Nutrition and health

Objectives:
Many studies have investigated the association between dietary iron intake and death due to cardiovascular disease (CVD), but the results were inconsistent. Therefore, this review article has been conducted.

Does dietary iron intake increase risk of death due to cardiovascular disease (cardiovascular disease mortality)?

Study design:
This review article included 19 prospective cohort studies including 720,427 participants (46,045 deaths due to cardiovascular disease).

Results and conclusions:
The investigators found when comparing the highest versus lowest level, the highest level of dietary heme iron intake significantly increased risk of death due to cardiovascular disease with 19% [pooled RR = 1.19, 95% CI = 1.01-1.39].

The investigators found every 1-mg/day increase in dietary heme iron intake significantly increased risk of death due to cardiovascular disease with 25% [pooled RR = 1.25, 95% CI = 1.17-1.33].

The investigators found every 1-mg/day increase in dietary heme iron intake significantly increased risk of death due to stroke with 17% [pooled RR = 1.17, 95% CI = 1.04-1.32].

The investigators found the association between dietary iron intake and cardiovascular disease mortality was linear [p nonlinearity > 0.05].

The investigators concluded higher dietary intake of heme iron (at least 1-mg/day) is associated with a greater risk of cardiovascular disease mortality. Therefore, reducing consumption of heme iron may help to prevent premature death due to cardiovascular disease.

Original title:
Dietary iron intake and risk of death due to cardiovascular diseases: A systematic review and dose-response meta-analysis of prospective cohort studies by Han M, Guan L, […], Lu J.

Link:
https://pubmed.ncbi.nlm.nih.gov/32674239/

Additional information of El Mondo:
Find more information/studies on significant/cohort studies, iron consumption and cardiovascular disease right here.

Food items of heme iron are:

• Beef or chicken liver
• Beef
• Canned light tuna
• Canned sardines
• Organ meats
• Oysters, clams, mussels
• Poultry

Objectives:
Previous studies lack consistent conclusions as to whether astaxanthin is actually linked to various health benefits as claimed. Therefore, this review article has been conducted.

Is there a causal relationship between astaxanthin consumption and improvements in risk factors for diabetes or cardiovascular disease?

Study design:
This review article included 14 RCTs.

Results and conclusions:
The investigators found that astaxanthin consumption was not associated with FBS, HbA1c, TC, LDL-C, TG, BMI, BW, DBP and SBP.

The investigators found that astaxanthin consumption was associated with an increase in HDL cholesterol levels [WMD = 1.473 mg/dL, 95% CI = 0.319 to 2.627, p = 0.012].

The investigators found that astaxanthin consumption during ≥12 weeks was associated with a decrease in CRP levels [WMD = -0.528 mg/L, 95% CI = -0.990 to -0.066].

The investigators found that >12 mg/day astaxanthin consumption was associated with a decrease in CRP levels [WMD = -0.389 mg/dL, 95% CI = -0.596 to -0.183].

The investigators concluded that astaxanthin consumption is causally associated with an increase in HDL cholesterol levels (good cholesterol) and a decrease in CRP levels for >12 mg/day astaxanthin consumption during ≥12 weeks. Significant associations are not observed for other outcomes.

Original title:
The effects of astaxanthin supplementation on obesity, blood pressure, CRP, glycemic biomarkers, and lipid profile: A meta-analysis of randomized controlled trials by Xia W, Tang N, [...], Zhu Y.

Link:
https://pubmed.ncbi.nlm.nih.gov/32755613/

Additional information of El Mondo:
Find here more information/studies about astaxanthin consumption and cholestrerol.

Objectives:
Dyslipidemia is a common metabolic disease worldwide and also an important predisposing factor for cardiovascular diseases (CVDs). Coffee is loved by people all over the world; however, the association between coffee consumption and blood lipids has yielded inconsistent results. Therefore, this review article has been conducted.

Is there a causal relationship between coffee consumption and dyslipidemia?

Study design:
This review article included 12 RCTs.

Results and conclusions:
The investigators found pooled results showed that coffee consumption significantly increased total cholesterol (TC) levels [WMD = 0.21 mmol/L, 95% CI = 0.04 to 0.39, p = 0.017].  
Significant means that there is an association with a 95% confidence.

