Increase in RDA for Vitamin C Could Help Reduce Heart Disease, Stroke, Cancer

The recommended dietary allowance, or RDA, of vitamin C is less than half what it should be, scientists argue in a recent report, because medical experts insist on evaluating this natural, but critical nutrient in the same way they do pharmaceutical drugs and reach faulty conclusions as a result.

The researchers, in Critical Reviews in Food Science and Nutrition, say there’s compelling evidence that the RDA of vitamin C should be raised to 200 milligrams per day for adults, up from its current levels in the United States of 75 milligrams for women and 90 for men.

Rather than just prevent the vitamin C deficiency disease of scurvy, they say, it’s appropriate to seek optimum levels that will saturate cells and tissues, pose no risk, and may have significant effects on public health at almost no expense – about a penny a day if taken as a dietary supplement.

“It’s time to bring some common sense to this issue, look at the totality of the scientific evidence, and go beyond some clinical trials that are inherently flawed,” said Balz Frei, professor and director of the Linus Pauling Institute at Oregon State University, and one of the world’s leading experts on the role of vitamin C in optimum health.

“Significant numbers of people in the U.S. and around the world are deficient in vitamin C, and there’s growing evidence that more of this vitamin could help prevent chronic disease,” Frei said. “The way clinical researchers study micronutrients right now, with the same type of so-called ‘phase three randomized placebo-controlled trials’ used to test pharmaceutical drugs, almost ensures they will find no beneficial effect. We need to get past that.”

Unlike testing the safety or function of a prescription drug, the researchers said, such trials are ill suited to demonstrate the disease prevention capabilities of substances that are already present in the human body and required for normal metabolism. Some benefits of micronutrients in lowering chronic disease risk also show up only after many years or even decades of optimal consumption of vitamin C – a factor often not captured in shorter-term clinical studies.

A wider body of metabolic, pharmacokinetic, laboratory and demographic studies suggests just the opposite, that higher levels of vitamin C could help reduce the chronic diseases that today kill most people in the developed world – heart disease, stroke, cancer, and the underlying issues that lead to them, such as high blood pressure, chronic inflammation, poor immune response and atherosclerosis.

“We believe solid research shows the RDA should be increased,” Frei said. “And the benefit-to-risk ratio is very high. A 200 milligram intake of vitamin C on a daily basis poses absolutely no risk, but there is strong evidence it would provide multiple, substantial health benefits.”

An excellent diet with the recommended five to nine daily servings of fruits and raw or steam-cooked vegetables, together with a six-ounce glass of orange juice, could provide 200 milligrams of vitamin C a day. But most Americans and people around the world do not have an excellent diet.

Even at the current low RDAs, various studies in the U.S. and Canada have found that about a quarter to a third of people are marginally deficient in vitamin C, and up to 20 percent in some populations are severely deficient – including college students, who often have less-than-perfect diets. Smokers and older adults are also at significant risk.

Even marginal deficiency can lead to malaise, fatigue, and lethargy, researchers note. Healthier levels of vitamin C can enhance immune function, reduce inflammatory conditions such as atherosclerosis, and significantly lower blood pressure.

  • A recent analysis of 29 human studies concluded that daily supplements of 500 milligrams of vitamin C significantly reduced blood pressure, both systolic and diastolic. High blood pressure is a major risk factor for heart disease and stroke, and directly attributes to an estimated 400,000 deaths annually in the U.S.
  • A study in Europe of almost 20,000 men and women found that mortality from cardiovascular disease was 60 percent lower when comparing the blood plasma concentration of vitamin C in the highest 20 percent of people to the lowest 20 percent.
  • Another research effort found that men with the lowest serum vitamin C levels had a 62 percent higher risk of cancer-related death after a 12-16 year period, compared to those with the highest vitamin C levels.

Laboratory studies with animals – which may be more accurate than human studies because they can be done in controlled conditions and with animals of identical genetic makeup – can document reasons that could explain all of these findings, Frei said.

Critics have suggested that some of these differences are simply due to better overall diet, not vitamin C levels, but the scientists noted in this report that some health benefits correlate even more strongly to vitamin C plasma levels than fruit and vegetable consumption.

Scientists in France and Denmark collaborated on this report. Research at OSU on these issues has been supported by the National Center for Complementary and Alternative Medicine, a division of the National Institutes of Health.

