News Briefs – April 2013
Vegetarian Diet Lowers Risk of Heart Disease by a Third
New research shows that those who adhere to a vegetarian diet have a 32% lower risk of hospitalization or death from cardiovascular disease than people who consume meat and fish. (Heart disease is the biggest cause of death in developed countries. This study is the largest yet to compare cardiovascular disease rates between vegetarians and meat eaters.)
The analysis included nearly 45,000 participants, of whom 34% were vegetarian. Most similar studies do not have such a significant representation of vegetarians, making the results of this study more accurate. Those on a vegetarian diet generally had lower BMI or body mass indices and fewer cases of diabetes.
After controlling for certain variables that may have affected the results, such as smoking, age, physical activity, alcohol intake, socioeconomic background, and educational level, the scientists came up with the statistic of 32% risk reduction. When the results were adjusted to leave out the impact of BMI, vegetarians still showed a 28% reduced chance of developing heart disease.
Most of the heart-health benefits were likely caused by effects on cholesterol and blood pressure.
This study, printed in the March 2013 issue of The American Journal of Clinical Nutrition, can now be found online at https://tinyurl.com/avdxebs with fee.
Vitamin D Blood Levels Dropping
A new Canadian government study has found that vitamin D levels are declining dramatically, falling 6.2% in a two-year period for those aged 6 to 79, with only 10% of the population meeting optimum levels, despite public health programs encouraging increas-ed vitamin D ingestion and supplementation.
Updated figures for the U.S. are not available, but previous studies have shown that the percentage of people with vitamin D insufficiency (blood levels below 50 nm/L, or 50 nanomoles per litre) is the same in each country. (Research studies continue to show that people with lower vitamin D levels are at a much higher risk of developing serious diseases.)
In this study, vitamin D levels fell a full 10.2% among children aged 6 to 11 within two years. The lowest levels overall were found in young adults age 20 to 39, and male adults had consistently lower vitamin D levels than females. Sufficient levels are seen as being above 50 nmol/L, and 32% did not meet this level. Optimum levels are higher than 100 nmol/L, and only 10% met this level.
Although 34% of the population took a vitamin D supplement, 15% of supplement users still had insufficient levels. Even testing in the summer months, when sunlight can produce vitamin D in the skin, one in four showed insufficient levels. The reasons for the decrease in vitamin D levels are not known, but could be due to a variety of factors, including increased ultraviolet light avoidance or reduced vitamin D food and supplement intake.
(A 2010 study published in Molecular Nutrition & Food Research reported that if all Canadians reached a vitamin D blood serum level of 105 nmol/L, there would be an annual reduction in healthcare costs of $14.4 billion; if the savings in the U.S. were equivalent, this would translate to a $132 billion healthcare saving.)
This study was published on the Statistics Canada website on February 4, 2013. It is available cost-free at https://tinyurl.com/akqrjar.
Did You Know…?
A University of Arizona study found that if one person comes to work sick, they will have infected 50 percent of all commonly touched surfaces, and half of all other workers in the office, within a four-hour period.
A Regular Walk is Sufficient to Reduce Risk of Serious Illness
A simple, regular walking routine is enough of a lifestyle change to reduce, by a full 25%, the chances of developing metabolic syndrome from a moderate to a low risk, which in turn lowers the odds of developing heart disease, strokes, and cancer. (Metabolic syndrome is the medical term for a combination of risk factors including elevated blood pressure and blood sugar, and large waist circumference. The syndrome puts people at significant danger of a list of life-threatening and debilitating conditions.)
A total of 38,000 men and women were involved in this analysis. Those in the moderate fitness category showed a markedly reduced prevalence of metabolic syndrome, compared to those in the low fitness category. Results showed that people do not have to commit to a structured exercise program, or take up jogging. The researchers found that simple activities, including a walk, for 30 minutes three to five times a week produced this benefit. This study was released online February 5, 2013, and will be published in a future issue of Mayo Clinic Proceedings. Available online at https://tinyurl.com/ac6l4z4 with fee payment, subscription.