The investigators found pooled results showed that coffee consumption significantly increased triglyceride (TG) levels [WMD = 0.12 mmol/L, 95% CI = 0.03 to 0.20, p = 0.006].  
Significant because the calculated p-value of 0.006 was less than the p-value of 0.05.

The investigators found pooled results showed that coffee consumption significantly increased LDL cholesterol (bad cholesterol) levels [WMD = 0.14 mmol/L, 95% CI = 0.05 to 0.24, p = 0.003].  

The investigators found pooled results showed that coffee consumption had no significant effect on HDL cholesterol (good cholesterol) levels [WMD = -0.01 mmol/L, 95% CI = -0.06 to 0.04, p = 0.707].
No significant means that there is no association with a 95% confidence.

The investigators found dose-response analysis results revealed significant positive nonlinear associations between coffee consumption and the increase in total cholesterol, LDL cholesterol and triglyceride levels.

The investigators concluded that coffee consumption is associated with an elevated risk for dyslipidemia and cardiovascular diseases. So a reasonable habit of coffee consumption (3 cups/d) is essential for the prevention of dyslipidemia.  

Original title:
Effect of coffee consumption on dyslipidemia: A meta-analysis of randomized controlled trials by Du Y, Lv Y, […], Luo Q.

Link:
https://pubmed.ncbi.nlm.nih.gov/33239163/

Additional information of El Mondo:
Find more information/studies on significant/RCTs/causal relationship, coffee consumption, lowering cholesterol levels and cardiovascular disease right here.

Dyslipidemia is elevation of plasma cholesterol, triglycerides (TGs), or both, or a low HDL cholesterol (good cholesterol) level that contributes to the development of atherosclerosis. Atherosclerosis is the main underlying cause of cardiovascular disease (CVD).

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:
Dietary sodium intake has received considerable attention as a potential risk factor of cardiovascular disease. However, evidence on the dose-response association between dietary sodium intake and cardiovascular disease risk is unclear. Therefore, this review article has been conducted.

Is there a dose-response association between dietary sodium intake and cardiovascular disease (CVD) risk?

Study design:
This review article included 36 cohort studies with a total of 616,905 participants.
The duration of follow-up ranged from 2.7 years to 29 years.

For dietary sodium intake assessment, 18 of the studies were based on twenty-four urinary excretion, 7 used food frequency questionnaires, 8 used 24 h dietary recall, 2 used dietary records; 1 used a self-administered questionnaire and 1 used single spot urine sodium excretion.
The daily dietary sodium intake ranged from 1.0 to 7.5 g.

The mean score (± standard deviation) for the quality of the included studies was 8.0 ± 1.0 according to the Newcastle-Ottawa Scale.

Results and conclusions:
The investigators found compared with individuals with low sodium intake, individuals with high sodium intake had an 19%-higher adjusted risk of cardiovascular disease [rate ratio = 1.19, 95% CI = 1.08 to 1.30].

The investigators found in dose-response meta-analysis that the risk of cardiovascular disease significantly increased by 6% when 1 g dose of sodium was ingested [rate ratio = 1.06, 95% CI = 1.01 to 1.11].

The investigators concluded that high sodium intake is an important risk factor of cardiovascular disease (CVD) and in dose-response meta-analysis, every 1 g of dietary sodium intake increases the risk of cardiovascular disease by 6%.

Original title:
Dietary Sodium Intake and Risk of Cardiovascular Disease: A Systematic Review and Dose-Response Meta-Analysis by Wang YJ, Yeh TL, [...], Chien KL.

Link:
https://www.mdpi.com/2072-6643/12/10/2934/htm

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

1 gram salt (sodium chloride) = 0.4 gram sodium.

Objectives:
Epidemiological studies on the impact of fish consumption on coronary heart disease (CHD) incidence have shown inconsistent results. Therefore, this review article has been conducted.

Does dietary intake of fish reduce coronary heart disease incidence and mortality?

Study design:
This review article included 40 prospective cohort studies (22 studies investigated the association between fish consumption and coronary heart disease incidence (28,261 persons with coronary heart disease and 918,783 participants) and 27 studies investigated the association between fish consumption and coronary heart disease mortality (10,568 events and 1,139,553 participants)).

