Nutrition and health

Objectives:
The actual effects of L-carnitine administration on leptin serum level is inconsistent. Therefore, this review article (meta-analysis) has been conducted.

Does L-carnitine supplementation reduce leptin serum level?

Study design:
This review article included 7 RCTs with 325 cases (group with L-carnitine administration) and 330 controls (group without L-carnitine administration).

Subgroup analysis to find the sources of heterogeneity showed that L-carnitine dosage [ 2 g: I2 = 00.0%, p = 0.408] and study population [diabetes: I2 = 46.7%, p = 0.153 and non-diabetes: I2 = 15.1%, p = 0.317] were the potential sources of heterogeneity.

Results and conclusions:
The investigators found that L-carnitine supplementation had no significant effect on serum leptin concentrations [WMD = -0.565 ng/mL, 95% CI = -2.417 to 1.287, p = 0.550, I2 = 84.3%, p  0.0001].

The investigators found in subgroup analysis that  ≥ 2 mg L-carnitine supplementation significantly reduced serum leptin concentrations [WMD = -2.742 ng/mL, 95% CI = -3.039 to -2.444, p  0.001].

The investigators found in subgroup analysis that L-carnitine supplementation significantly reduced serum leptin concentrations in diabetic patients [WMD = -2.946 ng/mL, 95% CI = -3.254 to -2.638, p  0.001].

The investigators found in subgroup analysis that L-carnitine supplementation during 12 weeks significantly reduced serum leptin concentrations [WMD = -2.772 ng/mL, 95% CI = -3.073 to -2.471, p  0.001].

The investigators concluded that at least 3 mg L-carnitine per day in the course of 12 weeks reduce serum leptin concentrations, especially in diabetic patients.

Original title:
The effect of L-carnitine supplementation on serum leptin concentrations: a systematic review and meta-analysis of randomized controlled trials by Nazary-Vannani A, Ghaedi E, […], Varkaneh HK.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29453657

Additional information of El Mondo:
Find more information/studies on diabetes and L-carnitine and diabetes right here.

L-carnitine is a non-essential amino acid, which is also found in foods.

Objectives:
What are the effects of olive oil consumption compared with other plant oils on blood lipids?

Study design:
This review article included 27 RCTs, comprising 1,089 participantes.

Results and conclusions:
The investigators found compared to other plant oils, HDL cholesterol levels (good cholesterol) increased significantly more for olive oil consumption [WMD = 1.37 mg/dL, 95% CI = 0.4 to 2.36].

The investigators found, however, olive oil consumption reduced total cholesterol levels [WMD = 6.27 mg/dL, 95% CI = 2.8 to 10.6], LDL cholesterol levels (bad cholesterol) [WMD = 4.2 mg/dL, 95% CI = 1.4 to 7.01] and triglyceride levels [WMD = 4.31 mg/dL, 95% CI = 0.5 to 8.12] significantly less than other plant oils.

The investigators found that there were no significant effects on Apo lipoprotein A1 and Apo lipoprotein B.

The investigators concluded that olive oil consumption decreases serum total cholesterol, LDL cholesterol and triglyceride levels less but increases HDL cholesterol levels more than other plant oils.

Original title:
Comparison of blood lipid-lowering effects of olive oil and other plant oils: A systematic review and meta-analysis of 27 randomized placebo-controlled clinical trials by Ghobadi S, Hassanzadeh-Rostami Z, […], Faghih S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29420053

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

Objectives:
In 2016, the World Health Organization (WHO) recommended point-of-use fortification of complementary foods with iron-containing micronutrient powders to improve iron status and reduce anaemia in children at risk of anaemia. This recommendation continues to be debated. Therefore, this review article (meta-analysis) has been conducted.

Does point-of-use fortification of foods with iron-containing micronutrient powders reduce anaemia in children at risk of anaemia?

Study design:
This review article included trials.

Results and conclusions:
The investigators found in an arbitrarily selected setting and with adherence as obtained under trial conditions, a small increase in haemoglobin concentration in preschool children with point-of-use fortification of foods with iron-containing micronutrient powders, by only 3.9 g/L, with the upper limit of the 95% CI virtually excluding an effect beyond 5.5 g/L. However, the attenuated effect that is likely to be achieved under real-world conditions is even lower.

The investigators found point-of-use fortification with NaFeEDTA improved geometric mean plasma ferritin concentrations by only 4 μg/L [95% CI = 29.7 to 33.7 μg/L].

The investigators concluded point-of-use fortification of foods with micronutrient powders containing iron gives only a small increase in haemoglobin concentration in preschool children. However, attention should be given to the phenomenon that small group differences in the distribution of continuous outcomes (haemoglobin concentration, ferritin concentrations) can give a false impression of relatively large effects on the prevalence of the dichotomised outcomes (anaemia, iron deficiency).

Original title:
Micronutrient powders to combat anaemia in young children: do they work? by Verhoef H, Teshome E and Prentice AM.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5776757/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition, study design/meta-analysis/significant and iron right here.