Extracts of Red Wine and Green Tea Block Alzheimer’s Process
Researchers have shown in a lab study that natural chemicals found in green tea and red wine disrupt the attachment of amyloid protein clumps to animal and human brain cells, blocking a key step of the Alzheimer’s disease pathway. (Alzheimer’s disease is characterized by a distinct build-up of amyloid protein in the brain. The amyloid clumps together to form toxic, sticky balls of varying shapes. These amyloid balls are the perfect shape to easily bind to the surface of nerve cells in the brain called neurons, causing the neurons to malfunction and eventually die.)
The team was able to prevent amyloid clumps from attaching to neurons by altering their shape using purified extracts of EGCG from green tea and resveratrol from red wine. The team formed amyloid clumps or balls in a test tube and added them to human and animal brain cells. When they added the extracts from red wine and green tea, which recent research has shown to re-shape amyloid proteins, the shape of the amyloid balls changed such that they could no longer bind to the neuron surface. This study was released February 5, 2013, but will not be published until a future issue of the Journal of Biological Chemistry. However, the full-text study is accessible online now at https://tinyurl.com/bckpxbs for download without cost.
Did You Know…?
Sprinkling six grams of cinnamon – about one and a half teaspoons, or half a tablespoon – on cooked breakfast foods lowers blood sugar by 25% for two hours, potentially reducing the risk of developing diabetes.
Cutting Salt Intake could Save Over One Million U.S. Lives
Scientists have concluded that a very small, graduated reduction in salt intake over a 10-year period, resulting in an overall 40% decrease in sodium intake, would save a total of 280,000 to 500,000 lives in the U.S. over this period. (The current food supply makes it challenging to choose lower sodium foods to achieve recommended daily levels, with about 80% of sodium coming from commercially prepared, processed, and restaurant foods. Excessive sodium intake contributes to high blood pressure, and nearly half of all cardiovascular disease deaths are related to high blood pressure, which boosts the risk of heart attack and stroke.)
If this level of sodium reduction could be achieved immediately, between 700,000 and 1.2 million lives could be saved over the same 10-year period. The researchers concluded that a 40% reduction in salt intake across the entire population could only be achieved gradually over a decade, which they believed is a potentially achievable public health goal. This study was released February 11, 2013 and will appear in a future issue of the journal Hypertension. It can be accessed online at https://tinyurl.com/ade3xh2 with fee payment.
Thigh Fat Linked to Loss of Mobility among Older Adults
Researchers have determined that an increase in fat in the thigh is predictive of slower walking speed and mobility loss in older but otherwise healthy adults. This suggests that prevention of age-related declines in walking speed and balance is not just about preserving muscle mass; it is also crucial to prevent fat gain in the upper-leg muscle. (Walking speed declines with age, and in older adults slower walking speed is a predictor of disability, nursing home admission, and even death. For this reason, walking speed is considered to be an important, and potentially modifiable, predictor of independent living for older adults.) Little is known about what precedes age-related decline in mobility, although many people gain weight with age, and the team speculated that gaining fat in the leg muscle itself may be related to diminished walking speed. Results confirmed that increased inter-muscular thigh fat and decreased thigh muscle were significant, but independent, predictors of walking speed decline. This just-released study will be published in the March 2013 issue of The American Journal of Clinical Nutrition. It has now been made available online at https://tinyurl.com/bhhfu7q with subscription or access fee.
Top Dementia Risk Factor is Blood Pressure, not Plaque
Researchers have found that the damage done to blood vessels in the brain, by high blood pressure or stroke, is a much greater risk for memory loss and other mental difficulties in seniors than the amyloid plaques in the brain that have long been tied to Alzheimer’s disease. Greater blood vessel damage was found to correspond to greater loss of memory and executive function. Magnetic resonance imaging (MRI) and positron emission tomography (PET) scans were used to measure amyloid plaques in the brain and vascular brain damage. The new study comes in the wake of other research showing that traumatic head injuries and concussions can markedly increase the risk of Alzheimer’s disease. The researchers suggested that, while brain scans may soon be able to detect abnormal levels of amyloid in the brain, health practitioners should not forget about cardiovascular disease which is also very common in this age group and could also cause cognitive problems. In fact, amyloid plaques often may not be the cause of cognitive symptoms. This study will be published in the April 2013 issue of the journal JAMA Neurology. Available online at https://tinyurl.com/cc9xfgr with fee or journal subscription.
