Pleasant Stone Farm Clinical Reports

Drinking five or more cups of green tea per day may reduce the risk of blood- and lymph-based cancers by about 50 per cent, says a new study from Japan.

Compared to people who drank only one cup per day, five cups of green tea a day were associated with a 42 per cent reduction in hematologic malignancies, and a 48 per cent risk reduction in lymphoid neoplasms, according to findings published in the American Journal of Epidemiology.

The study, led by Toru Naganuma from Tohoku University School of Medicine in Japan, adds to the ever-growing body of science supporting the anti-cancer benefits of green tea and its polyphenols.

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. Oolong tea is semi-fermented tea and is somewhere between green and black tea.

The four primary polyphenols found in fresh tealeaves are epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG), and epicatechin (EC).

Study details

Naganuma and his co-workers followed 41,761 adults participating in the Ohsaki National Health Insurance Cohort Study. A questionnaire completed at the start of the study allowed the researchers to quantify green tea consumption.

During nine years of follow-up, the researchers documented 157 hematologic malignancies, including 119 cases of lymphoid neoplasms and 36 cases of myeloid neoplasms.

The risk reductions observed for people who drank five or more cups a day, compared to those who drank only cup, was not affected by the gender of the participants, or their body mass index.

While the result does not prove causality, it does support other studies which reported a protective effect of green tea and its constituents.

Being an epidemiological study, no measures were made of the polyphenol content of the tea consumed, and no mechanistic study was performed to identify the active component or components of the beverages.

Global tea market

The global tea market is worth about €790 (£540, $941) million, with green tea accounting for about 20 per cent of total global production, while black tea accounts for about 78 per cent.

Consumer awareness of the benefits of green tea and green tea extracts continues to rise with growing numbers of studies, from 430 papers in 2000 to almost 1500 in 2003, reporting benefits of the main compounds, catechins.

This has seen European demand surge, having reached 500 metric tonnes in 2003. Companies such as DSM, with its Teavigo boasting 95 per cent purity of epigallocatechin gallate (EGCG), and Taiyo International, with its Sunphenon claiming more than 90 per cent purity, position themselves firmly in specific catechin markets.

Source: American Journal of Epidemiology
Published online ahead of print, doi:10.1093/aje/kwp187
“Green Tea Consumption and Hematologic Malignancies in Japan – The Ohsaki Study”
Authors: T. Naganuma, S. Kuriyama, M. Kakizaki, T. Sone, N. Nakaya, K. Ohmori-Matsuda, A. Hozawa, Y. Nishino, I. Tsuji

Phytosterols, commonly consumed to reduce cholesterol levels, may also “potentially prevent cancer development”, according to a new review of all the science.

The ingredients may work via the traditional route of reducing cholesterol, particularly in the membrane of cancer cells, and by activating an enzyme called caspase which is known to play an essential role in programmed cell death (apoptosis).

“This combined evidence strongly supports an anticarcinogenic action of phytosterols and hence advocates their dietary inclusion as an important strategy in prevention and treatment of cancer,” wrote the reviewers from the Department of Animal Science and the Richardson Centre for Functional Foods and Nutraceuticals, at the University of Manitoba.

The reviews findings are published in the European Journal of Clinical Nutrition.

Phytosterols, cholesterol-like molecules derived from plants, are increasingly well known to consumers due to their scientifically proven ability to reduce cholesterol levels. As consumer awareness has increased, the number of products containing plant sterols or plant stanols and their esters has increased.

Numerous clinical trials in controlled settings have reported that daily consumption of 1.5 to 3 grams of phytosterols/-stanols from foods can reduce total cholesterol levels by eight to 17 per cent, representing a significant reduction in the risk of cardiovascular disease.

Anti-cancer data

The Manitoba-based researchers “critically examine results from recent research regarding the potential effects and mechanisms of action of phytosterols on forms of cancer”.

According to emerging evidence, the phytosterols have shown potential in inhibiting cancers of the stomach, lung, ovaries, and breasts.