Objectives:
Does vegetable and/or fruit consumption reduce metabolic syndrome (MetS)?

Study design:
This review article included 20 cross-sectional studies, 1 case-control study and 5 cohort studies.

Results and conclusions:
The investigators found in 16 studies when comparing the highest versus the lowest category of vegetable consumption a significantly reduced risk of 11% [overall multivariable-adjusted RR = 0.89, 95% CI = 0.85-0.93, p 0.001] for metabolic syndrome.

The investigators found in 16 studies when comparing the highest versus the lowest category of fruit consumption a significantly reduced risk of 19% [overall multivariable-adjusted RR = 0.81, 95% CI = 0.75-0.88, p 0.001] for metabolic syndrome.

The investigators found in 8 studies when comparing the highest versus the lowest category of vegetable and fruit consumption a significantly reduced risk of 25% [overall multivariable-adjusted RR = 0.75, 95% CI = 0.63-0.90, p = 0.002] for metabolic syndrome.

The investigators concluded that vegetable and/or fruit consumption is negatively associated with metabolic syndrome. However, more well-designed prospective cohort studies are needed to elaborate the concerned issues further.

Original title:
Associations of vegetable and fruit consumption with metabolic syndrome. A meta-analysis of observational studies by Zhang Y and Zhang DZ.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29506604

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

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

Additional information of El Mondo:
Find more information/studies on cohort/case-control study/significant, dementia and vitamin D right here.
 

Objectives:
Individuals with mild cognitive impairment (MCI) are at high risk for developing dementia. Physical exercise is a promising intervention for cognitive decline. Systematic reviews regarding the effects of physical exercise on cognitive and psychological outcomes among MCI patients are limited and a systematic review exploring the effects of exercise modalities on the results has not been conducted. Therefore, this review article has been conducted.

Do individuals with mild cognitive impairment benefit from physical exercise?

Study design:
This review article included 11 studies. The exercise interventions can be classified into 3 types: (a) aerobic exercise, (b) resistance exercise and (c) multi-modal exercise.

Results and conclusions:
The investigators found that physical exercise had beneficial effects for global cognition [SMD = 0.30, 95% CI = 0.10-0.49, p = 0.002].

The investigators found subgroup analysis demonstrated that aerobic exercise programmes were consistently associated with medium effect size [SMD = 0.54-0.58].

The investigators found, however, the effects of physical exercise on domain-specific cognitive function and psychological outcomes in mild cognitive impairment patients remained inconclusive.

The investigators found sensitivity analysis showed that types of control exerted influence on the outcomes.

The investigators concluded that physical exercise, aerobic exercise in particular, benefits global cognition in mild cognitive impairment patients. The evidence of physical exercise on domain-specific cognitive function and psychological outcomes remains unclear, more trials with rigorous study design are necessary to provide the evidence.

Original title:
The effectiveness of physical exercise on cognitive and psychological outcomes in individuals with mild cognitive impairment: A systematic review and meta-analysis by Song D, Yu DSF, […], Lei Y.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29334638

Additional information of El Mondo:
Find here more information/studies on cohort/case-control study/significant, sport nutrition and dementia right here.
 

Objectives:
Plasmodium vivax (P. vivax) is the most geographically widespread species among human malaria parasites. Immunopathological studies have shown that platelets are an important component of the host innate immune response against malaria infections. Therefore, this review article (meta-analysis) has been conducted.

The aim of this review article is to quantify thrombocytopaenia in plasmodium vivax malaria patients and to determine the associated risks of severe thrombocytopaenia in patients with plasmodium vivax malaria compared to patients with plasmodium falciparum malaria.

Study design:
This review article included 58 observational studies (5,536 patients had thrombocytopaenia among a total of 29,664 patients investigated) across 12 endemic countries.  
29 of 58 studies were prospective studies. Of them, the vast majority of participants infected with P. vivax (66%, 19 552/29664) were from a single large study conducted in Indonesia. Half of the studies were conducted in India (50%) and the study period covered the years 1988-2015. Only 25% of the included studies had PCR confirmation of parasite species.

Not all studies included in this review used the same methods for platelet “labelling”.

Results and conclusions:
The investigators found pooled analysis showed that 18.7% [95% CI = 17.0-20.2%] of patients with P. vivax malaria had platelet counts  150 000/mm³. Of these, 10.1% [95% CI = 9.0-10.8%] of the patients infected with P. vivax had either severe thrombocytopaenia (9%) or very severe thrombocytopaenia (13%).
There was an absence of statistical heterogeneity [I2 = 0%], suggesting a high level of homogeneity between studies in each gradient of thrombocytopaenia.

