Brewing the Perfect Green Tea: Best Brewing Time and Temperature for Optimal Potency

Here is something for all of you who have always asked themselves how to prepare their tea to "get the most out of it". Well, I know normal people would go by taste, but are we normal? No! We want maximal antioxidant-content and a decent amount of caffeine to jack us up and this is where the results from a recent study (Ziaedini. 2010) come into play.

The scientists from the Iranian Institute of Research and Development in Chemical Industries investigated the effect of different brewing times and temperatures on the amount of antioxidants and caffeine you'll get in your tea. Here are the results (cf. table 1):

Table 1: Diffusion coefficients of catechins and caffeine obtained for conventional extraction of green tea leaves.

Obviously it takes a decent temperature of ~70°C to achieve maximal diffusion of the constituents in the short and in the long term. In spite of that, a close look at one of the graphs (cf. figure 1)

Figure 1: EGCG content as a function of time for different water temperatures in °C

shows that even with decent temperatures (>70°C) it takes some time for the antioxidant content (in this case the infamous ECGC content) to achieve significant levels - and lets be honest, do you like, or even, can you really drink a tea that has been brewed for 10 or even 20 minutes? If you can, you're the man (or woman) - if not you probably better buy some capped extract ;-)

Melatonin for Patients With Metabolic Syndrome!?

When was the last time your mother asked you, whether you would get enough sleep? Can't remember? Well, a recent study by scientists (Kozirog. 2010) from the Department of Internal Diseases and Clinical Pharmacology at the Medical University of Lodz suggests you better listen to your mothers words and get a decent amount of sleep, just to make sure you reap the benefits of melatonin.

In the study 30 patients with metabolic syndrome (MS) were treated with 5mg/day of melatonin 2hr before bedtime for 2 month. The results were quite remarkable:

Melatonin administered for 2 months significantly improved antioxidative defense (increase in CAT activity, decrease in TBARS level) and lipid profile (decrease in LDL-C), and lowered blood pressure.

It is not news that lack of sleep contributes to metabolic disorders. What is interesting, however, is that direct supplementation with melatonin, which is secreted at dawn and in the course of the night reverses existing symptoms of the metabolic syndrome. In view of the complex endocrine interactions and the various hormonal responses which depend on sufficient and regular sleep, my suggestion is however not (only) to supplement tons of melatonin, but just to get a good nights sleep everyday, or, in other words, to practice "sleep hygiene", instead.

Again: Green Tea Makes you Healthier, Maybe Less Hungry. It Won't make you Leaner!

While most green tea products are advertised as "fat-burner" or "weight loss supplements" a recent study by  Stendall-Hollins et al. (Stendall-Hollins. 2010) confirmed, what attentive readers of the SuppVersity will already know: Green Tea certainly is healthy, but consumption of the brew or capped extracts, alone, won't make you lose weight:

The effect of daily decaffeinated green tea intake on weight, body composition and changes in resting metabolic rate, energy intake, glucose, insulin, homeostasis model assessment - insulin resistance (HOMA-IR) and lipids was evaluated in overweight breast cancer survivors. Participants had a mean weight of 80.2 kg; body mass index (BMI) 30.1 kg m(-2); and body fat 46.4%. Participants (n = 54) were randomised to 960 mL of decaffeinated green or placebo tea daily for 6 months. Results: Mean (SD) tea intake among study completers (n = 39) was 5952 (1176) mL week(-1) and was associated with a significant reduction in energy intake (P = 0.02). Change in body weight of -1.2 kg (green tea) versus +0.2 kg (placebo) suggests a weight change effect, although this was not statistically significant. Decaffeinated green tea intake was associated with elevated high-density lipoprotein (HDL) levels (P = 0.003) and nonsignificant improvements in the HDL/LDL ratio and HOMA-IR (-1.1 +/- 5.9: green tea; +3.2 +/- 7.2: herbal). Conclusions: Intake of decaffeinated green tea for 6 months was associated with a slight reduction in body weight and improved HDL and glucose homeostasis in overweight breast cancer survivors.

With reference to the loss in body weight it has to be said, that the participants in the green tea group drastically reduced their caloric intake (-1.096.5 kJ/day; cf. figure 1):

Figure 1: Dietary intake and physical activity characteristics of breast cancer survivors participating in the green tea study (n = 39)

It would be interesting to further investigate these anorectic effects green tea had on the subjects of the study. At least for those of you who feel they are hungry all day, drinking green tea may thus offer a partial solution to your weight problems.