News Briefs – July / August 2014Michael Downey July 1, 2014
Unsat Fats with Nitrate-Rich Veggies Lower Blood Pressure
New findings indicate that a diet combining unsaturated fats with nitrite-rich vegetables can provide protection from hypertension, or high blood pressure. This may help to explain why some previous studies have shown that a Mediterranean diet can reduce blood pressure. (The Mediterranean diet typically includes unsaturated fats found in olive oil, nuts and avocados, along with vegetables that are rich in nitrites and nitrates, such as spinach, celery, and carrots. Diets supplemented with extra-virgin olive oil or nuts can reduce the incidence of cardiovascular problems like stroke, heart failure and heart attacks.)
When these two food groups are combined, the reaction of unsaturated fatty acids with nitrogen compounds in the vegetables results in the formation of nitro fatty acids. The study concluded that the protective effect of the Mediterranean diet comes from combining unsaturated fats with vegetables abundant in nitrite and nitrate. The findings were early-released online by Proceedings of the National Academy of Science. An abstract of the study can be read online at https://tinyurl.com/kbmmv8g at no cost.
Bad Cholesterol Contributes to Spread of Cancer in the Body
Scientists have discovered that LDL cholesterol, commonly known as bad cholesterol, is a major underlying cause of the spread of cancer throughout the body. (Bad cholesterol is low density lipoprotein, or LDL, cholesterol. One factor that makes cancer so difficult to treat is that it can quickly spread around the body.)
This study found that LDL regulates the machinery which controls the migration of cells, providing a major insight into why cancer spreads throughout the body. Most of our body cells stick to neighbouring cells through the help of Velcro-like molecules on their surface known as integrins. Unfortunately, integrins also help cancer cells that have broken away from a cancerous tumour to take root elsewhere in the body.
This study found that having high amounts of bad cholesterol helps the integrins in cancer cells to move outwards and helps the cell take root elsewhere. LDL is needed to keep integrins on the cell surface of cancer cells. Reducing the number of integrins at the cell surface stops cancer cells from migrating. In contrast, high levels of good or HDL cholesterol keep integrins inside cancer cells, inhibiting cancer cell spread. Malignant cancer cells take up greater amounts of LDL cholesterol for their use. Lowering bad cholesterol could substantially reduce the ability of cancer cells to spread. This study was published online recently by the journal Cell, although it will not be published in print until a future issue. It can now be accessed in full at https://tinyurl.com/m8ja25x without charge.
(Ed. note: Strategies for reducing LDL cholesterol include avoiding processed fats such as heat treated oils, margarines, and baked goods. Increasing your blood level of vitamin D helps to reduce LDL and increase HDL levels.)
Short Exercise Bursts Inhibit Diabetes Better Than Long Sessions
Researchers have reported that very brief bursts of intense exercise before meals help control blood sugar in people with insulin resistance more effectively than one daily 30-minute session of moderate exercise. (Intense but very short energy bursts are known as exercise snacking. Previous research has shown that more frequent breaks in sedentary time are beneficial for waist circumference, blood glucose control, and other metabolic parameters. Exercise snacking, whether before meals or not, provides more breaks in sedentary time, and thus may be important for public health. Other research found that interval exercising every second day is just as effective as continuous exercise every day, despite the significantly lower volume of exercise. Reducing post-meal blood sugar spikes is important for reducing the risk of developing type 2 diabetes.)
In this study, 30 minutes of moderate-intensity exercise did not improve blood sugar control, while the same amount of exercise done as three brief, pre-meal exercise snacks resulted in a mean 12% reduction in post-meal glucose level, averaged over three meals. This effect was even sustained across the subsequent day. Walking and other exercise taken as snacks improved blood sugar control similarly. The current study and others show that if the exercise is intense, it may only need to be performed every second day, further adding to the time efficient nature of this interval exercise. So the timing and intensity of exercise should be considered for optimizing glucose control.
This study will appear in a future edition of the journal Diabetologia. However, you can click a link to download a copy of the full-text study at https://tinyurl.com/yzl5xus without charge.