No evidence of publication bias was found.

Results and conclusions:
The investigators found higher fish consumption was significantly associated with a 9%-lower coronary heart disease risk [RR = 0.91, 95% CI = 0.84 to 0.97, I2 = 47.4%].

The investigators found a significant correlation between fish consumption and coronary heart disease risk in the female subgroup [RR = 0.85, 95% CI = 0.78 to 0.92, I2 = 5.6%], the subgroup with a follow-up period of ≥10 years [RR = 0.91, 95% CI = 0.84 to 0.99, I2 = 51.5%] and the subgroup with an article quality of ≥7 points [RR = 0.90, 95% CI = 0.83 to 0.98, I2 = 50.6%].
However, it was not found in the male subgroup, the subgroup with a follow-up period of 10 years and the subgroup with an article quality of 7 points.

The investigators found higher fish intake was significantly associated with a 15%-lower coronary heart disease mortality risk [RR = 0.85, 95% CI = 0.77 to 0.94, I2 = 51.3%].

The investigators found the summary results did not change significantly in sensitivity analysis.

The investigators found dose-response analysis showed that the coronary heart disease incidence and mortality were reduced by 4%, respectively, with a 20 g/day increment in fish consumption.

The investigators concluded that a higher dietary intake of fish reduces coronary heart disease incidence and mortality. This finding has important public health implications in terms of the prevention of coronary heart disease. Since most of the research was conducted in male groups and Western countries, further research needs to be performed in female groups and other regions.

Original title:
Fish Consumption and Coronary Heart Disease: A Meta-Analysis by Zhang B, Xiong K, […], Ma A.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7468748

Additional information of El Mondo:
Find more information/studies/nutritional advices on fish consumption and coronary heart disease right here.

In practice, higher fish consumption means at least twice a week of fish consumption (150 grams of fish at a time).

Objectives:
Observational studies regarding the putative associations between dietary intake of homocysteine metabolism-related B-vitamins (vitamin B6, folate and vitamin B12) and stroke risk have yielded inconsistent results. Therefore, this review article has been conducted.

Does dietary intake of vitamin B6, folate or vitamin B12 reduce stroke risk?

Study design:
This review article included 1 nested case-control study and 11 prospective cohort studies comprising 389,938 participants and 10,749 cases (persons with stroke).

The studies were published from 2002 through to 2019 and the follow-up period ranged from 4.2 to 19 years.

All 12 studies provided risk estimates adjusted for cigarette smoking and most studies also adjusted for other conventional risk factors, including BMI, energy intake, alcohol consumption, hypertension and/or physical activity.

Study quality scores ranged from 5 to 9; the mean quality score was 7.4.

There was no evidence of publication bias.

Results and conclusions:
The investigators found for the highest versus the lowest category of dietary vitamin B6 intake, a significantly reduced risk of 16% for stroke [RR = 0.84, 95% CI = 0.73 to 0.97, I2 = 48.8%].

The investigators found in dose-response analysis that each 0.5 mg/d increment in vitamin B6 dietary intake was associated with a 6% reduction in the risk of stroke [RR = 0.94, 95% CI = 0.89 to 0.99, I2 = 77.0%].

The investigators found for the highest versus the lowest category of dietary folate intake, a significantly reduced risk of 15% for stroke [RR = 0.85, 95% CI = 0.78 to 0.94, I2 = 11.5%].

The investigators found in dose-response analysis that each 100 μg/d increase in dietary folate intake was associated with a 6% reduction in the risk of stroke [RR = 0.94, 95% CI = 0.90 to 0.98, I2 = 46.8%].

The investigators found, in contrast, no significant association between dietary vitamin B12 intake and the risk of stroke, with an RR of 1.01 [95% CI = 0.97 to 1.06] per 3 μg/d increase.

The investigators concluded increased dietary intake of vitamin B6 (at least 0.5 mg/d) and dietary folate intake (at least 100 μg/d) is associated with a reduced risk of stroke, supporting the notion that increasing habitual folate and vitamin B6 intake may provide a small but beneficial effect with respect to stroke.

Original title:
Dietary Intake of Homocysteine Metabolism-Related B-Vitamins and the Risk of Stroke: A Dose-Response Meta-Analysis of Prospective Studies by Chen L, Li Q, [...], Wang F.

