Increasing interest in the health benefits of tea has led to the inclusion of tea extracts in dietary supplements and functional foods. However, epidemiologic evidence regarding the effects of tea consumption on cancer and cardiovascular disease risk is conflicting. While tea contains a number of bioactive chemicals, it is particularly rich in catechins, of which epigallocatechin gallate (EGCG) is the most abundant. Catechins and their derivatives are thought to contribute to the beneficial effects ascribed to tea. Tea catechins and polyphenols are effective scavengers of reactive oxygen species in vitro and may also function indirectly as antioxidants through their effects on transcription factors and enzyme activities. The fact that catechins are rapidly and extensively metabolized emphasizes the importance of demonstrating their antioxidant activity in vivo. In humans, modest transient increases in plasma antioxidant capacity have been demonstrated following the consumption of tea and green tea catechins. The effects of tea and green tea catechins on biomarkers of oxidative stress, especially oxidative DNA damage, appear very promising in animal models, but data on biomarkers of in vivo oxidative stress in humans are limited. Larger human studies examining the effects of tea and tea catechin intake on biomarkers of oxidative damage to lipids, proteins, and DNA are needed.

Tea catechins and polyphenols: health effects, metabolism, and antioxidant functions.

OBJECTIVES: To introduce the UK SF36 Version II (SF36-II), and to (a) gain population norms for the UK SF36-II in a large community sample as well as to explore the instrument's internal consistency reliability and construct validity, and (b) to derive the Physical Component Summary (PCS) and Mental Component Summary (MCS) algorithms for the UK SF36-II. DESIGN: Postal survey using a questionnaire booklet, containing the SF-36-II and questions on demographics and long term illness. SETTING: The sample was drawn from General Practitioner Records held by the Health Authorities for Berkshire, Buckinghamshire, Northamptonshire, and Oxfordshire. SAMPLE: The questionnaire was sent to 13,800 randomly selected subjects between the ages of 18-64 inclusive. OUTCOME MEASURES: Scores for the eight dimensions of the UK SF36-II and the PCS and MCS summary scores. RESULTS: The survey achieved a response rate of 64.4% (n = 8889). Internal consistency of the different dimensions of the questionnaire were found to be high. Normative data for the SF-36 are reported, broken down by age and sex, and social class. Factor analysis of the eight domains produced a two factor solution and provided weights for the UK SF36-II. CONCLUSION: The SF36-II domains were shown to have improved reliability over the previous version of the UK SF36. Furthermore, enhancements to wording and response categories reduces the extent of floor and ceiling effects in the role performance dimensions. These advances are likely to lead to better precision as well as greater responsiveness in longitudinal studies.

https://jech.bmj.com/content/jech/53/1/46.full.pdf

Assessment of the SF-36 version 2 in the United Kingdom.

The diesel engine is the most efficient prime mover commonly available today. Diesel engines move a large portion of the world's goods, power much of the world's equipment, and generate electricity more economically than any other device in their size range. But the diesel is one of the largest contributors to environmental pollution problems worldwide, and will remain so, with large increases expected in vehicle population and vehicle miles traveled (VMT) causing ever-increasing global emissions. Diesel emissions contribute to the development of cancer; cardiovascular and respiratory health effects; pollution of air, water, and soil; soiling; reductions in visibility; and global climate change. Where instituted, control programs have been effective in reducing diesel fleet emissions. Fuel changes, such as reduced sulfur and aromatics content, have resulted in immediate improvements across the entire diesel on- and off-road fleet, and promise more improvements with future control. In the United States, for example, 49-state (non-California) off-road diesel fuel sulfur content is 10 times higher than that of national on-road diesel fuel. Significantly reducing this sulfur content would reduce secondary particulate matter (PM) formation and allow the use of control technologies that have proven effective in the on-road arena. The use of essentially zero-sulfur fuels, such as natural gas, in heavy-duty applications is also expected to continue. Technology changes, such as engine modifications, exhaust gas recirculation, and catalytic aftertreatment, take longer to fully implement, due to slow fleet turnover. However, they eventually result in significant emission reductions and will be continued on an ever-widening basis in the United States and worldwide. New technologies, such as hybrids and fuel cells, show significant promise in reducing emissions from sources currently dominated by diesel use. Lastly, the turnover of trucks and especially off-road equipment is slow; pollution control agencies need to address existing emissions with in-use programs, such as exhaust trap retrofits and smoke inspections. Such a program is underway in California. These and other steps that can be continued and improved will allow the use of the diesel engine, with its superior fuel consumption, to continue to benefit society while greatly reducing its negative environmental and health impacts. The next ten years can and must become the "Decade of Clean Diesel."

https://energy.gov/sites/prod/files/2014/03/f9/2002_deer_lloyd.pdf

Diesel engines: environmental impact and control.

