Association of Hot Tea Consumption with Regional Adiposity Measured by Dual-Energy X-Ray Absorptiometry in NHANES 2003-2006.

OBJECTIVE: This study aimed to investigate the potential antiobesity benefits of hot tea consumption at the population level. METHODS: Using data from the National Health and Nutrition Examination Survey (NHANES) 2003-2006, the association between hot tea consumption and dual-energy x-ray-measured body fat was examined in a large representative sample of US adults (n = 5,681, 51.9% women). RESULTS: Compared with non-tea drinkers, men who consumed 0.25 to 1 cup per day of hot tea had 1.5% (95% CI: 0.4% to 2.6%) and 1.7% (95% CI: 0.4% to 3.0%) less total and trunk body fat, respectively. The associations were stronger among men 45 to 69 years old compared with younger men (20-44 years). For men who consumed 1 or more cups per day of hot tea, lower total (-1.2%, 95% CI: -2.3% to -0.2%) and trunk body fat (-1.3%, 95% CI: -2.6 to -0.1%) was observed among men 45 to 69 years old only. In women, those who drank 1 or more cups per day had 1.5% lower (95% CI: -2.7% to -0.3%) trunk body fat compared with non-tea drinkers. CONCLUSIONS: Consumption of hot tea might be considered as part of a healthy diet in order to support parameters associated with metabolic health and may be particularly important in older male age groups in supporting reduced central adiposity.

Nutrient limitation and morphological plasticity of the carnivorous pitcher plant Sarracenia purpurea in contrasting wetland environments.

* Plasticity of leaf nutrient content and morphology, and macronutrient limitation were examined in the northern pitcher plant, Sarracenia purpurea subsp. purpurea, in relation to soil nutrient availability in an open, neutral pH fen and a shady, acidic ombrotrophic bog, over 2 yr following reciprocal transplantation of S. purpurea between the wetlands. * In both wetlands, plants were limited by nitrogen (N) but not phosphorus (P) (N content < 2% DW(-1), N : P < 14) but photosynthetic quantum yields were high (F(V)/F(M) > 0.79). Despite carnivory, leaf N content correlated with dissolved N availability to plant roots (leaf N vs , r(2) = 0.344, P < 0.0001); carnivorous N acquisition did not apparently overcome N limitation. * Following transplantation, N content and leaf morphological traits changed in new leaves to become more similar to plants in the new environment, reflecting wetland nutrient availability. Changes in leaf morphology were faster when plants were transplanted from fen to bog than from bog to fen, possibly reflecting a more stressful environment in the bog. * Morphological plasticity observed in response to changes in nutrient supply to the roots in natural habitats complements previous observations of morphological changes with experimental nutrient addition to pitchers.

Evaluation of the evolution of increased competitive ability (EICA) hypothesis: loss of defense against generalist but not specialist herbivores.

The evolution of increased competitive ability (EICA) hypothesis predicts that invasive plant species may escape their specialized natural enemies in their introduced range and subsequently evolve with a decrease in investment in anti-herbivore chemical defenses relative to native conspecifics. We compared the chemical profile of 10 populations of US native and 20 populations of European invasive Solidago gigantea. To test for differences in inducibility between native and invasive populations, we measured secondary chemistry in both damaged and undamaged plants. We also performed bioassays with three specialist and two generalist insect herbivores from four different feeding guilds. There was no evidence that invasive populations had reduced concentrations of sesquiterpenes, diterpenes, or short-chain hydrocarbons (SCH), although significant variation among populations was detected. Sesquiterpene and diterpene concentrations were not influenced by damage to the host plant, whereas SCH concentrations were decreased by damage for both native and invasive plants. Performance of the three specialist insects was not affected by the continental origin of the host plant. However, larval mass of the generalist caterpillar Spodoptera exigua was 37% lower on native plants compared to invasive plants. The other generalist insect, a xylem-tapping spittlebug that occurs on both continents, performed equally well on native and invasive plants. These results offer partial support for the defense predictions of the EICA hypothesis: the better growth of Spodoptera caterpillars on European plants shows that some defenses have been lost in the introduced range, even though our measures of secondary chemistry did not detect differences between continents. Our results show significant variation in chemical defenses and herbivore performance across populations on both continents and emphasize the need for analysis across a broad spatial scale and the use of multiple herbivores.