 

Reference 

Frei B, Birlouez-Aragon I, Lykkesfeldt J. Authors’ Perspective: What is the Optimum Intake of Vitamin C in Humans? Crit Rev Food Sci Nutr 2012; 52 (9): 815-29.

 

Awakenings: Encephalitis lethargica and L-DOPA

This is the remarkable story of a group of patients who contracted sleeping-sickness during the great epidemic just after World War I. Frozen for decades in a trance-like state, these men and women were given up as hopeless until 1969, when Dr. Oliver Sacks gave them the then-new drug L-DOPA, which had an astonishing, explosive, “awakening” effect (the drama film Awakenings 1990).

The following text is an edited excerpt from an article by Foster and Hoffer [2004]:

 

“Encephalitis lethargica is a viral epidemic encephalitis that occurred in many parts of the world between 1915 and 1926. Also known as sleeping sickness or sleepy sickness, those who survived the initial infection typically displayed long term apathy, paralysis of the extrinsic eye muscles and extreme muscular weaknesses [Sacks 1982]. There is still disagreement over which virus was involved in this disease but the disorder often preceded Parkinsonism, suggesting that there must have been similarities in neurological damage. Although little or nothing has been published on the roll of oxidative stress in Encephalitis lethargica, damage by reactive oxygen species has been implicated in other forms of such disorders, as for example in Japanese encephalitis [Liao et al. 2003].”

“In 1969, Sacks [1983] began treating Encephalitis lethargica patients, some of whom had been catatonic for years, with high doses of L-DOPA. The dramatic improvements that followed were later documented in his book Awakenings and in a film of the same name [Sacks 1982, Awakenings 1990].”


Watch Awakenings

“It was discovered through the use of L-DOPA by Parkinson’s disease patients that, although its initial results were dramatically effective, a growing tolerance to it developed. This resulted in a need to increase dosages over time. Eventually side-effects of the drug, such as dyskinesias (abnormal movements), gastrointestinal symptoms, insomnia, hallucinations and even psychosis, became worse than its benefits [Katzenschlager and Lees 2002].”

“A similar picture emerged in the treatment of Encephalitis lethargica patients. Sacks [1982, screenplay Awakenings 1990] described treating 20 such patients with L-DOPA. The initial dose was 500 mg daily but, if required, was increased gradually to 6 g. Many patients showed great early progress, which Sacks termed an Awakening. Unfortunately, this dramatic improvement in health began to reverse. Sacks’ book Awakening first appeared in 1973. By the time his revised 1982 edition was published, seventeen of his patients were dead, mainly from Parkinsonism and all had relapsed. Sacks [1982] describes the experiences of an Encephalitis lethargica patient receiving high dose L-DOPA as follows:

For the first time, then, the patient on L-DOPA enjoys a perfection of being, an ease of movement and feeling and thought, a harmony of relation within and without. Then his happy state – his world – starts to crack, slip, break down, and crumble; he lapses from his happy state, and moves toward perversion and decay.”

“The evidence just presented suggests that dopamine deficiency probably plays an important role, not just in Parkinson’s disease, but also in Encephalitis lethargica” … “However, attempts to correct such deficiencies with L-DOPA, especially at high dosages, while initially beneficial appear to quickly produce a wide range of negative side effects.”

“The most logical interpretation of the L-DOPA experience is that patients with untreated Parkinson’s disease, Encephalitis lethargica” … “all display two distinct types of symptoms. Some of these are due directly to a deficiency of dopamine and are quickly improved by L-DOPA. A second set of symptoms, however, are the result of neurological damage caused by the metabolites of dopamine. The use of L-DOPA, therefore, increases the severity of these symptoms over time until they outweigh any improvement observed from the correction of dopamine deficiency. It is suggested that the damaging side-effects of L-DOPA’s use stem not directly from the drug but from its oxidation products which include dopachrome and other chrome indoles which are hallucinogenic, toxic to neurons and have been seen to hasten death in Parkinsonism patients [Graham 1978, Graham et al. 1978].”

“At least part of the neurological damage seen in Encephalitis lethargica” … “appears to be caused by dopachrome and other chrome indoles, produced by the oxidation of dopamine. The use of L-DOPA in these patients probably accelerates production of such neurotoxins. If this hypothesis is correct, it follows that combining L-DOPA with very high dose antioxidants may permit the beneficial use of this drug”.

