Nutrition and health

Objectives:
Do omega-3 fatty acid supplements (EPA and DHA) improve sarcopenia-related performances among the elderly?

Study design:
This review article included 10 RCTs with 552 participants.
The number of study participants ranged from 24 to 126 and the durations of the interventions spanned 10 to 24 weeks.
The doses ranged from 0.16 to 2.6 g/day of EPA and from 0 to 1.8 g/day of DHA.
The mean ages of the participants across the RCTs ranged from 63 to 75 years old.

Results and conclusions:
The investigators found in subgroup analyses that omega-3 fatty acid supplements (EPA and DHA) at more than 2 g/day significantly increased muscle mass among the elderly [SMD = 0.67 kg, 95% CI = 0.16 to 1.18, p 0.05].

The investigators found in subgroup analyses that omega-3 fatty acid supplements (EPA and DHA) during more than 6 months significantly improved walking speed among the elderly [SMD = 1.78 m/sec, 95% CI = 1.38 to 2.17, p 0.05].

The investigators concluded that taking at least 2 grams of omega-3 supplements (EPA and DHA) per day increases muscle mass among the elderly, while taking omega-3 supplements for at least 6 months increases walking speed among the elderly.

Original title:
Effects of Omega-3 Fatty Acids on Muscle Mass, Muscle Strength and Muscle Performance among the Elderly: A Meta-Analysis by Huang YH, Chiu WC, […], Wang YH.

Link:
https://www.mdpi.com/2072-6643/12/12/3739/htm

Additional information of El Mondo:
Find more information/studies on EPA and DHA consumption and elderly right here.
EPA and DHA are present in fish.
 

Objectives:
Does calcium combined with vitamin D supplementation reduce risk of osteoporosis in postmenopausal women?

Study design:
This review article included 10 RCTs.

Results and conclusions:
The investigators found calcium combined with vitamin D supplementation significantly increased total bone mineral density [SMD = 0.537, 95% CI = 0.227 to 0.847] in postmenopausal women.

The investigators found calcium combined with vitamin D supplementation significantly increased lumbar spine bone mineral density [SMD = 0.233, 95% CI = 0.073 to 0.392, p 0.001] in postmenopausal women.

The investigators found calcium combined with vitamin D supplementation significantly increased arms bone mineral density [SMD = 0.464, 95% CI = 0.186 to 0.741] in postmenopausal women.

The investigators found calcium combined with vitamin D supplementation significantly increased femoral neck bone mineral density [SMD = 0.187, 95% CI = 0.010 to 0.364] in postmenopausal women.

The investigators found calcium combined with vitamin D supplementation significantly reduced risk of hip fracture with 13.6% [RR = 0.864, 95% CI = 0.763 to 0.979] in postmenopausal women.

The investigators found in subgroup analysis that calcium combined with 400 IU/d (10 mcg/d) vitamin D supplementation significantly increased femoral neck bone mineral density [SMD = 0.335, 95% CI = 0.113 to 0.558] in postmenopausal women.

The investigators found in subgroup analysis that dairy products fortified with calcium and vitamin D significantly increased total bone mineral density [SMD = 0.784, 95% CI = 0.322 to 1.247] in postmenopausal women.

The investigators found in subgroup analysis that dairy products fortified with calcium and vitamin D significantly increased lumbar spine bone mineral density [SMD = 0.320, 95% CI = 0.146 to 0.494] in postmenopausal women.

The investigators concluded that dairy products fortified with calcium and vitamin D have a favourable effect on bone mineral density. Furthermore, calcium combined with vitamin D supplementation could prevent osteoporosis hip fracture in postmenopausal women.

Original title:
Effects of combined calcium and vitamin D supplementation on osteoporosis in postmenopausal women: a systematic review and meta-analysis of randomized controlled trials by Liu C, Kuang X […], Li D.

Link:
https://pubmed.ncbi.nlm.nih.gov/33237064/

Additional information of El Mondo:
Find more information/studies on dairy products consumption, calcium and vitamin D right here.

Objectives:
Isoflavones have a structure similar to 17β-estradiol, so they may be useful to postmenopausal women in preventing bone loss related to estrogen deficiency. Therefore, this review article has been conducted.

Do isoflavone supplements increase bone mineral density (BMD) in postmenopausal women?

Study design:
This review article included 63 RCTs, involving 6,427 postmenopausal women.

Isoflavone interventions were generally safe and well tolerated.

Results and conclusions:
The investigators found statistically significant differences in bone mineral density at the last follow-up visit between the two groups (isoflavones vs. control) at the lumbar spine [MD = 21.34 mg/cm², 95% CI = 8.21 to 34.47 mg/cm², p = 0.001], the femoral neck [MD = 28.88 mg/cm², 95% CI = 15.05 to 42.71 mg/cm², p 0.0001] and the distal radius [MD = 19.27 mg/cm², 95% CI = 5.65 to 32.89 mg/cm², p = 0.006].
This improved bone mineral density was found for genistein 54 mg/day and ipriflavone (a synthetic isoflavone) 600 mg/day.

The investigators concluded isoflavone interventions, genistein (54 mg/day) and ipriflavone (600 mg/day) in particular, have beneficial effects on bone mineral density outcomes and are safe in postmenopausal women. They may be considered as a complementary or alternative option in the prevention and treatment of menopause-related osteoporosis.

Original title:
Effects of Isoflavone Interventions on Bone Mineral Density in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Sansai K, Takuathung MN, [...], Koonrungsesomboon N.

Link:
https://pubmed.ncbi.nlm.nih.gov/32524173/

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

Objectives:
Has oral supplementation of vitamin B (vitamins B1, B6, B12 and folic acid alone or combined) preventive effect on cognitive decline in cognitively unimpaired individuals?

Study design:
This review article included 20 RCTs, ranging from 23 to 2,919 participants per study, with a total of 12,697 participants.
8 of these 20 RCTs were deemed appropriate for the meta-analysis.

