PUFA Cause DNA Damage In Humans, Vitamin E Abolishes It

haidut

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One more study showing the negative effects of PUFA consumption, and this one was done in humans. Consuming 15% of calories as PUFA caused DNA damage and adding just 80mg of tocopherol acetate greatly mitigated the damage. However, consuming only 5% of PUFA did not cause observable damage. So, maybe this is a "safe" level of PUFA consumption achievable by most Peatarians much more easily than the advice of Ray to get as close to zero PUFA as possible.
Finally, since tocopherol acetate has only 50% of the effectiveness of alpha tocopherol (as Ray has written), the study suggests people can get by on as little as 40mg of alpha tocopherol even with 15% PUFA intake.


http://www.fasebj.org/content/13/15/2138.full
"...The effect of increasing dietary intakes of polyunsaturated fatty acids (PUFAs) and vitamin E on indices of oxidative DNA damage was investigated. Twenty-one healthy male, nonsmokers aged 28.9 ± 1.3 years participated in a free-living, split plot/change over trial in which half the volunteers consumed diets containing 5% PUFA as food energy for 4 wk and, after a 10 wk washout period, consumed a 15% PUFA diet for another 4 wk. The other volunteers followed an identical protocol, except that they consumed the 15% PUFA diet first. The diets were provided to volunteers either with or without an additional 80 mg dα-tocopherol acetate/day; otherwise total fat, carbohydrates, protein, and basal vitamin E contents remained unchanged. DNA damage induced by 200 μM H2O2 in lymphocytes from volunteers as well as endogenous DNA damage in the form of oxidized pyrimidines, measured by alkaline single-cell gel electrophoresis (the comet assay), significantly decreased after consumption of the 5% PUFA diet (P<0.001 and P=0.01, respectively), but significantly increased after consumption of the 15% PUFA diet when α-tocopherol levels were in the range of 5–7 mg/day (P=0.008 and P=0.03, respectively). These changes were abolished by an additional 80 mg dα-tocopherol/day. This study indicates that increasing dietary levels of PUFA to 15% may adversely affect some indices of DNA stability. However, increasing the dietary intake of vitamin E by 80 mg/day ameliorates the damaging effects of PUFA."
 
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Judd Crane

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However, consuming only 5% of PUFA did not cause observable damage. So, maybe this is a "safe" level of PUFA consumption achievable by most Peatarians much more easily than the advice of Ray to get as close to zero PUFA as possible.
How does a 5% limit of PUFA stand in light of todays evidence?
 

Noodlz2

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I've seen Ray recommend a limit of 4g a day, which would be about 2% of 2000 calories, and even lower than that for the average person here who is probably eating more total calories.
 

Hugh Johnson

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I've eaten so much PUFA in my youth that I'm probably a mutant at this point.

Anyway, I really appreciate all your posts in this forum. It would be only half as good without you.
 

laleto12

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I've eaten so much PUFA in my youth that I'm probably a mutant at this point.

Anyway, I really appreciate all your pwosts in this forum. It would be only half as good without you.
what did you eat that you refer "so much"?
 

cs3000

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One more study showing the negative effects of PUFA consumption, and this one was done in humans. Consuming 15% of calories as PUFA caused DNA damage and adding just 80mg of tocopherol acetate greatly mitigated the damage. However, consuming only 5% of PUFA did not cause observable damage. So, maybe this is a "safe" level of PUFA consumption achievable by most Peatarians much more easily than the advice of Ray to get as close to zero PUFA as possible.
Finally, since tocopherol acetate has only 50% of the effectiveness of alpha tocopherol (as Ray has written), the study suggests people can get by on as little as 40mg of alpha tocopherol even with 15% PUFA intake.


http://www.fasebj.org/content/13/15/2138.full
"...The effect of increasing dietary intakes of polyunsaturated fatty acids (PUFAs) and vitamin E on indices of oxidative DNA damage was investigated. Twenty-one healthy male, nonsmokers aged 28.9 ± 1.3 years participated in a free-living, split plot/change over trial in which half the volunteers consumed diets containing 5% PUFA as food energy for 4 wk and, after a 10 wk washout period, consumed a 15% PUFA diet for another 4 wk. The other volunteers followed an identical protocol, except that they consumed the 15% PUFA diet first. The diets were provided to volunteers either with or without an additional 80 mg dα-tocopherol acetate/day; otherwise total fat, carbohydrates, protein, and basal vitamin E contents remained unchanged. DNA damage induced by 200 μM H2O2 in lymphocytes from volunteers as well as endogenous DNA damage in the form of oxidized pyrimidines, measured by alkaline single-cell gel electrophoresis (the comet assay), significantly decreased after consumption of the 5% PUFA diet (P<0.001 and P=0.01, respectively), but significantly increased after consumption of the 15% PUFA diet when α-tocopherol levels were in the range of 5–7 mg/day (P=0.008 and P=0.03, respectively). These changes were abolished by an additional 80 mg dα-tocopherol/day. This study indicates that increasing dietary levels of PUFA to 15% may adversely affect some indices of DNA stability. However, increasing the dietary intake of vitamin E by 80 mg/day ameliorates the damaging effects of PUFA."

it's confusing how the studies on Vit E protection from PUFA oxidation vary. some of them even mention it having a pro-oxidant effect. its not about the form of alpha tocopherol because that study used synthetic and it protected lymphocytes

Seems it actually might be best to keep Vit E on the lower end for protection - with doses in the 100s of mgs potentially having opposite effect. human study https://www.ahajournals.org/doi/10.1161/01.ATV.21.6.1029 800iu in high PUFA diet prolonged ldl oxidation lag time but increased end oxidative stress markers a lot

so optimal to stick to low dose 1mg of a-tocopherol per 1g PUFA like in the lymphocytes study, with higher becoming detrimental?


Antioxidant and prooxidant activity of alpha-tocopherol in human plasma and low density lipoprotein - PubMed maybe a lack of vitamin C that contributes to vit E becoming pro-oxidant?
 
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