News Briefs – March 2009

VITAMIN C LINKED TO LOWER BLOOD PRESSURE

A study in young adult women links high blood levels of vitamin C with lower blood pressure. This “strongly suggests that vitamin C is specifically important in maintaining a healthy blood pressure,” said lead author Dr. Gladys Block, of the University of California, Berkeley, in an interview with News Briefs.
Previous research linked high plasma levels of vitamin C with lower blood pressure among middle-age and older adults, typically those with higher than optimal blood pressure readings, Block and colleagues report in the December 17, 2009 issue of Nutrition Journal.
The current study involved 242 black and white women, between 18 and 21 years old, with normal blood pressures, who were participants in the National Heart, Lung and Blood Institute Growth and Health Study. The girls had entered the trial when they were 8 to 11 years old. Over a 10-year period, their plasma levels of ascorbic acid (vitamin C) and blood pressure were monitored.
At year 10, Block and her colleagues found that blood pressure, both the systolic and diastolic (top and bottom reading), was inversely associated with ascorbic acid levels. In other words, more vitamin C, lower numbers.
Specifically, women with the highest levels of ascorbic acid had a decline of about 4.66 mm Hg in systolic and 6.04 mm Hg in diastolic blood pressure compared with women with the lowest ascorbic acid levels. This difference still held true after researchers allowed for differences in body mass, race, education levels, and dietary fat and sodium intake.
Women with the lowest levels of plasma ascorbic acid likely consumed average amounts of fruits, vegetables, and fortified foods while those with the highest plasma ascorbic acid levels likely ate diets rich in fruits and vegetables or took multivitamins or vitamin C supplements, the researchers note.
Further analyses of vitamin C and blood pressure changes over the previous year, “also strongly suggested that the people with the highest blood level of vitamin C had the least increase in blood pressure,” Block said.
Since these findings imply a possible association between vitamin C and blood pressure in healthy young adults, Block and colleagues call for further investigations in this population.

HONEY – NATURAL PRESERVATIVE: STUDY

Antioxidant-rich honey is a healthy alternative to chemical additives and refined sweeteners in commercial salad dressings, said a new University of Illinois study.
“To capitalize on the positive health effects of honey, we experimented with using honey in salad dressings,” said Nicki Engeseth, an associate professor of food chemistry at U of I, in an interview with News Briefs. “We found that the antioxidants in honey protected the quality of the salad dressings for up to nine months while sweetening them naturally.”
Engeseth’s study substituted honey for EDTA, an additive used to keep the oils in salad dressings from oxidizing, and high-fructose corn syrup, used by many commercial salad-dressing producers to sweeten their salad dressing recipes.
“We chose clover and blueberry honeys for the study after an analysis of the sweetening potential, antioxidant activity, and phenolic profiles of 19 honeys with varying characteristics,” said the scientist.
The dressings were also compared to a control dressing that contained ingredients found in current commercial salad dressings, she said.
Why do manufacturers usually avoid using honey in salad dressings? Engeseth explained a problem the scientists encountered in using honey in a salad dressing system. “Salad dressings are emulsions – they contain oil and water; and to keep these ingredients together in one phase, manufacturers rely on emulsifiers and thickening agents to avoid thinning of the dressing and separation of the oil and water phase,” she said. When the researchers found that enzymes in the honey broke the emulsion by attacking the starch that was used to thicken the dressing, they came up with a new formulation that used xanthan gum as a thickening agent, which they then used in all the dressings, she said.
The researchers then stored the dressings under various conditions, including 37 degrees Celsius (accelerated storage) for six weeks and 23 degrees Celsius and 4 degrees Celsius for one year, followed by an evaluation of their oxidative stability.
“After nine months of storage, both types of honey were as effective as EDTA in protecting against oxidation or spoilage. Blueberry honey performed slightly better than clover,” she said.
Engeseth said that many consumers prefer products with natural ingredients and that salad dressings made with honey should appeal to these consumers.
“There’s such a wide range of salad dressings on the market – some unique salad dressings as well as inexpensive products that perform beautifully. If manufacturers are interested in developing salad dressings that have a healthy twist, we’ve demonstrated that using honey as both an antioxidant and a sweetener is one way to do this,” she said. 