Results and conclusions:
The investigators found meta-analysis did not yield a significant overall effect of supplementation with vitamin B on cognitive function [SMD = 0.02, 95% CI = -0.034 to 0.08]. A sensitivity analysis focusing on specific risk factors did not alter this result.
Some studies reported isolated significant effects of the intervention on secondary outcomes. However, these findings were outnumbered by the number of cognitive tests that did not yield significant effects.

The investigators concluded there is no overall evidence that oral vitamin B supplementation prevent cognitive decline in cognitively unimpaired individuals. The results of this review do not provide evidence that population groups with certain risk factors would profit more from the intervention than others.

Original title:
Vitamin B-Can It Prevent Cognitive Decline? A Systematic Review and Meta-Analysis by Behrens A, Graessel E, [...], Donath C.

Link:
https://systematicreviewsjournal.biomedcentral.com/articles/10.1186/s13643-020-01378-7

Additional information of El Mondo:
Find more information/studies on vitamins B1, B6, B12 and folic acid and dementia right here.

Objectives:
Previous studies did not draw a consistent conclusion about the effects of vitamin K combined with vitamin D on human skeletal quality. Therefore, this review article has been conducted.

Does vitamin K combined with vitamin D supplementation increase bone mineral density (BMD)?

Study design:
This review article included 8 RCTs with a total of 971 participants.

Results and conclusions:
The investigators found vitamin K combined with vitamin D supplementation significantly increased total bone mineral density (BMD) [pooled effect size = 0.316, 95% CI = 0.031 to 0.601].

The investigators found vitamin K combined with vitamin D supplementation significantly decreased levels of undercarboxylated osteocalcin [effect size = -0.945, 95% CI = -1.113 to -0.778].

The investigators found simultaneously, subgroup analysis showed that K2 or vitamin K (not specified) supplement less than 500 μg/d, when combined with vitamin D significantly increased total bone mineral density compared with the control group fed a normal diet or the group with no treatment [effect size = 0.479, 95% CI = 0.101 to 0.858 and effect size = 0.570, 95% CI = 0.196 to 0.945, respectively).

The investigators concluded the combination of vitamin K and D supplement increases the total bone mineral density (BMD) and decreases levels of undercarboxylated osteocalcin and a more favorable effect is expected when less than 500 μg/d vitamin K2 is used.

Original title:
The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trials by Kuang X, Liu C, […], Li D.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32219282

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

Undercarboxylated osteocalcin represents inadequately carboxylated osteocalcin and this fraction increases with vitamin K insufficiency.

Objectives:
Is there a causal relationship between dietary intake of dairy products and a positive effect on bone mineral density (BMD) in healthy postmenopausal women?

Study design:
This review article included 6 RCTs with a total of 618 participants. Milk was the main dairy product used in the trials.

Results and conclusions:
The investigators found there was a significant association between dairy product consumption and bone mineral density of the lumbar spine [SMD = 0.21, 95% CI = 0.05 to 0.37, p = 0.009], femoral neck [SMD = 0.36, 95% CI = 0.19 to 0.53, p  0.001], total hip [SMD = 0.37, 95% CI = 0.20 to 0.55, p  0.001] and total body [SMD = 0.58, 95% CI = 0.39 to 0.77, p  0.001].

The investigators found subgroup analysis showed a positive effect of dairy product consumption on the bone mineral density of the total hip starting from 12 months and the femoral neck starting from 18 months. There was also a positive association with the bone mineral density in the 4 sites in people living in low-calcium intake countries.

The investigators concluded that there is a causal relationship between dietary intake of dairy products, particularly milk during at least 12 months and a positive effect on bone mineral density (BMD) in healthy postmenopausal women. Therefore, dairy product consumption should be considered an effective public health measure to prevent osteoporosis in postmenopausal women.

Original title:
Effects of dairy products on bone mineral density in healthy postmenopausal women: a systematic review and meta-analysis of randomized controlled trials by Shi Y, Zhan Y, [...], Jiang Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32185512

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

Menopause is the point when a woman no longer has menstrual periods for at least 12 months. Postmenopause is the stage after menopause.

Objectives:
Does a high LDL cholesterol level (bad cholesterol) increase risk of Alzheimer's disease (AD)?

Study design:
This review article included 26 case-control studies involving 7,033 participants (2,266 Alzheimer's disease patients and 4,767 non-dementia controls).

There was no significant evidence of publication bias according to the results of Egger's test [p = 0.084].

Results and conclusions:
The investigators found results from the meta-analysis of 26 studies revealed higher levels of LDL cholesterol (>121 mg/dL) in Alzheimer's disease than that of non-dementia controls [SMD = 0.35, 95% CI = 0.12 to 0.58, p 0.01], which was consistent with the results of the fixed-effect model [SMD = 0.16, 95% CI = 0.10 to 0.22, p 0.01].
Sensitivity analyses showed that no single study exerted substantial influence on the pooled effect size after sequentially omitting a study.

The investigators found subgroup analysis of age showed LDL cholesterol levels in Alzheimer's disease patients aged 60-70 were higher than that of non-dementia [60 ≤ age 70: SMD = 0.80, 95% CI = 0.23 to 1.37, p 0.01].  

The investigators concluded that elevated concentration of LDL cholesterol (>121 mg/dL) is a risk factor for Alzheimer's disease. This strong association is significant in patients with Alzheimer's disease aged 60-70 years, but vanishes with increasing age. This review article provides a promising strategy for reducing the risk of Alzheimer's disease in patients with hyperlipidemia, which may be achieved by regulating LDL cholesterol concentration between 103.9 and 121 mg/dL with statins. Prospective studies that exclude potential confounders, more scientific design and adequate long-term follow-up are needed to validate this hypothesis.

Original title:
Low-Density Lipoprotein Cholesterol and Alzheimer's Disease: A Systematic Review and Meta-Analysis by Zhou Z, Liang Y, […], Zhao M.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7002548/

Additional information of El Mondo:
Find more information/studies on cholesterol and Alzheimer's disease right here.
 

Objectives:
Several epidemiological studies have been performed to evaluate the association of dietary intake of vitamin C-oriented foods (DIVCF) with risk of fracture and bone mineral density (BMD) loss, but the results remain controversial. Therefore, this review article has been conducted.

