Le miracle des antioxydants

Qui n'a pas entendu parler des merveilleux antioxydants? Si vous me dites que vous n'avez jamais vu un livre de recettes contre le cancer ou entendu un expert vous parler de ces particules sauveuses de nos cellules dégénérées, vous devez vivre bien loin... Je me demande bien quelle sera la prochaine mode. On parie??

Si vous vous fiez au discours en vogue pour savoir quoi manger, cette petite étude vous fera réfléchir et vous dire, je l'espère, que tout est bon avec modération, que tout est mauvais avec excès et que vous faites bien de vous fier à votre corps et vos envie. Le corps cherche l'équilibre et pour le maintenir, on devrait faire la même chose. Plus je fais de biologie, plus je me persuade que l'approche problème-réponse ou bien-mal est loin de notre réalité. Nous sommes un équilibre dynamique et tout ce qu'on met dans notre corps et dans nos vies viennent changer l'équilibre et le perturber, même nos solutions. Je ne crois plus au bien et au mal, juste à l'équilibre des forces. Personne ne peut nous dire quoi faire sans savoir ou on se trouve et ce dont on a besoin. Et la meilleure personne pour savoir ça, c'est mon corps, c'est moi, c'est mon instinct.

J'arrête de prêcher et vous laisse assister en direct à la mort d'une pauvre particule sur laquelle on avait mis trop d'espérances.

Antioxydants: friend or foe?

Thursday, February 7, 2008
By Amy Thomas

For the past decade we've heard all about the amazing benefits of antioxidants; as a result many of us try to incorporate into our diets the recommended deeply colored fruits and vegetables chocked full of anti-aging, heart-healthy, and life-prolonging metabolites. But recently, the all-healing properties of antioxidants are in question, and some scientists now suggest they may increase the risk of cancer and cause harm in people being treated for cancer. The messages are conflicting, and many people are left wondering what to believe.



Anti-oxidants are found naturally in a number of deeply colored foods-dark red cherries and tomatoes, orange carrots, yellow corn and saffron, and blueberries. Their reported health benefits have led to the increasing use of certain nutritional supplements known to have strong antioxidant activity, including β-carotene, selenium, lycopene, and vitamins A, C, and E.



Research reports have posed concern that cancer cells could use antioxidants, particularly vitamin C, to repair themselves and guard against radiation and chemotherapy damage. Studies investigating whether antioxidants reduce the benefit of cancer treatment have provided mixed results, so the Mayo clinic performed a systematic review on the topic. Although the review doesn't answer all the questions, the scientists did determine that antioxidants do not lower the overall risk of cancer, and some antioxidants may increase cancer risk, so at this time, supplementation is not recommended until further research is available.



While we wait to hear about the value of other antioxidant supplements in cancer prevention and treatment, at least one popular supplement has been identified as dangerous. Beta carotene, the orange photosynthetic pigment in carrots that is the precursor to vitamin A, is linked to an increased risk of lung cancer and increased cancer mortality. Most studies report the risk associated with taking at least 30 mg of the supplement daily. Unlike the supplements, foods rich in beta-carotene have not been linked to increased cancer risk and the amount of beta-carotene from consuming 5 servings of fruits and vegetables per day is still recommended to maintain adequate levels of vitamin A. (1.8 milligrams or 1800 micrograms) Beta-carotene is also found in sweet potatoes, carrots, kale, spinach, turnip greens, winter squash, broccoli, romaine lettuces, cantaloupe, thyme, cilantro, and collard greens.



On evaluating other antioxidant supplements, the Mayo review suggested that selenium, a micronutrient found naturally in nuts, cereals, meat, fish, and eggs, might have beneficial properties for cancer patients, although these findings are not confirmed. Selenium will not be recommended for general use until more evidence is available. While the report found neither benefit nor harm from Vitamin E supplements, too much vitamin E is known to cause stomach upset, diarrhea, and bleeding, and could exacerbate symptoms often already a problem for people being treated for cancer.



These reports are not closing the door to use of antioxidants during cancer treatment. Many antioxidants have shown promise in preventing certain side effects of chemotherapy and radiation, warranting further study of their risks and benefits. Vitamin A and E may prolong survival in lung cancer patients being treated with cyclophosphamide; glutathione is being studied as a protective agent for cyclophosphamide-related bladder damage and oxaliplatin-induced neuropathy; and vitamins E and C may offer protection against radiation proctitis in patients with prostate, cervical, and endometrial cancer.



In summary:

* Antioxidants do not lower the risk of cancer
* Antioxidant supplements, but not those occurring naturally in foods, may reduce the efficacy of certain cancer treatments
* Beta-carotene supplements should be avoided, especially in smokers
* Continue to eat the recommended 5 daily servings of fruits and vegetables per day to get adequate vitamins, pro-vitamins, dietary minerals, and fiber
* Tell your doctor if you are taking any nutritional supplements

Note: All clinical content on this site is physician-reviewed, except material generated by our community members.

Source: http://www.healthcentral.com/diet-exercise/c/26240/20143/friend-foe/pf/