cognitive decline have been divergent, likely due to confounds from dose-response effects. Therefore, this review article (meta-analysis) has been conducted.

Does alcohol, coffee or tea consumption reduce the risk of cognitive deficits (such as dementia or Alzheimer's disease)?

Study design:
This review article included 29 prospective cohort studies from America, Japan, China and some European countries (131,777 participants for alcohol, 333,843 participants for coffee and 20,411 participants for tea).

The NOS score was 8.

Results and conclusions:
The investigators found dose-response relationships showed that compared to non-drinkers, low consumption (11 g/day) of alcohol significantly reduced the risk of cognitive deficits or only dementias, but there was no significant effect of heavier drinking (>11 g/day).

The investigators found dose-response relationships showed that compared to non-drinkers, low consumption of coffee significantly reduced the risk of any cognitive deficit (2.8 cups/day) or dementia (2.3 cups/day).
However, coffee drinking was not a significant protective factor for cognitive deficits in groups of average age 60 years.

The investigators found dose-response relationships showed that compared to non-drinkers, every cup of green tea per day significantly reduced risk of cognitive deficits with 6% [relative risk = 0.94, 95% CI = 0.92 to 0.97].  

The investigators concluded that light consumption of alcohol (11 g/day) and coffee (2.8 cups/day) reduces risk of cognitive deficits. Cognitive benefits of green tea consumption increases with the daily consumption.

Original title:
Alcohol, coffee and tea intake and the risk of cognitive deficits: a dose-response meta-analysis by Ran LS, Liu WH, […], Wang W.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8061189/

Additional information of El Mondo:
Find more information/studies on alcohol, coffee and tea consumption and dementia right here.

Objectives:
Do magnesium intakes reduce risk of all-cause, cancer and cardiovascular disease (CVD) mortality?

Study design:
This review article included 19 prospective cohort studies with a total of 1,168,756 participants (52,378 deaths from all causes (all-cause mortality), 23,478 from cardiovascular disease (CVD) and 11,408 from cancer).
The follow-up period was 3.5 to 32 years.

Results and conclusions:
The investigators found dietary magnesium intake was significantly associated with a lower risk of 13% for all-cause mortality [pooled effect size (ES) = 0.87, 95% CI = 0.79 to 0.97, p = 0.009, I2 = 70.7%, p 0.001].

The investigators found dietary magnesium intake was significantly associated with a lower risk of 20% for cancer mortality [pooled ES = 0.80, 95% CI = 0.67 to 0.97, p = 0.023, I2 = 55.7%, p = 0.027].

The investigators found for supplemental and total magnesium intakes, no significant associations with risks of all-cause, cardiovascular disease and cancer mortality.

The investigators found, however, linear dose-response meta-analysis indicated that each additional intake of 100 mg/d of dietary magnesium was significantly associated with a 6% and 5% reduced risk of all-cause and cancer mortality, respectively.

The investigators concluded that higher intake of dietary magnesium (at least 100 mg/d of dietary magnesium) is associated with a reduced risk of all-cause and cancer mortality, but not cardiovascular disease mortality. Supplemental and total magnesium intakes are not associated with the risk of all-cause, cardiovascular disease and cancer mortality. These findings indicate that consumption of magnesium from dietary sources may be beneficial in reducing all-cause and cancer mortality and thus have practical importance for public health.  

Original title:
Total, Dietary, and Supplemental Magnesium Intakes and Risk of All-Cause, Cardiovascular, and Cancer Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Cohort Studies by Bagheri A, Naghshi S, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33684200/

Additional information of El Mondo:
Find more information/studies on magnesium consumption, cardiovascular disease and cancer right here.

Objectives:
Previous population studies on the associations between dietary fatty acids (FAs), plasma FAs levels and the risk of age-related macular degeneration (AMD) have yielded inconclusive results. Therefore, this review article (meta-analysis) has been conducted.

Do higher dietary fatty acids (EPA and DHA) intakes or higher plasma fatty acids levels reduce risk of age-related macular degeneration?

Study design:
This review article included 11 prospective cohort studies with 167,581 participants. During the follow-up periods (ranging from 3 to 28 years), 6,318 cases of age-related macular degeneration were recorded.

Results and conclusions:
The investigators found that each 1 g/day increment of dietary intake of docosahexaenoic acid (DHA) and eicosatetraenoic acid (EPA) combined significantly reduced risk of early age-related macular degeneration with 33% [RR = 0.67, 95% CI = 0.51 to 0.88].
Significantly means that there is an association with a 95% confidence.