Does dietary intake of vitamin C-oriented foods decrease risk of fracture and bone mineral density loss?

Study design:
This review article included 4 cohort studies, 11 case-control studies and 2 cross-sectional studies with a total of 19,484 subjects.

The studies received a quality score of ≥5, indicating that the methodological quality of the studies was generally good.

No evidence of publication bias was found in the evaluation of dietary intake of vitamin C-oriented foods and the risk of hip fracture.

Results and conclusions:
The investigators found that the people with a higher dietary intake of vitamin C-oriented foods had a significantly 34% [RR = 0.66, 95% CI = 0.47 to 0.94, I2 = 79.5%, p = 0.000] lower risk of hip fracture.

The investigators found that the people with a higher dietary intake of vitamin C-oriented foods had a significantly 42% [RR = 0.58, 95% CI = 0.38 to 0.89] lower risk of hip fracture in case-control studies.
However, this reduced risk was not significant in cohort studies [RR = 0.92, 95% CI = 0.59 to 1.44]. 

The investigators found that the people with a higher dietary intake of vitamin C-oriented foods had a significantly 34% [RR = 0.66, 95% CI = 0.48 to 0.92] lower risk of osteoporosis.

The investigators found higher dietary intake of vitamin C-oriented foods was negatively associated with the risk of bone mineral density loss at the lumbar spine [pooled r = 0.15, 95% CI = 0.09 to 0.23] and at the femoral neck [pooled r = 0.20, 95% CI = 0.11 to 0.34].

The investigators concluded that higher dietary intake of vitamin C-oriented foods reduces the risk of hip fracture, osteoporosis and bone mineral density loss, suggesting that people should consume more vitamin C to decrease the risk of hip fracture, osteoporosis and bone mineral density loss, particularly lumbar spine and femoral neck.

Original title:
Can Dietary Intake of Vitamin C-Oriented Foods Reduce the Risk of Osteoporosis, Fracture, and BMD Loss? Systematic Review With Meta-Analyses of Recent Studies by Zeng LF, Luo MH, […], Liu J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7008177/

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

Objectives:
Current evidence on associations between intakes of linoleic acid (LA), the predominant n-6 (ω-6) fatty acid and mortality is inconsistent and has not been summarized by a systematic review and meta-analysis. Therefore, this review article has been conducted.

Does higher linoleic acid intake, assessed by dietary surveys or biomarkers decrease mortality from all causes, cardiovascular disease (CVD) and cancer?

Study design:
This review article included 44 prospective cohort studies with 811,069 participants with dietary intake assessment (170,076 all-cause, 50,786 cardiovascular disease and 59,684 cancer deaths) and 65,411 participants with biomarker measurements (9,758 all-cause, 6,492 cardiovascular disease and 1,719 cancer deaths).

Meta-regressions suggested baseline age and dietary assessment methods as potential sources of heterogeneity for the association between linoleic acid and total mortality.

Results and conclusions:
The investigators found when compared with the lowest categories of dietary linoleic acid intake, that the highest categories of dietary linoleic acid intake significantly reduced total mortality risk with 13% [pooled RR = 0.87, 95% CI = 0.81 to 0.94, I2 = 67.9%].

The investigators found when compared with the lowest categories of dietary linoleic acid intake, that the highest categories of dietary linoleic acid intake significantly reduced cardiovascular disease mortality risk with 13% [pooled RR = 0.87, 95% CI = 0.82 to 0.92, I2 = 3.7%].

The investigators found when compared with the lowest categories of dietary linoleic acid intake, that the highest categories of dietary linoleic acid intake significantly reduced cancer mortality risk with 11% [pooled RR = 0.89, 95% CI = 0.85 to 0.93, I2 = 0%].

The investigators found for each standard deviation increment in linoleic acid concentrations in adipose tissue/blood compartments a significantly reduced total mortality risk of 9% [pooled RR = 0.91, 95% CI = 0.87 to 0.95, I2 = 64.1%].

The investigators found for each standard deviation increment in linoleic acid concentrations in adipose tissue/blood compartments a significantly reduced cardiovascular disease mortality risk of 11% [pooled RR = 0.89, 95% CI = 0.85 to 0.94, I2 = 28.9%].

The investigators found for each standard deviation increment in linoleic acid concentrations in adipose tissue/blood compartments a significantly reduced cancer mortality risk of 9% [pooled RR = 0.91, 95% CI = 0.84 to 0.98, I2 = 26.3%].

The investigators concluded higher linoleic acid intake, assessed by dietary surveys or biomarkers, reduces risk of mortality from all causes, cardiovascular disease and cancer. These data support the potential long-term benefits of PUFA intake in lowering the risk of cardiovascular disease and premature death.

Original title:
Dietary intake and biomarkers of linoleic acid and mortality: systematic review and meta-analysis of prospective cohort studies by Li J, Guasch-Ferré M, […], Hu FB.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32020162

Additional information of El Mondo:
Find more information/studies on linoleic acid intake and mortality right here.
Linoleic acid is a PUFA.
 

Objectives:
Alzheimer's disease (AD) is a common type of dementia, which has caused heavy global economic and health burden and the using of statins to treat Alzheimer disease has caused widely debated. Therefore, this review article has been conducted.

Does statin use decrease Alzheimer disease?

Study design:
This review article included a total of 9 RCTs containing 1,489 patients. Of them, 742 patients in the statins group, 747 patients in the control group (group without statins).

There were 9 studies used the MMSE scale, 5 studies used the ADAS-Cog scale, 4 studies used the NPI scale and 6 studies used the ADL scale.

Sensitivity analysis and publication bias test were both negative and the results were relatively reliable and stable.

Results and conclusions:
The investigators found meta-analysis of the 9 studies that reported the MMSE scale scores indicated that there was no significant effect of statins as compared with control group [pooled WMD = 1.09, 95% CI = -0.00 to 2.18, p = 0.05, I2 = 87.9%].

The investigators found meta-analysis of the 5 studies that reported the ADAS-Cog scale scores also indicated that there was no significant effect of statins as compared with control group [pooled WMD = -0.16, 95% CI = -2.67 to 2.36, p = 0.90, I2 = 80.1%].