Link:
https://academic.oup.com/advances/advance-article/doi/10.1093/advances/nmaa061/5854025

Additional information of El Mondo:
Find more information/studies on vitamin B6, folate and lowering of stroke right here.

Objectives:
Hypertension is regarded as a major and independent risk factor of cardiovascular diseases and numerous studies observed an inverse correlation between vitamin C intake and blood pressure. Therefore, this review article has been conducted.

Does a high serum vitamin C reduce blood pressure?

Study design:
This review article included 11 cross-sectional studies and 7 case-control studies. These studies comprised 22,200 observational subjects and were conducted from the year 1990 to 2017. Of the 18 articles, 14 were published in the English language and 4 were in Chinese.

Assessed with NOS, all the case-control studies yield a high quality averaging with 7.143 scores. And the result of AHRQ indicates a moderate quality with all cross-sectional studies scoring between 4 and 7.

Results and conclusions:
The investigators found random-effects model showed serum level of vitamin C of hypertensive subjects was 15.13 μmol/L lower than the normotensives [MD = -15.13, 95% CI = -24.19 to -6.06, p = 0.001, I2 = 98%].

The investigators found subgroup analysis showed that hypertensive subjects who took antihypertensive drugs had a 15.97 μmol/L lower serum vitamin C compared with normotensive ones.

The investigators found serum vitamin C had a significant inverse relation with both systolic blood pressure [Fisher′s Z = -0.17, 95% CI = -0.20 to -0.15, p 0.00001] and diastolic blood pressure [Fisher′s Z = -0.15, 95% CI = -0.20 to -0.10, p 0.00001].

The investigators concluded people with hypertension have a relatively low serum vitamin C and vitamin C is inversely associated with both systolic blood pressure and diastolic blood pressure.

Original title:
Association between Serum Vitamin C and the Blood Pressure: A Systematic Review and Meta-Analysis of Observational Studies by Ran L, Zhao W, […], Bu H.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7211237/

Additional information of El Mondo:
Find more information/studies on vitamin C and lowering of blood pressure 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:
Is there a causal relationship between black or green tea consumption and lowering blood pressure in subjects with elevated blood pressure (BP) or hypertension?
 
Study design:
This review article included 5 RCTs with 408 individuals.

None of the studies reported any side effects.

Results and conclusions:
The investigators found regular tea consumption significantly reduced systolic blood pressure [WMD = -4.81 mmHg, 95% CI = -8.40 to -1.58, p = 0.004] in subjects with elevated blood pressure (BP) or hypertension.

The investigators found regular tea consumption significantly reduced diastolic blood pressure [WMD = -1.98 mmHg, 95% CI = -3.77 to -0.20, p = 0.029] in subjects with elevated blood pressure (BP) or hypertension.

The investigators found, however, excluding the most heterogeneous trials showed that regular tea intake significantly reduced systolic blood pressure and diastolic blood pressure by about -3.53 and -0.99 mmHg, respectively.

The investigators found based on meta-regression findings, the longer the duration of tea intake (≥3 months), the higher the decrease in both systolic blood pressure and diastolic blood pressure.

The investigators found categorized studies, according to the tea type, revealed that the hypotensive effects of green tea were more pronounced compared to black tea.

The investigators concluded regular tea consumption, particularly green tea during ≥3 months reduces systolic blood pressure and diastolic blood pressure in subjects with elevated blood pressure (BP) or hypertension. Hence, it may be applicable to physicians, health care providers and particularly hypertension patients.

Original title:
The Effects of Regular Consumption of Green or Black Tea Beverage on Blood Pressure in Those With Elevated Blood Pressure or Hypertension: A Systematic Review and Meta-Analysis by Mahdavi-Roshan M, Salari A, […], Ashouri A.

Link:
https://www.sciencedirect.com/science/article/abs/pii/S0965229919316899?via%3Dihub

Additional information of El Mondo:
Find more information/studies on green tea consumption and lowering of blood pressure 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:
Epidemiologic studies, including trials, suggest an association between potassium intake and blood pressure (BP). However, the strength and shape of this relationship is uncertain. Therefore, this review article has been conducted.

What is the strength and shape of the relationship between potassium intake and blood pressure (BP)?
 
