Stephen Cherniske: First of all, the widely cited association between IGF-1 and prostate cancer has been debunked.106,107 That said, the concern for tumor acceleration does make sense because IGF has angiogenic activity that would favor tumor growth. But IGF-1 has only been shown to accelerate tumor growth in test tubes. Test tubes and petri dishes do not have immune systems, which are upregulated by IGF-1. In fact, the preponderance of the evidence shows that IGF-1 does not promote cancer in any living organism, whether animal or human. Even direct injection of IGF-1 does not promote tumor growth in animals.108 In Europe, IGF-1 is routinely given to cancer patients to help them gain weight.
Aside from this, it is important to note that increases in IGF-1 after DHEA supplementation are significant but modest, and there are no published studies in which DHEA administration caused IGF-1 to rise above the normal range. Moreover, scores of published studies demonstrate the essential role that IGF-1 plays in the repair and regeneration of the brain, skeleton, and cardiovascular and immune systems.109-112 Conversely, low IGF-1 levels have been associated with dementia, atherosclerosis, osteoporosis, and sarcopenia,54,113 and a study in the journal Gerontology shows that men who maintain youthful levels of IGF-1 do not experience the decline in testosterone or muscle mass, or the accumulation of fat, that has been considered an inevitable consequence of aging.114