The investigators found meta-analysis of the 4 studies that reported the NPI scale scores indicated that treatment with statins significantly slowed the rise in the NPI scale scores as compared with control group [pooled WMD = -1.16, 95% CI = -1.88 to -0.44, p = 0.002, I2 = 45.4%].

The investigators found meta-analysis of the 6 studies that reported the ADL scale scores indicated that treatment with statins significantly improve patients' daily living ability [pooled WMD = -4.06, 95% CI = -6.88 to -1.24, p = 0.005, I2 = 86.7%].

The investigators found results of subgroup analysis indicated that the use of statins in the short term (≤ 12 months) associated with the change of the MMSE scale scores [pooled WMD = 1.78, 95% CI = 0.53 to 3.04, p = 0.005, I2 = 79.6%].

The investigators concluded statins used in Alzheimer disease patients have beneficial effects on the scores of MMSE scale in the short term (≤ 12 months) and statins slow the deterioration of neuropsychiatric status and improve activities of daily living ability in Alzheimer disease patients.

Original title:
The efficacy of statins in the treatment of Alzheimer's disease: a meta-analysis of randomized controlled trial by Xuan K, Zhao T, […], Sun Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31930449

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

Objectives:
Despite growing evidence for the association between other dietary macronutrients and bone health, limited and inconsistent knowledge is available regarding carbohydrate intake. Therefore, this review article has been conducted.

Does a high carbohydrate intake increase risk of fracture?

Study design:
This review article included observational studies.

Results and conclusions:
The investigators found no association between carbohydrate intake and the risk of fracture in high versus low intake meta-analysis [overall relative risk = 1.24, 95% CI = 0.84 to 1.84, p = 0.27, I2 = 57.7%, p = 0.05].

The investigators found, moreover, there was no relationship between carbohydrate intake and the risk of fracture in both linear [overall RR = 1.00, 95% CI = 0.94 to 1.05, p = 0.88, I2 = 68.1%, p = 0.48] and nonlinear [p non-linearity = 0.14] models.

The investigators concluded high carbohydrate intake does not increase risk of fracture.

Original title:
Dietary carbohydrate intake and risk of bone fracture: a systematic review and meta-analysis of observational studies by Mozaffari H, Daneshzad E and Azadbakht L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31982636

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

Objectives:
Which factors increase risk of dementia?

Study design:
This review article included 34 prospective cohort studies, among which 24 were eligible for meta-analysis. A total of 159,594 non-demented adults were enrolled at baseline before 65 years and 13,540 people were diagnosed with dementia after follow-up.

Results and conclusions:
The investigators found obesity significantly increased risk of dementia with 78% [RR = 1.78, 95% CI = 1.31-2.41].

The investigators found diabetes mellitus significantly increased risk of dementia with 69% [RR = 1.69, 95% CI = 1.38-2.07].

The investigators found current smoking significantly increased risk of dementia with 61% [RR = 1.61, 95% CI = 1.32-1.95].

The investigators found hypercholesterolemia significantly increased risk of dementia with 57% [RR = 1.57, 95% CI = 1.19-2.07].
However, the sensitivity analyses showed that the result of hypercholesterolemia was not reliable, which need to be confirmed by more high-quality studies.

The investigators found hypertension significantly increased risk of dementia with 41% [RR = 1.41, 95% CI = 1.23-1.62] for borderline blood pressure.

The investigators found hypertension significantly increased risk of dementia with 72% [RR = 1.72, 95% CI = 1.25-2.37] for high systolic blood pressure.
However, the sensitivity analyses showed that the result of high systolic blood pressure was not reliable, which need to be confirmed by more high-quality studies.

The investigators found hyperhomocysteinemia, psychological stress and heavy drinking were also associated with elevated dementia risk.

The investigators found, in addition, physical exercise, a healthy diet and hormone therapy in middle age were associated with the reduction of dementia risk.

The investigators concluded middle-aged people with obesity or diabetes and current smokers in midlife are at higher risk of developing dementia later in life.

Original title:
Midlife Modifiable Risk Factors for Dementia: A Systematic Review and Meta-analysis of 34 Prospective Cohort Studies by Li XY, Zhang M, [...], Tan L.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31902364

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

Objectives:
Is there a relationship between the levels of vitamin C, vitamin E and β-carotene in the plasma and Alzheimer's disease risk?

Study design:
This review article included studies with data of levels of vitamin C, vitamin E and β-carotene in the plasma of Alzheimer's disease patients.

Results and conclusions:
The investigators found meta-analysis showed that, compared with the control group, the level of vitamin E in the plasma of Alzheimer's disease patients declined significantly [SMD = -1.49 μmol/L, 95% CI = -2.08 to -0.89 μmol/L, p 0.001].

However, no differences were determined in the levels of the plasma vitamin C and β-carotene between the two groups [vitamin C: SMD = -1.43 μmol/L, 95% CI = -3.05 to 0.19 μmol/L, p = 0.083 and β-carotene: SMD = -0.61 μmol/L, 95% CI = -1.40 to 0.18 μmol/L, p = 0.131].

The investigators concluded increasing vitamin E level in the plasma through vitamin E riched diet is useful to prevent Alzheimer's disease. However, it is not yet believed the beneficial role on Alzheimer's disease to increase vitamin C and β-carotene.

Original title:
Meta-analysis of vitamin C, vitamin E and β-carotene levels in the plasma of Alzheimer's disease patients by Dong R, Yang Q, […], Zhao H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30081996  

Additional information of El Mondo:
Find more information/studies on vitamin E, C, β-carotene and dementia right here.
 

Objectives:
Although several studies have been conducted on the association of vitamins with glaucoma, it is often noticed that the results are conflicting leaving physicians and patients in doubt about the effect of vitamins on glaucoma. Therefore, this review article has been conducted.

Does dietary vitamin intake reduce risk of the eye disease glaucoma? 

Study design:
This review article included 5 cohort studies with a total of 940 open-angle glaucoma (OAG) cases and 123,697 controls (persons without open-angle glaucoma).