Study design:
This review article included 32 RCTs with a duration ≥4 weeks using the recently developed 1‐stage cubic spline regression model. This model allows use of trials with at least 2 exposure categories.
Most trials were conducted in adults with hypertension using a crossover design and potassium supplementation doses that ranged from 30 to 140 mmol (1173 and 5474 mg) per day.

Results and conclusions:
The investigators found a U‐shaped relationship between 24‐hour active and control arm differences in potassium excretion and blood pressure (BP) levels, with weakening of the blood pressure reduction effect above differences of 30 mmol/d and a blood pressure increase above differences ≈80 mmol/d.

The investigators found achieved potassium excretion analysis also identified a U‐shaped relationship. The blood pressure lowering effects of potassium supplementation were stronger in participants with hypertension and at higher levels of sodium intake.

The investigators found blood pressure increased with high potassium excretion in participants with antihypertensive drug‐treated hypertension but not in their untreated counterparts.

The investigators concluded that an adequate intake of potassium (≤30 mmol (1173 mg) per day) is desirable to achieve a lower blood pressure level but excessive potassium supplementation (>80 mmol (3128 mg) per day) should be avoided, particularly in specific subgroups.

Original title:
Potassium Intake and Blood Pressure: A Dose‐Response Meta‐Analysis of Randomized Controlled Trials by Filippini T, Naska A, […], Whelton PK.

Link:
https://www.ahajournals.org/doi/full/10.1161/JAHA.119.015719?url_ver=Z39.88-2003&rfr_id=ori%3Arid%3Acrossref.org&rfr_dat=cr_pub++0pubmed&

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

Objectives:
Is there a causal relationship between tomato consumption and lowering effects on cholesterol, triglycerides or fasting blood sugar levels?
 
Study design:
This review article included 6 RCTs.

Results and conclusions:
The investigators found tomato consumption significantly reduced total plasma cholesterol levels [WMD = -4.39 mg/dL, 95% CI = -7.09 to -1.68, I2 = 48%, p = 0.05].

The investigators found tomato consumption significantly reduced plasma triglyceride (TG) levels [WMD = -3.94 mg/dL, 95% CI = -7.67 to -0.21, I2 = 90%, p = 0.001].
A higher reduction effect was found on younger participants.

The investigators found tomato consumption significantly reduced plasma LDL cholesterol (bad cholesterol) levels [WMD = -2.09 mg/dL, 95% CI = -3.73 to -0.81, I2 = 78%, p = 0.001].
A higher reduction effect was found on younger participants.

The investigators found tomato consumption significantly increased plasma HDL cholesterol (good cholesterol) levels [WMD = 2.25 mg/dL, 95% CI = 0.41 to 4.10, I2 = 97%, p = 0.001].

The investigators found tomato consumption had no significant effect on plasma fasting blood sugar levels [WMD = 0.59 mg/dL, 95% CI = -0.28 to 1.46, I2 = 95%, p = 0.001].

The investigators concluded that tomato consumption increases plasma HDL cholesterol (good cholesterol) levels and decreases plasma total cholesterol, LDL cholesterol (bad cholesterol) and triglyceride levels.

Original title:
Effect of Tomato Consumption on Fasting Blood Glucose and Lipid Profiles: A Systematic Review and Meta-Analysis of Randomized Controlled Trials by Li H, Chen, A, [...],Yin X.

Link:
https://pubmed.ncbi.nlm.nih.gov/32243013/

Additional information of El Mondo:
Find more information/studies on tomato consumption and lowering of cholesterol levels right here.

Patients with heart disease often have high LDL cholesterol, low HDL cholesterol and high triglycerides levels.

Objectives:
Do dietary calcium intakes or calcium supplements increase risk of cardiovascular disease?
 
Study design:
This review article included 26 prospective cohort studies and 16 RCTs.

Results and conclusions:
The investigators found in cohort studies that dietary calcium intakes ranging from 200 to 1500 mg/d did not affect the risk of cardiovascular disease [relative risk = 0.96, 95% CI = 0.87 to 1.05].

The investigators found in cohort studies that dietary calcium intakes ranging from 200 to 1500 mg/d did not affect the risk of coronary heart disease [relative risk = 0.98, 95% CI = 0.88 to 1.08].

