News Briefs: July/August 2017
RESVERATROL REDUCES ARTERY STIFFNESS IN DIABETICS
Scientists have reported that resveratrol may reduce artery stiffness in people with Type 2 diabetes. (Resveratrol is a natural compound found in red wine, peanuts, berries, and the skin of red grapes. This adds to emerging evidence that some interventions may reverse the blood vessel abnormalities that occur with aging and that are more pronounced in people with diabetes and obesity. As the largest artery, the aorta, becomes stiffer, the risk of heart attacks and strokes increases.)
Researchers used a test (carotid-femoral pulse wave velocity) to measure aortic stiffness in 57 patients with Type 2 diabetes after patients consumed daily doses of 100 mg per day of resveratrol for two weeks followed by 300 mg a day of resveratrol for two weeks, and after comparable placebo dosing for a total of four weeks. Participants were also tested on several other measures of the ability of blood vessels to relax and expand as needed to accommodate changes in blood flow, an important indicator of healthy blood vessel function.
There was an insignificant reduction in aortic stiffness in the overall group; but in those with high arterial stiffness at the start of the study, the 300 mg dose of resveratrol reduced aortic stiffness by 9.1%, and the 100 mg dose lowered reduced aortic stiffness by 4.8%, while stiffness increased with the placebo treatments. The effect may be more about improving structural changes in the aorta than increasing the relaxation of blood vessels, said the author.
Resveratrol also activates the longevity gene (SIRT1) in humans, and this may be a potential mechanism for the supplements to reduce aortic stiffness. The abstract to this study was presented May 4, 2017 at the 2017 Arteriosclerosis, Thrombosis, and Vascular Biology Peripheral Vascular Disease Scientific Sessions. It has not yet been published.
ANTIBIOTICS LINKED TO HIGHER RISK OF MISCARRIAGE
Scientists have found that many classes of common antibiotics are associated with a 60 to 200% increase in the risk of miscarriage during early pregnancy. These risky drugs included macrolides, quinolones, tetracyclines, sulfonamides, and metronidazole. (Infec-tions are prevalent during pregnancy. Previous studies found links between antibiotic use and a decreased risk of prematurity and low birth weight.)
Researchers investigated 8,702 pregnant women who had experienced spontaneous abortions and 87,020 pregnant women who had not. The average time of miscarriage was at 14 weeks. Of those miscarriages, 16.4% had been exposed to antibiotics. But among the non-miscarriages, only 12.6% had taken antibiotics. The risk increased by three times with some antibiotic types. However, the increased risk was not seen for all antibiotics, which is reassuring for users who need to access infection-fighting drugs during pregnancy. Not associated with greater miscarriage risks were the antibiotics erythromycin and nitrofurantoin. (Nitrofurantoin is often used to treat urinary tract infections in pregnant women.)
The women studied were between the ages of 15 and 45 years. The authors hope that these findings may be useful for policymakers to update guidelines for the treatment of infections during pregnancy.
This study was published in the May 1, 2017 issue of the Canadian Medical Assn. Journal. It appears on the journal website at https://tinyurl.com/kelrz8j free of charge.
DID YOU KNOW…?
A European study of almost 20,000 men and women found that mortality from cardiovascular disease was 60% lower in people with the highest concentrations of vitamin C in their blood.
COMMON PAINKILLERS INCREASE RISK OF HEART ATTACK IN ONE WEEK
Researchers have reported on an international epidemiological study that found a link between use of common painkillers, known as non-steroidal anti-inflammatory drugs or NSAIDs, both prescription and over-the-counter, and an increased risk of heart attack. (Earlier findings had linked such drugs to cardiac risks, but the number of study participants was too small. This study is the largest investigation of its kind to examine actual patient experiences with NSAIDs.)
The study included medical records of 447,000 people from three countries, but because it is epidemiological in nature, it cannot prove cause-and-effect. The team examined records for use of any NSAIDs, including ibuprofen (Advil, Motrin), diclofenac (Voltaren, Cambia), celecoxib (Celebrex), and naproxen (Midol, Aleve). The findings showed higher incidence of heart attacks among users versus nonusers of these drugs. Surprisingly, the risk rose substantially during the first week of use, and this risk escalated with higher doses and frequency of use. Overall, the increased risk of a heart attack was between 20% and 50% greater for those using NSAIDs than those not taking them. The one exception was aspirin. Only aspirin, which is also an NSAID, was found not to be linked to higher risk of heart attack.