Results and conclusions:
The investigators found a significantly reduced risk of 55% [pooled OR = 0.45, 95% CI = 0.30-0.68, I2 = 0%] for open-angle glaucoma for dietary intake of vitamin A.

The investigators found a significantly reduced risk of 61% [pooled OR = 0.39, 95% CI = 0.23-0.67, I2 = 0%] for open-angle glaucoma for dietary intake of vitamin C.

The investigators found a significantly reduced risk of 61% [pooled OR = 0.39, 95% CI = 0.22-0.70, I2 = 0%] for open-angle glaucoma for dietary intake of green leafy vegetables (a source for vitamin A, C and nitrate).

The investigators concluded dietary intake of vitamin A, C and green leafy vegetables show a beneficial association with the eye disease open-angle glaucoma.

Original title:
The Effect of Vitamins on Glaucoma: A Systematic Review and Meta-Analysis by Ramdas WD, Schouten JSAG and Webers CAB.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5872777/

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

Objectives:
The associations of various dietary or circulating antioxidants with the risk of all-cause mortality in the general population have not been established yet. Therefore, this review article has been conducted.

Do dietary or circulating antioxidants reduced risk of all-cause mortality in the general population?

Study design:
This review article included 41 prospective observational studies with a total of 507,251 participants and 73,965 cases of all-cause mortality.

Results and conclusions:
The investigators found for the highest compared with the lowest category of circulating total carotenes concentrations a significantly reduced risk of 40% [RR = 0.60, 95% CI = 0.46 to 0.74] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating vitamin C concentrations a significantly reduced risk of 39% [RR = 0.61, 95% CI = 0.53 to 0.69] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating selenium concentrations a significantly reduced risk of 38% [RR = 0.62, 95% CI = 0.45 to 0.79] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating β-carotene concentrations a significantly reduced risk of 37% [RR = 0.63, 95% CI = 0.57 to 0.70] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating α-carotene concentrations a significantly reduced risk of 32% [RR = 0.68, 95% CI = 0.58 to 0.78] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating total carotenoids concentrations a significantly reduced risk of 32% [RR = 0.68, 95% CI = 0.56 to 0.80] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating lycopene concentrations a significantly reduced risk of 25% [RR = 0.75, 95% CI = 0.54 to 0.97] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of circulating α-tocopherol concentrations a significantly reduced risk of 16% [RR = 0.84, 95% CI = 0.77 to 0.91] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of total carotenoids a significantly reduced risk of 24% [RR = 0.76, 95% CI = 0.66 to 0.85] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of total antioxidants a significantly reduced risk of 23% [RR = 0.77, 95% CI = 0.73 to 0.81] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of selenium a significantly reduced risk of 21% [RR = 0.79, 95% CI = 0.73 to 0.85] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of α-carotene a significantly reduced risk of 21% [RR = 0.79, 95% CI = 0.63 to 0.94] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of β-carotene a significantly reduced risk of 18% [RR = 0.82, 95% CI = 0.77 to 0.86] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of vitamin C a significantly reduced risk of 12% [RR = 0.88, 95% CI = 0.83 to 0.94] for all-cause mortality.  

The investigators found for the highest compared with the lowest category of dietary intakes of total carotenes a significantly reduced risk of 11% [RR = 0.89, 95% CI = 0.81 to 0.97] for all-cause mortality.  

The investigators found for the highest compared with the lowest category a nonsignificant inverse association between dietary zinc, zeaxanthin, lutein and vitamin E and all-cause mortality risk.

The investigators found in nonlinear dose-response meta-analyses a linear inverse association in the analyses of dietary β-carotene and total antioxidant capacity, as well as in the analyses of circulating α-carotene, β-carotene, selenium, vitamin C and total carotenoids.

The investigators found the association appeared to be U-shaped in the analyses of serum lycopene and dietary vitamin C.

The investigators concluded that a diet with high antioxidant properties reduces the risk of all-cause mortality. These findings confirm current recommendations that promote higher intake of antioxidant-rich foods such as fruit and vegetables.

Original title:
Dietary Antioxidants, Circulating Antioxidant Concentrations, Total Antioxidant Capacity, and Risk of All-Cause Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Observational Studies by Jayedi A, Rashidy-Pour A, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30239557

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Objectives:
Low carbohydrate diets, which restrict carbohydrate in favour of increased protein or fat intake, or both, are a popular weight-loss strategy. However, the long-term effect of carbohydrate restriction on mortality is controversial and could depend on whether dietary carbohydrate is replaced by plant-based or animal-based fat and protein. Therefore, this review article has been conducted.

Is there a relationship between carbohydrate diet and all-cause mortality?

Study design:
This review article included 8 cohort studies with a total of 432,179 participants, of which 40,181 deaths.

Results and conclusions:
The investigators found in the meta-analysis of 8 cohort studies, low carbohydrate consumption (40 En%) significantly increased all-cause mortality risk with 20% [pooled HR = 1.20, 95% CI = 1.09-1.32].

The investigators found in the meta-analysis of 8 cohort studies, high carbohydrate consumption (>70 En%) significantly increased all-cause mortality risk with 23% [pooled HR = 1.23, 95% CI = 1.11-1.36].

The investigators found, however, results varied by the source of macronutrients: all-cause mortality increased when carbohydrates were exchanged for animal-derived fat or protein [HR = 1.18, 95% CI = 1.08-1.29] and all-cause mortality decreased when the substitutions were plant-based [HR = 0.82, 95% CI = 0.78-0.87].

The investigators found a U-shaped relationship between carbohydrate intake and all-cause mortality, with minimum risk observed with 50-55% of energy from carbohydrate.

The investigators concluded that both high (>70 En%) and low percentages of carbohydrate diets (40 En%) are associated with increased all-cause mortality, with minimal risk observed at 50-55 En% carbohydrate intake. Low carbohydrate dietary patterns favouring animal-derived protein and fat sources, from sources such as lamb, beef, pork and chicken, are associated with higher all-cause mortality, whereas those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter and whole-grain breads, are associated with lower all-cause mortality, suggesting that the source of food notably modifies the association between carbohydrate intake and all-cause mortality.

