Hi, I don't know where this fit in the already active posts. Feel free of translate it to the proper place.
Accoriding to this study doing an intermittent fasting while consuming vit C and E don't report benefits. But the detail is that this study was made while the participants ate a high carbohidrate diet. I don't know the validity of this, but the most remarkable affirmation is that intermittent fasting arise ROS in a low amounts, then the body try to adapt to this stres,s and that is what report benefits. If you kill those ROS with much antioxidants the effect is null according to them.
Here is the study
http://www.ncbi.nlm.nih.gov/pubmed/25546413
Abstract
Caloric restriction has consistently been shown to extend lifespan and ameliorate aging-related diseases. These effects may be due to diet-induced reactive oxygen species acting to upregulate sirtuins and related protective pathways, which research suggests may be partially inhibited by dietary antioxidant supplementation. Since caloric restriction is not sustainable long-term for most humans, we investigated an alternative dietary approach, intermittent fasting, which is proposed to act on similar biological pathways. We hypothesized that a modified intermittent fasting diet, where participants maintain overall energy balance by alternating between days of fasting (25% of normal caloric intake) and feasting (175% of normal) would increase expression of genes associated with aging and reduce oxidative stress and that these effects would be suppressed by antioxidant supplementation. To assess the tolerability of the diet and to explore effects on biological mechanisms related to aging and metabolism, we recruited a cohort of 24 healthy individuals in a double crossover, double-blinded randomized clinical trial. Study participants underwent two three-week treatment periods: intermittent fasting and intermittent fasting with antioxidant (Vitamins C and E) supplementation. We found strict adherence to study-provided diets and that participants found the diet tolerable, with no adverse clinical findings or weight change. We detected a marginal increase (2.7%) in SIRT3 expression due to the intermittent fasting diet, but no change in expression of other genes or oxidative stress markers analyzed. We also found that intermittent fasting decreased plasma insulin levels (1.01 uU/mL). Although our study suggests that the intermittent fasting dieting paradigm is acceptable in healthy individuals, additional research is needed to further assess the potential benefits and risks.
From another page talking about the same study
http://www.sciencealert.com/doing-the-5-2-diet-avoid-antioxidants-new-research-suggests
Doing the 5:2 diet? Avoid antioxidants, new research suggests
Researchers from the University of Florida (UoF) and the Harvard Medical School in the US decided to investigate just how good it is for people’s health, knowing that previous experiments with fasting mice had seen an increase in their lifespans.
They worked with 24 healthy participants aged between 19 and 30 who over a three-week period alternated between one day of eating 25 percent of their daily caloric intake, and the next, eating 175 percent of their daily caloric intake. For the men, this meant 650 calories on the fasting days and 4,550 calories on the feasting days, and for women, it was slightly less. The participants then spend another three weeks doing the same thing, but also taking antioxidant Vitamins C and E supplements in a pill form. The participants resumed their normal diets for two weeks between the two three-week periods to get them back to where they started.
Now let’s just talk about what they actually ate for a second here, because it’s amazing.
According to the press release, on their fasting days, they ate just one meal, but it was a doozy - roast beef, gravy, and mashed potatoes, followed by Oreo cookies and orange sherbet. If that sounds like a feasting day to you, well, check this out - on the feasting days they ate bagels with cream cheese, oatmeal sweetened with honey and raisins, turkey sandwiches, apple sauce, spaghetti with chicken, yogurt, and soft drinks. Oh and they also got lemon pound cake, Snickers bars and vanilla ice cream. WHERE DO I SIGN UP.
“Most of the participants found that fasting was easier than the feasting day, which was a little bit surprising to me,” said one of the team, Michael Guo from the Harvard Medical School. “On the feasting days, we had some trouble giving them enough calories.”
Throughout the experiment, various factors were measured, including changes in weight, blood pressure, heart rate, glucose levels, cholesterol, and their levels of inflammation markers and genes called SIRT3, which are responsible for protective cell responses.
The researchers found that the act of intermittent fasting was causing a slight increase the SIRT3 and SIRT1 genes, which encode proteins called SIRT3 and SIRT1. These proteins belong to a class of proteins called sirtuins, which previous experiments have shown can extend the lifespan of mice if their levels are increased. But here’s the catch - they only work in this way in response to oxidative stress, and the team found that they only increased during the three weeks were antioxidants were avoided. When the participants started taking the supplements, these increases disappeared.
Oxidative stress occurs when there are too many ‘free radicals’ - DNA-damaging toxins - for the body’s immune response to handle, and this happens on a small scale when a person is fasting. In response, the body triggers the production of protective SIRT3 proteins. The same phenomenon
could occur when you exercise - the ‘good stress’ you put your body under could be unnecessarily mitigated by the intake of extra antioxidants.
“The hypothesis is that if the body is intermittently exposed to low levels of oxidative stress, it can build a better response to it,” study co-author Martin Wegman from the UoF College of Medicine
said in a press release.
“You need some pain, some inflammation, some oxidative stress for some regeneration or repair,” adds one of the team, Christiaan Leeuwenburgh from the Institute on Aging at the UoF. “These young investigators were intrigued by the question of whether some antioxidants could blunt the healthy effects of normal fasting.”
Interestingly, the team found that the increase in SIRT 1 and 3 genes appeared even in the absence of weight-loss, which suggests weight-loss isn’t the trigger here. They also found that levels of insulin dropped as a result of the diet, which means it could also have an anti-diabetic effect. They explain in the journal Rejuvenation Research:
We also found that plasma insulin levels decreased as a result of IF (the intermittent fasting diet), but not IFAO (the intermittent fasting with antioxidant supplementation diet). This suggests that the IF diet may have a beneficial effect on glucose metabolism by lower insulin levels, and perhaps have an anti-diabetic effect. Furthermore, the finding that IFAO did not lower insulin levels suggests that the insulin-lowering effects might be stimulated by IF-induced oxidative stress, which is quenched by the further antioxidant supplementation.”
The sample size is pretty small, so it's not enough evidence to start cutting antioxidants out of your diet just yet, but it's a fascinating result all the same. And it shows that if you want roast beef and gravy with orange sherbet on top, it’s okay with science (but probably not with any of the humans around you).
