1 00:00:01,920 --> 00:00:07,080 Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, 2 00:00:07,120 --> 00:00:11,120 Speaker 1: Lauren Bogelbaum. Here, With all the unknowns that exist around 3 00:00:11,119 --> 00:00:14,680 Speaker 1: breast cancer and most cancers for that matter, it's generally 4 00:00:14,720 --> 00:00:17,360 Speaker 1: safe to say that the disease doesn't result from any 5 00:00:17,400 --> 00:00:21,919 Speaker 1: single behavior, food, habit, or action. A complex combination of 6 00:00:21,920 --> 00:00:25,120 Speaker 1: genetic and environmental factors contributes to the development of breast 7 00:00:25,120 --> 00:00:28,840 Speaker 1: cancer in certain individuals, and scientists continue to seek out 8 00:00:28,840 --> 00:00:34,480 Speaker 1: answers around which factors could be controlled, monitored, or even eliminated. Now, 9 00:00:34,560 --> 00:00:37,320 Speaker 1: a study from researchers at the National Institutes of Health 10 00:00:37,440 --> 00:00:41,000 Speaker 1: or NIH suggests that permanent hair dye maybe one of 11 00:00:41,040 --> 00:00:44,040 Speaker 1: those factors that increases the risk of breast cancer and 12 00:00:44,159 --> 00:00:49,000 Speaker 1: should receive further examination. The study, published online in December 13 00:00:49,000 --> 00:00:52,320 Speaker 1: of twenty nineteen and the International Journal of Cancer, details 14 00:00:52,320 --> 00:00:55,640 Speaker 1: how scientists at the National Institute of Environmental Health Sciences, 15 00:00:55,640 --> 00:00:58,480 Speaker 1: part of the ni H, discovered that regular use of 16 00:00:58,480 --> 00:01:02,840 Speaker 1: permanent hair dye was to an overall nine increase in 17 00:01:02,880 --> 00:01:07,520 Speaker 1: breast cancer risk. The statistics were especially significant in African 18 00:01:07,520 --> 00:01:10,720 Speaker 1: American women. Those who used permanent dies every five to 19 00:01:10,800 --> 00:01:14,360 Speaker 1: eight weeks or more frequently had a sixty higher risk 20 00:01:14,400 --> 00:01:17,280 Speaker 1: of breast cancer compared with white women, who had an 21 00:01:17,280 --> 00:01:21,600 Speaker 1: eight percent increased risk. Semi permanent and temporary dies didn't 22 00:01:21,640 --> 00:01:24,240 Speaker 1: seem to have this effect. Neither was found to increase 23 00:01:24,319 --> 00:01:29,080 Speaker 1: risk of breast cancer. For the NIH study, researchers used 24 00:01:29,160 --> 00:01:32,000 Speaker 1: data from forty six thousand, seven hundred and nine women 25 00:01:32,040 --> 00:01:35,080 Speaker 1: who participated in the Sister Study, which included more than 26 00:01:35,120 --> 00:01:37,920 Speaker 1: fifty thou women across the United States in Puerto Rico 27 00:01:38,080 --> 00:01:41,400 Speaker 1: from two thousand three to two thousand nine. The participants 28 00:01:41,400 --> 00:01:43,600 Speaker 1: of the Sister Study were all between the ages of 29 00:01:43,640 --> 00:01:46,600 Speaker 1: thirty five and seventy four, and each had a sister 30 00:01:46,600 --> 00:01:50,040 Speaker 1: who had been diagnosed with breast cancer. The idea is 31 00:01:50,080 --> 00:01:54,400 Speaker 1: that because sisters typically share the same environment, genes, and experiences, 32 00:01:54,920 --> 00:01:58,440 Speaker 1: researchers may stand a better chance at pinpointing risk factors 33 00:01:58,680 --> 00:02:03,880 Speaker 1: and developing effective can through prevention strategies. But permanent hair 34 00:02:03,960 --> 00:02:07,600 Speaker 1: dye was only part of the equation. Researchers also found 35 00:02:07,640 --> 00:02:10,720 Speaker 1: that chemical hair straighteners were associated with an increased risk 36 00:02:10,760 --> 00:02:13,639 Speaker 1: of breast cancer. The data showed that women who used 37 00:02:13,639 --> 00:02:16,480 Speaker 1: hair straighteners every five to eight weeks or more frequently 38 00:02:16,720 --> 00:02:21,160 Speaker 1: were about more likely to develop breast cancer. Straighteners were 39 00:02:21,240 --> 00:02:24,520 Speaker 1: used much more frequently among the African American participants, but 40 00:02:24,639 --> 00:02:27,839 Speaker 1: the association between the product and increased breast cancer risk 41 00:02:28,080 --> 00:02:32,639 Speaker 1: was similar in both African American and white women. So 42 00:02:33,280 --> 00:02:36,240 Speaker 1: does this mean permanent hair dye and chemical hair straighteners 43 00:02:36,240 --> 00:02:40,520 Speaker 1: should be strictly banned from regular use. Researchers aren't sure. 44 00:02:41,440 --> 00:02:45,080 Speaker 1: Human bodies are complicated, and further investigation is necessary to 45 00:02:45,160 --> 00:02:49,239 Speaker 1: replicate the results and hopefully explain what caused those results. 46 00:02:49,840 --> 00:02:53,040 Speaker 1: In the meantime, keep in mind that cancers usually can't 47 00:02:53,080 --> 00:02:56,480 Speaker 1: be explained by the involvement of any single factor. In 48 00:02:56,520 --> 00:03:00,680 Speaker 1: other words, don't panic, but anyone concerned about their breast 49 00:03:00,680 --> 00:03:09,560 Speaker 1: cancer risk may want to reevaluate their cosmetic routines. Today's 50 00:03:09,560 --> 00:03:12,760 Speaker 1: episode was written by Michelle Konstantinovski and produced by Tyler Clang. 51 00:03:13,200 --> 00:03:15,120 Speaker 1: Brain Stuff is a production of I Heart Radio's How 52 00:03:15,120 --> 00:03:17,120 Speaker 1: Stuff Works. For more in this and lots of other 53 00:03:17,160 --> 00:03:19,840 Speaker 1: health related topics, visit our home planet, how stuff Works 54 00:03:19,840 --> 00:03:22,520 Speaker 1: dot com. And for more podcasts for my heart Radio, 55 00:03:22,720 --> 00:03:25,440 Speaker 1: visit the iHeart Radio app, Apple Podcasts, or wherever you 56 00:03:25,520 --> 00:03:26,760 Speaker 1: listen to your favorite shows.