Original title:
Dietary carbohydrate intake and mortality: a prospective cohort study and meta-analysis by Seidelmann SB, Claggett B, […], Solomon SD.

Link:
https://www.thelancet.com/journals/lanpub/article/PIIS2468-2667(18)30135-X/fulltext

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The most easy way to follow a diet with 50-55 En% carbohydrates is to choose only meals/products with 50-55 En% carbohydrates.
However, the most practical way to follow a diet with 50-55 En% carbohydrates is all meals/products that you eat on a daily basis should contain on average 50-55 En% carbohydrates. Check here which products contain 50-55 En% carbohydrates.
 

Objectives:
Oxidative stress has been found to be implicated in the development of Alzheimer's disease (AD). Therefore, this review article has been conducted.

Is there an association between selenium level in the brain and Alzheimer’s disease? 

Study design:
This review article included 14 studies with 40 observations on selenium concentrations in Alzheimer’s disease and control brains (persons without Alzheimer’s disease).

The effect size as standardized mean difference (SMD) was generated using review manager 5.3.

The funnel plot with Egger's [p = 0.88] and Begg's tests [p = 0.24] detected no significant publication bias.

Results and conclusions:
The investigators found random-effects meta-analysis indicated a decrease [SMD = - 0.42] in brain tissue selenium levels in patients with Alzheimer’s disease as compared to non-Alzheimer’s disease controls.
The results of sensitivity analysis indicated that no single study/observation had significantly influenced the overall outcome.

The investigators found the subgroup meta-analysis demonstrated that the selenium levels were decreased in the temporal, hippocampal and cortex regions of the brains in patients with Alzheimer’s disease.
The results of sensitivity analysis indicated that no single study/observation had significantly influenced the overall outcome.

The investigators concluded there is consolidated evidence for a significant decrease of selenium status in Alzheimer’s disease brains compared to controls (persons without Alzheimer’s disease). In line with the evidence supporting selenium's antioxidant role and the involvement of oxidative stress in Alzheimer’s disease development, these findings support new therapeutic strategies aimed at brain tissue selenium homeostasis in Alzheimer’s disease.

Original title:
Brain Selenium in Alzheimer's Disease (BRAIN SEAD Study): a Systematic Review and Meta-Analysis by Varikasuvu SR, Prasad VS, [...], Manne M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/30171594

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Objectives:
Total dietary fat intake might influence the risk of fracture; however, conflicting findings have been reported to date. Therefore, this review article has been conducted.

Is there an association between dietary fat intake and risk of fracture?

Study design:
This review article included 6 observational studies.

Results and conclusions:
The investigators found no significant association between total dietary fat intake and risk of fracture [pooled effect size = 1.31, 95% CI = 0.95-1.79, p = 0.09].

The investigators found dietary saturated fat intake significantly increased risk of fracture with 79% [pooled effect size = 1.79, 95% CI = 1.05-3.03, p = 0.03].

The investigators found dietary monounsaturated fatty acids (MUFAs) intake derived from animal sources significantly increased risk of fracture with 129% [pooled effect size = 2.29, 95% CI = 1.50-3.50, p 0.0001].

The investigators concluded that both dietary saturated fat and monounsaturated fatty acids (MUFAs) intake derived from animal sources increase risk of fracture.

Original title:
Dietary fat, saturated fatty acid, and monounsaturated fatty acid intakes and risk of bone fracture: a systematic review and meta-analysis of observational studies by Mozaffari H, Djafarian K, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29947872

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A diet high in saturated fat is a diet that is largely made up of meals/products with more than 10 En% saturated fat. Practically, this means that all meals/products that you eat on a daily basis should on average contain more than 10 En% saturated fat. Check here which products contains more than 10 En% saturated fat.
More than 10 En% saturated fat means that the total amounts of saturated fat make up for more than 10% of the total kcal of the diet.
 

Objectives:
Is there an association between consumption of food groups and the occurrence of age-related macular degeneration (AMD)?

Study design:
This review article included 26 prospective cohort studies with a total of 211,676 subjects and 7,154 cases of age-related macular degeneration.

Results and conclusions:
The investigators found no significant association between age-related macular degeneration and vegetables, fruit, nuts, grains, dairy products or dietary fats such as oils, butter and margarine when comparing the highest vs. the lowest consumption.

The investigators found a significantly reduced risk of 18% for total age-related macular degeneration [RR = 0.82, 95% CI = 0.75-0.90, p  0.05] when comparing the highest vs. the lowest fish consumption.

The investigators found a significantly reduced risk of 16% for early age-related macular degeneration [RR = 0.84, 95% CI = 0.73-0.97, p  0.05] when comparing the highest vs. the lowest fish consumption.

The investigators found a significantly reduced risk of 21% for late age-related macular degeneration [RR = 0.79, 95% CI = 0.70-0.90, p  0.05], when comparing the highest vs. the lowest fish consumption. 

The investigators found a significantly increased risk of 17% for early age-related macular degeneration [RR = 1.17, 95% CI = 1.02-1.34] when comparing the highest vs. the lowest meat consumption. However, no association was found for late age-related macular degeneration.

The investigators found a significantly increased risk of 20% for early age-related macular degeneration [RR = 1.20, 95% CI = 1.04-1.39] when comparing the highest vs. the lowest alcohol consumption.

The investigators concluded that high fish consumption decreases risk of age-related macular degeneration, while high intake of meat and alcohol increases risk of age-related macular degeneration.

Original title:
Food groups and risk of age-related macular degeneration: a systematic review with meta-analysis by Dinu M, Pagliai G, […], Sofi F.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29978377

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Objectives:
Cardiovascular risk factors are closely linked with dementia risk, but whether heart disease predisposes to dementia is uncertain. Therefore, this review article has been conducted.

Does heart disease increase risk of dementia?

Study design:
This review article included 16 studies (1,309,483 individuals) regarding coronary heart disease and 7 studies (1,958,702 individuals) about heart failure.