The investigators found in cohort studies that dietary calcium intakes ranging from 200 to 1500 mg/d did not affect the risk of stroke [relative risk = 0.94, 95% CI = 0.85 to 1.04].

The investigators found in RCTs that calcium supplements significantly increased risk of coronary heart disease with 20% [relative risk = 1.20, 95% CI = 1.08 to 1.33, I2 = 0.0%].

The investigators found in RCTs that calcium supplements significantly increased risk of myocardial infarction with 21% [relative risk = 1.21, 95% CI = 1.08 to 1.35, I2 = 0.0%].

The investigators concluded that 200-1500 mg/d calcium intake from dietary sources do not increase the risk of cardiovascular disease, including coronary heart disease and stroke, while calcium supplements increase coronary heart disease risk, especially myocardial infarction.

Original title:
The Evidence and Controversy Between Dietary Calcium Intake and Calcium Supplementation and the Risk of Cardiovascular Disease: A Systematic Review and Meta-Analysis of Cohort Studies and Randomized Controlled Trials by Yang C, Shi X, […], Sun G.

Link:
https://pubmed.ncbi.nlm.nih.gov/31625814/

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

Objectives:
Is there a causal relationship between daily egg consumption and positive effects on blood pressure?
 
Study design:
This review article included 15 RCTs with a total of 748 participants and mean age range from 23.3 to 67.1 years old.

All included studies used whole egg as an intervention which varied from one egg/day to three eggs/day and duration of supplementation ranged from 3 to 12 weeks.

No evidence of publication bias was seen in the meta-analyse (review article) of systolic blood pressure [Begg’s p = 0.235, Eggers’s p = 0.433] and diastolic blood pressure [Begg’s p = 0.254, Eggers’s p = 0.267].

No heterogeneity was found among included studies.

Results and conclusions:
The investigators found, overall, egg consumption had no significant effect on systolic blood pressure [WMD = 0.046 mmHg, 95% CI = - 0.792 to 0.884, p = 0.914, I2 = 0.0%, p = 0.453] and diastolic blood pressure [WMD = -0.603 mmHg, 95% CI = -1.521 to 0.315, p = 0.198, I2 = 38.1%, p = 0.067].
Subgroup analyses had no effect on pooled results.
Sensitivity analysis indicated that excluding each trial did not significantly change the overall observed effects of egg consumption.

The investigators found nonlinear dose-response meta-analysis did not reveal a significant effect of egg consumption [p-nonlinearity = 0.76] and study duration on diastolic blood pressure [p-nonlinearity = 0.63].

The investigators found subgroup analyses based on study design, sex, population health status, obesity and hypertension status, diet adherence, study duration and amount of egg consumption did not affect the overall effects of egg consumption on systolic blood pressure and diastolic blood pressure values.

The investigators concluded that 1-3 eggs/day during 3 to 12 weeks have no effect on blood pressure. However, high-quality RCTs with longer durations are needed to further confirm the effects of egg consumption on blood pressure.

Original title:
Effect of Egg Consumption on Blood Pressure: a Systematic Review and Meta-analysis of Randomized Clinical Trials by Kolahdouz-Mohammadi R, Malekahmadi M, […], Soltani S.

Link:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7189334/

Additional information of El Mondo:
Find more information/studies on causal relationship/significantly, egg consumption and lowering of blood pressure right here.

Objectives:
Does Alzheimer disease increase risk of stroke?

Study design:
This review article included 8 studies, representing 121,719 individuals (Alzheimer disease = 73,044 and non-Alzheimer disease = 48,675).

Results and conclusions:
The investigators found patients with Alzheimer disease had a significantly increased risk of 42% [relative risk = 1.42, 95% CI = 1.23 to 1.64] for hemorrhagic stroke.

The investigators concluded Alzheimer disease increases risk of hemorrhagic stroke.

Original title:
Risk of hemorrhagic and ischemic stroke in patients with Alzheimer disease: A synthesis of the literature by Waziry R, Chibnik LB, […], Hofman A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/31949087

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

Objectives:
Is there a causal relationship between strawberry consumption and positive effects on cardiovascular risk factors?
 
Study design:
This review article included 11 RCTs (6 for blood pressure, 7 for lipid profile, 7 for fasting blood glucose and 6 for C-reactive protein).

