Today saw some scary headlines like ‘Vitamin E-rich oils linked to lung inflammation‘ and ‘Vitamin E In Canola And Other Cooking Oils Linked To Asthma, Other Lung Problems‘. The claim is that some types of vitamin E can lead to reduced lung function (capacity and efficiency). So what does that mean for active people such as athletes, bodybuilders and beach body enthusiasts?
The study behind these headlines looked at the relationship between α-tocopherol (alpha-tocopherol) and γ-tocopherol (gamma-tocopherol), two of the eight forms of vitamin E, and found that where low levels of α-tocopherol existed in comparison to γ-tocopherol in the blood, there were potential negative effects on both lung capacity and lung strength. They concluded that γ-tocopherol was probably contributing to the rising incidence of lung inflammation, airway hyperresponsiveness and possibly asthma in the US.
The effect was most noticeable in the US where there is greater use of canola, soybean and corn oils, all of which have higher concentrations of γ-tocopherol. In contrast, in Europe the use of olive oil, wheat germ oil, almond and sunflower oil results in relatively higher levels of α-tocopherol instead. The average blood plasma level of γ-tocopherol is four or more times higher in the US than that of countries that consume olive and sunflower oil.
Luckily the study concluded that adequate levels of α-tocopherol counteract the issue:
Furthermore, in our mechanistic studies in vitro and in animals, γ-tocopherol potently increases inflammation and lung hyperresponsiveness when the α-tocopherol tissue concentration is low but this effect of γ-tocopherol is ablated when the α-tocopherol tissue concentration is elevated through supplementation.
In other words, as long as you have enough α-tocopherol in your diet, you shouldn’t need to be concerned. The people most affected were those with the lowest concentrations of vitamin E in their systems.
Sunflower seeds, Almonds and Hazelnuts are good sources of α-tocopherol as well as the oils mentioned above. There is a more complete list of general vitamin E sources here.
For anyone taking vitamin E supplements, this issue is probably redundant since you will (ideally) be taking a mixed tocopherol/tocotrienol source or one of the much cheaper d-alpha-tocopherol supplements (not a good idea!).
Also, it should be noted that gamma-tocopherol (γ-tocopherol) may have a positive purpose within the body, although it is not entirely clear what that is yet. For example:
Limited research in the test tube and in animals indicates that gamma-tocopherol or its metabolites may play a role in protecting the body from free radical-induced damage (8, 9), but these effects have not been convincingly demonstrated in humans. In one prospective study, increased levels of plasma gamma-tocopherol were associated with a significantly reduced risk of developing prostate cancer.
So don’t try to eliminate it from your diet!