Mediterranean Diet reduces Heart Attack, Stroke in High Risk Groups
A study has found that the Mediterranean diet, supplemented with extra-virgin olive oil or nuts, reduces the incidence of major cardiovascular events including heart attack, stroke, and cardiovascular death, among people who already have a high risk of cardiovascular problems. (People who follow a traditional Mediterranean diet have high intakes of olive oil, fruit, nuts, vegetables, and cereals, moderate intakes of fish and poultry, and low intakes of red and processed meats, dairy foods, and sweets. They also drink wine in moderation, and only with meals. Previous studies have suggested a Mediterranean diet protects against cardiovascular events and heart disease, but none has ruled out the possibility that other health factors or lifestyle could be responsible.) This five-year randomized study is one of the largest and longest dietary intervention trials to date. The 7,447 subjects with high cardiovascular risk followed a Mediterranean diet that was supplemented with extra-virgin olive oil or with nuts, or a low-fat diet. Compared to those following the low-fat diet, those on the Mediterranean diet with extra-virgin olive oil were 30% less likely to experience a cardiovascular event, and those on the Mediterranean diet with nuts were 28% less likely.
This research was released online February 25, 2013 by The New England Journal of Medicine and is now available at https://tinyurl.com/av8z5zy without cost.
Strong Inverse Link between Vitamin D Levels and Mortality
A study has found a strong association between the level of vitamin D in the blood and the risk of general (all-cause) mortality, as well as the specific risk of mortality from cardiovascular diseases, cancer, and respiratory diseases. (Serum 25-hydroxyvitamin D concentration has been linked to mortality in several studies, although target levels have been under debate. Blood levels of vitamin D are commonly categorized as follows: deficiency is less than 30 nanomoles per litre; insufficiency is between 30 and 50 nanomoles per litre; and sufficiency is over 50 nanomoles per litre.)
At the 10-year mark, the researchers assessed the number of deaths, and the causes of those deaths, among 5,469 people whose blood levels of vitamin D had been measured at the outset (when their ages ranged from 50-74 years) and over a five-year follow-up period. Compared to those with sufficient vitamin D levels, the risk of all-cause mortality for those with insufficient D levels was found to be 17% greater. And compared to those with sufficient vitamin D levels, the risk of all-cause mortality for those with deficient D levels was found to be 71% greater.
Turning to specific causes of death, the team found that, compared to those with sufficient levels, those with deficient D levels showed a 39% higher mortality from cardiovascular disease; and a 42% higher mortality from cancer; and a 150% higher mortality from respiratory disease.
This study was released February 27, 2013 by The American Journal of Clinical Nutrition and will appear in a future issue. It is now available for subscription or one-time fee payment at https://tinyurl.com/cx5xetv.
Starch-Based IV Fluids Given to the Seriously Ill cause Needless Deaths
Researchers have completed a study that indicates that the starch-based colloid fluids given intravenously by some hospitals to seriously ill patients with very low blood pressure increase the risk of death by 10%, relative to those given the less expensive saline-based crystalloid fluids. (Starch-based IV fluids are widely given to help treat shock after severe blood loss following trauma, burns, and surgery, or after severe infections. Until now, the safety of colloids containing hydroxyethyl starch has been debated for years. They are used to increase blood volume, but recent studies have linked their use to renal failure and to adverse reactions. Crystalloids work in the same way but do not contain starch.) The study included 9,147 seriously ill patients after trauma, burns, surgery, or severe infections, randomly allocated to receive either colloid fluids or saline fluids in their resuscitation. Those receiving colloids were 10 percent more likely to die.) The researchers are calling on health authorities to stop using colloid fluids immediately. This study was released February 28, 2013, in the Cochrane Database of Systematic Reviews 2013. Available online at https://tinyurl.com/d5wzxnw with fee payment.
Did You Know…?