… “high doses of natural methyl acceptors, such as thiamin (vitamin B1), riboflavin (vitamin B2), niacin (vitamin B3) and ubiquinone (Coenzyme Q10) should delay disorder progression. This is because they are capable of decreasing the conversion of dopamine to dopachrome and so preventing the toxic impacts of this and other chrome indoles [Hoffer 1998].”

 

References 

Awakenings (1990). Film. Directed by:  Penny Marshall. USA: Columbia Pictures.

Foster HD, Hoffer A (2004)  The two faces of L-DOPA: benefits and adverse side effects in the treatment of Encephalitis lethargica, Parkinson’s disease, multiple sclerosis and amyotrophic lateral sclerosis. Medical Hypotheses 62: 177–181.

Graham DG (1978) Oxidative pathways for catecholamines in the genesis of neuromelanin and cytotoxic quinones. Mol Pharmacol 14 (4): 633–643.

Graham DG, Tiffany SM, Bell WR, Gutknecht WF (1978) Autoxidation versus covalent binding of quinones as the mechanism of toxicity of dopamine, 6-hydroxydopamine, and related compounds towards C1300 neuroblastoma cells in vitro. Mol Pharmocol 14 (4): 644–653.

Hoffer A (1998) Vitamin B-3 Schizophrenia: discovery, recovery, controversy. Quarry Press, Kingston, Ontario.

Katzenschlager R, Lees AJ (2002) Treatment of Parkinson’s disease: levodopa as the first choice. J Neurol 249 (Suppl 2): 19–24.

Liao SL, Raung SL, Chen CJ (2003) Japanese encephalitis virus stimulates superoxide dismutase activity in rat glial cultures. Neurosci Lett 324 (2): 133–136.

Sacks O (1982) Awakenings. Pan Books. London.

Sacks O (1983) The origin of “Awakenings”. Br Med J (Clin Res Ed) 287 (6409): 1968–1969.

 

An Integrative Approach to ADHD (Lecture)

Professor Sanford Newmark, MD, explores in this lecture (2011) the importance of the Integrative Approach-seeing the child in the context of family, friends, school and community, rather than as a set of symptoms that need to be fixed.

Dr. Newmark is a clinical Professor in the Department of Pediatrics at the University of California. He is the head of the Pediatric Integrative Neurodevelopmental Program at the Osher Center for Integrative Medicine, specializing in the treatment of autism, ADHD and other developmental or chronic childhood conditions.

Topics in this lecture include an overview of the genetic, environmental and neurobiological aspects, non-pharmaceutical therapies including nutrition, food sensitivities, vitamin and mineral supplements, parenting, school, and complementary therapies.

 

The Cancer Report

The Cancer Report (2010) catalogs how allopathic medicine established dominance in the early part of the 20th Century, and how natural medicines were arbitrarily banned from the medical profession, despite the basis of this decision being scientifically unsound.

The wholesale transition from natural medicines to chemical ones was based on financial and political reasons, at the expense of the patients. This documentary exposes the carnage of the cancer industry, the financial interests that molded it, and why it is so resistant to change.

“My studies have proven conclusively that untreated cancer victims actually live up to four times longer than treated individuals. For a typical type of cancer, people who refused treatment lived for an average of 12-1/2 years. Those who accepted surgery or other kinds of treatment [chemotherapy, radiation, cobalt] lived an average of only three years.”

— Dr. Hardin Jones, Physiology,
University of California, Berkeley

Read More

 

Garlic Compound Fights Source of Food-Borne Illness Better Than Antibiotics

Researchers at Washington State University have found that a compound in garlic is 100 times more effective than two popular antibiotics at fighting the Campylobacter bacterium, one of the most common causes of intestinal illness. Their work was published recently in the Journal of Antimicrobial Chemotherapy.

Researchers at Washington State University have found that a compound in garlic is 100 times more effective than two popular antibiotics at fighting the Campylobacter bacterium, one of the most common causes of intestinal illness.

The discovery opens the door to new treatments for raw and processed meats and food preparation surfaces.

“This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply,” said Xiaonan Lu, a postdoctoral researcher and lead author of the paper.

