Just for him.

The Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study was a huge prospective trial that randomized nearly 30,000 male smokers 50-69 in Finland between 1985 and 1988 to alpha-tocopherol, beta-carotene, both, or neither. At baseline, they reported their use of hair dye. This analysis sought to determine if self-reported hair dye use was associated with an increased risk of prostate cancer in the patient cohort. The short answer is, yes. Over 28 years of observation, the risk of prostate cancer was higher among men who used hair dye (HR 1.77). Baldness and the degree of graying were not associated with prostate cancer risk. The problem is a mere 75 men (out of nearly 30,000) reported hair dye use with 13 of those developing prostate cancer. Furthermore, no data was collected on duration or frequency of hair dye use. | Lim, Cancer 2021