Limitations: High-dosage (400 IU/d) trials were often small and were performed in patients with chronic diseases. The generalizability of the findings to healthy adults is uncertain. Precise estimation of the threshold at which risk increases is difficult.
Discussion
In our meta-analysis, we identified a dose-dependent relationship between vitamin E supplementation and all-cause mortality. Specifically, all-cause mortality progressively increased for dosages approximately greater than 150 IU/d. This dosage is substantially lower than the tolerable upper intake level for vitamin E, which is currently designated at 1000 mg of any form of supplementary alpha-tocopherol per day (corresponding to 1100 IU of synthetic vitamin E per day or 1500 IU of natural vitamin E per day) (1).
I haven't read the whole article, but apparently gamma-tocopherol per se wasn't a consideration. I think the only thing you can say with certainty is that more study is needed.
Thank you for doing this work for us (along with your follow-up below). I was too lazy!
I would suggest that no conclusion can be reached for healthy adults as the result of this study. Somebody needed to write a paper or spend some grant money, but had little interest in coming up with meaningful answers to relevant questions.