“This is the first step in developing or thinking about new intervention strategies,” saif Michael Konkel, a co-author who has been researching Campylobacter jejuni for 25 years.

“Campylobacter is simply the most common bacterial cause of food-borne illness in the United States and probably the world,” Konkel said. Some 2.4 million Americans are affected every year, according to the U.S. Centers for Disease Control and Prevention, with symptoms including diarrhea, cramping, abdominal pain and fever.

The bacteria also are responsible for triggering nearly one-third of the cases of a rare paralyzing disorder known as Guillain-Barré syndrome.

Most infections stem from eating raw or undercooked poultry or foods that have been cross-contaminated via surfaces or utensils used to prepare poultry.

Lu and his colleagues looked at the ability of the garlic-derived compound, diallyl sulfide, to kill the bacterium when it is protected by a slimy biofilm that makes it 1,000 times more resistant to antibiotics than the free floating bacterial cell. They found the compound can easily penetrate the protective biofilm and kill bacterial cells by combining with a sulfur-containing enzyme, subsequently changing the enzyme’s function and effectively shutting down cell metabolism.

The researchers found the diallyl sulfide was as effective as 100 times as much of the antibiotics erythromycin and ciprofloxacin and often would work in a fraction of the time.

Two previous works published last year by Lu and WSU colleagues in Applied and Environmental Microbiology and Analytical Chemistry found diallyl sulfide and other organosulfur compounds effectively kill important food-borne pathogens, such as Listeria monocytogenes and Escherichia coli O157:H7.

Konkel cautioned that the recent work is still at the basic stage, well removed from an actual application. While eating garlic is a generally healthy practice, it is unlikely to prevent Campylobacter-related food poisoning.

However, “diallyl sulfide may be useful in reducing the levels of the Campylobacter in the environment and to clean industrial food processing equipment, as the bacterium is found in a biofilm in both settings,” he said.

“Diallyl sulfide could make many foods safer to eat”, said Barbara Rasco, a co-author on all three recent papers and Lu’s advisor for his doctorate in food science. “It can be used to clean food preparation surfaces and as a preservative in packaged foods like potato and pasta salads, coleslaw and deli meats.”

“This would not only extend shelf life but it would also reduce the growth of potentially bad bacteria,” she said.

 

Reference
Lu X, Samuelson DR, Rasco BA, Konkel ME. Antimicrobial effect of diallyl sulphide on Campylobacter jejuni biofilms. J Antimicrob Chemother. 2012 May 1. [Epub ahead of print]

 

Researchers Show Prebiotic Can Reduce Severity of Colitis

MSU food science and human nutrition researcher Jenifer Fenton

Researchers at Michigan State University have shown a prebiotic may help the body’s own natural killer cells fight bacterial infection and reduce inflammation, greatly decreasing the risk of colon cancer.

Prebiotics are fiber supplements that serve as food for the trillions of tiny bacteria living in the gut. When taken, they can stimulate the growth of the “good” bacteria. The evolution of prebiotic supplements (as well as probiotics, which are actual bacteria ingested into the system) provide new therapeutic targets for researchers and physicians.

In research published in the Journal of Nutrition, MSU’s Jenifer Fenton reports that mice given the prebiotic galacto-oligosaccharide, or GOS, saw the severity of their colitis (one of the main forms of inflammatory bowel disease) significantly reduced.

In fact, the mice fed GOS – a synthetic compound that is known to stimulate beneficial bacteria and is found in foods such as biscuits and infant formula – saw a 50 percent reduction in colitis.

Research has shown certain types of foods and fibers can reduce colon cancer risk, said Fenton of the Department of Food Science and Human Nutrition.

“There is something unique about certain types of fibers, such as GOS, and how they alter cells and influence the immune system to change disease risk, either for the good or bad,” she said. “Our overall goal is to identify either dietary patterns or diet components to reduce inflammation and cancer risk.

“In this case, we used prebiotics to stimulate changes in bacteria in the gut that may have a beneficial impact on the colon.”

Fenton worked closely on the project with Elizabeth Gardner, also with the Department of Food Science and Human Nutrition and who previously has looked at the impact diet plays in fighting off the flu. In applying some of the lessons learned in those studies to mice with bacterially induced colitis, the researchers found mice given GOS had significantly less inflammation and fewer abnormal cells, two precursors for colon cancer.

