Voeding en gezondheid

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.

 

Zout verhoogt de kans op het krijgen van maagkanker

Research Question:
Systematic literature searches of case-control studies to evaluate the relationship between salt intake and gastric cancer show a positive relationship, but a quantitative analysis of longitudinal cohort studies is missing. It was therefore carried out this review article.

Eating salt increases the chance of getting stomach cancer?

Study Design:
This overview article contained 10 cohort studies with 268718 participants, of which 1474 people who got stomach cancer. The follow-up duration was 6-15 years. There was no question of heterogeneity between the studies and publication bias.

Results and conclusions:
The researchers found that compared with the lowest salt intake, the highest salt intake the likelihood of getting stomach cancer significantly with 68% [RR = 1.68, 95% CI = 1.17-2.41, p = 0.005] did increase. Significant is, there is a link at a 95% reliability.

The researchers found that compared with the lowest salt intake, the relatively high salt intake the likelihood of getting stomach cancer significantly with 41% [RR = 1.41, 95% CI = 1.03-1.93, p = 0.032] did increase.

The associations was stronger among the Japanese population and a higher consumption of selected salt-rich foods was also associated with a high risk.

The researchers concluded that a high salt intake the likelihood of getting stomach cancer did increase.

Original title:
Habitual salt intake and risk of gastric cancer: A meta-analysis of prospective studies by D'Elia L, Rossi G, [...], Strazzullo P.

Link:
http://www.clinicalnutritionjournal.com/article/S0261-5614%2812%2900005-2/fulltext

Additional information about El Mondo:
The Health Council recommends up to 6 grams of salt per day. 6 grams of salt is equivalent to 2400 mg sodium.
A salt of America product contains nutritional seen at least 0.5 grams of sodium per 100 grams (100 ml).
A low-sodium product contains nutritional seen up to 0.1 grams of sodium per 100 grams (100 ml) or up to 0.12 grams of sodium per 100 kcal.
Read more about sodium sodium in the presentation.