There was little evidence of heterogeneity in the analysis and no evidence of publication bias.

Results and conclusions:
The investigators found overall, strawberry consumption significantly reduced C-reactive protein (CRP) levels by 0.63 mg/L [95% CI = -1.04 to -0.22] but did not affect blood pressure, lipid profile or fasting blood glucose in the main analyses.

The investigators found stratified by baseline endpoint levels, that strawberry consumption significantly reduced total cholesterol levels among people with baseline levels >5 mmol/L [-0.52 mmol/L, 95% CI = -088 to -0.15] and reduced LDL-cholesterol levels among people with baseline levels >3 mmol/L [-0.31 mmol/L, 95% CI = -0.60 to -0.02].

The investigators concluded strawberry consumption reduces C-reactive protein (CRP) levels and improves total cholesterol and LDL-cholesterol (bad cholesterol) in individuals with high baseline levels (level at the beginning of the study).

Original title:
Effects of strawberry intervention on cardiovascular risk factors: a meta-analysis of randomized controlled trials by Gao Q, Qin LQ, […], Dong JY.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32238201

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Find more information/studies on fruit consumption and lowering of cholesterol levels 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:
Does fish consumption decrease risk of cardiovascular disease, depression, mortality and cancer?
 
Study design:
This review article included a total of 34 meta-analyses of prospective observational studies, reporting summary relative risks (SRR) for 40 different outcomes obtained from 298 primary prospective cohort studies.

The summary relative risk (SRR) for each meta-analysis was recalculated by using a random-effects model.

Results and conclusions:
The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 8% lower risk of all-cause mortality [SRR = 0.92, 95% CI = 0.87 to 0.97].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 25% lower risk of cardiovascular mortality [SRR = 0.75, 95% CI = 0.65 to 0.87].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 12% lower risk of coronary heart disease [SRR = 0.88, 95% CI = 0.79 to 0.99].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 25% lower risk of myocardial infarction [SRR = 0.75, 95% CI = 0.65 to 0.93].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 14% lower risk of stroke [SRR = 0.86, 95% CI = 0.75 to 0.99].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 20% lower risk of heart failure [SRR = 0.80, 95% CI = 0.67 to 0.95].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 12% lower risk of depression [SRR = 0.88, 95% CI = 0.79 to 0.98].

The investigators found moderate-quality evidence showed that each 100-g/d increment in fish consumption was associated with a 35% lower risk of liver cancer [SRR = 0.65, 95% CI = 0.48 to 0.87].

The investigators concluded evidence of moderate quality shows that 100-g/d fish consumption is associated with a lower risk of cardiovascular disease, depression, mortality and liver cancer and therefore, can be considered as a healthy animal-based dietary source of protein. Further research is needed for outcomes for which the quality of the evidence was rated low and very low, considering types of fish consumed, different methods of cooking fish and all potential confounding variables.

Original title:
Fish Consumption and the Risk of Chronic Disease: An Umbrella Review of Meta-Analyses of Prospective Cohort Studies by Jayedi A and Shab-Bidar S.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32207773

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

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:
Do fermented dairy foods and probiotics supplementation improve risk factors (such as metabolic syndrome, type 2 diabetes, cholesterol) of cardiovascular diseases?

Study design:
This review article included 20 prospective cohort studies and 52 RCTs.

Results and conclusions:
The investigators found in prospective cohort studies, that fermented milk was associated with a 4% reduction in risk of stroke, ischemic heart disease and cardiovascular mortality [RR = 0.96, 95% CI = 0.94 to 0.98].

The investigators found in prospective cohort studies, that yogurt intake was associated with a risk reduction of 27% [RR = 0.73, 95% CI = 0.70 to 0.76] for type 2 diabetes.

The investigators found in prospective cohort studies, that yogurt intake was associated with a risk reduction of 20% [RR = 0.80, 95% CI = 0.74 to 0.87] for metabolic syndrome development.

The investigators found in RCTs, that probiotic supplementation added into dairy matrices produced a greater reduction in lipid biomarkers than when added into capsules/powder in hypercholesterolemic subjects.

