News Briefs – May 2008
CANCER’S SECRETS REVEALED
Canadian scientists say they’ve discovered that cancer cells spread by releasing protein “bubbles,” a finding that might alter our concept of how cancer works.
Janusz Rak, PhD, and colleagues at the Research Institute of the McGill University Health Center in collaboration with Ab Guha, PhD, of the University of Toronto, found that cancer cells communicate with healthy cells by releasing “vesicles” – bubble-like structures containing cancer-causing proteins – that can trigger specific mechanisms when they merge into non-malignant cells. Rak said the finding demonstrates that cancer is a multi-cell process, where the cells “talk” to one another extensively.
Until now, scientists had assumed that cancer is caused by a single cell developing damage or a mutation, followed by a runaway reproduction of that cancerous cell. Instead, it appears that a cancerous cell “tricks” healthy (or healthier) cells in other areas to become cancerous.
“This goes against the traditional view that a single ‘mutated’ cell will simply multiply uncontrollably to the point of forming a tumour,” said Rak. “This discovery opens exciting new research avenues, but we also hope that it will lead to positive outcomes for patients.” The study appears in the current online edition of the journal Nature Cell Biology.
WINE A CURB FOR PANCREATIC CANCER?
Resveratrol, a compound found in the skin of red grapes and red wine, may help induce pancreatic cancer cells to malfunction and die, a lab study has found. A handful of foods, including raspberries, blueberries and peanuts, contain resveratrol, but it is most abundant in the skin of red grapes and, therefore, red wine.
Researchers at the University of Rochester Medical Center in New York treated human pancreatic cancer cells with resveratrol – alone and in the presence of radiation – and found that, combined with radiation, resveratrol disrupted the activity of the cancer cells’ mitochondria (energy-producing centres needed for cells to function).
Readers will have heard of several previous studies on the potential antioxidant benefits of resveratrol with respect to longevity or heart disease prevention. The recent study is different in that it suggests this red wine compound may help disrupt the progress of pancreatic cancer.
Until there are further studies in animals, what the results mean for cancer patients will not be clear. It is important to note that this was a lab study and there is no evidence yet as to whether resveratrol from red wine would affect tumours in the body the same way it does cancer cells in a lab dish. Resveratrol is available in over-the-counter supplements but there is no evidence that taking them aids cancer treatment.
The study team stressed that it used a relatively high dose of resveratrol of 50 micrograms per milliliter – about twice the concentration found in red wine. The study appears in the March 2008 edition of the journal Advances in Experimental Medicine and Biology.
REISHI-GREEN TEA COMBO FIGHTS SARCOMA
Both the reishi mushroom and green tea have held a place in traditional medicine, in China and other Asian countries, for the general promotion of health. Recent scientific studies have confirmed that either reishi or green tea can enhance the body’s immune functions, holding potential for prevention of many types of cancer.
Now a study by Chinese scientists has found that combining the active ingredients in the reishi mushroom and green tea creates synergetic effects that inhibit the growth of tumours and delay death in mice with sarcomas. (Sarcomas are usually-malignant tumours in connective tissue such as bone or muscle.)
Yan Zhang, of Pharmanex BJ Clinical Pharmacology Center in Beijing, reported the results of two studies at the Experimental Biology 2008 conference in San Diego on April 8.
In one case, the weight of cancerous sarcoma cells was reduced by 45 per cent when the mice were given a high-potency combination of extracts from reishi and green tea (polysaccharides and triterpenes from the mushroom and tea polyphenols from the tea) compared to those receiving either extract alone. Also, death was delayed in mice who received the combination compared with mice on either reishi or green tea extracts alone. The effect on sarcoma, one of the four main types of cancer, seems to be a synergistic one, says the senior author of the paper, Jia-Shi Zhu, PhD, of Pharmanex research Institute in Provo, Utah.
PRENATAL VITAMINS CUT CANCER RISK IN HALF
A new study has found that many hundreds of Canadian children a year in Canada could be spared devastating forms of cancer if women who are pregnant or trying to conceive take a prenatal multivitamin fortified with folic acid.
Of course, there have been numerous studies showing the importance of taking folic acid supplements during pregnancy but this latest study is significant because it is goes beyond the well-accepted link between insufficient folate during pregnancy and neural tube defects (defects of the brain and spine, including spina bifida). Also, this study is believed to be the largest of its kind ever undertaken, pulling together the data from seven previous studies into one review.
The Canadian study shows that expectant women who take folic acid supplements during the first trimester of pregnancy can lower the risk in their children of leukemia, brain tumours, and neuroblastoma. (Neuroblastoma is one of the most devastating cancers in the young. A solid tumour, it can occur anywhere in the body but usually arises in the adrenal gland, which sits above the kidney. Neuroblastoma affects one in every 6,000 to 7,000 children in North America. Leukemia, on the other hand, accounts for 25 to 35% of new childhood cancer cases each year, making it the most frequently diagnosed pediatric cancer.)
