Voeding en gezondheid | Voedingsadvies El Mondo

200-1000 mg vitamine C per dag verlaagt de oxidatieve stress

Research Question:
How many mg of vitamin C per day is needed to reduce the increased oxidative stress among athletes?

Study Design:
This overview article contained 12 studies. They were crossover or Rcts. The vitamin C supplementation period ranged from acute to 5 months.

Results and conclusions:
Antioxidants supplements are widely used by athletes in order to avoid the increased oxidative stress. The increased oxidative stress leads to muscle damage, a lowered immune system and fatigue.

The researchers conclude that 200-1000 mg of vitamin C per day reduces the oxidative stress while more than 1000 mg per day seems to reduce the training-induced adaptations by decreasing the mitochondrial biogenesis or by any changes of the vascular function.

200 mg of vitamin C per day, obtained by five servings of fruits and vegetables, may be enough to reduce the oxidative stress without the threshold adjustments to exceed the optimal training harms.

During periods of increased oxidative stress athletes can benefit from swallowing more than 200 mg of vitamin C per day for 1 to 2 weeks.

Original title:
Effect of Vitamin C Supplements on Physical Performance by Ballard AJ.

Link:
http://journals.lww.com/acsm-csmr/Fulltext/2012/07000/Effect_of_Vitamin_C_Supplements_on_Physical.8.aspx

Additional information about El Mondo:
Oxidative stress is caused by an imbalance between pro-oxidants and antioxidants. This imbalance can be caused by an increased level of reactive oxygen particles and/or reactive nitrogen particles or a decrease in antioxidant in the immune system. Antioxidants include vitamin C, E, zinc, beta carotene and flavonoids. Pro-oxidants include exhaust fumes, cigarette smoke, particulate matter.

Het eten van vis verlaagt de kans op cerebrovasculaire ziekten

Research questi
on: offer eating fish and swallowing PUFA fatty acids protection against cerebrovascular diseases (diseases in the blood vessels of the brain)?

Study design
: this overview article contained 26 prospective cohort studies and 12 Rcts with 34817 794000 participants, of which with a cerebrovascular diseas
e.There was no indication of publication bias and heterogeneity between the studies and within the subgr

oups.Results and conclusi
ons: the meta-analysis of cohort studies showed a pooled relative risk of 0.94 [95% CI = 0.90-0.96] see for cerebrovascular disease at 2-4 servings of fish per week compared with 1 serving of fish per week. In other words, people who ate fish 2-4 times a week, ran significant 6% less chance of getting a cerebrovascular disease than those who ate fish once a week. Significant is, there is a link at 95% reliability.

The meta-analysis of cohort studies also showed that people who ate fish 5 times or more a week, ran significant 12% [pooled RR = 0.88, 95% CI = 0.81-0.96] less chance of getting a cerebrovascular disease than those who ate fish once a week.

The meta-analysis of Rcts with primary prevention as outcome showed that people who swallowed PUFA fatty acids, ran non-significant 2% [pooled RR = 0.98, 95% CI = 0.89-1.08] less chance of getting a cerebrovascular disease than people who swallowed no PUFA fatty acids. Non-significant is, there is no link with 95% reliability.

The meta-analysis of Rcts with secondary prevention as outcome showed that people who swallowed PUFA fatty acids, ran non-significant 17% [pooled RR = 1.17, 95% CI = 0.99-1.38] more chances of getting a cerebrovascular disease than people who swallowed no PUFA fatty acids. Non-significant is, there is no link with 95% reliability.

The meta-analysis also showed that the pooled relative risks for ischemic and hemorrhagic cerebrovascular outcomes came broadly in line with those of cerebrovascular disease.

The researchers concluded that eating fish the chance of getting this reduced risk was reduced but a cerebrovascular disease not found in swallowing of PUFA fatty acids. In other words, the researchers found no causal link between PUFA fatty acids and the reduced risk of getting a cerebrovascular disease.

Original title: Assoc
iation between fish consumption, long chain omega 3 fatty acids, and risk or cerebrovascular disease: systematic review and meta-analysis by Chowdhury R, Stevens S, [...], Franco OH.

Link:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3484317/

Additional information about El Mon
do: In fish are fatty acids. Two of these fatty acids are EPA and DHA. EPA and DHA are also called PUFA fatty acids called. Polyunsaturated fatty acids or PUFA is English for polyunsaturated fatty aci
ds.For years it was assumed that a causal link existed between EPA and DHA and the reduced risk of heart disease. But this causal link is now by scientific studies in the form of review articles of Rcts brought down. In other words, at present is no longer considered scientifically proven that EPA and DHA chances of getting heart disease decrease. The science thinks now that EPA and DHA in combination with other good substances in fish are responsible for the reduced risk of heart disease. But it could also be that people who eat fish, a healthy lifestyle than people who do not eat fish.

Because science is no longer behind the causal link between EPA and DHA and the reduced risk of heart disease state, nutritionists recommend eating fish above the swallowing of EPA and DHA supplements to.