UV TEETH WHITENING COMES WITH RISK

Ultraviolet (UV) light-enhanced tooth bleaching is not only “a con,” but is dangerous to your eyes and skin, says the February 2009 issue of one of the Royal Society of Chemistry’s journals. The light treatment gives absolutely no benefit over bleaching without UV, and damages skin and eyes up to four times as much as sunbathing, reports a study in Photochemical & Photobiological Sciences.
While some natural sunlight is important for the body’s production of vitamin D, the UV-dental treatment is at least as damaging to skin and eyes as sunbathing at the beach for a midsummer afternoon – one lamp actually gave four times that level of radiation exposure. And as with sunbathing, fair-skinned or light-sensitive people are at even greater risk, said lead author Ellen Bruzell of the Nordic Institute of Dental Materials.
Bruzell also found the same thing with bleaching damaged teeth. She saw more exposed grooves on the enamel surface of bleached teeth than on unbleached teeth. These grooves make the teeth more vulnerable to mechanical stress.
Tooth bleaching is one of the most popular cosmetic dental treatments available. It uses a bleaching agent – usually hydrogen peroxide – to remove stains such as those from red wine, tea and coffee and smoking. UV light, however, is claimed to further activate the oxidation process, improving bleaching efficiency. The authors of the Photochemical & Photobiological Sciences article say there is very little substantive evidence to support this latter claim, and their new study finds no benefit to using UV light.

STATIN DRUGS DO NOT PREVENT CANCER

Laboratory work in animals showed limited activity when statins were given to prevent breast cancer, according to a report in the February, 2009 issue of Cancer Prevention Research, a journal of the American Association for Cancer Research.
Statins, sold under brand names like Lipitor and Zocor, are primarily given to lower cholesterol and prevent heart disease but the use of these drugs in cancer prevention has been more controversial. Results of epidemiology studies – which rely on looking backward rather than forward and thus are subject to confounding factors – have yielded mixed results when examining breast cancer.
Scientists under the auspices of the National Cancer Institute conducted laboratory work in animals to determine if statins actually prevent (both ER-positive and ER-negative) breast cancer. In the current study, scientists tested atorvastatin and lovastatin.
“We saw no real efficacy from either statin,” said Lubet in an e-mail interview with Vitality’s News Briefs. “Prior studies have shown some but limited efficacy in breast cancer models when these drugs were given through a method that would be the equivalent of intravenously in humans. However, that is not the way people take statins.”
Lubet said the research into statin use and cancer prevention would continue. “There is always the question of whether there will be a subset of breast cancer where this class of agents will be effective, but the answer at this point is that the present preclinical studies do not support the use of statins as general breast cancer preventive agents,” said Lubet.

NEWSNOTES

• Child abuse ‘alters stress gene’: Abuse in early childhood permanently alters how the brain reacts to stress, a Canadian study suggests. Analysis of brain tissue, at Institute of Psychiatry at Kings College London, from adults who had committed suicide found key genetic changes in those who had suffered abuse as a child. It affects the production of a receptor known to be involved in stress responses, the researchers said. The current issue of Nature Neuroscience study underpins the impact of stress on early brain development, experts said.

• B vitamins reduce strokes: According to a new Canadian study, people with heart disease who take high doses of B vitamins are somewhat less likely to suffer from stroke, especially if they’re under age 70. The findings were reported February 19, 2009, at the American Stroke Association’s International Stroke Conference in San Diego.

• Tea lowers stroke risk: New study findings presented at the American Heart Association’s International Stroke Conference on February 19th suggest that regardless of country of origin or type of tea consumed – black or green – the consumption of three cups of tea per day lowers stroke risk. Tea is associated with an average 21 per cent lower risk of ischemic stroke compared to non tea drinkers. (There remains some controversy about whether the addition of milk to tea eliminates the benefit.)

• Lack of vitamin D causes obesity: According to a study on 90 women aged 16 to 24, conducted by scientists from McGill University Health Centre (MUHC) in Hamilton, and at the University of Southern California, a low vitamin D level in blood can cause shortness in height (stunted growth) and high body mass index (obesity).