According to researchers at Toronto Hospital for Sick Children, the study found the multivitamins were associated with a 47% risk reduction for neuroblastoma, 39% for leukemia and 27% for brain tumours. Combined, these three cancers affect about 1,000 children a year in Canada alone.
It is not known which vitamins or minerals, and in what amounts, could be protecting babies from cancer. But folic acid, which plays a crucial role in cellular function, may be acting alone. One theory is that a shortage of folic acid may impair DNA’s synthesis and repair, or may change the way genes that normally suppress or turn on cancer, or turn cancer off, are read.
Last year, the “Sick Kids” team, working with researchers from London, Ontario, reported that folic-acid-fortified multivitamin supplements consistently protect babies against other congenital anomalies, including the condition commonly called “a hole in the heart,” limb defects, cleft palate and hydrocephalus (water buildup on the brain that can lead to irreversible brain damage).
Only 40 to 50% of Canadian women take prenatal vitamins. The new study was published in the April 23, 2008 issue of the journal Clinical Pharmacology & Therapeutics.
- Pollution-pneumonia link? High levels of pollution may have contributed to the deaths of thousands of people in England from pneumonia in recent years, a study suggests. A team at the University of Birmingham reported a correlation between the two in the local areas examined, but concedes social factors may have played a role. The report appeared in the April 2008 issue of the Journal of Epidemiology and Community Health.
- Vitamin K2 may cut cancer risk: An increased intake of vitamin K2 (menaquinones) may reduce the risk of prostate cancer by 35%, suggests the results of the European Prospective Investigation into Cancer and Nutrition. The findings did not hold true for vitamin K1 (phylloquinones). The study is not considered conclusive and is detailed in the April 2008 issue of the American Journal of Clinical Nutrition. While dietary sources of menaquinones include meat and some fermented food products like cheese and natto, menaquinones from dairy had a stronger inverse association with advanced prostate cancer than did those from meat.
- ‘Big brain’ keeps dementia at bay: Having a large hippocampus (a part of the brain involved with memory) seems to provide protection against the symptoms of dementia, one study suggests. A US team compared the brains of 35 people who had Alzheimer’s “plaques,” some of whom died with sharp minds and others who showed no dementia symptoms. The hippocampus, an area at the base of the brain, was on average 20% larger in those with cognitive functions intact. The Alzheimer’s Society cautioned that it was a “relatively small study”; small studies are considered unreliable. The unique finding was presented at a meeting of the American Academy of Neurology on April 15.
- Ayurvedic herb lowers heart disease risk: An extract from Withania somnifera (Ashwagandha) roots and leaves reduced stress-related parameters related to the risk of cardiovascular disease, according to a human clinical study published in the April 2008 issue of the Journal of the American Nutraceutical Association. C-reactive protein (CRP) – linked to heart disease – was lowered in those taking the extract, as was the stress hormone cortisone. Also, the levels of the anti-aging hormone DHEA increased. Although further studies are needed to confirm the observations, it is worth noting that this was a randomized, double-blind, placebo controlled human clinical trial – considered the “gold standard” in scientific reliability.
- Vitamin D may curb PAD: People with low vitamin D levels may face an increased risk – as much as 64% higher – for peripheral artery disease (PAD), according to researchers at the Albert Einstein College of Medicine of Yeshiva University. PAD is a common disease that occurs when arteries in the legs become narrowed by fatty deposits, causing pain and numbness and impairing the ability to walk.
The scientists reported their findings on April 20 at the American Heart Association’s Arteriosclerosis, Thrombosis and Vascular Biology Annual Conference 2008. The study analyzed data from a national survey measuring vitamin D levels in the blood of 4,839 US adults; as an epidemiological study, it should be viewed with skepticism because such studies don’t necessarily detect a cause-and-effect relationship (just a general unexplained link).
- Big eaters bear big babies? New research by the Universities of Exeter and Oxford provides the first evidence that a child’s sex may be determined by the mother’s diet. The study shows a clear link between higher energy intake around the time of conception (in other words, a higher-calorie diet) and the birth of sons. The study was small and not conclusive. This research was published April 23, 2008 in the journal Proceedings of the Royal Society B: Biological Sciences.
- Vitamin E and Alzheimer’s patients: People with Alzheimer’s disease who take vitamin E appear to live longer than those who do not take vitamin E, according to new research. The 847 subjects took vitamin E alone, or Alzheimer’s drugs alone, or a combination of both, depending on their group. The study found people who took vitamin E (with or without a cholinesterase inhibitor) were 26% less likely to die than people who did not take vitamin E. The study, which was small and does not draw any conclusions about the effects of vitamin E on the public in general, was presented at the American Academy of Neurology 60th Anniversary Annual Meeting in Chicago, April 12, 2008.
- Calorie restriction combats pancreatic cancer: The longevity diet known as “calorie restriction” (CR) sharply reduces the development of pancreatic lesions that lead to cancer, according to new research. The study was reported April 15 at the American Association for Cancer Research annual meeting by researchers from the University of Texas at Austin and the University of Texas M.D. Anderson Cancer Center. The incidence of pancreatic cancer was just 7% in the CR group compared to 45 and 57% in the two non-CR groups; this finding makes sense because fat tissue is a major source of inflammation, believed to be a factor in this type of cancer. (Coincidentally, another study in the March 2007 issue of the Public Library of Science, found that non-obese people following a CR diet had less oxidative damage to their muscles, a type of damage linked to aging.)