Results and conclusions:
The investigators found that a history of coronary heart disease was associated with a 27% increased risk of dementia [pooled relative risk = 1.27, 95% CI = 1.07-1.50, I2 = 80%].

The investigators found that a history of heart failure was associated with a 60% increased dementia risk [pooled relative risk = 1.60, 95% CI = 1.19-2.13, I2 = 59%].

The investigators found among 9 prospective population-based cohort studies, a significantly increased risk of 26% for dementia among patients with coronary heart disease [pooled relative risk = 1.26, 95% CI = 1.06-1.49, I2 = 0%].
Significantly means that there is an association with a 95% confidence.

The investigators found among 4 prospective population-based cohort studies, a significantly increased risk of 80% for dementia among patients with heart failure [pooled relative risk = 1.80, 95% CI = 1.41-2.31, I2 = 0%].
Significantly means it can be said with a 95% confidence that heart failure really increased the risk of getting dementia with 80%. 

The investigators concluded that both coronary heart disease and heart failure are associated with an increased risk of dementia.

Original title:
Coronary heart disease, heart failure, and the risk of dementia: A systematic review and meta-analysis by Wolters FJ, Segufa RA, […], Sedaghat S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29494808

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Objectives:
Inflammatory markers are often elevated in patients with dementia, including Alzheimer's disease (AD). However, it remains unclear whether inflammatory markers are associated with the risk of developing dementia. Therefore, this review article has been conducted.

Do inflammatory markers increase risk of dementia and Alzheimer's disease (AD)?

Study design:
This review article included 13 studies in 6 countries.

Results and conclusions:
The investigators found a significantly increased risk of 37% [HR = 1.37, 95% CI = 1.05-1.78] for all-cause dementia for the highest vs. lowest quantile of C-reactive protein. However, this increased risk was not significant for Alzheimer's disease.

The investigators found a significantly increased risk of 40% [HR = 1.40, 95% CI = 1.13-1.73] for all-cause dementia for the highest vs. lowest quantile of interleukin-6. However, this increased risk was not significant for Alzheimer's disease.

The investigators found a significantly increased risk of 54% [HR = 1.54, 95% CI = 1.14-2.80] for all-cause dementia for the highest vs. lowest quantile of α1-antichymotrypsin. However, this increased risk was not significant for Alzheimer's disease.

The investigators found a significantly increased risk of 40% [HR = 1.40, 95% CI = 1.03-1.90] for all-cause dementia for the highest vs. lowest quantile of lipoprotein-associated phospholipase A2 activity. However, this increased risk was not significant for Alzheimer's disease.

The investigators concluded that several inflammatory markers are associated with an increased risk of all-cause dementia; however, these markers are not specific for Alzheimer's disease. Whether inflammatory markers closely involved in Alzheimer's disease pathology are associated with the risk of Alzheimer's disease remains to be elucidated.

Original title:
Inflammatory markers and the risk of dementia and Alzheimer's disease: A meta-analysis by Darweesh SKL, Wolters FJ, […], Hofman A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29605221

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Objectives:
β-amyloid (Aβ) accumulates abnormally to senile plaque which is the initiator of Alzheimer's disease (AD). As one of the Aβ-degrading enzymes, insulin-degrading enzyme (IDE) remains controversial for its protein level and activity in Alzheimer's brain. Therefore, this review article has been conducted.

Is there an association between insulin-degrading enzyme protein level and risk of Alzheimer's disease (AD)?

Study design:
This review article included 7 studies for IDE protein level (Alzheimer's disease cases = 293 and controls (persons without Alzheimer's disease)  = 126), 3 for mRNA level (Alzheimer's disease cases = 138 and controls = 81) and 3 for enzyme activity (Alzheimer's disease cases = 123 and controls = 75).

Results and conclusions:
The investigators found the insulin-degrading enzyme protein level was significantly lower in Alzheimer's disease patients than in controls [SMD = -0.47, 95% CI = -0.69 to -0.24, p 0.001].
But insulin-degrading enzyme mRNA and enzyme activity had no significant difference [SMD = 0.02, 95% CI = -0.40 to 0.43 and SMD = 0.06, 95% CI = -0.41 to 0.53, respectively].

The investigators found in subgroup analyses (to get more information) that insulin-degrading enzyme protein level was decreased in both cortex and hippocampus of Alzheimer's disease patients [SMD = -0.43, 95% CI = -0.71 to -0.16, p = 0.002 and SMD = -0.53, 95% CI = -0.91 to -0.15, p = 0.006 respectively].
However, insulin-degrading enzyme mRNA was higher in cortex of Alzheimer's disease patients [SMD = 0.71, 95% CI = 0.14 to 1.29, p = 0.01] but not in hippocampus [SMD = -0.26, 95% CI [= -0.58 to 0.06].

The investigators concluded that Alzheimer's disease patients have lower insulin-degrading enzyme protein level. Further relevant studies are still needed to verify whether insulin-degrading enzyme is one of the factors affecting Aβ abnormal accumulation and throw new insights for Alzheimer's disease detection or therapy.

Original title:
Characteristics of Insulin-degrading Enzyme in Alzheimer's Disease: A Meta-analysis by Zhang H, Liu D, […], Zhou H.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29357797

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Objectives:
Is there a dose-response association between serum 25(OH)D (vitamin D level in blood) and risk of dementia and Alzheimer's disease (AD)?

Study design:
This review article included 7 prospective cohort studies and 1 retrospective cohort study involving 1,953 cases of dementia and 1,607 cases of Alzheimer's disease among a total of 28,354 participants.

Results and conclusions:
The investigators found no association between vitamin D insufficiency (10-20 ng/mL) and risk of dementia [pooled HR = 1.09, 95% CI = 0.95 to 1.24].
No association because RR of 1 was found in the 95% CI of 0.95 to 1.24. RR of 1 means no risk/association.

The investigators found no association between vitamin D insufficiency (10-20 ng/mL) and risk of Alzheimer's disease [pooled HR = 1.19, 95% CI = 0.96 to 1.41].