Commenting on the mechanism, Peter Jones and his colleagues stated that phytosterols may be linked to increased activity of caspase enzymes. This is achieved by the sterols being incorporated into the cell membranes, resulting in changes to the structure and function of the membranes. These changes ultimately result in an activation of caspase enzymes, said the researchers.

A second potential mechanism could also involve the sterols ‘traditional’ modus operandi of reducing blood cholesterol. “High blood cholesterol level and hence the concentration of cholesterol in lipid rafts of cell membranes are associated with reduced apoptosis of cancer cells,” they said.

Saftey concerns at a recommended daily intake level of two grams appear unfounded, added the researchers, noting that such a dose “does not cause any major health risks”.

“Mounting evidence supports a role for phytosterols in protecting against cancer development,” wrote the researchers.

“Hence, phytosterols could be incorporated in diet not only to lower the cardiovascular disease risk, but also to potentially prevent cancer development,” they concluded.

Healthy heart market

According to a recent market research conducted by Frost & Sullivan, the heart health market is dominated by four ingredients: phytosterols; omega-3s; beta-glucans and soy protein. Phytosterols are the most heart health targeted, said the market analysts, and benefited from approved health claims in many markets (as well as recently approval from the European Food Safety Authority).

The European market was valued at €421m in 2007 and growing at 20 per cent.

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.

Source: European Journal of Clinical Nutrition
Volume 63, Pages 813-820, doi:10.1038/ejcn.2009.29
“Anticancer effects of phytosterols”
Authors: T.A. Woyengo, V.R. Ramprasath, P.J.H. Jones

Daily supplements with the omega-3 fatty acid docosahexaenoic acid (DHA) may improve both memory function and heart health in healthy older adults, according to a new study from Martek.

The results, specific to people with a decline in cognitive function that occurs naturally with age, were presented at the Alzheimer’s Association 2009 International Conference on Alzheimer’s Disease (ICAD 2009) in Vienna.

Almost 500 people took part in the randomised, double-blind, placebo-controlled, multi-center, six month study, which also recorded improvements in the heart rate of people receiving the DHA supplement. The study was funded by Martek Biosciences.

“In our study, healthy people with memory complaints who took algal DHA capsules for six months had almost double the reduction in errors on a test that measures learning and memory performance versus those who took a placebo,” said Yurko-Mauro, PhD, associate director of clinical research at Martek and lead researcher of the study.

“The benefit is roughly equivalent to having the learning and memory skills of someone three years younger.”

Cognitive decline occurs naturally as we age, and precedes diseases such as Alzheimer’s. However, according to other findings also presented at ICAD 2009 in Vienna, the omega-3 fatty acid supplements did not benefit people already suffering from Alzheimer’s disease.

Scientists from Oregon Health and Science University, the University of California, San Diego, Boston University, and Martek report that DHA had no general impact on the cognitive health of people with mild to moderate Alzheimer’s.

Implications

“These two studies raise the possibility that [interventions] for Alzheimer’s must be given very early in the disease for them to be truly effective,” said William Thies, PhD, chief medical and scientific officer at the Alzheimer’s Association.

“For that to happen, we need to get much better at early detection and diagnosis of Alzheimer’s, in order to test therapies at earlier stages of the disease and enable earlier intervention,” he added.

Alzheimer’s data

The Alzheimer’s study involved 402 people with an average age of 76, ‘probable’ Alzheimer’s, dietary DHA intakes of no greater than 200 mg per day, and a Mini-mental state exam score (MMSE) between 14 and 26. The participants were randomly assigned to receive a daily DHA dose of 2 grams per day, or placebo, for 18 months.

Results of the double-blind, randomised, placebo-controlled clinical trial, funded by the National Institutes of Health, showed no evidence for benefit in the studied population. Blood levels of DHA did increase, however.

“These trial results do not support the routine use of DHA for patients with Alzheimer’s,” said lead researcher Joseph Quinn, MD.

