News
Higher intakes of vitamin B9 may reduce risk of colon cancer
24 February 2010
Dietary vitamin B9 (folate) protects against the development of colon cancer, says a new study.
09 June 2014
A new US study suggests that the form of vitamin E called gamma-tocopherol, found in soybean, corn and canola oils, is associated with decreased lung function, while alpha-tocopherol, contained in olive and sunflower oils, does support lung function.
The observational study examined the lung function and measured the concentrations of vitamin E, alpha- and gamma-tocopherol, in the blood plasma of 4,526 adults at several points in time over 20 years (1). The study results showed that a high level of gamma-tocoperol, 10 micromolar in blood plasma, was associated with a 10 to 17% reduction in lung function – a reduced lung capacity found in an asthmatic condition. Parti- cipants with asthma and high gamma-tocopherol levels had the lowest lung function.
The researchers commented that earlier research in animals showed that gamma-tocopherol seems to incre- ase lung inflammation and airway hyperresponsiveness, a characteristic of asthma (2). On the other hand, alpha-tocopherol decreased lung inflammation, protecting healthy lung function. The effects on inflammation seem to be linked to an enzyme (protein kinase C-alpha), which binds both forms of vitamin E: while alpha-tocopherol inhibits the action of the protein, gamma-tocopherol increases its action. Both forms, which are the most abundant vitamin E forms in diet and tissues, may have similar effects in humans. Asthma is a complex dysfunction, involving over 90 genes. Many factors can initiate a reaction, including allergens and environmental irritants like smoke particulates.
Considering the rate of affected people found in this study, there could be 4.5 million individuals in the US with reduced lung function as a result of their high gamma-tocopherol consumption, the researchers con- cluded. Rates of asthma in the US have been climbing in the last 40 years, coinciding with a switch in US diets from lard and butter to gamma-tocopherol-rich soybean, canola and corn oils. Looking at other count- ries’ rates of asthma, those with significantly lower rates of asthma have diets high in olive and sunflower oils (3). In the US, the average blood plasma level of gamma-tocopherol is four or more times higher than those of European and Scandinavian countries that consume sunflower and olive oil.
24 February 2010
Dietary vitamin B9 (folate) protects against the development of colon cancer, says a new study.
23 March 2012
A new experiment using rodents and a study in postmenopausal women hypothesize that vitamin E supplements may be related to bone loss. Experts criticize that neither feeding rodents with extremely high doses of vitamin E nor measuring bone formation indirectly via a fault-prone marker in women would justify translating the findings into recommendations for supplement users.
15 March 2012
High levels of the amino acid homocysteine in the bloodstream have been linked to an increased risk of stroke and heart attack.