Selenium is known as the anti cancer mineral and is an essential trace element involved in several key metabolic activities via enzymes that are essential to protect against free radical (oxidative) damage and to regulate the immune system. Selenium is an essential part of glutathione peroxidase, an enzyme found to remove one of the major free radicals, hydrogen peroxide.
A number of very large studies on selenium supplementation, such as those in China and Finland have found significant reductions in cancer rates. In support of this a study just last week found that supplementation with 200 micrograms of selenium glycinate for 6 weeks increase the activities of blood enzymes such as glutathione, and reduces the levels of PSA, prostate-specific antigen, a marker for prostate cancer. It was only a small study of 30 middle-aged US men but the authors of the study said “If selenium could lower PSA [prostate-specific antigen] in healthy, middle-aged men, then it could be proposed that selenium can lower prostate cancer risk in some men, especially as part of an overall dietary plan,” (Zhang et al 2011).
Other studies have shown that high levels of selenium in the body have been linked with lower levels of lung, prostate and colorectal cancers. Selenium is thought to reduce the risk of developing cancers in two ways. Firstly, as selenium is an anti¬oxidant it helps protect the body from dangerous free radicals. Secondly, selenium has been known to prevent or slow down tumour growth. It does this in such a way that selenium enhances immune cell activity and suppresses the development of the blood vessel leading to the tumour resulting in reduced or no cancer growth. Studies have also shown that people with low levels of selenium have a greater incident of heart disease.
Good sources of selenium in the diet are whole grains, asparagus, garlic, eggs, mushrooms, lean meats and seafood's but the best known source is brazil nuts.
Zhang. W, E. Joseph, C. Hitchcock, R.A. DiSilvestro. 2011. Selenium glycinate supplementation increases blood glutathione peroxidase activities and decreases prostate-specific antigen readings in middle-aged US men. Nutrition Research, doi: 10.1016/j.nutres.2010.10.012
Wednesday, March 2, 2011
Nutrition science and the common Cold
Time to go back to some basics and take a few supplements when the next cold (flu) comes around. Here is the latest update from the Cochrane review.
In a major study of 13 therapeutic trials and two preventative trials with almost 1400 participants Zinc supplements significantly reduced the severity of cold symptoms, as well as the length of illness (Singh and Das, 2010). They reported a significant difference between the zinc and control group for the proportion of participants symptomatic after seven days of treatment . The authors concluded that zinc administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people. When supplemented for at least five months, it reduces cold incidence, school absenteeism and prescription of antibiotics in children. One of the actions of zinc is to inhibit rhinoviral replication and has been tested in trials for treatment of the common cold.
In a review of studies on Vitamin C (Hemilä 2007) the researchers found it useful for people exposed to brief periods of severe physical exercise. In five trials with participants exposed to short periods of extreme physical stress (including marathon runners and skiers) vitamin C halved the common cold risk.
In a review of 16 controlled clinical trials (Linde et al 2006) investigating the effectiveness of Echinacea preparations (a herb) for preventing and treating common colds, the researchers found taking Echinacea preparations after the onset of cold symptoms shortens the duration or decreases the severity of symptoms when compared with a placebo.
In summary when you get the flu take Zinc, Echinacea and if you are exercising take vitamin C. That is what the science shows so forget the flu vaccine with its very questionable benefits, high cost and serious side effects. Last year in the UK they spent more than 2 billion pound on the swine flu without a single reduction in symptoms or disease.
It should also be mentioned that vitamin C and zinc work hand in hand for lots of other things in the body including healthy skin and arteries. They have lots of positive side effects.
Hemilä H, Chalker E, Douglas B. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD000980. DOI: 10.1002/14651858.CD000980.pub3. Cochrane Acute Respiratory Infections Group.
Linde K, Barrett B, Bauer R, Melchart D, Woelkart K. Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2006, Issue 1. Art. No.: CD000530. DOI: 10.1002/14651858.CD000530.pub2. : Cochrane Acute Respiratory Infections Group
Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews 2011, Issue 2. Art. No.: CD001364. DOI: 10.1002/14651858.CD001364.pub3. Cochrane Acute Respiratory Infections Group.
In a major study of 13 therapeutic trials and two preventative trials with almost 1400 participants Zinc supplements significantly reduced the severity of cold symptoms, as well as the length of illness (Singh and Das, 2010). They reported a significant difference between the zinc and control group for the proportion of participants symptomatic after seven days of treatment . The authors concluded that zinc administered within 24 hours of onset of symptoms reduces the duration and severity of the common cold in healthy people. When supplemented for at least five months, it reduces cold incidence, school absenteeism and prescription of antibiotics in children. One of the actions of zinc is to inhibit rhinoviral replication and has been tested in trials for treatment of the common cold.
In a review of studies on Vitamin C (Hemilä 2007) the researchers found it useful for people exposed to brief periods of severe physical exercise. In five trials with participants exposed to short periods of extreme physical stress (including marathon runners and skiers) vitamin C halved the common cold risk.
In a review of 16 controlled clinical trials (Linde et al 2006) investigating the effectiveness of Echinacea preparations (a herb) for preventing and treating common colds, the researchers found taking Echinacea preparations after the onset of cold symptoms shortens the duration or decreases the severity of symptoms when compared with a placebo.
In summary when you get the flu take Zinc, Echinacea and if you are exercising take vitamin C. That is what the science shows so forget the flu vaccine with its very questionable benefits, high cost and serious side effects. Last year in the UK they spent more than 2 billion pound on the swine flu without a single reduction in symptoms or disease.
It should also be mentioned that vitamin C and zinc work hand in hand for lots of other things in the body including healthy skin and arteries. They have lots of positive side effects.
Hemilä H, Chalker E, Douglas B. Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD000980. DOI: 10.1002/14651858.CD000980.pub3. Cochrane Acute Respiratory Infections Group.
Linde K, Barrett B, Bauer R, Melchart D, Woelkart K. Echinacea for preventing and treating the common cold. Cochrane Database of Systematic Reviews 2006, Issue 1. Art. No.: CD000530. DOI: 10.1002/14651858.CD000530.pub2. : Cochrane Acute Respiratory Infections Group
Singh M, Das RR. Zinc for the common cold. Cochrane Database of Systematic Reviews 2011, Issue 2. Art. No.: CD001364. DOI: 10.1002/14651858.CD001364.pub3. Cochrane Acute Respiratory Infections Group.
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