Skin & Eye Health
Caffeine and Exercise May Protect Against Harmful UVB Rays
The combined effects of exercise and caffeine may help reduce the risk of developing skin cancers caused by sun exposure, according to findings presented at the American Association for Cancer Research Annual Meeting 2012 in Chicago, Illinois.
For the study, researchers led by Yao-Ping Lu, PhD, associate research professor of chemical biology at the Ernest Mario School of Pharmacy at Rutgers University, pretreated mice with ultraviolet B (UVB) radiation. They then placed the mice into groups to receive 1 of 4 interventions: plain water (control group), caffeinated water, exercise wheel, or exercise wheel and caffeinated water. All 4 groups were further exposed to UVB radiation for a total of 14 weeks.
The authors determined that the caffeine and exercise group had 62% fewer nonmelanoma skin tumors than the controls, and the volume of tumors was 85% less. The researchers also discovered that caffeine consumption and exercise reduced inflammation in the mice by 92% and led to a weight reduction of 63%.
The authors suggest that an explanation of how exercise and caffeine protect against sun exposure cancers relies on the way fat, inflammation, and cancer are interrelated.
Immune Suppression Triggered by Certain Melanomas
The results of a study published in the March 2012 issue of Science Translational Medicine indicate that the activation of an inflammatory immune response by certain melanoma tumors helps the tumors protect themselves from being destroyed.
The researchers investigated the molecule B7-H1, which is expressed by some melanoma tumors, to determine the mechanism by which the immune system triggers its own inhibition. They found that tumor cells used interferon gamma, an active component of the body’s immune response, to turn on B7-H1, which contributes to immune suppression. The tumors grew in a more aggressive manner once they were able to evade immune system detection.
“We were surprised to find that aggressive tumors can not only escape or hide from infiltrating immune cells, but can go on the attack—using interferon gamma as a weapon against the immune system,” said lead author Lieping Chen, MD, professor of immunobiology at Yale School of Medicine.
Dr. Chen said that this counterattack mechanism may be responsible for tumor growth in up to 40% of melanoma patients, and that therapies to block this pathway may prove beneficial for patients with B7-H1 melanomas.
Inflammation Helps Prevent Progression of AMD
New research from scientists at Trinity College Dublin suggests that manipulating the levels of a proinflammatory cytokine called interleukin-18 (IL- 18) in the retinas of patients with dry age-related macular degeneration (AMD) could help prevent the development of the more severe wet form of the disease.
AMD is the loss of vision in the center of the visual field as a result of damage to the retina of the eye. In both the dry and wet forms of the disease, drusen—or yellowish-white deposits that accumulate in the macula—form for unknown reasons. The dry form of the disease can progress to the wet form, wherein blood vessels grow from the choroid behind the retina and leak fluid and blood.
Through the study of drusen from donor eyes with AMD and mice models, lead scientists Dr. Sarah Doyle and Dr. Matthew Campbell determined that drusen accumulating in the macula can lead to the formation of the inflammatory components IL-18 and IL-1beta.
“Traditionally, inflammation in the retina or indeed the eye in general is not beneficial and is a pathological hallmark of many eye diseases, including AMD,” Dr. Doyle noted. “However, we have identified that one inflammatory component termed IL-18 acts as a so-called anti-angiogenic factor, preventing the progression of wet AMD.”
Fast Fact: From 1970 to 2009, the incidence of melanoma increased 8-fold among young women and 4-fold among young men.