The investigators found that each 1 g/day increment of dietary intake of docosahexaenoic acid (DHA) significantly reduced risk of early age-related macular degeneration with 50% [RR = 0.50, 95% CI = 0.32 to 0.78].
Significantly means it can be said with a 95% confidence that each 1 g/day increment of dietary intake of docosahexaenoic acid (DHA) really reduces risk of early age-related macular degeneration with 50%.

The investigators found that each 1 g/day increment of dietary intake of eicosatetraenoic acid (EPA) significantly reduced risk of early age-related macular degeneration with 60% [RR = 0.40, 95% CI = 0.18 to 0.87].
Significantly because RR of 1 was not found in the 95% CI of 0.18 to 0.87. RR of 1 means no risk/association.

The investigators found that higher plasma docosahexaenoic acid (DHA) levels significantly reduced risk of advanced age-related macular degeneration with 28% [RR = 0.72, 95% CI = 0.55 to 0.95].

The investigators found that higher plasma eicosatetraenoic acid (EPA) levels significantly reduced risk of advanced age-related macular degeneration with 43% [RR = 0.57, 95% CI = 0.40 to 0.81].

The investigators concluded that 1 g/day of dietary intake DHA and 1 g/day of dietary intake EPA and higher plasma DHA and EPA levels are associated with a reduced risk of age-related macular degeneration.

Original title:
Dietary fatty acid intake, plasma fatty acid levels, and the risk of age-related macular degeneration (AMD): a dose-response meta-analysis of prospective cohort studies by Zhong Y, Wang K, [...], Yao K.

Link:
https://pubmed.ncbi.nlm.nih.gov/33469697/

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

A high plasma EPA and DHA content can be obtained by eating a lot of oily fish and/or by taking EPA and DHA supplements (fish oil supplements).
Oily fish contains more EPA and DHA than non-oily fish.

Early age-related macular degeneration: most people do not experience adverse symptoms or vision loss in the early stage of age-related macular degeneration, but night vision problems are often reported. Though no pigmentary abnormalities are apparent upon examination, medium-sized drusen (>63 μm and ≤125 μm) are present.

Objectives:
Previous studies on the association between alcohol intake and risk of fracture have reached conflicting findings. Therefore, this review article has been conducted.

Does alcohol consumption increase risk of fractures?

Study design:
This review article included 38 prospective cohort studies with a total sample size of 5,053,117 participants and 169,560 cases of fracture.

Results and conclusions:
The investigators found in a random-effects meta-analysis, that alcohol consumption significantly increased risk of total fractures with 35% [RR = 1.35, 95% CI = 1.01 to 1.81] and any fractures with 24% [RR= 1.24, 95% CI = 1.11 to 1.38].
Significant because RR of 1 was not found in the 95% CI of 1.01 to 1.81. RR of 1 means no risk/association.

The investigators found, however, no significant association between alcohol intake and risk of hip fractures [RR = 1.19, 95% CI = 0.96 to 1.48], osteoporotic fractures [RR = 2.01, 95% CI = 0.76 to 5.34], vertebral fractures [RR = 0.98, 95% CI = 0.68 to 1.40] and wrist fractures [RR = 0.99, 95% CI = 0.85 to 1.16].
No significant because RR of 1 was found in the 95% CI of 0.85 to 1.06. RR of 1 means no risk/association.

The investigators concluded that alcohol consumption is positively associated with risk of total fractures and any fractures.

Original title:
A systematic review and meta-analysis of prospective cohort studies on the association between alcohol intake and risk of fracture by Asoudeh F, Salari-Moghaddam A, […], Esmaillzadeh A.

Link:
https://pubmed.ncbi.nlm.nih.gov/33596741/

Additional information of El Mondo:
Find more information/studies on alcohol and osteoporosis right here.
 

Objectives:
Recent evidence suggests that diet can modify the risk of future cognitive impairment and dementia. A biologically plausible rationale and initial clinical data indicate that the antioxidant activities of dietary carotenoids may assist the preservation of cognitive function. Therefore, this review article has been conducted.

Does carotenoid supplementation improve cognitive performance among healthy adults?

Study design:
This review article included 9 RCTs, involving 2,228 subjects in the treated group (group with carotenoid supplementation) and 2,174 subjects in control group (group without carotenoid supplementation).
The age of all participants varied from 45 to 78 years.
The majority of clinical trials assessed the effect of xanthophylls such as lutein, zeaxanthin, and astaxanthin, whereas only 1 study determined the effects of β-carotene.
The duration of carotenoid supplementation ranged from 2 weeks to 12 months.
The dosage of carotenoids administered in the studies ranged from 0.5 mg/d to 50 mg/d.
There was no evidence of publication bias.