The investigators found a meta-analysis of 11 observational studies showed an equal risk of developing severe/very severe thrombocytopaenia between the patients with P. vivax malaria and those with P. falciparum malaria [OR = 1.98, 95% CI = 0.92-4.25], indicating that thrombocytopaenia is as equally a common manifestation in P. vivax and P. falciparum malaria patients.
In a subgroup of 3 studies, a pooled analysis showed patients with severe P. vivax malaria and those with severe P. falciparum malaria had an equal risk of developing severe/very severe thrombocytopaenia.
Further stratification by age groups showed children with severe P. vivax malaria (60/278) had a higher risk of developing very severe thrombocytopaenia than in those with severe P. falciparum malaria (13/145) [OR = 2.80, 95% CI = 1.48-5.29]. However an equal risk was observed for adult severe cases with P. vivax malaria and those with P. falciparum malaria [45/186 vs 70/207, OR = 1.19, 95% CI = 0.51-2.77, p = 0.22].

The investigators found in a subset of 4 studies a decreased platelet counts in patients with P. vivax malaria compared to the healthy controls [p  0.001 in all four studies].

The investigators found a pooled analysis of 4 studies showed that 15% [95% CI = 9-21%] of P. vivax malaria patients with thrombocytopaenia developed minor bleeding episodes. These bleeding manifestations were epistaxis, haematemesis, petechiae and purpura.

The investigators found a pooled analysis of 2 studies with PCR confirmed parasite species showed an equal risk of mortality with severe thrombocytopaenia in P. vivax malaria patients (10.2%, 5/49) and P. falciparum malaria patients (14%, 8/57) [OR = 1.16, 95% CI = 0.30-4.60, p = 0.87].

The investigators concluded there is some evidence of the clinical relevance of severe thrombocytopaenia in P. vivax malaria patients. However, due to the low number of studies with small sample sizes within the subset of studies that provided clinically relevant information, the confidence in the estimates is limited. Therefore, there is a need for future well designed, large-scale, prospective studies among patients infected with P. vivax from different countries and epidemiological settings with various age and gender groups represented to substantiate these findings.

Original title:
Severe thrombocytopaenia in patients with vivax malaria compared to falciparum malaria: a systematic review and meta-analysis by Naing C and Whittaker MA.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5808388/

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition and study design/meta-analysis/significant right here.

Objectives:
Does poultry intake reduce risk of stroke?

Study design:
This review article included 7 prospective cohort studies involving 354,718 participants.

Results and conclusions:
The investigators found for the highest versus lowest categories of poultry intake a non-significantly reduced risk of 8% for total stroke [pooled RR = 0.92, 95% CI = 0.82-1.03, I2 = 19.8%, p = 0.28].

The investigators found in subgroup analysis for the highest versus lowest categories of poultry intake, a significantly reduced risk of 14% for total stroke among US people [RR = 0.86, 95% CI = 0.77-0.95, I2 = 0.0%, p = 0.38].

The investigators found in subgroup analysis for the highest versus lowest categories of poultry intake, a significantly reduced risk of 17% for total stroke among women [RR = 0.83, 95% CI = 0.72-0.93, I2 = 0.0%, p = 0.63].

The investigators found in subgroup analysis no association between the highest poultry intake and ischemic stroke risk [RR = 0.91, 95% CI = 0.79-1.02, I2 = 0.0%, p = 0.93].

The investigators found in subgroup analysis no association between the highest poultry intake and hemorrhagic stroke risk [RR = 0.82, 95% CI = 0.59-1.04, I2 = 20.5%, p = 0.28].

The investigators found one serving per week increment in poultry intake was not associated with the risk of stroke [RR = 1.00, 95% CI = 0.96-1.03, I2 = 69.0%, p = 0.004].

The investigators found nonlinear dose-response meta-analysis showed a lower risk of stroke at consumption of 1 serving/week.  

The investigators concluded that 1 serving/week poultry intake reduces risk of stroke, particularly among US people and women.

Original title:
Dietary poultry intake and the risk of stroke: A dose-response meta-analysis of prospective cohort studies by Mohammadi H, Jayedi A, […], Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29460808

Additional information of El Mondo:
Find more information/studies on poultry intake and cardiovascular diseases right here.
1 serving poultry corresponds to 100 gram raw poultry.
This meal provides 75 grams of poultry.
Poultry are chickens, turkeys, geese and ducks.

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/

Additional information of El Mondo:
Find here more information/studies on cohort/case-control study/significant, dairy products consumption and elderly right here.
 

Objectives:
New studies indicate that resveratrol can significantly reduce plasma lipids, but the result of randomized clinical trials (RCTs) on resveratrol effect and the serum lipid profile are contradictory. Therefore, this review article (meta-analysis) has been conducted.  

Do resveratrol supplements reduce plasma lipids, like cholesterol levels?

Study design:
This review article included 21 RCTs.

Results and conclusions:
The investigators found resveratrol supplements had no significant effects on both:
-total cholesterol (TC) [WMD = 0.08 mmol/L, 95% CI = -0.23 to 0.08, p = 0.349, I2 = 87.8%];
-low-density lipoprotein (LDL-C or bad cholesterol) [WMD = -0.04 mmol/L, 95% CI = -0.21 to 0.12, p  = 0.620, I2 = 93.4%] and;
-high density lipoprotein (HDL-C or good cholesterol) [WMD = -0.01 mmol/L, 95% CI = -0.04 to 0.02, p = 0.269, I2 = 88.6%].

