Vitamin Information Center

Despite great advances in medicine, cancer is still a very common disease. At current rates, more than a third of us will suffer from cancer during our lifetime and about one in four of us will die from it. According to the American Cancer Society, 7.6 million people worldwide died from cancer in 2007.

Research statistics report that 30 to 40% of cancers are directly linked to nutrition, which shows the importance of a healthy diet in cancer prevention. Meanwhile, scientists continue to investigate foods known to be anti-carcinogenic in order to develop strategies for both cancer prevention (chemoprevention) and treatment (chemotherapy). As Hippocrates said over 2000 years ago, “Let food be thy medicine.”

The problem with current chemotherapeutic treatments is that most are not completely selective for carcinogenic cells—they harm normal cells too—and decrease the quality of life for cancer patients. Scientists are hoping that by developing chemopreventive or chemotherapeutic agents based on natural micronutrients, they will be able to develop drugs that target cancer cells with less or no harm to normal cells.

Vitamin E is an important antioxidant micronutrient. Research shows that vitamin E not only improves skin health, boosts the immune system, protects against heart disease, aging and Alzheimer’s, but also has a role in protection against some types of cancer. Unlike some vitamins, which consist of a single compound, vitamin E consists of eight different compounds, four tocopherols and four tocotrienols. Our food contains all eight compounds. Tocopherols are most commonly found in nuts and vegetable oils, whereas tocotrienols are primarily derived from palm oil, oat, rye, wheat germ, barley and rice bran.

Even though the vitamin E family consists of 8 members, most research has traditionally focused on alpha-tocopherol. Alpha-tocopherol is the most abundant form of vitamin E in the plasma and tissue of humans as well as in vitamin supplements, while the seven other types of vitamin E were greatly ignored for many years. Recent research over the last few years has led to the conclusion that the eight vitamin E compounds have different anti-carcinogenic potencies which need to be considered.

The cancer preventive properties of vitamin E were first suspected when studies showed that people in the Mediterranean area who consume diets rich in vitamin E have a lower risk of colon cancer than people in Northern Europe and the U.S. (Eur J Clin Nutr. 1989; 43:49-55, Cancer Causes Control. 1995; 6:525-31.) More recently, the Melbourne Colorectal Cancer Study showed that dietary vitamins E and C were protective for both colon and rectal cancer, and that for both vitamins there was a dose-response effect of increasing protection. (Nutr Cancer. 2006; 56:11-21.)

Another clinical study supported a preventive effect of vitamin E in the development of prostate cancer. This study included over 29,000 elderly male smokers and showed that those taking vitamin E for six years had 32% fewer diagnoses of prostate cancer and 41% fewer prostate cancer deaths than men who did not take vitamin E. (J Natl Cancer Inst. 1998; 90:440-446.) The ongoing NIH sponsored Selenium and Vitamin E Cancer Prevention Trial (SELECT) is investigating selenium and vitamin E for prostate cancer prevention based on the encouraging results of earlier studies.

In the past few years most of the research has focused on structural variations of the natural forms of vitamin E with the aim of developing the anti-carcinogenic potency of these agents. The scientific community is hoping to take some of the synthetic derivatives to clinical trials, so it will be interesting to see if any of these compounds will be eventually developed into chemopreventive or chemotherapeutic agents.

But you should be aware that all vitamin E supplements are NOT created equal. Many contain synthetic vitamin E, and many do not contain all of the various types of natural vitamin E that the body requires. Make certain that your supplement contains both natural tocopherols and tocotrienols in their natural forms if you want to get the most out of what vitamin E has to offer. Only products that contain the complete vitamin E family—tocopherols plus tocotrienols—provide the full spectrum of benefits of vitamim E.

The Anti-Aging Bottom Line: A careful examination of the research performed so far on vitamin E and cancer leads me to conclude that vitamin E possesses strong anti-carcinogenic properties. While food is by far the preferred source of vitamin E, it is practically impossible to get protective amounts of vitamin E from food alone. Therefore, I feel that taking supplemental vitamin E is absolutely essential to achieving vibrant health and longevity.

Patients turn to alternatives
As many as 61 percent of cancer patients use complementary therapies such as prayer, relaxation, meditation and massage, researchers from the American Cancer Society report.

For the study, published in the Sept. 1 issue of Cancer, researchers collected data on 4,139 cancer survivors. Of these, 61.4 percent of the patients used prayer; 44.3 percent used relaxation techniques; 42.4 percent used faith/spiritual healing; 40.1 percent used nutritional supplements such as vitamins; 15 percent used meditation; 11.2 percent used massage; and 9.7 percent participated in support groups.

On the other hand, only 0.4 percent of the patients used hypnosis; 1 percent used biofeedback therapy; and 1.2 percent used acupressure or acupuncture.

The benefits of these therapies are still unclear, researchers said.

Older neighborhoods good for you
People who live in older neighborhoods appear less likely to be overweight, according to a new study. The key, the researchers say, is walkability. Older communities encourage people to drive less and walk more, they said, because they tend to have better sidewalks, shady trees and businesses nearby to walk to.