A 2013 study found that children who were the first-born in their families have a 21% lower insulin sensitivity, potentially raising the risk of developing diabetes, and have slightly higher blood pressure, compared to children who have older siblings.
Toxic Metal Levels Found to be Higher in Autistic Children
Scientists have found that children with autism have higher levels of several toxic metals in their blood and urine compared to typical children, and they called for further study to determine if this link is causal. The study involved 55 children with autism, aged 5-16 years, compared to 44 controls of similar age and gender. The autism group had 41% higher lead levels in their red blood cells, and 74% higher lead levels in their urine. The scientists also discovered urine levels to be 77% higher in thallium, 115% higher in tin, and 44% higher in tungsten. Lead, thallium, tin, and tungsten are toxic metals that can impair brain development and function, and also interfere with the normal functioning of other body organs and systems.
It was also found that 38 to 47 percent of the variation of autism severity was directly associated with the level of several toxic metals, with cadmium and mercury being the most strongly associated. In the paper, the authors state: “We hypothesize that reducing early exposure to toxic metals may help ameliorate symptoms of autism, and treatment to remove toxic metals may reduce symptoms… these hypotheses need further exploration.”
This study was published in the February 2013 issue of the journal, Biological Trace Element Research. It is now available online at https://tinyurl.com/cd2w2vv with subscription or access fee.
Pollution Exposure Linked to Deaths after Heart Attacks
New research has found that higher air pollution exposure may contribute to an increased risk of death among patients who have been admitted to hospital with heart attacks. (Studies have examined links between air pollution and the risk of developing heart disease, but very few studies have investigated its effect on survival after heart attack. This is the largest study ever to investigate the links between fine air-borne particulate matter and patient survival after hospital admission for acute coronary syndrome or ACS.)
In the study, death rates were found to be higher with increased exposure to tiny particles that measure 2.5 micrometres in diameter or less, approximately 30 times thinner than a human hair. The main sources of particles of this size are emissions from road traffic and industry, including power generation. It was estimated that the risk of death would be reduced by 12% if ACS patients were exposed to only naturally occurring pollution particles of this size, rather than the high levels to which they are actually exposed.
Released February 20, this study will appear in a future issue of the European Heart Journal. It is now available at https://tinyurl.com/appknf5 without cost.
Did You Know…?
Total American apple consumption averages out to 120 apples per person per year.
Red Grapes Protect against Hearing Loss and Cognitive Decline
Scientists have found that resveratrol, a substance found in red grapes and red wine, appears to protect against hearing loss and cognitive decline. (Nearly 20% of North Americans live with some degree of hearing loss, and for the majority hearing progressively gets worse as they get older. Among troops returning from war zones, noise-induced hearing loss is a growing medical issue. Resveratrol is a powerful antioxidant with anti-inflammatory properties and is a red-grape constituent. Resveratrol is also present in blueberries and other plants.) Scientists found that laboratory rats would suffer less from long-term effects of noise-induced hearing loss if they consumed resveratrol before listening to extended periods of loud noise. Researchers focused on the effects of resveratrol on inflammation, the response to injury that is believed to be the cause of many health problems including Alzheimer’s disease, cancer, aging, and hearing loss. Resveratrol was found to protect against the specific inflammatory processes associated with hearing loss and aging.
This study was released early but will not appear in print until a future issue of the journal Otolaryngology – Head and Neck Surgery. Available at https://tinyurl.com/a7j7wb5 with access fee or journal subscription.
Whole Grains, not Grain Fibre, behind Chronic Disease Prevention
New research has concluded that the association between increased intake of whole grains and decreased risk of chronic diseases is due to the overall content of the whole grains themselves. On the basis of results of 11 major studies, the current review established that whole grains are central to a healthy diet, and pinpointed the dose necessary. This study found that the most nutritionally significant part of the grain is the aleurone, a protein found in a layer of the seed that contains a combination of magnesium, iron, zinc, and ferullic acid. The scientists found that increasing whole grain consumption by 40 grams, or ideally 50 grams, daily could have a considerable impact on public health. This paper was electronically published by the journal, Biofactors, and will appear in a future print issue.
