Hey, catch up, you guys! Dean Ornish has been demonstrating (via high tech imaging) improvements in coronary artery flow and heart perfusion through lifestyle changes (diet, stress reduction via yoga and meditation etc.) for 25 years--read his early "Dr. Dean Ornish's Program for Reversing Heart Disease," and his recent "Spectrum," in which he shows that this works for prostate cancer too, and probably would for breast cancer, but he can't demonstrate that for ethical reasons (won't explain now). This is solid science--read it! And for more on diet and gene expression, please read Colin Campbell, "The China Study," --he is Professor Emeritus of Nutritional Biochemistry at Cornell U, not another dumb diet book. Yes, you can have a gene, but some things can either turn it on and produce that protein, or keep it turned off, and the protein is not produced.
This does not mean, however, that it can totally suppress a retrovirus--there are limits, alas. But yes, in short, Dean Ornish is very much for real, and has long been one of my medical heroes. Read him! Best wishes, Chris