Objectives:
Given their potent antioxidation properties, carotenoids play a role in delaying and preventing dementia and mild cognitive impairment (MCI). However, observational studies have found inconsistent results regarding the associations between blood carotenoid levels and the risk of dementia and MCI. Therefore, this review article has been conducted.

Objectives:
Magnesium, an essential cation for numerous cellular processes, is a major component of bone. However, its relationship with the risk of fractures is still uncertain. Therefore, this review article has been conducted.

Objectives:
Prospective cohorts are inconsistent regarding the association between dietary calcium intake and the risk of stroke. Therefore, this review article has been conducted.

Objectives:
Although relationships between the intake of whole grains and refined grains and the incidence of cardiovascular disease (CVD) events and all-cause mortality have been investigated, the conclusions have been inconclusive. Therefore, this review article has been conducted.

Objectives:
Does a high dietary intake of vitamin B6 or a high blood PLP levels (vitamin B6 level in blood) reduce the risk of colorectal cancer?

Study design:
This review article included 20 cohort studies and 8 case-control studies.

Results and conclusions:
The investigators found higher dietary intake of vitamin B6 significantly reduced the risk of colorectal cancer with 20% [combined OR = 0.80, 95% CI = 0.68 to 0.94].

Objectives:
There is an equivocal and inconsistent association between legume consumption and health outcomes and longevity. Therefore, this review article has been conducted.

Does a higher legume dietary intake reduce mortality and stroke risk?

Study design:
This review article included 32 cohort studies (31 publications) involving 1,141,793 participants and 93,373 deaths from all causes (all-cause mortality).

The certainty of evidence was judged from low to moderate.

Objectives:
Does orange juice consumption causally improve lipid profile?

Study design:
This review article included 9 RCTs with a total of 386 participants.
The mean age of the participants ranged from 36 to 56 years.
All the RCTs used a parallel study design.
The dosage of orange juice ranged from 250 to 1000 mL/d.
The duration of interventions ranged from 3 to 12 weeks.

Results and conclusions:

Objectives:
Findings on the association of dietary intake and tissue biomarkers of linoleic acid (LA) with the risk of prostate cancer are conflicting. Also, no meta-analysis summarized available findings in this regard. Therefore, this review article has been conducted.

Do higher tissue levels or higher dietary intakes of linoleic acid reduce prostate cancer risk in men?

Objectives:
Previous studies have suggested that selenium as a trace element is involved in bone health, but findings related to the specific effect of selenium on bone health remain inconclusive. Therefore, this review article has been conducted.

Do both high dietary selenium intake and high serum selenium levels increase bone density?

Study design:
This review article included 8 cross-sectional studies, 7 case-control studies and 3 prospective cohort studies and 1 RCT with a total of 69,672 subjects.

Objectives:
The effect of probiotic/synbiotic supplementation on gestational diabetes mellitus (GDM) is controversial. Therefore, this review article has been conducted.

Do probiotic/synbiotic supplements improve glucose and lipid metabolism in pregnant women with gestational diabetes mellitus?