U.S. researchers from Brigham Hospital and Harvard Medical School in Boston have recently found that regular coffee consumption reduces the risk of getting basal cell carcinoma (BCC, or “White skin cancer”) for women who drink more than three cups of coffee by 20 percent; With men, the figure was still nine percent. In the study, the data from among 113,000 adults (including 73,000 women) was analysed over a span of 20 year. During the observation period, 22,786 new BCC cases, 1,953 squamous carcinomas (SCC) and 741 melanomas appeared. “Our study shows that coffee consumption may be an important option in contributing to the prevention of BCC,” says study leader Dr. Fengju Song, a postdoctoral fellow in the Department of Dermatology at Brigham and Women’s Hospital and Harvard Medical School, Boston.
“The amount of caffeine consumption had a direct relationship to the risk. The more coffee the participants drank, the lower was their risk of skin cancer.” The scientists were surprised to find that only in the cases of BCC was there an inverse relationship. Animal studies have hinted at a link between coffee consumption and the risk of skin cancer, but epidemiological studies are said not to have conclusively come to a similar outcome. Since the precise mechanism is not yet known, for now all we have is an end conclusion. According to Song, more studies need to investigate the association between coffee consumption and BCC, as well as the specific mechanism behind this relationship. This prospective study is the latest of those which have in recent years pointed out the positive health effects of coffee.
Sun cream with caffeine?
Several epidemiological studies have already shown in the past that coffee drinkers are less likely to suffer skin cancer. As early as 2007 The Women’s Health Initiative (WHI) published a study involving 93,000 subjects, in which it was shown that even one cup of coffee daily reduced the risk of non-melanotic skin cancer by ten per cent, six or more cups reduced the diagnosed risk of BCC or SCC by 36 percent. The protective effect was weaker with tea and with decaffeinated coffee was not present, which suggests a causal role for caffeine. In a study published in Autumn 2011 by the Ernest Mario School of Pharmacy, Rutgers University, a possible mechanism for the protective effects of caffeine was described. The treatment of high-risk mice with caffeinated water led to a decline in spinalioma of 72 percent in comparison to a control group. Some cancer researchers, including Professor Allan Conney, director of the Susan Lehman Cullman Laboratory for Cancer Research in Piscataway / New Jersey, suggest that the inhibition of the enzyme ATR plays a role. This enzyme is involved in DNA repair. It marks damaged areas, which are then patched up by repair enzymes. This prevents apoptosis of the cell. Paradoxically, this step also benefits cancer cells, which are then protected from being destroyed. Several agents that inhibit ATR are currently being tested in clinical trials for their ability to reinforce the effect of cancer therapy, which also frequently targets DNA.
In order to investigate whether ATR actually plays a role in the development of skin cancer, the research team under Conney experimented with genetically engineered mice which do not express ATR. They simulated the effect of caffeine on the skin. The outcome: the gene-modified mice were largely protected from skin cancer. Even under UV irradiation they developed 69 percent fewer skin tumors, and invasive tumors were observed as much as four times less frequently. The protective effect was nonetheless only detectable at the beginning of the study. If constant UV radiation continues long enough, there occurs in all of the animals the formation of spinaliomas. Conney assumes therefore that caffeine has a considerable preventive effect, but cannot nevertheless stop the growth of an existing tumor. The researcher considers it quite possible that caffeine will in the future become a component of sun creams. This matter can’t however be clarified in the lab, but only in clinical studies.
Coffee as a mood lifter
According to a report in the Archives of Internal Medicine, coffee might protect women against depression. Dr. Michel Lucas, of the Harvard School of Public Health in Boston, has learned from an evaluation of the Nurses’ Health Study that women who consumed three to four cups of coffee a day showed a 15 percent-lesser relative risk of depression compared to women who drank less than one cup per week. The coffee consumption of nurses from New England, who had been continuously surveyed since 1980 on their living habits, was matched up against subsequent diagnoses of depressive illness. It resulted in a dose-dependent inverse association: The more coffee the nurses consumed, the less likely was diagnosis of subsequent depression. What speaks in favour of a causality aside from this dose-response relationship was that the association was found only for caffeinated coffee. Decaffeinated drinks showed no “protective” effect at all. The bottom line was that for the coffee drinkers in the highest category (550 mg of caffeine a day) there was 20 percent-reduced morbidity (relative risk 0.80, 95 -percent confidence interval 0.68 to 0.95) compared to women with the lowest caffeine intake (< 100 mg/day).
A treatment recommendation certainly cannot be derived from this study. Caffeine is undoubtedly the most widely consumed psychoactive substance. However whether it can improve the mood state of patients with depression over the long term is still an open question. Therapy studies have never been conducted and results from prospective observational studies are scarce.
Coffee protects against forgetfulness
Three to five cups of coffee per day, according to a Finnish-Swedish long-term study, is the secret recipe against Alzheimer’s disease and dementia in old age. Scientists at the University of Kuopio, Finland in 2009 set off together with colleagues from the Karolinska Institute in Stockholm and the National Institute of Public Health in Helsinki to track the health effects of caffeine. How much coffee the approx. 1,400 subjects consumed was determined by the research team via questionnaire. The study showed that middle-aged coffee drinkers at a later point suffered dementia and Alzheimer’s less often. The lowest risk, the researchers established, was for those coffee drinkers who consumed three to five cups a day. “The pathological processes that lead to Alzheimer’s disease possibly manifest themselves even a decade before the disease can actually be clinically detected,“ the study’s leader, Milia Kivipelto of the University of Kuopio, says.
The amount does it
“One cannot however make sweeping statements that coffee consumption is always healthy”, warns Univ.-Prof. Dr. Veronika Somoza, professor of Food Biofunctionality at the University of Vienna. “It depends on the amount. One should leave it at a moderate consumption of three, maximum four 150 millilitre cups per day to largely avoid the negative effects of caffeine.” With this consumption quantity, a lower risk of type 2 diabetes, Alzheimer’s disease, as well as certain cancers – colorectal or prostate cancer – has been shown. “The emphasis is nevertheless on reduced risk. Coffee does not totally prevent such a disease. For health reasons decaffeinated coffee would be best,” adds Somoza. “One has the protective effects against, say, type-2 diabetes, but at the same time prevents the potential negative effects on the central nervous system, such as an increased heart rate.”