The investigators found resveratrol supplements had significant effects on
triacylglycerol (TG) [WMD = 0.58 mmol/L, 95% CI = 0.34 to 0.82, p 0.0001, I2 = 99.8%]. But after removing 1 study the significance was eliminated.

The investigators also found that sex, age, BMI, resveratrol dosage and intervention duration could not change the results.

The investigators concluded that resveratrol supplements do not change lipid profile concentration, like cholesterol levels. Confirmation of this conclusion will require more studies exclusively on dyslipidemic patients in which the intake of lipid lowering agents is among the exclusion criteria.

Original title:
Effect of resveratrol on lipid profile: An updated systematic review and meta-analysis on randomized clinical trials by Haghighatdoost F and Hariri M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29305228

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

Objectives:
Does the consumption of various types of tomato products reduce prostate cancer risk and is there a potential dose-response relationship?

Study design:
This review article included 30 studies, which summarized data from 24,222 cases (subjects with prostate cancer) among 260,461 participants.

Results and conclusions:
The investigators found that higher total tomato consumption was associated with a reduced risk of 19% for prostate cancer [RR = 0.81, 95% CI = 0.71 to 0.92, p = 0.001].

The investigators found in subgroup analysis that higher tomato foods consumption was associated with a reduced risk of 16% for prostate cancer [RR = 0.84, 95% CI = 0.72 to 0.98, p = 0.030].

The investigators found in subgroup analysis that higher cooked tomatoes and sauces consumption was associated with a reduced risk of 16% for prostate cancer [RR = 0.84, 95% CI = 0.73 to 0.98, p = 0.029]. 

The investigators found in subgroup analysis, however, no association between higher raw tomatoes consumption and prostate cancer risk [RR = 0.96, 95% CI = 0.84 to 1.09, p = 0.487].

The investigators found there was a significant dose-response association for total tomato consumption [p = 0.040], cooked tomatoes and sauces [p  0.001] and raw tomatoes [p = 0.037], but there was not a significant association with tomato foods [p-linear = 0.511, p-nonlinear = 0.289].

The investigators concluded that increased tomato consumption, particularly cooked tomatoes and sauces reduces prostate cancer risk. Furthermore, there are dose-response relationships for total tomato consumption and for cooked tomatoes and sauces. Further studies are required to determine the underlying mechanisms of these associations.

Original title:
Processed and raw tomato consumption and risk of prostate cancer: a systematic review and dose-response meta-analysis by Rowles JL, Ranard KM, […], Erdman JW Jr.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29317772

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

Objectives:
Zinc is an essential trace element for living organisms and their biological processes. Zinc plays a key role in more than 300 enzymes and it is involved in cell communication, proliferation, differentiation and survival. Zinc also plays a role in regulating the immune system with implications in pathologies where zinc deficiency and inflammation are observed. Therefore, this meta-analysis (systematic review) has been conducted.

Do zinc deficiency increase risk of autoimmune disorders?

Study design:
This review article included 62 case-control studies.

The manner of collecting and investigating zinc samples was very heterogeneous.

Results and conclusions:
The investigators found in fixed model that serum zinc concentration of autoimmune disease patients was significantly lower than in controls [mean effect = -1.19, 95% CI = -1.26 to -1.11].

The investigators found in fixed model that plasma zinc concentration of autoimmune disease patients was significantly lower than in controls [mean effect = -3.97, 95% CI = -4.08 to -3.87].

The investigators concluded that a deficiency of zinc in serum and plasma increases risk of autoimmune disorders in humans.

Original title:
Zinc Status and Autoimmunity: A Systematic Review and Meta-Analysis by Sanna A, Firinu D, […], Valera P.

Link:
http://www.mdpi.com/2072-6643/10/1/68/htm

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

An autoimmune disease is a condition in which your immune system mistakenly attacks your body. These are the most common autoimmune diseases:  