The study, which is to appear in the September issue of The American Journal of Preventive Medicine, looked at the fitness and address information of more than 450,000 residents of Salt Lake County in Utah. With each extra decade of a neighborhood’s age, the researchers said, the risk of obesity was 13 percent lower for men and 8 percent lower for women.

Vitamin C used against cancer
New research with mice suggests that intravenous doses of vitamin C could one day reduce the size of cancerous tumors in people. The findings are preliminary and still must be confirmed in humans.

In the study, published in the Proceedings of the National Academy of Sciences, researchers found that intravenous vitamin C produced hydrogen peroxide, which reduced cancerous tumors in the mice by 43 percent to 51 percent.

A new study by the National Cancer Institute has found that people with one or more chronic illness are the primary factor behind the use of dietary supplements. Cancer survivors also contribute to the use of supplements, although not specifically as cancer treatments.

Dr. Melissa Farmer Miller, the study’s lead author, told Reuters that its important for cancer patients to inform their physicians about any non-prescription medications or natural products they may be taking, as a lack of information exists on the risks and benefits of many supplements. In addition, there may be potential for drug interactions with medications, such as tamoxifen, that many cancer survivors may be taking.

“We really are just beginning to build an evidence base on the benefits of dietary supplements,” said Miller, of the National Cancer Institute in Bethesda, Maryland.

“Even if there’s not a benefit, there is a potential for them to cause harm,” she said, noting that the use of supplements is growing among all Americans.

To determine whether cancer survivors are using supplements at greater rates than the general population, Miller and her team analyzed information from 1,844 cancer survivors and compared it with a random sampling of 7,343 people with no history of cancer.

The team found that vitamins were the only type of supplement use independently associated with having a cancer diagnosis. However, those participants with a  chronic illness were 82 percent more likely than those without a chronic disease to be using two or more supplements, regardless of whether or not they also had cancer.

Other factors associated with the use of dietary supplements were greater physical activity, consumption of fruits and vegetables, being female, being of older age and the use of other alternative and complementary medicines.

Miller said it was not possible at this time to conclude whether or not people living with cancer should either take supplements, or avoid them.

“The primary message should always be to promote a healthy diet,” she said.

She said that doctors and other cancer patient caregivers should be up to date on the literature about various supplements, and should be aware of any supplements their patients may be taking. Cancer patients should also be informed as much as possible about any supplement before they take it, Miller added, noting that it can often be tough due to the lack of regulatory oversight of dietary supplements in the U.S. and the  limited information available on their risks and benefits.

“Consumers are really kind of out there on their own, and should confer with their health care providers about supplement use.”

Dr. Miller‘s report was published in the March 2008 issue of the Journal of the American Dietetic Association.

A summary of the report can be viewed at http://www.adajournal.org/article/S0002-8223(07)02206-7/abstract.

Ghrelin regulates hunger pangs

High levels of the “hunger hormone” ghrelin have an antidepressant effect, US researchers claim.

Blocking the body’s response to ghrelin has been suggested as a weight loss treatment but it may also produce unintended effects on mood, they said.

The Nature Neuroscience study found mice with increased levels of the hormone showed fewer signs of depression and anxiety.

Experts said the idea was interesting but further studies were needed.

Ghrelin is released by the empty stomach into the bloodstream before moving to the brain, where it triggers feelings of hunger.

Treatment with the hormone itself - or a drug designed to cancel its effects - might be able to help both people who are eating too little, such as cancer patients, or those who eat too much, researchers believe.

In the latest study, Dr Jeffrey Zigman and colleagues restricted the food intake of laboratory mice for 10 days, causing their ghrelin levels to quadruple.

Compared with mice who had free access to food, the calorie-restricted mice showed lower levels of depression and anxiety when subjected to mazes and other behaviour tests.

Hormone response

The team also looked at mice genetically engineered to be unable to respond to ghrelin.

When they were fed a restricted-calorie diet they did not experience the antidepressant or anti-anxiety effects.

The researchers found the same thing when they induced higher ghrelin levels by subjecting the mice to stress.

Those mice that could not respond to ghrelin had greater levels of depression-like symptoms than the normal mice.

“Our findings in mice suggest that chronic stress causes ghrelin levels to go up, and that behaviours associated with depression and anxiety decrease when ghrelin levels rise,” said Dr Zigman, a researcher at UT Southwestern Medical Center in Dallas.

“An unfortunate side effect, however, is increased food intake and body weight,” he added.

He said the results made sense from an evolutionary standpoint, as hunter-gatherers may have had a survival advantage in remaining calm and collected in times of hunger in order for them to successfully find food.

The researchers are now hoping to look at the antidepressant effect of the hormone in conditions such as anorexia.

Professor Stephen Bloom, an expert in appetite regulation at Imperial College London, said it was reasonable to believe that ghrelin had an impact on behavioural responses other than just hunger.

But he said there was a lot of research to be done before it could be confirmed that a hormone released in the stomach can have an effect on mood in the brain.

“The role of ghrelin in the gut and in the brain are likely to be completely different,” he said.

New research has suggested that vitamin C could be effective in curing cancer.

Doctors reported yesterday that three cancer patients who were given large intravenous doses over a period of several months had their tumours shrunk and their lives extended.
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