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11 August 2009
Compounds from green tea may lead to stronger bones by promoting bone formation, while also inhibiting bone resorption, which leads to weakening, suggests a new cell study.
The new study looked at three tea compounds called epigallocatechin (EGC), gallocatechin (GC), and gallocatechin gallate (GCG), and found that EGC produced the greatest bone boosting potential.
"Our study has provided the first laboratory evidence on the bone promotion effects of the green tea catechin EGC as was demonstrated by the promotion of osteoblastic differentiation and inhibition of osteoclast formation,” wrote researchers from the Chinese University of Hong Kong report their findings in the Journal of Agricultural and Food Chemistry.
Osteoblasts are cells responsible for bone formation, while osteoclasts are cells which break down bone, leading to resorption and weakening.
The study is consistent with data from epidemiological studies. A study published in the American Journal of Clinical Nutrition (Oct. 2007, Vol 86, pp. 1243-1247) reported that bone mineral density levels were 2.8 per cent greater in tea drinkers than non-tea drinkers, suggesting the beverage has the potential to aid in the prevention of osteoporosis.
The condition is currently second only to cardiovascular disease in terms of global healthcare burden, according to the World Health Organisation, affecting some 200 million people today but the number of sufferers is set to increase steadily with growing numbers of elderly living longer, and obesity adding extra strain on bones.
Green tea contains between 30 and 40 per cent of water-extractable polyphenols, while black tea (green tea that has been oxidized by fermentation) contains between 3 and 10 per cent.
The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin, epicatechin gallate, and epicatechin.
The Hong Kong based researchers used rat cells to study the effects of EGC, GC, and GCG on bone health.
EGC was found to stimulate bone mineralisation, while simultaneously inhibiting the formation of osteoclasts. The other catechins were found to have a significantly weaker effect, said the researchers.
“The present study illustrated that the tea catechins, EGC in particular, had positive effects on bone metabolism through a double process of promoting osteoblastic activity and inhibiting osteoclast differentiations,” wrote the authors.
"Our observations would serve as groundwork for further studies,” they concluded.
Source: Journal of Agricultural and Food Chemistry
Published online ahead of print, ASAP Article, doi: 10.1021/jf901545u
"Effects of Tea Catechins, Epigallocatechin, Gallocatechin, and Gallocatechin Gallate, on Bone Metabolism"
Authors: C.H. Ko, K.M. Lau, W.Y. Choy, P.C. Leung
. GET THE NUTRITION YOU NEED & ENJOY TASTIER FOOD!
Many studies have shown that organically grown food has more minerals and nutrients that we need than food grown with synthetic pesticides. There’s a good reason why many chefs use organic foods in their recipes—they taste better. Organic farming starts with the nourishment of the soil, which eventually leads to the nourishment of the plant and, ultimately our bodies.
2. SAVE MONEY
Growing your own food can help cut the cost of the grocery bill. Instead of spending hundreds of dollars and month at the grocery store on foods that don’t really nourish you, spend time in the garden, outside, exercising, learning to grow your own food.
3. PROTECT FUTURE GENERATIONS
The average child receives four times more exposure than an adult to at least eight widely used cancer-causing pesticides in food. Food choices you make now will impact your child’s future health.
“We have not inherited the Earth from our fathers,
we are borrowing it from our children.”
– Lester Brown
4. PREVENT SOIL EROSION
The Soil Conservation Service estimates more than 3 billion tons of topsoil are eroded from the United States’ croplands each year. That means soil erodes seven times faster than it’s built up naturally. Soil is the foundation of the food chain in organic farming. However, in conventional farming, the soil is used more as a medium for holding plants in a vertical position so they can be chemically fertilized. As a result, American farms are suffering from the worst soil erosion in history.
5. PROTECT WATER QUALITY
Water makes up two-thirds of our body mass and covers three-fourths of the planet. The Environmental Protection Agency (EPA) estimates pesticides - some cancer causing - contaminate the groundwater in 38 states, polluting the primary source of drinking water for more than half the country’s population.
6. SAVE ENERGY
American farms have changed drastically in the last three generations, from family-based small businesses dependent on human energy to large-scale factory farms. Modern farming uses more petroleum than any other single industry, consuming 12 percent of the country’s totally energy supply. More energy is now used to produce synthetic fertilizers than to till, cultivate and harvest all the crops in the United States. If you are growing your own food in the city, you are cutting down on transportation and pollution costs.