Prescription Painkillers Causing More Deaths than Heroin and Cocaine Combined
A new scientific review has found evidence of a sharp increase in deaths from painkillers in the U.S. and Canada, with the number of deaths involving commonly prescribed painkillers higher than the number of deaths by overdose from heroin and cocaine combined.
In a first-of-its-kind systematic review of published study literature, the team found that prescribed painkillers were involved in more than 16,000 deaths in 2010 in the U.S. alone. The U.S. and Canada now rank number one and number two in per capita opioid consumption. The study found evidence for at least 17 different determinants of increasing opioid-related mortality, including: dramatically increased prescriptions and sales of opioids; increased use of strong, long-acting opioids such as oxycontin and methadone; the combining of opioids with other drugs or alcohol; and social and demographic factors. Increased Internet sales of pharmaceuticals, as well as errors by both doctors and patients, played a significant role. Physicians, users, the health care system, and the social environment all play a role, according to the study findings.
This study was posted online June 12, 2014 ahead of print in a later issue of the American Journal of Public Health. The entire report can now be accessed online at https://tinyurl.com/l7rwm5x without charge.
(Ed note: To learn more about the risks of prescription medication, and to read stories from both patients and researchers, visit: RxISK.org, the website founded by activist physician Dr. David Healy.)
Hair Dye, Hair-Waving Products Linked to Carcinogens in Blood
New research findings link frequency of dye and perm use to increased levels of carcinogens in the blood, potentially increasing the risk of various cancers, including bladder cancer. (Previous studies found that hairdressers have an excess risk for bladder cancer, and researchers believe this risk comes from exposure to carcinogenic aromatic amines in some hair dyes, which have also been linked to increased risk for non-Hodgkin lymphoma and leukemia. One study found that people with allergies to substances such as hair dye and latex rubber may have an immune system that can be triggered into defending against some types of cancer.)
To measure long-term exposure to known and suspected carcinogenic aromatic amines, still detected in some hair dyes despite being officially phased out decades ago, scientists assessed blood samples from 295 female hairdressers, 32 regular users of hair dyes, and 60 people who had not used hair dyes in the past year. They also gathered data on their jobs, hobbies, and lifestyle that could skew results. Levels of aromatic amines were found in all subjects, but among hairdressers the weekly levels of aromatic amines called o- and m-toluidines were shown to correspond directly with the number of permanent light hair colour treatments they applied to clients. (Toluidines are known to be carcinogenic.) Higher concentrations of o-toluidines were also associated with use of a hair-waving product.
This study was released online June 9, 2014 ahead of print publication at a later date in the journal Occupational and Environmental Medicine. The full-text report can now be read online at https://tinyurl.com/nsupxdr free of charge.
Low-Carb Diet Reduces Inflammation in Diabetes Patients
New research has found that a low-carbohydrate diet, but not a low-fat diet, reduces inflammation in patients with Type 2 diabetes. (Patients with Type 2 diabetes have higher levels of inflammation, and it is believed this may contribute to their higher risk of cardiovascular disease and other complications. It has been proposed that dietary strategies can modulate inflammatory activity.)
In a two-year clinical trial, a low-carbohydrate diet was compared with a traditional low-fat diet in 61 patients with Type 2 diabetes. Only patients in the low-carbohydrate group exhibited reduced levels of inflammatory markers in blood, despite the fact that weight loss was similar in both groups, around nine pounds. Glucose levels decreased more in the low-carbohydrate patients; they had lowered their carb intake an average of 25 percent. After six months, inflammation was significantly reduced in the low-carbohydrate group while no changes were observed in the low-fat diet group.
This study was published in the May 2014 issue of the Annals of Medicine. The full study can be read online at https://tinyurl.com/mtdvkuh free of charge.
Stess Hormone Levels Linked to Memory Decline
A new study suggests a link between high levels of cortisol, a stress hormone, and short-term memory loss in older individuals. (Scientists know that stress can increase risks for certain conditions, such as cardiovascular disease, impaired immune function and psychological disorders. Although short-term boosts in cortisol are important for our survival by making us more alert in the moment, exceptionally high or extended spikes in the stress hormone can yield negative effects such as digestion problems, anxiety, weight gain and high blood pressure. Although chronic stress boosts stress hormones, some people simply have naturally higher corticosterone levels.)
