Q. I read that years of dying her hair dark may have contributed to Jacquie Kennedy developing lymphoma. Is that a risk? Do chemicals in hair products impact our brains?

A. All substances that touch the skin have the potential to be pulled into the body in at least three ways: directly through the pores, by following a hair shaft down to the follicle, and through following lipid pathways between cells. In terms of an impact to the brain, Permanents and relaxers contain many chemicals that can seep into the body and once able to enter lymph fluid or blood can spread to any part of the brain and body. The CDC reported that “skin contact represents a significant route of exposure for chemicals that have the potential to be absorbed through the skin and that subsequently can cause systemic effects including, but not limited to, neurotoxicity, cancers, and effects on the reproductive system. None of this is great for the brain. Jacqueline Kennedy reportedly used dark hair dyes for years. She also smoked. Who knows what specifically could be linked with lymphoma? Research has been inconclusive, although more recent studies are interesting. National Cancer Institute studies, for example. Hair Dyes and Cancer Risk - NCI (https://www.cancer.gov/about-cancer/causes-prevention/risk/myths/hair-dyes-fact-sheet)