7. KEEP CHEMICALS OFF YOUR PLATE
Many pesticides approved for use by the EPA were registered long before extensive research linking these chemicals to cancer and other diseases had been established. Now the EPA considers 60 percent of all herbicides, 90 percent of all fungicides and 30 percent of all insecticides carcinogenic. A 1987 National Academy of Sciences report estimated that pesticides might cause an extra 4 million cancer cases among Americans. If you are growing your own food, you have control over what does, or doesn’t, go into it. The bottom line is that pesticides are poisons designed to kill living organisms and can also harm humans. In addition to cancer, pesticides are implicated in birth defects, nerve damage and genetic mutations.
8. PROTECT FARM WORKERS & HELP SMALL FARMERS
A National Cancer Institute study found that farmers exposed to herbicides had six times more risk than non-farmers of contracting cancer. In California, reported pesticide poisonings among farm workers have risen an average of 14 percent a year since 1973 and doubled between 1975 and 1985. Field workers suffer the highest rates of occupational illness in the state. Farm worker health is also a serious problem in developing nations, where pesticide use can be poorly regulated. An estimated 1 million people are poisoned annually by pesticides.
Although more and more large-scale farms are making the conversion to organic practices, most organic farms are small, independently owned family farms of fewer than 100 acres. It’s estimated the United States has lost more than 650,000 family farms in the past decade. And the U.S. Department of Agriculture predicted that half of this country’s farm production will come from 1 percent of farms by the year 2000, organic farming could be one of the few survival tactics left for family farms.
9. PROMOTE BIODIVERSITY
Mono-cropping is the practice of planting large plots of land with the same crop year after year. While this approach tripled farm production between 1950 and 1970, the lack of natural diversity of plant life has left the soil lacking in natural minerals and nutrients. To replace the nutrients, chemical fertilizers are used, often in increasing amounts. Single crops are also much more susceptible to pests, making farmers more reliant on pesticides. Despite a tenfold increase in the use of pesticides between 1947 and 1974, crop losses due to insects have doubled—partly because some insects have become genetically resistant to certain pesticides.
10. HELP BEAUTIFY YOUR COMMUNITY
Besides being used to grow food, community gardens are also a great way to beautify a community, and to bring pride in ownership.
A whey-protein-rich ingredient may improve blood vessel function in healthy individuals, reports a new randomised, double-blind study supported by Glanbia.
Two weeks of supplementation with a proprietary peptide (NOP847, Glanbia Nutritionals) resulted in a 1.5 per cent improvement in blood flow, report researchers from the University of Connecticut in the open access Nutrition Journal.
According to the researchers, the whey protein-derived ingredient, isolated from hydrolysate, may work via an angiotensin converting enzyme (ACE)-inhibitory activity.
ACE inhibitors work by inhibiting the conversion of angiotensin I to the potent vasoconstrictor, angiotensin II, thereby improving blood flow and blood pressure.
“The results of this preliminary study suggest that in individuals with normal endothelial function, the acute ingestion of a peptide derived from whey improves both conduit and resistance vascular responses,” wrote the authors, led by Kevin Ballard.
If further studies support the vascular benefits of the ingredient, it could see it enter the already buoyant heart health market. According to a recent market research conducted by Frost & Sullivan, the market is dominated by four ingredients: phytosterols; omega-3s; beta-glucans and soy protein.
Cardiovascular disease (CVD), which cost €192 billion in health care costs across the 27-member state EU in 2007 according to the European Heart Network, can be sub-classified into categories such as hypercholesterolemia, hypertension, heart attack and stroke.
Ballard and his co-workers recruited 20 healthy men and women with an average age of 25, and an average BMI of 24.3 kg/m2, and randomly assigned them to receive the whey ingredient (five grams per day) or placebo for two weeks. After this time, the subjects underwent a two week washout period before being crossed over to the other intervention.
According to the study’s results, there was no difference between the groups’ flow-mediated dilation (FMD), a measure of a blood vessel's healthy ability to relax, at the start of the study. While placebo had no effect on FMD, supplementation with the whey ingredient was associated with a significant improvement in FMD for up to 90 minutes following ingestion or between 1.1 and 2.2 per cent.
Furthermore, blood flow in the arm improved by 2.7 per cent per minute following whey protein supplementation, but did not change following placebo, said the researchers.
“These findings indicate that supplementation with a novel whey-derived peptide in healthy individuals improves vascular function,” wrote Ballard and his co-workers.
Looking to the next stage in research, the scientists noted that an investigation into how the ingredient functions in people with vascular dysfunction would be “informative”.