This tab will answer the following nutritional question: How can nutrition contribute positively to my health?

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of randomized, placebo-controlled double blind clinical trials (RCTs) will answer the following question:
"Do taking dietary supplements make sense?" Yes for a positive conclusion and no for a negative conclusion.

One swallow does not make a summer. A famous Dutch saying that could not be any more obvious. Just because one single scientific study about a certain topic makes certain claims, it does not necessarily mean it is true. On the other hand, a review article (a collection of scientific studies on a certain topic) of cohort studies or case-control studies will answer the following question:
"Should I change my diet?".

Find scientific studies on vitamin A: type vitamin A in Search field.

Nutritional advice

Olive oil consumption reduces stroke

Objectives:
Increasing evidence suggests that the Mediterranean diet can reduce the risk of cardiovascular disease. Olive oil is the hallmark of this dietary pattern. Therefore, this review article has been conducted.

Does olive oil consumption reduce risk of cardiovascular disease?

Study design:
This review article included case-control, prospective cohort studies and a randomised controlled trial investigating the specific association between olive oil consumption and the risk of cardiovascular disease (101,460 participants) or stroke (38,673 participants). The results of all observational studies were adjusted for total energy intake.

Evidence of heterogeneity was apparent for cardiovascular disease, but not for stroke. Both the Egger test (p = 0.06) and the funnel plot suggested small-study effects.

Results and conclusions:
The investigators found in case-controle studies a non-significant reduced risk of 27% [relative risk = 0.73, 95% CI = 0.44-1.21] for cardiovascular disease for a 25g increase in olive oil consumption.

The investigators found in cohort studies a non-significant reduced risk of 4% [relative risk = 0.96, 95% CI = 0.78-1.18] for cardiovascular disease for a 25g increase in olive oil consumption.

The investigators found in cohort studies olive oil consumption significantly reduced risk of stroke with 26% [relative risk = 0.74, 95% CI = 0.60-0.92].

The investigators found random-effects model showed a significant reduced risk of 18% [RR = 0.82, 95% CI = 0.70, 0.96] for combining all cardiovascular events (CHD and stroke).

The investigators concluded available studies support an inverse association of olive oil consumption with stroke and with stroke and cardiovascular disease combined. This finding is in agreement with the recent successful results of the PREDIMED randomised controlled trial.

Original title:
Olive oil consumption and risk of CHD and/or stroke: a meta-analysis of case-control, cohort and intervention studies by Martínez-González MA, Dominguez LJ and Delgado-Rodríguez M.

Link:
https://www.ncbi.nlm.nih.gov/pubmed/24775425

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

Perioperative antioxidant supplementations with NAC, PUFA and vitamin C prevent atrial fibrillation after cardiac surgery

Antioxidants and atrial fibrillation.jpg

Objectives:
What is the impact of antioxidants (N-acetylcysteine (NAC), polyunsaturated fatty acids (PUFAs) and vitamins) on incidence of postoperative atrial fibrillation (POAF) and duration of length of hospital stay?

Study design:
This review article included 23 RCTs that reported outcomes of 4278 patients undergoing cardiac surgery.
A total of 10 RCTs with 1,026 patients (513 cases were allocated to the NAC and 513 cases to the control group, with a mean age of 63.2 years and 76.8% being males), 8 RCTs with 2,687 patients (with a mean age of 64.17 years and 77.6% being males), and 5 RCTs with 565 patients (with a mean age of 65.17 years and 73.6% being males) investigated the effect of NAC, PUFA and antioxidant vitamins on POAF, respectively.

There was no publication bias.

Results and conclusions:
The investigators found pooled effects estimates on postoperative atrial fibrillation showed a significant reduction after:
NAC [OR = 0.56, 95% CI = 0.40-0.77, p 0.001, I2 = 15%, p = 0.3];
PUFA [OR = 0.84, 95% CI = 0.71-0.99, p = 0.03] and;
Vitamin C treatment [OR = 0.50, 95% CI = 0.27-0.91, p = 0.02, I2 = 50%].

The investigators found hospital length of stay was not significant reduced after NAC therapy [SMD = 0.082, 95% CI = -0.09 to 0.25, p = 0.3, I2 = 0.0%, p = 0.7], but could be significant decreased with PUFA [SMD = -0.185, 95% CI = -0.35 to -0.018, p = 0.03, I2 = 11%, p = 0.3] and vitamin C [SMD = -0.325, 95% CI = -0.50 to -0.14, p 0.01, I2 = 60.4%, p = 0.056].
Significant because the p-values were less than the p-value of 0.05.

The investigators concluded perioperative antioxidant supplementations with N-acetylcysteine, polyunsaturated fatty acids and vitamin C prevent atrial fibrillation after cardiac surgery. Moreover, polyunsaturated fatty acids and vitamin C are capable to reduce hospital stay, whereas N-acetylcysteine lacks this capacity.

Original title:
Antioxidant supplementations for prevention of atrial fibrillation after cardiac surgery: an updated comprehensive systematic review and meta-analysis of 23 randomized controlled trials by Ali-Hassan-Sayegha S, Mirhosseinia SJ, […], Liakopoulose OJ.

Link:
http://icvts.oxfordjournals.org/content/early/2014/02/19/icvts.ivu020.long

Additional information of El Mondo:
Find more studies on cardiovascular diseases, antioxidants, NAC, PUFA, vitamin C and p-value of 0.05/95% CI right here.