Dietary flavan-3-ols intake and metabolic syndrome risk in Korean adults

Flavan-3-ols are a subclass of flavonoids found in a variety of foods including teas. The effects of flavan-3-ols on the risk of metabolic syndrome (MetS) have been investigated, generally focusing on tea catechins or individual flavan-3-ol rich foods, but there is little information on dietary flavan-3-ols intake and risk of MetS in population-based studies. In this cross-sectional study, we examined the association between dietary flavan-3-ols intake and the risk of MetS in Korean adults. Subjects comprised 1,827 men and 2,918 women aged 20-69 years whose data was included in the 2008 Korean National Health and Nutrition Examination Survey. This survey was conducted between January 2008 and December 2008. Total flavan-3-ols intakes were calculated from 24-hour dietary recalls using a flavonoids database. Thirty percent of the male subjects and 24% of the female subjects were reported as having MetS. In the female subjects, flavan3-ols intake was inversely associated with the risk of MetS after adjusting for potential confounders (5th vs. 1st quintile, OR = 0.64, 95% CI = 0.45-0.91, P for trend = 0.384). The main food source of flavan-3-ols was green tea followed by apples and grapes. Among MetS components, flavan3-ols intake was inversely associated with the risk of high blood pressure after adjusting for potential confounders (5th vs. 1st quintile, OR = 0.64, 95% CI = 0.45-0.90, P for trend = 0.005). No significant association between flavan-3-ols intake and risk of MetS was found in the male subjects. After stratified analysis by obesity (BMI ≥ 25 or BMI < 25), however, flavan3-ols intake was inversely related to the risk of hypertension in non-obese men. These results suggest that dietary flavan-3-ols intake may have beneficial effects on MetS risk by reducing the risk of hypertension. The effects of flavan-3-ols intake dependent on obesity need further investigation

The limits to complexity: A thermodynamic history of bioenergy

The history of civilization is biased toward the use of bioenergy because of the biophysics of life and the structure of our natural environment. Energy physically drives the creation and maintenance of complex systems, which is shown here from simple molecular structures to empires. Only a fraction of the complexity currently supported by fossil fuels can be maintained using the energy in plant biomass alone, which is limited by global net primary productivity. From the dawn of civilization, agricultural land has always been used for energy for transportation, via feed for animals, and there has always been a trade-off between “food, fuel, and environment.” The United States (USA), Germany, and Brazil now use roughly 12% of agricultural land for biofuels, but energy efficiency improvements by 2050 could require only 11% of US agricultural land or 15% of forest land for biofuels to support all modes of US transportation. Despite its limitations, bioenergy has been extensively used for thousands of years and probability theory suggests it will continue to be a critical energy resource