It appeared, Fenton said, the positive results were linked to the significant enhancement of the body’s own natural killer cells, found in the immune system and crucial in fighting off new infections in the body.

“Our results suggest GOS may be effective in reducing colitis severity by priming the innate immune system,” she said.

The next step is to verify how that mechanism works; finding that link could help researchers apply the lessons learned to other intestinal ailments.

 

References

Gopalakrishnan A, Clinthorne JF, Rondini EA, McCaskey SJ, Gurzell EA, Langohr IM, Gardner EM, Fenton JI. Supplementation with Galacto-Oligosaccharides Increases the Percentage of NK Cells and Reduces Colitis Severity in Smad3-Deficient Mice. 2012 Apr 11. [Epub ahead of print]

Department of Food Science & Human Nutrition, Michigan State University (06.06.2012)

 

Is Your Child’s Brain Starving? (Lecture)

Food, Not Drugs for Life and Learning: 

This is a lecture (2007) on how diet can contribute to attention deficit hyperactivity disorder (ADHD) by Dr. Michael R. Lyon, MD. He is an Adjunct Professor at the University of British Columbia’s Food, Nutrition and Health Program. Dr. Lyon is also a member of the Expert Advisory Committee for Health Canada’s Natural Health Products Directorate, as well as Medical and Research Director of the Canadian Centre for Functional Medicine.

Dr. Lyon has designed and conducted numerous clinical trials on natural health products. His extensive clinical research also includes the development of treatment strategies for children with learning and behavioural difficulties, as well as ADHD. Two of Michael R. Lyon’s published works include: Is Your Child’s Brain Starving? Food Not Drugs for Life and Learning and How to Prevent and Treat Diabetes with Natural Medicine.

Beehive Extract Shows Potential as Prostate Cancer Treatment

Proteomics reveals how ancient remedy slows prostate tumor cell proliferation: 

An over-the-counter natural remedy derived from honeybee hives arrests the growth of prostate cancer cells and tumors in mice, according to a new paper from researchers at the University of Chicago Medicine.

Caffeic acid phenethyl ester, or CAPE, is a compound isolated from honeybee hive propolis, the resin used by bees to patch up holes in hives. Propolis has been used for centuries as a natural remedy for conditions ranging from sore throats and allergies to burns and cancer. But the compound has not gained acceptance in the clinic due to scientific questions about its effect on cells.

In a paper published in Cancer Prevention Research, researchers combined traditional cancer research methods with cutting-edge proteomics to find that CAPE arrests early-stage prostate cancer by shutting down the tumor cells’ system for detecting sources of nutrition.

“If you feed CAPE to mice daily, their tumors will stop growing. After several weeks, if you stop the treatment, the tumors will begin to grow again at their original pace,” said Richard B. Jones, PhD, assistant professor in the Ben May Department for Cancer Research and Institute for Genomics and Systems Biology and senior author of the study. “So it doesn’t kill the cancer, but it basically will indefinitely stop prostate cancer proliferation.”

Natural remedies isolated from plant and animal products are often marketed as cure-alls for a variety of maladies, usually based on vague antioxidant and anti-inflammatory claims. While substances such as ginseng or green tea have been occasionally tested in laboratories for their medicinal properties, scientific evidence is commonly lacking on the full biological effects of these over-the-counter compounds.

“It’s only recently that people have examined the mechanism by which some of these herbal remedies work,” Jones said. “Our knowledge about what these things are actually doing is a bit of a disconnected hodge-podge of tests and labs and conditions. In the end, you’re left with a broad, disconnected story about what exactly these things are doing and whether or not they would be useful for treating disease.”

To study the purported anti-cancer properties of CAPE, first author Chih-Pin Chuu (now at the National Health Research Institutes in Taiwan) tested the compound on a series of cancer cell lines. Even at the low concentrations expected after oral administration, CAPE successfully slowed the proliferation of cultured cells isolated from human prostate tumors.

CAPE was also effective at slowing the growth of human prostate tumors grafted into mice. Six weeks of treatment with the compound decreased tumor volume growth rate by half, but when CAPE treatment was stopped, tumor growth resumed its prior rate. The results suggested that CAPE stopped cell division rather than killing cancerous cells.

