Everyone knows that sun exposure, asbestos, and hepatitis C can all increase your risks for developing cancer. But the connection between cancer and other less-known risk factors can be more surprising. For example, working the night shift, drinking very hot tea and alcohol, being tall, having breast implants, and absorbing barbeque smoke through your skin have all been linked to a higher risk for certain cancers. Let’s take a look at these five strange cancer risk factors:
Working the night shift
With advanced economic development, night-shift work fuels prosperity, and more and more workers are doing it. But can the night shift play a role in cancer? The connection between working the night shift and the development of common cancer types has been supported in recent research. In one review, for example, researchers found that the more cumulative night shifts worked, the higher the risk of breast cancer—particularly among women.
In another study, investigators analyzed data from the Nurses’ Health Study and the Nurses’ Health Study II, and noted that long-term rotating shift work also increased the risk of breast cancer development. One potential reason for these effects may be due to the disruption of the circadian rhythm, which can also affect telomere length, according to some experts. Generally, shorter telomere length has been associated with increased cancer risk. Finally, in a case-control study, rotating shift work was correlated with an increased risk of colorectal cancer, especially following long-term exposures.
Hot tea plus alcohol or tobacco
Drinking burning-hot tea may increase the risk of esophageal cancer, particularly among alcohol drinkers and smokers, according to the results of two studies. In one population-based cohort-study involving over 400,000 individuals aged 30-79 years, researchers compared cancer risk in control participants who only drank burning-hot tea less than once per week with those who drank burning-hot tea and ≥ 15 g alcohol daily, as well with those who drank burning-hot tea daily and smoked cigarettes. The median follow-up was 9.2 years. They found the greatest risk for esophageal cancer in those who drank alcohol and burning-hot tea (HR: 5.00; 95% CI: 3.64-6.88). The HR for those who smoked and drank burning-hot tea was also increased, but to a lesser extent (HR: 2.03; 95% CI: 1.55-2.67).
In another recent study, researchers investigated the impact of drinking piping-hot tea on esophageal squamous cell carcinoma (ESCC) risk among 1,962 control participants and 1,355 patients with ESCC in China. According to findings, most tea drinkers were male and the odds ratio of drinking piping-hot tea for the risk of ESCC was 2.15 (95% CI: 1.52-3.05) vs never-drinkers. The investigators also noted a significant joint effect of drinking both piping-hot tea and alcohol on the risk of ESCC development (P=0.019).
Every 10 cm increase in stature heightens the risk of cancer by 10%, according to a recent study published in Proceedings of the Royal Society B: Biological Sciences. Data from four large-scale surveillance projects involving 23 cancer categories were pooled for this analysis. The association between cancer risk and height could be due to an increased number of cells in taller people. Alternatively, height could indirectly increase cancer risk, because factors that boost cancer risk may also independently increase adult height. Of note, melanoma showed a notably higher increased risk with respect to height.
Breast implants may increase the relative risk of anaplastic large-cell lymphoma (ALCL) in the breast, according to a 2018 study in JAMA Oncology. Researchers found that there was a small but significant increase in risk for ALCL in patients with breast implants in this population-based, case-control study. The investigators called for increased awareness of this risk and consideration of alternative procedures to breast implants. Specifically, they found that the relative risk for breast-ALCL in women with breast implants was 421.8, and that the absolute cumulative risk was 29 per million at age 50 years and 82 per million at age 70 years.
The FDA has also recently launched an investigation into this association, having received over 460 reports of ALCL linked to breast implants—including 9 related deaths—as of September 2018.
However delicious, regular barbequing can be bad for you in many ways. Carcinogenic polycyclic aromatic hydrocarbons (PAHs), for example, are produced when you burn meat with coal, wood, and gas, and can spread to the air. And these harmful PAHs can be absorbed through inhalation and dermal exposure. Chinese researchers found that urine levels of PAH were higher via skin absorption from cotton clothing than through inhalation of lightweight PAHs. Dermal absorption, however, was highest in those who ate barbeque. In other words, when barbequing, the cotton clothes you wear can introduce more PAH carcinogens into your body than the air you breathe. In addition to the stink, here’s another reason to change your clothes after grilling!