The researchers suggest that stress hormones lead to a weathering of the brain. Although previous studies have shown that cortisol produces negative effects in other regions of the brain, this is the first study to show that it affects the prefrontal cortex, which is the area of the brain linked to short-term memory. The team studied 21-month-old rats, the rodent equivalent of 65-year-old humans. Short-term memory lapses related to cortisol start around this age in humans. Older rats with high corticosterone levels performed worst on maze tasks, which require a good memory. In detail, the older rats with high stress hormone levels chose the correct direction only 58 percent of the time, compared with the older rats with low stress levels that chose correctly 80 percent of the time.
The researchers suggested that short-term memory decline in older adults might be slowed or prevented by treatments that decrease cortisol levels. This could include treating people with naturally high levels of cortisol or those who encounter recurring, long-term stress as a result of traumatic life events. The study emphasized that stress hormones are just one of many factors involved in mental decline and memory loss in aging.
This study was published June 18, 2014 in the Journal of Neuroscience. It can now be downloaded at https://tinyurl.com/oa59r7w for an access fee.
Maintaining Mobility Staves Off Major Disability in Older Adults
Scientists have reported that taking even just a 20-minute walk every day to help maintain the ability to walk without assistance is key to functioning independently and reducing the risk of major disabilities and reduced life quality in older adults. (Reduced mobility is common in older adults and is a risk factor for illness, hospitalization, disability, and death.) This is the largest randomized controlled trial ever conducted on physical activity and health education in older adults. The study enrolled 1,635 men and women aged 70 to 89 who led sedentary lifestyles and were at risk of mobility disability. Participants were randomly assigned to either a structured, moderate-intensity physical activity program, or to a health education program focused on topics related to successful aging. After more than two years of follow-up, the team found that the risk of major mobility disability was reduced by 18% among participants in the physical activity group, meaning that they were more capable of walking without assistance for about a quarter mile.
This study was published in the Journal of the American Medical Association on May 27, 2014 and can now be read in full online at https://tinyurl.com/kx9hgf5 free of charge.
Did You Know…?
A 2014 Swedish study suggests that probiotics, which are beneficial intestinal bacteria, may protect against bone loss and osteoporosis.
Damaged Protein May Be Prematurely Aging Humans
Scientists have found that the condition of key proteins in the mitochondria could be used to predict and eventually treat premature aging. Also, restricting diet appears to be one way to block this aging. (Mitochondria are units inside each cell that generate the energy required to keep our bodies going but they also generate free radicals. A complex of 96 proteins is at the heart of the mitochondrial power station. With age, the ability of mitochondria to effectively produce energy decreases, which is viewed as a key factor in the aging of the body. Calorie restriction is a system of substantially reduced calorie intake that has been shown to dramatically extend the natural maximum life span of almost all species on which CR has been tested.)
Interventions such as calorie restriction have been shown to cause mice to live longer than their normal maximum life span and researchers found that these interventions also resulted in more efficient assembly of important mitochondrial proteins into complexes. Inefficient assembling of mitochondrial proteins generates toxic free radicals deep inside of cells where they can do the most damage and are tucked away from antioxidants produced by the body or acquired from the diet.
Essentially, scientists found that the aging process is slower than normal in mice that managed to form mitochondrial protein complexes more efficiently and that they actually could help the mice mitochondria to do so. Human cells age faster if complex assembly is corrupted. These data go a long way to explain how calorie restriction can improve mitochondrial function, extend lifespan, and reduce or postpone many age-associated diseases. Scientists will now look for this mechanism in humans and attempt to find ways to improve protein assembly in mitochondria.
This report was published in the May 12, 2014 issue of the journal Nature Communications. The full text of the study is now available online at https://tinyurl.com/nylescv
Prescription Sleeping Pills Increase Cardio Events in Heart Failure Patients
Heart failure patients who take prescribed sleeping pills have nine times the risk of cardiovascular events, according to newly presented research. (Sleeping problems are a frequent side effect of heart failure, and it is common for patients to be prescribed sleeping pills when they are discharged from hospital. Because they often also take several other drugs for heart failure, such as diuretics, blood thinners, and blood pressure medications, it has been difficult to determine the specific risks of sleeping pills alone for this group.)
