According to a new study, avoiding environmental toxins may slow the aging process. The study was published online on May 28 in the journal Trends in Molecular Medicine by researchers at the University of North Carolina School of Medicine in Chapel Hill.
Exposure to carcinogens (cancer-causing substances) is known to increase one’s risk for cancer; in addition, scientists now are of the opinion that a type of environmental toxins, known as gerontogens, may increase the aging process. Toxins present in tobacco smoke, ultraviolet rays and chemotherapy drugs are all suspected gerontogens, which are capable of accelerating the rate at which a person ages.
The researchers note that genetic studies have determined that only 30% of aging is genetic; thus, the other 70% is due to environmental factors. To determine the impact of environmental factors on aging, they have developed a simple test to help determine exactly which toxins might be worth avoiding to decrease the risk of premature aging. Aging is a result of a biological process known as senescence; healthy cells become damaged and lose their ability to divide. Over time, these damaged cells accumulate in the body; they consume resources and release hormones with inflammatory properties.
The investigators developed a method that exposed mice to certain gerontogens; they then measure the accumulation of senescence cells in their bodies. The mice were divided into different groups—each group was exposed to a different environmental factor. Some were made obese, others were exposed to tobacco smoke, ultraviolet light, and arsenic. The investigators found that both tobacco smoke and ultraviolet light were strongly associated with accelerated aging; however, obesity and arsenic exposure did not appear to have a measurable impact on senescence. They note that it is highly likely that other gerontogens are present in the environment that can accelerate the aging process.
Previous human studies have also shown that breast cancer patients who underwent chemotherapy aged more rapidly. The findings were based on a blood test that measured the levels of P16, which is a gene that increases rapidly in number as one ages. P16 is also one of the markers by which senescence is measured.
Take home message:
Two environmental factors that can accelerate aging were identified in this study: tobacco smoke and ultraviolet light. Abstinence from smoking will not only slow the aging process but also will decrease the risk of cancer and lung diseases such as COPD. In addition, with today’s tough anti-smoking policies, second-hand smoke exposure is much reduced. It is well known that exposure to ultraviolet light from the sun accelerates skin aging and increases the risk of skin cancer; thus, minimizing exposure and use of a sunscreen can be beneficial.