The investigators found in RCTs, that probiotic supplementation by capsules/powder produced a greater reduction in type 2 diabetes biomarkers than when added into dairy matrices in diabetic subjects.

The investigators found in RCTs, that probiotic supplementation by both treatments (dairy matrix and capsules/powder) resulted in a significant reduction in anthropometric parameters in obese subjects.

The investigators concluded fermented milk consumption is associated with reduced cardiovascular risk, while yogurt intake is associated with a reduced risk of type 2 diabetes and metabolic syndrome development in the general population. Furthermore, probiotic supplementation added into dairy matrices is beneficial for lowering lipid concentrations and reduce anthropometric parameters. Additionally, probiotic capsule/powder supplementation contributes to type 2 diabetes management and reduces anthropometric parameters. However, these results should be interpreted with caution due to the heterogeneity of the studies and the different probiotic strains used in the studies.

Original title:
Fermented Dairy Products, Probiotic Supplementation, and Cardiometabolic Diseases: A Systematic Review and Meta-analysis by Companys J, Pla-Pagà L, […], Valls RM.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32277831

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

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:
Does tea consumption decrease risk of cardiovascular disease and all-cause mortality among adults?
 
Study design:
This review article included 39 prospective cohort studies.

Strength of evidence was rated as low and moderate (depending on study population age group) for cardiovascular disease-specific mortality outcome and was rated as low for cardiovascular disease events, stroke and all-cause mortality outcomes.

Results and conclusions:
The investigators found linear meta-regression showed that each cup (236.6 mL) increase in daily tea consumption (estimated 280 mg and 338 mg total flavonoids/d for black and green tea, respectively) was associated with an average 4% lower risk of cardiovascular disease mortality, a 2% lower risk of cardiovascular disease events, a 4% lower risk of stroke and a 1.5% lower risk of all-cause mortality.

The investigators found subgroup meta-analysis showed that each cup (236.6 mL) increase in daily tea consumption (estimated 280 mg and 338 mg total flavonoids/d for black and green tea, respectively) was associated with a 11% [pooled adjusted RR = 0.89, 95% CI = 0.83 to 0.96, p = 0.001, I2 = 72.4%, n = 4] lower risk of cardiovascular disease mortality in elderly individuals.

The investigators found subgroup meta-analysis showed that each cup (236.6 mL) increase in daily tea consumption (estimated 280 mg and 338 mg total flavonoids/d for black and green tea, respectively) was associated with a 8% [pooled adjusted RR = 0.92, 95% CI = 0.90 to 0.94, p 0.0001, I2 = 0.3%, n = 3] lower risk of all-cause mortality in elderly individuals.

The investigators found, generally, studies with higher risk of bias appeared to show larger magnitudes of associations than studies with lower risk of bias.

The investigators concluded that daily a cup (236.6 mL) of tea (estimated 280 mg and 338 mg total flavonoids/d for black and green tea, respectively) is associated with a lower risk of cardiovascular disease and all-cause mortality among elderly individuals.

Original title:
Dose-Response Relation between Tea Consumption and Risk of Cardiovascular Disease and All-Cause Mortality: A Systematic Review and Meta-Analysis of Population-Based Studies by Chung M, Zhao N, […], Wallace TC.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32073596

Additional information of El Mondo:
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Objectives:
Does flaxseed supplementation decrease plasma lipoprotein(a) levels?

Study design:
This review article included 7 RCTs with 629 individuals.

Results and conclusions:
The investigators found flaxseed supplementation significantly reduced plasma lipoprotein(a) levels [MD = -2.06 mg/dL, 95% CI = -3.846 to -0.274, p = 0.024, I2 = 0%, p = 0.986].

The investigators found subgroup analysis also revealed that longer duration only showed significant lowering effect of flaxseed supplementation on plasma lipoprotein(a) levels.

The investigators concluded that long duration of flaxseed supplementation decreases plasma lipoprotein(a) levels. However, future well-designed and long-term clinical trials are required to confirm these results.

Original title:
Impact of flaxseed supplementation on plasma lipoprotein(a) concentrations: A systematic review and meta-analysis of randomized controlled trials by Hadi A, Askarpour M, […], Ghavami A.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/32073724

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Lipoprotein(a) is a risk factor for atherosclerosis and related diseases, such as coronary heart disease and stroke.