The investigators found vitamin D deficiency (10 ng/mL) significantly increased risk of dementia with 33% [pooled HR = 1.33, 95% CI = 1.08 to 1.58].
Significantly means it can be said with a 95% confidence that vitamin D deficiency really increased the risk of getting dementia with 33%. 

The investigators found vitamin D deficiency (10 ng/mL) non-significantly increased risk of Alzheimer's disease with 31% [pooled HR = 1.31, 95% CI = 0.98 to 1.65].

The investigators found lower risk of dementia was observed at serum 25(OH)D of 25 ng/mL, whereas the risk of Alzheimer's disease decreased continuously along with the increase of serum 25(OH)D up to 35 ng/mL.

The investigators concluded that vitamin D (serum 25(OH)D) levels of 25 to 35 ng/mL decrease risk of dementia and Alzheimer's disease. However, there is no conclusive evidence regarding serum 25(OH)D levels of >35 ng/mL.

Original title:
Vitamin D status and risk of dementia and Alzheimer's disease: A meta-analysis of dose-response by Jayedi A, Rashidy-Pour A and Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29447107

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Objectives:
Dairy product consumption may affect the risk of hip fracture, but previous studies have reported inconsistent findings. Therefore, this review article has been conducted.

Does consumption of dairy products reduce risk of hip fracture?

Study design:
This review article included 10 cohort studies (with a total of 8,613 hip fracture events and 363,557 participants. The length of follow-up ranged from 3 to 22 years) and 8 case-control studies (3,815 hip fracture cases and 6,415 controls/subjects without hip fracture).

Results and conclusions:
The investigators found in cohort studies no association between a high milk consumption and hip fracture risk [pooled RR = 0.91, 95% CI = 0.74-1.12, I2 = 75.0%, p  0.01].
There were no significant changes to the results after using the trim-and-fill method when including 4 missing articles [adjusted random effects summary RR = 1.06, 95% CI = 0.91-1.23].

The investigators found, however, case-control studies indicated that participants in the highest categories of milk consumption had a 29% reduction in the risk of hip fracture [OR = 0.71, 95% CI = 0.55-0.91, I2 = 54%, p = 0.04].
There were no significant changes to the results after using the trim-and-fill method when including 1 missing article [adjusted random effects summary OR = 0.74, 95% CI = 0.57-0.97].

The investigators found in cohort studies no association between a high total dairy consumption and hip fracture risk [pooled RR = 1.02, 95% CI = 0.93-1.12]. No association because RR of 1 was found in the 95% CI of 0.93 to 1.12. RR of 1 means no risk/association.

The investigators found cohort studies indicated that participants in the highest categories of yoghurt consumption had a 25% reduction in the risk of hip fracture [RR = 0.75, 95% CI = 0.66-0.86].
 

The investigators found cohort studies indicated that participants in the highest categories of cheese consumption had a 32% reduction in the risk of hip fracture [RR = 0.68, 95% CI = 0.61-0.77].

The investigators found the summary RR for an increased milk consumption of 200 g/day was 1.00 [95% CI = 0.94-1.07, I2 = 87%, p heterogeneity  0.01] among cohort studies.

The investigators found in cohort studies there was a nonlinear positive association between milk consumption and hip fracture risk [p nonlinearity  0.01], with a rapid increase in risk when milk consumption increased from 0 to 600 g/d. However, there was no further increase in risk with milk consumption between 600 and 1200 g/d.

The investigators found in case-control studies there was a nonlinear association between milk consumption and hip fracture risk [p nonlinearity = 0.28], with a reduction in risk with milk consumption of 200-600 g/d. However, the confidence intervals were wide for all outcomes.

The investigators concluded that a high consumption of yogurt and cheese is associated with a lower risk of hip fracture in cohort studies.

Original title:
Dairy product consumption and risk of hip fracture: a systematic review and meta-analysis by Bian S, Hu J, [...], Ma J.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5778815/

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Objectives:
Does exercise training delay the decline in cognitive function among individuals who are at risk of/or have Alzheimer's disease?  

Study design:
This review article included 19 controlled studies with 23 interventions including 1,145 subjects with a mean age of 77.0 ± 7.5.
The studies included an exercise-only intervention and a nondiet, nonexercise control group and reported pre- and post-intervention cognitive function measurements.

Most subjects were at risk of Alzheimer's disease because they had mild cognitive impairment (64%) or a parent diagnosed with Alzheimer's disease (1%) and 35% presented with Alzheimer's disease.

Exercise interventions were performed 3.4 ± 1.4 days per week at moderate intensity (3.7 ± 0.6 metabolic equivalents) for 45.2 ± 17.0 minutes per session for 18.6 ± 10.0 weeks and consisted primarily of aerobic exercise (65%).

Results and conclusions:
The investigators found overall, there was a modest favourable effect of exercise on cognitive function [d+ = 0.47, 95% CI = 0.26 to 0.68].

The investigators found within-group analyses revealed that exercise improved cognitive function [d+w = 0.20, 95% CI = 0.11 to 0.28], whereas cognitive function declined in the control group [d+w = -0.18, 95% CI = -0.36 to 0.00].

The investigators found within-group analyses revealed that aerobic exercise had a moderate favourable effect on cognitive function [d+w = 0.65, 95% CI = 0.35 to 0.95), but other exercise types did not [d+w = 0.19, 95% CI = -0.06 to 0.43].

The investigators concluded that exercise training (3.4 days per week at moderate intensity for 45.2 minutes per session during 18.6 weeks) delays the decline in cognitive function that occurs in individuals who are at risk of/or have Alzheimer's disease, with aerobic exercise having the most favourable effect. Additional randomized controlled clinical trials that include objective measurements of cognitive function are needed to confirm these findings.

Original title:
Can Exercise Improve Cognitive Symptoms of Alzheimer's Disease? A Meta-Analysis by Panza GA, Taylor BA, […], Pescatello LS.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29363108

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Metabolic Equivalents (METs) are commonly used to express the intensity of physical activities.
MET is the ratio of a person's working metabolic rate relative to their resting metabolic rate.
One MET is defined as the energy cost of sitting quietly and is equivalent to a caloric consumption of 1 kcal/kg/hour.