Secular changes in NSAID use and invasive colorectal cancer incidence: an ecological study

Decreasing human body temperature in the United States since the industrial revolution

In the US, the normal, oral temperature of adults is, on average, lower than the canonical 37°C established in the 19^th century. We postulated that body temperature has decreased over time. Using measurements from three cohorts—the Union Army Veterans of the Civil War (N = 23,710; measurement years 1860–1940), the National Health and Nutrition Examination Survey I (N = 15,301; 1971–1975), and the Stanford Translational Research Integrated Database Environment (N = 150,280; 2007–2017)—we determined that mean body temperature in men and women, after adjusting for age, height, weight and, in some models date and time of day, has decreased monotonically by 0.03°C per birth decade. A similar decline within the Union Army cohort as between cohorts, makes measurement error an unlikely explanation. This substantive and continuing shift in body temperature—a marker for metabolic rate—provides a framework for understanding changes in human health and longevity over 157 years.

Lifestyle factors and their combined impact on the risk of colorectal polyps

Understanding patterns of shared and type-specific etiologies for colorectal polyps may provide insights into colorectal carcinogenesis. The authors present the first systematic comparison of risk factors by colorectal polyp type in a large colonoscopy-based case-control study of 3,764 polyp-free controls and 2,543 polyp patients, including 1,444 cases with adenomas only, 662 cases with hyperplastic polyps (HPPs) only, and 437 cases with synchronous HPPs and adenomas. Surveys were completed to obtain information on usual dietary intake and other lifestyle factors. Six lifestyle factors, including cigarette smoking, obesity, no regular use of nonsteroidal anti-inflammatory drugs, high intake of red meat, low intake of fiber, and low intake of calcium, were found to be independently associated with the risk of polyps. The risk of polyps increased progressively with an increasing number of adverse lifestyle factors. Compared with participants with no or only 1 risk factor, odds ratios for those with 5 to 6 risk factors were 2.72 (95% confidence interval: 1.94, 3.79) for adenoma only, 4.12 (95% confidence interval: 2.78, 6.09) for HPPs only, and 9.03 (95% confidence interval: 5.69, 14.34) for synchronous HPPs and adenomas. This study provides strong evidence that lifestyle modification is important for the prevention of colorectal polyps, especially advanced and multiple adenomas, which are established precursors of colorectal cancer.

Epidemiology of colorectal cancer in Asia

The prevalence of colorectal cancer is increasing in Asia. However, the age-standardized rate has reached a plateau in some countries. Some studies have shown a male predominance difference and increasing risk in the elderly, but not in the younger population. 'Right shifting' of colorectal cancer, not accountable by difference in age or the indications for endoscopic examination, has also been noted. Westernized diet is associated with colorectal cancer, but controversy remains on how it causes colorectal cancer. Alcohol consumption, obesity, diabetes mellitus, consumption of red and processed meat and cigarette smoking are linked to bowel cancer epidemiologically. Only high dietary calcium has a consistent negative (or 'protective') effect. The efficacy of fish oil, vitamin D, soy, phytoestrogens, folate, methionine, riboflavin and vitamin B6 has not been established. Aspirin and non-steroidal anti-inflammatory drugs use decrease risk of colorectal cancer after 5-10 years of use. There is no evidence for a detrimental effect of proton pump inhibitors or benefit of statins in colorectal cancer. In conclusion, there is a rising trend and prevalence of colorectal cancer in Asia. Dietary modification or supplementation may not be effective in preventing colorectal cancer. Surveillance of colorectal cancer in high-risk groups, according to current recommendation, is probably most effective.