In a subset of people who carried the “e4″ version of the “ApoE” gene, however, the researchers noted a slower rate of decline on the primary test of mental function (the ADAS-cog). ApoE-e4 is known to increase the risk of developing Alzheimer’s but does not appear to modify the rate of disease progression.

“This is an intriguing exploratory result,” said Quinn. “However it must be treated with appropriate caution. The finding requires further study for confirmation.”

The golden touch on age-related cognitive decline

The Memory Improvement with DHA Study (MIDAS) involved 485 healthy older people with an average age of 70 and a mild memory complaint. The participants were randomly assigned to receive either 900 mg per day of algal DHA or placebo for 6 months.

Results of the randomised, double-blind, placebo-controlled, multi-centre study showed that participants taking DHA supplements made significantly fewer errors on the Paired Associate Learning (PAL) test compared to when they started the study.

Furthermore, plasma DHA levels doubled during the study in the DHA group, and correlated with the PAL response.

The researchers also noted a significant decrease in heart rate in the DHA group, while blood pressure and weight did not change.

“Six month supplementation with DHA (900mg/d) improves memory function and decreases heart rate in healthy older adults with ARCD. This improvement on the PAL is associated with a shift in the normative distribution to a younger age,” wrote the MIDAS investigators.

Sources:
Alzheimer’s Association 2009 International Conference on Alzheimer’s Disease (ICAD 2009) in Vienna
Presentation #O1-04-02, 12 July 2009
“A clinical trial of docosahexanoic acid (DHA) for the treatment of Alzheimer’s disease”
Authors: J.F. Quinn, R. Raman, R.G. Thomas, K. Ernstrom, K. Yurko-Mauro, E.B. Nelson, L. Shinto, A.K. Nair, P. Aisen

Alzheimer’s Association 2009 International Conference on Alzheimer’s Disease (ICAD 2009) in Vienna
Presentation #O1-04-01

“Results of the MIDAS Trial: Effects of Docosahexaenoic Acid on Physiological and Safety Parameters in Age-Related Cognitive Decline”
Authors: K. Yurko-Mauro, D. McCarthy, E. Bailey-Hall, E.B. Nelson, A. Blackwell, MIDAS Investigators

Increased intakes of whole grains, and bran in particular, may reduce the incidence of hypertension in men, according to new findings from Harvard.

Data from over 30,000 men participating in the Health Professionals Follow-Up Study indicated that increased intakes of whole grains are associated with a 19 per cent lower incidence of hypertension.

The researchers, led by Alan Flint from Harvard School of Public Health, report their findings online in the American Journal of Clinical Nutrition.

“These findings have implications for future dietary guidelines and prevention of hypertension,” they wrote.

High blood pressure (hypertension),defined as having a systolic and diastolic blood pressure (BP) greater than 140 and 90 mmHg, is a major risk factor for cardiovascular disease (CVD) – a disease that causes almost 50 per cent of deaths in Europe, and reported to cost the EU economy an estimated €169bn ($202bn) per year.

While the potential heart health benefits of whole grains have been reported before, the Harvard researchers note that no studies have reported if the total grams of whole grains are linked to the risk of hypertension.

The 31,684 male health professionals aged between 40 and 75 without known hypertension, cancer, stroke, or heart disease were followed for 18 years. During this time, 9,227 cases of incident hypertension were documented.

Comparing the highest intakes of whole grains to the lowest intakes, the researchers calculated that whole grains were associated with a 19 per cent reduction in the incidence of hypertension.

When they subsequently looked at total bran, a 15 per cent reduction in the incidence of hypertension was observed for men with the highest intakes, compared to the lowest.

“In summary, we found an independent inverse association between intake of whole grains and incident hypertension in men,” wrote the researchers. “Bran may play an important role in this association,” they concluded.

Source: American Journal of Clinical Nutrition
Published online ahead of print, doi:10.3945/ajcn.2009.27460
“Whole grains and incident hypertension in men”
Authors: A.J. Flint, F.B. Hu, R.J. Glynn, M.K. Jensen, M. Franz, L. Sampson, E.B. Rimm