The health consequences of smoking: Cancer

This review summarizes available information on epidemiological and experimental data showing an association of tea consumption with cancer prevention Studies showing cancer risk associated with tea consumption are also summarized Tea is grown in about 30 countries and, next to water, is the most widely consumed beverage in the world Experimental studies demonstrating the chemopreventive effects of tea have been conducted principally with green tea; limited studies have also assessed the usefulness of black tea Majority of these studies have been carried out in skin tumor model system where consumption through drinking water of water extracts of tea or a polyphenolic fraction isolated from tea has been shown to afford protection against chemical carcinogen- or ultraviolet radiation-induced skin tumorigenesis Tea consumption has also been shown to afford protection against chemical carcinogen-induced lung, forestomach, esophagus, duodenum, pancreas, liver, breast and colon carcinogenesis in specific bioassay models Evidence has also accumulated showing that tea polyphenols prevent tumor promoter- and ultraviolet B-induced inflammatory responses in murine skin The species and strains of animals, dose, route, frequency and duration of carcinogen administration, as well as types, route of administration and duration of tea or its polyphenolic component(s) treatment are described in detail A brief description regarding mechanism(s) responsible for the broad chemopreventive effects of tea is provided Epidemiologic studies, though inconclusive, in general suggest a possible preventive effect of tea consumption on human cancer On the basis of available information, epidemiologic and experimental studies are ongoing to draw the possible relationship between tea consumption and cancer causation and prevention Appropriate strategies for future clinical chemoprevention trials to translate animal data to human cancer risk are warranted

Tea in chemoprevention of cancer

In a Canadian population-based case-control study of 480 males and 152 female case-control pairs, the relative risk for development of bladder cancer for ever used versus never used cigarettes was 3.9 for males and 2.4 for females, with a dose-response relationship in both sexes. A reduced risk was associated with the use of filter cigarettes compared to nonfilter cigarettes. After control for cigarette usage, a significant risk was noted for male pipe smokers. For male ex-smokers the risk after 15 years of no smoking was less than one-half that of current male smokers. Bladder cancer risk was found for workers in the chemical, rubber, photographic, petroleum, medical, and food processing industries among males and for workers occupationally exposed to dust or fumes among both sexes. Bladder cancer risk was elevated for males consuming all types of coffee, regular coffee, and instant coffee and for females consuming instant coffee, but no dose-response relationship was found. Risk was found for males consuming water from nonpublic supples but not for females. No risk was observed in males or females consuming nitrate-containing foods, beverages other than coffee, or fiddlehead greens. Hair dye usage in females and phenacetin usage in males and females carried no risk. Divergent findings by area for aspirin suggested that an overall association was not causal. Reevaluation of the data on artificial sweeteners confirmed a significant bladder cancer risk in males and a dose-response relationship. The cumulated population attributable risk for bladder cancer was 90% for males from cigarette smoking, industrial exposure, and exposure to nonpublic water supplies and 29% for females from cigarette smoking, industrial exposure, and instant coffee consumption.

Tobacco Use, Occupation, Coffee, Various Nutrients, and Bladder Cancer

Artificial sweeteners and human bladder cancer

A case-control study was conducted in three Canadian provinces using 532 cases of bladder cancer and an equal number of controls individually matched on age, sex, and neighborhood of residence. Increased risk was associated with an occupational history in the chemical, rubber, photographic, petroleum and food processing industries for males, and also with medically-related occupations, though for some the numbers exposed were too small to attain statistical significance. Exposure to dust and fumes in other industries was a risk factor for both males and females and in specific occupations, including crop spraying, welding, occupations involving exposure to diesel and traffic fumes, metal machining and barbers. Use of hair dyes was significantly increased among male cases, though exposure was in nearly all cases limited to 5 y before diagnosis. Use of a non-public water supply at any time was a highly significant risk factor for males. A strong association wih cigarette smoking was seen for both sexes. A highly significant risk from drinking instant coffee was observed for both males and females, though for the latter, most of the association seems due to confounding by smoking.

B. Morrison

Papers

Tobacco Use, Occupation, Coffee, Various Nutrients, and Bladder Cancer

Artificial sweeteners and human bladder cancer

Epidemiological study of bladder cancer