1. Addison’s disease: Caused by an adrenal hormone insufficiency. Addison’s disease can lead to muscle weakness and fatigue, nausea, weight loss, irritability, low blood pressure, low blood sugar and depression.
2. Celiac disease (gluten allergy): Celiac disease is a reaction to gluten (found in barley, rye and wheat) that causes damage to the lining of the small intestine.
3. Graves’ disease: Caused by extremely overactive thyroid gland. People who have Graves’ disease may have difficulty sleeping, bulging of the eyes, irritability, brittle hair, unexplained weight loss, sensitivity to heat, muscle weakness, light menstrual periods and shakiness of the hands. On the other hand, some people with Graves’ disease may experience no symptoms at all.
4. Hashimoto’s disease: Caused by inflammation of the thyroid gland. Although sometimes no symptoms occur, Hashimoto’s thyroiditis often results in a goiter (enlargement of the thyroid gland, which may be visible as a bulge in the neck), weight gain, fatigue, muscle weakness, depression, cold sensitivity, dry hair and skin, and constipation.
5. Inflammatory bowel disease: This disease refers to a group of inflammatory diseases of the colon and small intestine.
6. Multiple Sclerosis or MS: This disease affects the brain and spinal cord. People who have MS may experience weakness, trouble with balance and coordination, problems speaking and walking, tremors, paralysis and numbness in the extremities.
7. Psoriasis: This is a skin condition that causes redness and irritation as well as thick, flaky, silver-white patches.
8. Pernicious anemia: Caused by the inability to absorb vitamin B12 leading to a decrease in red blood cells.
9. Reactive arthritis: Caused by inflammation of joints, the urethra and eyes.
10. Raynaud’s phenomenon: People with Raynaud’s have a problem with blood flow, resulting in numbness, tingling of the fingers, discoloration, toes and tip of the nose with exposure to cold temperatures.
11. Rheumatoid arthritis: In rheumatoid arthritis, autoimmunity causes the immune system to attack tissues in the joints. It typically affects the small joints in your hands and feet causing painful swelling, stiffness and loss of movement in the joints that can eventually result in bone erosion and joint deformity.
12. Scleroderma: Scleroderma is a connective tissue disease that causes changes in skin, muscles, blood vessels and internal organs.
13. Sjögren’s syndrome: Caused by destruction of the glands that produce tears and saliva causing dry eyes and mouth.
14. Systemic lupus erythematosus: In lupus, antibodies made by the immune system attack the body. Systemic lupus erythematosus can affect skin, kidneys, joints and brain.
15. Type 1 diabetes: In type 1 diabetes, the immune system attacks cells in the pancreas that produce insulin. When your insulin levels are insufficient, your body cannot control your blood glucose level, which can lead to a number of problems, including kidney failure, stroke, vision loss, circulation problems and heart disease.

Objectives:
Anemia is a worldwide public health problem that can be related to many causes, including vitamin A deficiency. Therefore, this review article (meta-analysis) has been conducted.

The aim of this review article is to examine the effect of vitamin A supplementation (VAS) on iron status biomarkers and anemia in humans.

Study design:
This review article included 21 clinical trials and 2 cohort studies, with children, teenagers, pregnant or lactating women.

Results and conclusions:
The investigators found clinical trials showed that vitamin A supplementation significantly reduced risk of anemia by 26% and raised hemoglobin levels, compared to non-treated group, independent of the life stage.

The investigators found clinical trials showed that vitamin A supplementation did not alter the prevalence of iron deficiency among children and teenagers [RR = 0.82, 95% CI = 0.60 to 1.12, p = 0.204].
However, a significant increase in serum ferritin levels was observed in trials conducted among pregnant and lactating women [WMD = 6.61 μg/L, 95% CI = 6.00 to 7.21 μg/L, p 0.001]. Significant because the found p value of 0.001 was lower than p value of 0.05.

The investigators concluded that vitamin A supplementation alone reduces risk of anemia, by improving hemoglobin and ferritin levels in individuals with low serum retinol levels.

Original title:
Effect of vitamin A supplementation on iron status in humans: a systematic review and meta-analysis by da Cunha MS, Campos Hankins NA and Arruda SF.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29336593

Additional information of El Mondo:
Find more information/studies on food fortification/malnutrition, vitamin A and study design/meta-analysis/significant right here.

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

Additional information of El Mondo:
Find here more information/studies about elderly and sport nutrition.

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.

Objectives:
There are some indications of regional differences in the association between fish consumption and clinical outcomes. Therefore, this review article (meta-analysis) has been conducted.  

Are there regional differences in the association between fish consumption and risk of all-cause mortality and cardiovascular (CVD) mortality?

Study design:
This review article included 14 prospective cohort studies (10 publications) with 911,348 participants, of which 75,451 incident deaths.

Results and conclusions:
The investigators found dose-response meta-analysis showed a 20 g/d increment in fish consumption significantly reduced risk of cardiovascular mortality with 4% [relative risk = 0.96, 95% CI = 0.94-0.98, I2 = 0%, n = 8]. However, subgroup analysis resulted in a significant association only in Asian studies and not in Western studies.

The investigators found dose-response meta-analysis showed a 20 g/d increment in fish consumption significantly reduced risk of all-cause mortality with 2% [relative risk = 0.98, 95% CI = 0.97-1.00, I2 = 81.9%, n = 14]. However, subgroup analysis resulted in a significant association only in Asian studies and not in Western studies.

The investigators found analysis of Western studies suggested a nearly U-shaped association, with a nadir at fish consumption of 20 g/d in analysis of both outcomes. Meanwhile, the associations appeared to be linear in Asian studies.

The investigators concluded that fish consumption, particularly 20 g/d reduces boh risk of cardiovascular mortality and all-cause mortality. Furthermore, there is potential evidence of regional differences in the association between fish consumption and mortality. Therefore, it may be helpful to examine the associations by considering types of fish consumed and methods of fish preparation.