• Alzheimer’s risk from ‘extreme’ power lines? Older people living within 50 meters of major power lines are at increased risk of dying from Alzheimer’s disease or senile dementia, research from Switzerland shows. The risk increased steadily with the amount of time a person had been living in close proximity to a 220-380 kV power line, says Anke Huss, PhD, of the University of Bern and her colleagues. These lines are extra-high voltage lines used for long-distance transmission of large amounts of electricity, not the normal lines running along Toronto streets. Household appliances such as radio alarm clocks can produce magnetic fields similar to those emitted by power lines, the researcher pointed out, but reducing risk is a simple matter of avoiding being very close to such devices for long periods; for example, not sleeping with your head close to a radio alarm clock or keeping an electric blanket on all night long. At present, the researcher admitted, there is no accepted biological mechanism to explain why magnetic fields might increase Alzheimer’s risk.

• Diabetes rates soar: The UK is seeing an explosion of diabetes linked to growing obesity rates, experts are warning. From 1997 to 2003 there was a 74 per cent rise in new cases of diabetes. And by 2005, more than 4 per cent of the population was classed as having diabetes – nearly double the rate of 10 years earlier. The bulk of cases are type 2 diabetes – which is linked to lifestyle, especially to being overweight or obese – the February 2009 issue of the Journal of Epidemiology and Community Health reports.

• Tanning injections risky: Repeated warnings about so-called tan jabs appear to be going unheeded, some experts believe. An increasing number of people are receiving injections of a substance meant to produce a natural all-over tan. Melanotan is a synthetic hormone which stimulates the body’s production of melanin, the substance which gives the skin its colour. On February 18, 2009, an article on the British Medical Journal website warned that using melanotan I and II could damage the immune and cardiovascular systems, as well as triggering other problems.

• Grapes and blood pressure: According to an article published in the February, 2009 edition of the Journal of Gerontology: Biological Sciences, grapes help lower blood pressure and improve heart function in lab rats fed an otherwise salty diet. (Research on humans is needed to draw conclusions.)

• Second hand smoke affects dementia risk: Using new methods in the largest clinical trial to date, a team led by Cambridge University professor David Llewellyn found that even people who had never smoked but kept constant company with smokers performed less well in cognitive tests, suggesting a risk for dementia. (The higher risk for actual, first-hand smokers was already known.)

• Cause of teen obesity? Parents: There may be a reason teenagers eat more burgers and fries than fruits and vegetables: their parents. In a new policy brief released today by the UCLA Center for Health Policy Research, researchers found that adolescents are more likely to eat at least five servings of fruits and vegetables a day if their parents do. Contrarily, teens whose parents eat fast food or drink pop are more likely to do the same.

HEALTH NOTES

Are those plums genetically modified? Here’s how to tell.

Here’s what you should look for: Find a plum among the stack that has a small sticker on it.

• A four-digit number means the produce is conventionally grown.
• A five-digit number beginning with 9 means it’s organic.
• A five-digit number beginning with 8 means it is GM.

This method won’t always work if the food is Canadian-grown or lacks stickers altogether; but most plums are imported from the US and carry a sticker.

Staying fit in an economic downturn

Tough economic times are causing many people to tighten the belt on personal finances. But trimming fat from the budget, such as cancelling gym memberships, doesn’t have to lead to an expanding waistline. Experts at Dana-Farber Cancer Institute offer the following free and low-cost strategies to help maintain good health as well as possibly reduce various cancer risks.

• Get walking. Use the stairs rather than an elevator.
• Walk or ride a bike, rather than driving.
• Take an exercise break or quick walk at work.
• Play a team sport.
• Use a stationary bicycle or treadmill, while watching TV
• An apple a day: A diet that is low in processed sugars, red meat and calories, but high in fruits and vegetables and loaded with antioxidants is one of the simplest ways to help maintain a healthy weight and reduce the risk of certain cancer.
• Butt out: Buying cigarettes and other tobacco products can really take a bite out of a budget. Kicking the habit can result in both a healthy lifestyle and a significant financial savings.
• Follow the 4 Ds: deep breaths; drink water; do something to de-focus from cigarettes and delay reaching for a smoke—the urge will pass.
• Limit alcohol intake. It saves money, keeps weight low and lowers the risk of cancer.