If you ingest 300 mg of the tea flavonoid EGCG every day, you might live up to 14 percent longer. If, that is, you react in the same way as lab animals did for nutritionists at Harbin Medical University in China. The results of their experiments will be published soon in Aging Cell.
If you ingest 300 mg of the tea flavonoid EGCG every day, you might live up to 14 percent longer. If, that is, you react in the same way as lab animals did for nutritionists at Harbin Medical University in China. The results of their experiments will be published soon in Aging Cell.
Tea, and green tea in particular, contains catechins such as catechin, epigallocatechin [EGC], epicatechin-gallate [ECG] and epigallocatechin-gallate [EGCG]. Researchers suspect that EGCG in particular is the reason why epidemiological and animal studies show that tea consumption extends life expectancy. For more of our posts on the life-extending properties of tea click here.
Recent review articles suggest that substances like EGCG inhibit the activity of free radicals and inflammatory proteins such as TNF-alpha. [Proc Jpn Acad Ser B Phys Biol Sci. 2012;88(3):88-101.] As we age, we become more sensitive to damage from radicals, and inflammatory proteins such as TNF-alpha become more active. As a result the chance of crucial molecules in cells being damaged increases, and diseases such as cancer or diabetes are more likely to develop.
According to a 2001 study, the average Dutchman consumes 50 mg catechins daily from drinking tea. [Eur J Clin Nutr. 2001 Feb;55(2):76-81.] The Chinese converted this level of consumption to an equivalent dose for rats, and arrived at 5 mg EGCG per kg bodyweight a day. For simplicity’s sake they assumed that catechins and EGCG were interchangeable.
When the researchers gave their lab animals 5 mg EGCG per kg/day nothing happened. So they increased the dose by a factor 5, and then they did obtain results. Rats given 25 mg EGCG per kg/day from the age of 2 months lived longer.
The average lifespan [actually the median lifespan] of the rats that were not given EGCG was 92.5 weeks. The average lifespan of the rats in the EGCG group was 105 weeks. So the rats in the EGCG group lived fourteen percent longer.
EGCG had no effect on the rats’ insulin levels or their blood pressure. The EGCG rats weighed slightly less than the control rats. Blood analysis revealed however that the liver and kidneys of the EGCG rats remained healthier longer than those of the control group.
Microscopic analysis of liver and kidney tissues after the rats had died confirmed this too. The Chinese measured the histological activity index for the liver and the tubular injury score for the kidneys. The higher the scores, the worse the condition of the liver and kidneys. The scores for the tissues in the EGCG rats were significantly lower than those of the tissues in the control group.
The Chinese think that EGCG kept the rats’ liver and kidneys healthy by inhibiting TNF-alpha and activating SIRT1, thereby extending their lifespan. “Our study suggests that long-term consumption of phytochemicals with antioxidant and anti-inflammatory activities could be beneficial in promoting health and extending lifespan”, they write.
If you weigh 80 kg, the human equivalent of the EGCG dose used in the study is about 320 mg per day. Products containing this amount can be found in any drugstore or supplements store.
The phytochemical, EGCG, extends lifespan by reducing liver and kidney function damage and improving age-associated inflammation and oxidative stress in healthy rats.
Niu Y, Na L, Feng R, Gong L, Zhao Y, Li Q, Li Y, Sun C.
Source
Department of Nutrition and Food Hygiene, College of Public Health, Harbin Medical University, Harbin, Heilongjiang, P. R. China.
Abstract
It is known that phytochemicals have many potential health benefits in humans. The aim of this study was to investigate the effects of long-term consumption of the phytochemical, epigallocatechin gallate (EGCG), on body growth, disease protection and lifespan in healthy rats. 68 male weaning Wistar rats were randomly divided into the control and EGCG groups. Variables influencing lifespan such as blood pressure, serum glucose and lipids, inflammation and oxidative stress were dynamically determined from weaning to death. The median lifespan of controls was 92.5 weeks. EGCG increased median lifespan to 105.0 weeks and delayed death by approximately 8-12 weeks. Blood pressure and serum glucose and lipids significantly increased with age in both groups compared with the levels at 0 week. However, there were no differences in these variables between the 2 groups during the whole lifespan. Inflammation and oxidative stress significantly increased with age in both groups compared with 0 week, and were significantly lower in serum and liver and kidney tissues in the EGCG group. Damage to liver and kidney function was significantly alleviated in the EGCG group. In addition, EGCG decreased the mRNA and protein expressions of transcription factor NF-?B, and increased the upstream protein expressions of silent mating type information regulation 2 homolog 1 (SIRT1) and forkhead box class O 3a (FOXO3a). In conclusion, EGCG extends lifespan in healthy rats by reducing liver and kidney damage and improving age-associated inflammation and oxidative stress through the inhibition of NF-?B signaling by activating the longevity factors FoxO3a and SIRT1. This article is protected by copyright. All rights reserved.
This article is protected by copyright. All rights reserved.