Original title:
Fish consumption and risk of all-cause and cardiovascular mortality: a dose-response meta-analysis of prospective observational studies by Jayedi A, Shab-Bidar S, […], Djafarian K.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/29317009

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

Objectives:
Is there a relationship between serum 25(OH)D (vitamin D blood level) and mortality risk in the general population?

Study design:
This review article included 14 prospective cohort studies that involved 5562 deaths out of 62548 individuals.
In the parametric model, which is based on 11 studies and 59231 individuals, the lowest quantile as the reference category has been used.

Evidence of heterogeneity for the RR was apparent when highest were compared with lowest categories [p = 0.008, I2 = 58%].

There was no evidence of publication bias.

Results and conclusions:
The investigators found for “highest compared with lowest” categories of 25(OH)D, a significant reduced risk of 29% for mortality [RR = 0.71, 95% CI = 0.50-0.91].

The investigators found in the parametric model, the estimated summary RRs of mortality were 0.86 [95% CI = 0.82-0.91], 0.77 [95% CI = 0.70-0.84] and 0.69 [95% CI = 0.60-0.78] for individuals with an increase of 12.5, 25 and 50 nmol 25(OH)D serum values/L, respectively, from a median reference category of ∼27.5 nmol/L.
However, no significant decrease in mortality was found above ∼87.5 nmol/L.

The investigators concluded there is a nonlinear decrease in mortality risk as circulating 25(OH)D increases, with optimal concentrations ∼75-87.5 nmol/L. Because many adults do not achieve these 25(OH)D values, large prospective randomized trials are urgently needed to investigate whether vitamin D supplementation is able to reduce mortality risk in the general population.

Original title:
Vitamin D deficiency and mortality risk in the general population: a meta-analysis of prospective cohort studies by Zittermann A, Iodice S, [...], Gandini S.

Link:
http://ajcn.nutrition.org/content/95/1/91.full

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

Objectives:
Low glycaemic index (GI) diets are beneficial in the management of hyperglycemia. Cardiovascular diseases are the major cause of mortality in diabetes therefore it is important to understand the effects of GI on blood lipids. Therefore, this review article has been conducted.

Does a low GI diet lower the cholesterol levels?

Study design:
This review article included 28 RCTs comparing low with high GI diets over at least 4 weeks. These 28 RCTs contained 1272 participants with studies ranged from 6 to 155 participants, one was powered on blood lipids and 3 had adequate allocation concealment.

Results and conclusions:
The investigators found that compared to high GI diet low GI diet significantly reduced total cholesterol by 0.13 mmol/L [95% CI = -0.22 to -0.04, p = 0.004, 27 trials, 1441 participants]. Significantly means, it can be said with 95% confidence that low GI diet really lowered the total cholesterol levels with 0.13 mmol/L.

The investigators found that compared to high GI diet low GI diet significantly reduced LDL-cholesterol by 0.16 mmol/L [95% CI = -0.24 to -0.08, p 0.0001, 23 studies, 1281 participants]. Significantly, because the p-value was less than 0.05.

The investigators found subgroup analyses suggested that reductions in LDL-cholesterol were greatest in studies of shortest duration and greatest magnitude of GI reduction. Furthermore, lipid improvements appeared greatest and most reliable when the low GI intervention was accompanied by an increase in dietary fiber.

The investigators found sensitivity analyses, removing studies without adequate allocation concealment, lost statistical significance but retained suggested mean falls of 0.10 mmol/L in both.

The investigators found no effects on HDL-cholesterol [MD = -0.03 mmol/L, 95% CI = -0.06 to 0.00, I2 = 0%], or triglycerides [MD was 0.01 mmol/L, 95% CI = -0.06 to 0.08, I2 = 0%].

The researchers concluded that low GI diets reduce total and LDL-cholesterol (bad cholesterol) but had no effect on HDL-cholesterol (good cholesterol) or triglycerides.

Original title:
Low glycemic index diets and blood lipids: A systematic review and meta-analysis of randomized controlled trials by Goff LM, Cowland DE, [...], Frost GS.

Link:
http://www.sciencedirect.com/science/article/pii/S0939475312001524

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

High LDL-cholesterol levels and high triglyceride levels increase the risk of getting cardiovascular diseases whereas high HDL-cholesterol levels decrease the risk of getting cardiovascular diseases.

A low GI diet is a diet with a GI value of 55 or lower.

Objectives:
Does soy isoflavone reduce the frequency and severity of hot flashes?

Study design:
This review article included 19 trials (13 included hot flash frequency, of which 10 for severity and 3 for composite scores).
17 trials were selected for meta-analyses to clarify the effect of soybean isoflavones on hot flash frequency (13 trials) and severity (9 trials).

Results and conclusions:
The investigators found intake of soy isoflavones (median = 54 mg aglycone equivalents) for 6 weeks to 12 months significantly reduced the frequency (combined fixed-effect and random effects model) of hot flashes by 20.6% [95% CI = -28.38 to -12.86, p 0.00001] compared with placebo [p heterogeneity = 0.0003, I2 = 67% for random effects model].