To determine the cellular changes that mediated this effect, the researchers then used an innovative proteomics technique invented by Jones and colleagues called the “micro-western array.” Western blots are a common laboratory tool used to measure the changes in protein levels and activity under different conditions. But whereas only one or a few proteins at a time can be monitored with Western blots, micro-western arrays allow researchers to survey hundreds of proteins at once from many samples.

Chuu, Jones and their colleagues ran micro-western arrays to assess the impact of CAPE treatment on the proteins of cellular pathways involved in cell growth – experiments that would have been prohibitively expensive without the new technique.

“What this allowed us to do is screen about a hundred different proteins across a broad spectrum of signaling pathways that are associated with all sorts of different outcomes. You can pick up all the pathways that are affected and get a global landscape view, and that’s never been possible before,” Jones said. “It would have taken hundreds of Westerns, hundreds of technicians, and a very large amount of money for antibodies.”

The micro-western array results allowed researchers to quickly build a new model of CAPE’s cellular effects, significantly expanding on previous work that studied the compound’s mechanisms. Treatment with CAPE at the concentrations that arrested cancer cell growth suppressed the activity of proteins in the p70S6 kinase and Akt pathways, which are important sensors of sufficient nutrition that can trigger cell proliferation.

“It appears that CAPE basically stops the ability of prostate cancer cells to sense that there’s nutrition available,” Jones said. “They stop all of the molecular signatures that would suggest that nutrition exists, and the cells no longer have that proliferative response to nutrition.”

The ability of CAPE to freeze cancer cell proliferation could make it a promising co-treatment alongside chemotherapies intended to kill tumor cells. Jones cautioned that clinical trials would be necessary before CAPE could be proven effective and safe for this purpose in humans. But the CAPE experiments offer a precedent to unlock the biological mechanisms of other natural remedies as well, perhaps allowing these compounds to cross over to the clinic.

“A typical problem in bringing some of these herbal remedies into the clinic is that nobody knows how they act, nobody knows the mechanism, and therefore researchers are typically very hesitant to add them to any pharmaceutical treatment strategy,” Jones said. “Now we’ll actually be able to systematically demonstrate the parts of cell physiology that are affected by these compounds.”

 

Reference

Chuu CP, Lin HP, Ciaccio MF, Kokontis JM, Hause RJ, Hiipakka RA, Liao S, Jones RB. Caffeic acid phenethyl ester suppresses the proliferation of human prostate cancer cells through inhibition of p70S6K and Akt signaling networks. Cancer Prev Res 2012; 5: 788-797.

 

Vitamin E in Diet Protects Against Many Cancers

Researchers find form commonly used in supplements has no such benefit. 

Vitamin E in vegetable oils and nuts prevents cancer, according to research done at Rutgers University and the Cancer Institute of New Jersey.

Next time you need to choose between vegetable oil and margarine in that favorite recipe, think about your health and reach for the oil.

While the question of whether vitamin E prevents or promotes cancer has been widely debated in scientific journals and in the news media, scientists at the Center for Cancer Prevention Research, at Rutgers Mario School of Pharmacy, and the Cancer Institute of New Jersey, believe that two forms of vitamin E – gamma and delta-tocopherols – found in soybean, canola and corn oils as well as nuts do prevent colon, lung, breast and prostate cancers.

“There are studies suggesting that vitamin E actually increases the risk of cancer and decreases bone density,” says Chung S. Yang, director of the center. “Our message is that the vitamin E form of gamma-tocopherols, the most abundant form of vitamin E in the American diet, and delta-tocopherols, also found in vegetable oils, are beneficial in preventing cancers while the form of vitamin E, alpha- tocopherol, the most commonly used in vitamin E supplements, has no such benefit.”

Director of the Center for Cancer Prevention Research at Rutgers Ernest Mario School of Pharmacy

Yang and colleagues, Nanjoo Suh and Ah-Ng Tony Kong, summarized their findings recently in Cancer Prevention Research, a journal of the American Association for Cancer Research. In a Commentary, Does Vitamin E Prevent or Promote Cancer? the Rutgers scientists discuss animal studies done at Rutgers as well as human epidemiological studies that have examined the connection between vitamin E and cancer.

Yang says Rutgers scientists conducting animal studies for colon, lung, breast and prostate cancer found that the forms of vitamin E in vegetable oils, gamma and delta-tocopherols, prevent cancer formation and growth in animal models.