- Acupuncture increases IVF odds: A review of seven clinical trials of acupuncture given with embryo transfer in women undergoing in vitro fertilization (IVF) suggests that acupuncture may improve rates of pregnancy. (Acupuncture has been used in China for centuries to regulate the female reproductive system.) According to the researchers, the results indicate that 10 women undergoing IVF would need to be treated with acupuncture to bring about one additional pregnancy. The study was published in the February 2008 online edition of the British Medical Journal.
- Chlorella an aid to mercury excretion? At the Japan Society for Bioscience, Biotechnology and Agrochemistry conference, held March 29, a study was presented confirming that methylmercury is excreted from mice in both feces and urine, after supplementation with chlorella. Eight-week-old female mice were separated into groups and orally administered either mercury alone or mercury and chlorella (and another group received nothing). After 24 hours, there was no significant excreting difference between the intervention groups. However, toward the end of the 24 hours, the chlorella group showed excreted more mercury than the animals that only received the toxic mercury. There is a possibility of bias because the study was sponsored by Chlorella Industry Co. Ltd., Tokyo, Japan.
- Physicians taking supplements: The majority of physicians are practising what they preach on a healthy lifestyle. They eat a balanced diet (82 %), exercise regularly (73%) and take vitamins and dietary supplements (72%). According to the “Life Supplemented” Healthcare Professionals (HCP) Impact Study, nurses are slightly more likely than physicians to eat a balanced diet (87%) and take supplements (89%); however, they are less likely to exercise regularly (67%). Note that the study was sponsored by a group that promotes the supplement suppliers.
- Bathing in carcinogens: A newly released study commissioned by the Organic Consumers Association (OCA), has found many leading “natural” and “organic” brand shampoos, body washes, lotions and other personal care products contain the undisclosed cancer-causing contaminant “1,4-Dioxane”. It is a suspected kidney toxicant, neuro-toxicant and respiratory toxicant, among others. Although previous studies have revealed 1,4-Dioxane is often present in conventional personal care products, this new study indicates the toxin is also present in leading “natural” and “organic” branded products. Among the many natural brands found to contain this cancer-causing chemical are such common labels as Ecover, Jason, Kiss My Face and Nature’s Gate. A complete list of the 99 brand names tested, along with the result for each, can be found at https://www.organicconsumers.org/bodycare/DioxaneResults08.cfm.
- Probiotics reverse alcohol damage? Probiotics may help reverse some of the damage done to the liver by chronic alcohol drinkers, according to a study in the April 2008 Journal of Hepatology, restoring some of what scientists call “neutrophil phagocytic capacity” in alcoholic cirrhosis. (This refers to the ability of the top cells, among those that serve to surround and devour invading microorganisms, to do their job in the liver.) The probiotic bacteria administered three times daily was Lactobacillus casei Shirota. The study was inconclusive because it was extremely small, including just 12 people, but may suggest a fertile avenue of future study.
8 glasses a day—and other water myths
Contrary to popular belief—and contrary to the prescription for health in many health articles—drinking up to eight glasses of water a day might not be beneficial for your health, researchers say.
(News Briefs has reported on other studies coming to the same conclusion but the most recent study is important because first, it adds further weight to the conclusion that thirst is the best guide to water consumption; and second, it included a review of all previous studies on this topic.)
Stanley Goldfarb, PhD, and Dan Negoianu, PhD, of the University of Pennsylvania in Philadelphia reviewed all the studies dealing with the healthy benefits of drinking lots of water. Their review, published in the April 2008 issue of the Journal of the American Society of Nephrology, concluded that people in hot, dry climates, athletes or people with certain diseases might do better with increased fluid intake, but for average healthy people, more water did not mean better health. Thirst is the best indicator that you need water.
“There is no clear evidence of benefit from drinking increased amounts of water,” Dr. Goldfarb wrote. Goldfarb and Negoianu analyzed the “four major myths” regarding the benefits of extra water drinking: that it leads to more toxin excretion, improves skin tone, makes one less hungry; and reduces headache frequency. Their conclusions? There is no evidence of any of these beliefs and they are merely folklore.
The idea that we all need the same amount of water or that we require a “minimum” of eight glasses a day was also found to be untrue in several previous studies, as was the often-asserted idea that we need to get water by drinking straight water. Our bodies determine water needs based on how much is excreted; and it pulls water out of all types of drinks and foods, which are almost completely water anyway. In fact, some people have died from drinking too much water.
The idea that coffee is dehydrating was also found in a study to be without merit; the dehydration effect of the coffee is more than compensated for by the water content of the beverage itself. Alcohol does have a dehydrating effect, however, one that is rectified the following day when you wake up with a thirst that won’t quit.