The investigators also found isoflavones significantly reduced hot flash severity by 26.2% [95% CI = -42.23 to -10.15, p = 0.001] compared with placebo [p heterogeneity 0.00001, I2 = 86% for random effects model].

The investigators found isoflavone supplements providing more than 18.8 mg of genistein (the median for all studies) were more than twice as potent at reducing hot flash frequency than lower genistein supplements.

The investigators concluded soy isoflavone supplements (54 mg per day for 6 weeks to 12 months), derived by extraction or chemical synthesis, are significantly more effective than placebo in reducing the frequency and severity of hot flashes. Additional studies are needed to further address the complex array of factors that may affect efficacy, such as dose, isoflavone form, baseline hot flash frequency and treatment duration.

Original title:
Extracted or synthesized soybean isoflavones reduce menopausal hot flash frequency and severity: systematic review and meta-analysis of randomized controlled trials by Taku K, Melby MK, […], Messina M.

Link:
http://journals.lww.com/menopausejournal/Abstract/2012/07000/Extracted_or_synthesized_soybean_isoflavones.11.aspx

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

Objectives:
In view of the vital role of oxidative stress in the pathogenesis of Alzheimer's disease (AD), the potential of antioxidant supplements to prevent AD have gained much interest, while there are conflicting results on this topic in recent years. Therefore, this review article has been conducted.

Does dietary intake of vitamin C and E and β-carotene decrease risk of Alzheimer's disease?

Study design:
This review article included 7 articles (dietary intake, but no supplements).

Results and conclusions:
The investigators found a significant decreased risk for Alzheimer disease of 24% [pooled relative risk = 0.76 95% CI = 0.67-0.84] for dietary intake of vitamin E and of 17% [pooled relative risk = 0.83, 95% CI = 0.72-0.94] for dietary intake of vitamin C.

However, the investigators found a non-significant decreased risk of 12% [pooled relative risk = 0.88, 95% CI = 0.73-1.03] for dietary intake of β-carotene.

The investigators concluded dietary intakes of vitamin C and E lower the risk of Alzheimer's disease, with vitamin E exhibiting the most pronounced protective effects. The findings will be of significance to the prevention and interventional treatment of Alzheimer's disease.

Original title:
Dietary intakes of vitamin E, vitamin C, and β-carotene and risk of Alzheimer's disease: a meta-analysis by Li FJ, Shen L and Ji HF.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/22543848

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

Objectives:
Does diabetes increase risk of incident dementia and mild cognitive impairment?

Study design:
This review article included 19 prospective longitudinal studies including 6184 subjects with diabetes and 38530 subjects without diabetes. All subjects were without dementia or mild cognitive impairment at baseline (=at the beginning of the study).

There was no publication bias.

Results and conclusions:
The investigators found persons with diabetes had a significant increased risk of 46% for Alzheimer's disease [RR = 1.46, 95% CI = 1.20-1.77]. Significant means that there is an association with a 95% confidence.

The investigators found persons with diabetes had a significant increased risk of 148% for vascular dementia [RR = 2.48, 95% CI = 2.08-2.96].

The investigators found persons with diabetes had a significant increased risk of 51% for any dementia [RR = 1.51, 95% CI = 1.31-1.74]. Significant because RR of 1 was not found in the 95% CI of 1.31 to 1.74. RR of 1 means no risk/association.

The investigators found persons with diabetes had a significant increased risk of 21% for mild cognitive impairment [RR = 1.21, 95% CI = 1.02-1.45].

The investigators concluded diabetes is a risk factor for incident dementia (including Alzheimer's disease, vascular dementia and any dementia) and mild cognitive impairment.

Original title:
Diabetes as a risk factor for dementia and mild cognitive impairment: a meta-analysis of longitudinal studies by Cheng G, Huang G, [...], Wang H.

Link:
http://onlinelibrary.wiley.com/doi/10.1111/j.1445-5994.2012.02758.x/epdf

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

Objectives:
An increased intake of magnesium might lower blood pressure (BP), yet evidence from clinical trials is inconsistent, perhaps as a result of small sample size or heterogeneity in study design. Therefore, this review article (meta-analysis) has been conducted.

Are there dose-dependent effects of magnesium supplementation on blood pressure?

Study design:
This review article included 20 RCTs included 14 of hypertensive and 6 of normotensive persons totaling 1220 participants.
The doses of magnesium ranged from 10 to 40 mmol/day (median: 15.4 mmol/day or 370 mg per day).

Results and conclusions:
The investigators found magnesium supplementation resulted in only a small overall non-significant reduction in blood pressure. The pooled net estimates of blood pressure change were -0.6 mmHg [95% CI = -2.2 to 1.0] for systolic blood pressure and -0.8 mmHg [95% CI = -1.9 to 0.4] for diastolic blood pressure.