In the study, patients were divided according to two different heart failure types: those with preserved ejection fraction and those with reduced ejection fraction. The first finding was that those in the reduced ejection group who were prescribed blood pressure drugs had 75 percent fewer cardiovascular events than those in that group who were not. Second, it was found that those in the preserved ejection faction group who were prescribed sleeping pills had nine times the risk of cardiovascular events than those in that group who were not. While the connection has not been clarified, many sleeping pills can depress respiratory activity, which could exacerbate sleep disordered breathing and lead to a worse cardiovascular prognosis.
This study was presented in Athens on May 20, 2014 at the annual meeting of the Heart Failure Association of the European Society of Cardiology. It has not yet been journal-published or posted online.
Calorie Restriction May Block Breast Cancer Spread
New research suggests that calorie restriction may improve outcomes for women with aggressive breast cancer. (Calorie restriction, or CR, is a program in which food intake is decreased by a substantial percentage, which has numerous health benefits and has been touted as way to help people live longer. Breast cancer patients are often treated with hormonal therapy to block tumour growth, and steroids to counteract the side effects of chemotherapy. However, both treatments can cause a patient to have altered metabolism which can lead to weight gain.)
In this animal study, scientists found that one of the most aggressive forms of breast cancer, known as the triple negative subtype, is less likely to spread, or metastasize, to new sites in the body when a CR diet is followed. The diet turned on an epigenetic program, meaning it affected what genes would be turned on or off, that protected mice from metastatic disease. When mouse models of triple negative cancer were fed 30 percent less than what they ate when given free access to food, the cancer cells decreased their production of compounds that are linked to the rapid spread of this cancer. Standard treatments for this cancer can trigger an average weight gain of 10 pounds in the first year of treatment, and recent studies have shown that too much weight makes treatments for breast cancer less effective. If calorie restriction is as effective in women as it is in animal models, then it would likely change the expression patterns of a large set of genes, hitting multiple targets at once without toxicity. A human clinical trial is planned.
This study was published May 26, 2014 in the journal Breast Cancer Research and Treatment. The full report can now be accessed at https://tinyurl.com/mllnrxw for a fee.
Processed Meat Linked to Higher Rish of Heart Failure in Men
Researchers have found that men who regularly eat processed red meat also have a significantly higher risk of developing heart failure and heart failure-related mortality. The risk of heart failure increases directly with the consumption of higher amounts of processed red meats. (Heart failure is the condition in which the heart cannot pump blood as well as it should. Heart failure is one of the most common, costliest, and deadliest cardiac conditions, according to the American Heart Association. About 50% of those diagnosed with heart failure will die within five years. Processed red meats, which are preserved by smoking, curing, salting or adding preservatives, typically contain salt, nitrates, phosphates and other food additives. Smoked meats also contain polycyclic aromatic hydrocarbons, which may contribute to increased heart failure risk.)
For this study, processed meat included sausages, cold cuts (ham or salami), blood pudding, and liver paté, and unprocessed meat included pork and beef or veal, including hamburger or ground-minced meat. The scientists followed over 37,000 men from 1998 until they were diagnosed with heart failure or died or until the study ended in 2010. Men who ate roughly 2.6 ounces of processed red meat per day, which is the equivalent of two or three slices of ham, showed a 28% greater risk of heart failure and more than twice the risk of death from heart failure compared with men who ate less than one ounce of processed red meat daily.
This evidence does not prove that a cause-and-effect relationship exists between a steady diet of processed meat and heart failure, only that an association exists; lifestyle and other factors that affect heart risk are often intertwined with diet choices. Based on their findings, however, the researchers recommended avoiding processed red meat altogether and eating unprocessed red meat no more than once or twice a week.
The risk associated with heart failure appeared to rise 8% with every 1.7 ounces of processed red meat eaten daily, while the risk of dying from heart failure jumped 38% for each such increase. The researchers expect to find similar results in an ongoing study of women.
This study was released online ahead of publication in a later print issue of the journal Circulation: Heart Failure. The full study report is now available online at https://tinyurl.com/pkfm75k free of charge.