Results and conclusions:
The investigators found results of the pooled meta-analysis showed a significant effect of carotenoid intervention on cognitive outcomes [Hedge's g = 0.14, 95% CI = 0.08 to 0.20, p 0.0001, I2 = 0.00%].
The sensitivity analysis did not change the overall findings obtained from the primary analysis.

The investigators concluded that these results highlight the potential role of carotenoids (0.5 mg/d to 50 mg/d) in the protection of mental functions even in subjects (healthy participants aged 45-78 years) without cognitive impairment. This is particularly important because the population is aging and preservation of cognitive function is crucial for individual autonomy and quality of life, even in non-demented subjects. Further well-powered and long-term trials are required to determine treatment duration, type of carotenoid and optimal dosage.

Original title:
Carotenoids and Cognitive Outcomes: A Meta-Analysis of Randomized Intervention Trials by Davinelli S, Ali S, […], Corbi G.

Link:
https://www.mdpi.com/2076-3921/10/2/223/htm

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

Objectives:
Increasing macular pigment optical density (MPOD) as a result of increased macular concentration of lutein and zeaxanthin may reduce the risk of age-related macular degeneration (AMD). Therefore, this review article has been conducted.

Have daily egg consumption beneficial effects on macular pigment optical density and serum lutein levels?

Study design:
This review article included 5 RCTs with a total of 296 participants.
There was no heterogeneity between studies.

Results and conclusions:
The investigators found that egg consumption significantly increased macular pigment optical density [WMD = +0.037, 95% CI = 0.004 to 0.069, p = 0.027] and serum lutein levels [WMD = +0.150 μmol/L, 95% CI = 0.037 to 0.263, p = 0.009].

The investigators found subgroup analyses showed that egg consumption had a larger effect on macular pigment optical density in studies with a parallel design and increased serum lutein levels to a greater extent in a healthy population.

The investigators concluded daily egg consumption have beneficial effects on macular pigment optical density and serum lutein level is inversely associated with reduced age-related macular degeneration progression. Further clinical trials are required to confirm the results of this review article.

Original title:
A positive effect of egg consumption on macular pigment and healthy vision: a systematic review and meta-analysis of clinical trials by Sikaroudi MK, Saraf-Bank S, […], Soltani S.

Link:
https://pubmed.ncbi.nlm.nih.gov/33491232/

Additional information of El Mondo:
Find here more information/studies about review article/significant, egg consumption and elderly diseases.
 

Objectives:
Does a high dietary intake of β-cryptoxanthin reduce the risk of osteoporosis and hip fracture?

Study design:
This review article included 7 cohort studies, 4 case-control studies and 4 cross-sectional studies with a total of 100,496 individuals.
The methodological qualities of all studies were rated as “fair” to “good”.
The number of populations in each study ranged from 59 to 25,566.

Results and conclusions:
The investigators found that a high dietary intake of β-cryptoxanthin significantly reduced risk of osteoporosis with 24% [OR = 0.76, 95% CI = 0.66 to 0.88, p = 0.0002, I2 = 36%, p = 0.11].

The investigators found in subgroup analysis that a high dietary intake of β-cryptoxanthin significantly reduced risk of osteoporosis with 28% [OR = 0.72, 95% CI = 0.58 to 0.91, p = 0.005, I2 = 59%] among women.

The investigators found in subgroup analysis that a high dietary intake of β-cryptoxanthin significantly reduced risk of osteoporosis with 20% [OR = 0.80, 95% CI = 0.65 to 1.00, p = 0.005, I2 = 11%] among men.

The investigators found that a high dietary intake of β-cryptoxanthin significantly reduced risk of hip fracture with 28% [OR = 0.72, 95% CI = 0.60 to 0.87, p = 0.0008, I2 = 55%].

The investigators found in subgroup analysis that a high dietary intake of β-cryptoxanthin significantly reduced risk of hip fracture with 29% [OR = 0.71, 95% CI = 0.54 to 0.94, p = 0.02, I2 = 71%] among women. 

The investigators concluded that a high dietary intake of β-cryptoxanthin reduces the risk of osteoporosis and hip fracture. Further longitudinal studies are needed to validate the causality of current findings.

Original title:
Effects of β-Cryptoxanthin on Improvement in Osteoporosis Risk: A Systematic Review and Meta-Analysis of Observational Studies by Kim SJ, Anh NH, […], Kwon SW.

Link:
https://www.mdpi.com/2304-8158/10/2/296/htm

Additional information of El Mondo:
Find more information/studies on β-cryptoxanthin and osteoporosis right here.
 

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:
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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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/

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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:
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

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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

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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:
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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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

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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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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

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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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