“When animals are exposed to cancer-causing substances, the group that was fed these tocopherols in their diet had fewer and smaller tumors,” Yang says. “When cancer cells were injected into mice these tocopherols also slowed down the development of tumors.”

In researching colon cancer, Yang pointed to another recently published paper in Cancer Prevention Research indicating that the delta-tocopherol form of vitamin E was more effective than other forms of vitamin E in suppressing the development of colon cancer in rats.

This is good news for cancer research. Recently, in one of the largest prostate cancer clinical trials in the United States and Canada, scientists found that the most commonly used form of vitamin E supplements, alpha-tocopherol, not only did not prevent prostate cancer, but its use significantly increased the risk of this disease among healthy men.

This is why, Yang says, it is important to distinguish between the different forms of vitamin E and conduct more research on its cancer preventive and other biological effects.

“For people who think that they need to take vitamin E supplements,” Yang says, “taking a mixture of vitamin E that resembles what is in our diet would be the most prudent supplement to take.”

 

Reference

Yang CS, Suh N, Kong AN. Does Vitamin E Prevent or Promote Cancer? Cancer Prev Res (Phila). 2012 Apr 16. [Epub ahead of print]

 

How Probiotic Bacteria Protect Against Inflammatory Bowel Diseases

A glimpse through the laser microscope – green indicates the presence of inflammatory messenger substances (chemokines) in the bowel tissue. Picture: TUM

Some lactic acid bacteria can alleviate inflammation and therefore prevent intestinal disorders. Scientists have now decoded the biochemical mechanism that lies behind the protective effect of the bacteria. In experiments with mice, the researchers succeeded in demonstrating that lactocepin – an enzyme produced by certain lactic acid bacteria – selectively degrades inflammatory mediators in diseased tissue. This new evidence might lead to new approaches for the treatment of inflammatory bowel diseases.

Yoghurt has been valued for centuries for its health-promoting effects. These effects are thought to be mediated by the lactic acid bacteria typically contained in yoghurt. Evidence from recent scientific studies show that some bacterial strains actually have a probiotic effect and can thus prevent disease. A team of biologists and nutrition scientists working with Prof. Dirk Haller from the Technische Universitaet Muenchen (TUM) has now discovered the mechanisms at work behind this protective effect (Cell Host & Microbe).

In experiments with mice, the scientists observed that lactocepin – an enzyme produced from the lactic acid bacterium Lactobacillus paracasei – can selectively interrupt inflammatory processes. As the scientists observed, lactocepin degrades messengers from the immune system, known as chemokines, in the diseased tissue. As a part of the “normal” immune response, chemokines are needed to guide defense cells to the source of the infection. In chronic intestinal disorders like Crohn’s disease and ulcerative colitis, the otherwise highly effective defense mechanism against infectious agents is malfunctioning. Chemokines such as “IP-10” then contribute to the tissue damage due to chronic inflammatory processes,  preventing the tissue from healing.

“Lactocepin is a familiar element in food technology research,” says Prof. Dirk Haller, who holds the Chair for Biofunctionality of Food at the TUM. “What is surprising, however, is its biomedical effect, namely the force with which the enzyme attacks and degrades very specific inflammatory mediators.” Haller is certain that, based on this mechanism, it will be possible to develop new approaches to the targeted prevention and treatment of chronic bowel diseases as well as skin disorders: “The anti-inflammatory effect of lactocepin is limited to specific areas and up to now it has no known side effects.”

The scientist therefore plans to carry out clinical studies in order to test the possible pharmaceutical application of the enzyme. Questions also remain to be answered in relation to the “production” of lactocepin by lactic acid bacteria. Some bacterial strains, such as Lactobacillus paracasei, produce highly potent lactocepins; however, the effectiveness of other microorganisms has not yet been proven. Dirk Haller therefore warns against false promises: “Not every product labeled as ‘probiotic’ actually earns this name.”

Reference 
von Schillde MA, Hörmannsperger G, Weiher M, Alpert CA, Hahne H, Bäuerl C, van Huynegem K, Steidler L, Hrncir T, Pérez-Martínez G, Kuster B, Haller D. Lactocepin Secreted By Lactobacillus Exerts Anti-Inflammatory Effects By Selectively Degrading Proinflammatory Chemokines. Cell Host & Microbe 2012; 11 (4): 387–396.