However, the investigators found an apparent dose-dependent effect of magnesium, with significant reductions of 4.3 mmHg systolic blood pressure [95% CI = 6.3 to 2.2, p 0.001) and non-significant reductions of 2.3 mmHg diastolic blood pressure [95% CI = 4.9 to 0.0, p = 0.09) for each 10 mmol/day (240 mg/day) increase in magnesium dose.

The investigators concluded there is a dose-dependent blood pressure reductions, especially systolic blood pressure from magnesium supplementation. However, adequately powered trials with sufficiently high doses of magnesium supplements need to be performed to confirm this relationship.

Original title:
The effect of magnesium supplementation on blood pressure: a meta-analysis of randomized clinical trials by Jeea SH, Miller ER, [...], Klagb MJ.

Link:
http://www.sciencedirect.com/science/article/pii/S0895706102029643

Additional information of El Mondo:
Find more studies/information on magnesium and lowering blood pressure right here.  

Objectives:
Quantification of the association between the intake of fruit and vegetables and risk of esophageal squamous cell carcinoma (ESCC) is controversial even though several studies have explored this association. Therefore, this review article (meta-analysis) has been conducted.

Does a high intake of vegetables and fruit decrease risk of esophageal squamous cell carcinoma?

Study design:
This review article included a total of 32 observational studies involving 10037 cases of esophageal squamous cell carcinoma.

There was no evidence of publication bias.

Results and conclusions:
The investigators found highest vs. lowest vegetable intake, significantly reduced risk of esophageal squamous cell carcinoma with 44% [SRR = 0.56, 95% CI = 0.45-0.69, p-heterogeneity 0.001]. Significant means there is an association with a 95% confidence.

The investigators found highest vs. lowest fruit intake, significantly reduced risk of esophageal squamous cell carcinoma with 47% [SRR = 0.53, 95% CI = 0.44-0.64, p-heterogeneity 0.001].

The investigators found similar results in a linear dose-response analysis and there was evidence of non-linear associations for intakes of fruit [p non-linearity 0.001] and vegetables [p non-linearity = 0.041].

The investigators concluded that intakes of vegetables and fruit reduce risk of esophageal squamous cell carcinoma. Further investigation with prospective designs, validated questionnaires and good control of important confounders is warranted.

Original title:
Intake of fruit and vegetables and risk of esophageal squamous cell carcinoma: A meta-analysis of observational studies by Liu J, Wang J, […], Lv C.

Link:
http://www.ncbi.nlm.nih.gov/pubmed/23319052

Additional information of El Mondo:
Find more information/studies on review, 95% CI and heterogeneity, vegetables and fruits and cancer right here.
 

Objectives:
Previous systematic reviews suggest beneficial effects of flavonoids on biomarkers of cardiovascular disease (CVD) risk, but have overlooked the impact of dose response or food complexity. Therefore, this review article has been conducted.

Do taking flavonoid supplements improve flow-mediated dilation (FMD) and blood pressure?

Study design:
This review article included 63 RCTs.

Results and conclusions:
The investigators found meta-analyses of combined flavonoid subclasses showed significant improvements in FMD [chronic: 0.73%, 95% CI = 0.17 to 1.30, 14 RCTs and acute: 2.33%, 95% CI = 1.58 to 3.08, 18 RCTs].

The investigators found meta-analyses of combined flavonoid subclasses showed significant improvements in blood pressures [systolic: -1.46 mmHg, 95% CI = -0.38 to -0.53, 63 RCTs and diastolic: -1.25 mmHg, 95% CI = -1.82 to -0.67, 63 RCTs].

The investigators found similar benefits were observed for the flavan-3-ol, catechol flavonoids (catechins, quercetin, cyanidin etc.), procyanidins, epicatechin and catechin subgroups.

The investigators found dose-response relationships were non-linear for FMD (R2 ≤ 0.30), with greater associations observed when applying polynomial regression analyses (R2 ≤ 0.72). However, there was no indication of a dose response for blood pressure.

The investigators concluded flavonoid subclasses supplements show significant improvements in FMD and blood pressure. However, the flavonoid bioactivity does not follow a classical linear dose-response association and this may have important biological implications.

Original title:
Relative impact of flavonoid composition, dose and structure on vascular function: A systematic review of randomised controlled trials of flavonoid-rich food products by Kay CD, Hooper L, […], Cassidy A.

Link:
http://onlinelibrary.wiley.com/doi/10.1002/mnfr.201200363/abstract;jsessionid=2CCB9E4E779A221E42AA38998C865DA6.d02t03?deniedAccessCustomisedMessage=&userIsAuthenticated=false

Additional information of El Mondo:
Find more information/studies on RCTs, lowering blood pressure and cardiovascular disease right here.

The optimal blood pressure for a healthy adult is120 mmHg systolic pressure and 80 mmHg diastolic pressure.

When blood flow increases through a vessel, the vessel dilates. This phenomenon has been coined flow-mediated dilatation (FMD). Flow-mediated dilation is an accepted technique to quantify endothelial function and has shown to have prognostic value for future cardiovascular disease (CVD).