This study was published May 9, 2017 in the journal BMJ. The full study details are available now at https://tinyurl.com/m2g72yd free of charge.
STUDY FINDS OSTEOARTHRITIS CAN BE PREVENTED WITH DIET, EXERCISE
Researchers have identified a crucial link between metabolism and osteoarthritis, suggesting that osteoarthritis may potentially be prevented with a good diet and regular exercise. They showed that certain metabolic changes caused by an inadequate diet and a sedentary lifestyle trigger the genetic reprogramming of cells in the body and joints. These metabolic changes negatively affect the ability of the cells to produce energy, forcing them to generate alternative energy sources in order to function. This places stress on cells, leading to the overproduction of glucose; when not used for energy, glucose transforms into lactic acid, which is difficult for the body to flush out. Abnormal levels of this acid in the body lead to the inflammation of the cartilage in the joint, impeding movement and causing pain.
The study author said that osteoarthritis has long been incorrectly identified as a wear-and-tear disease of aging, but in fact it can be controlled and its onset prevented with a healthy diet and lifestyle that can alter the metabolism of cells and tissues. This study was published in the May 2017 issue of Nature Reviews Rheumatology. The full study details can be read now at https://tinyurl.com/m57x9os cost-free.
PLANT-RICH DIET LOWERS RISK OF GOUT
A new study has found that, compared to a Western-style diet, a plant-rich diet is associated with a lower risk of developing gout. (Gout is a painful arthritic condition that typically starts in the big toe, although it can also affect other joints and areas around them. Affecting 3.9% of the population, it occurs when there is too much uric acid in the blood, causing the deposition of needle-like crystals in the joints. A plant-rich diet is known to help reduce the risk of heart disease.)
The large study followed more than 44,000 men for 26 years and the beneficial diet was known as the DASH diet, meaning Dietary Approaches to Stop Hypertension, shown to lower blood pressure and the risk of heart disease. This diet is abundant in vegetables, fruits, legumes, nuts, whole grains, and low-fat dairy. It is low in red and processed meats, salt, and sugar-containing drinks. (Conversely, the Western diet is high in meats, refined grains, french fries, sweets, and desserts.) After analyzing 26 years of follow-up data, the team found that a higher DASH adherence was tied to a lower risk of developing gout, while a higher Western pattern was linked to higher risk. Researchers concluded that the uric acid-lowering DASH diet translates to a reduced risk of gout.
This study was published online May 10, 2017 by the journal BMJ. It is available at https://tinyurl.com/mfdzvry
WHOLE TOMATOES MAY HELP PREVENT STOMACH CANCER
Scientists have found that whole tomato extract has the potential to treat and even prevent stomach cancer. They focused on extracts of two varieties of tomato, the San Marzano and Corbarino, and found that they block the growth of stomach cancer cells and inhibit their migration. (Previous studies had suggested that compounds such as lycopene and carotene in tomatoes may have anti-cancer properties. There are about 28,000 cases of stomach cancer diagnosed annually in the U.S., and about 60% of these are aged 65 or older.)
The researchers found that the anti-cancer effects of the tomato extracts were not down to one particular compound and that tomatoes should be considered in their entirety. The team noted that certain varieties of tomatoes may have different effects on cancer cells, something that future studies should investigate. The study was posted online May 10, 2017 and will appear later in the Journal of Cellular Physiology. It is available at https://tinyurl.com/ljtkewo for a fee.
DIESEL POLLUTANTS DAMAGE HEART FUNCTION
According to new research, diesel pollution, emitted mainly from diesel road vehicles, is linked to heart damage. (Strong past evidence indicates that inhaling fine particulate matter, known as PM2.5, boosts the risk of heart attack, heart failure, and death by an indirect means. In other words, this indirect effect is probably caused by its localized inflammation of the lungs, followed by a more systemic inflammation affecting the whole body.) The current study examined whether PM2.5 may damage the heart directly through lung inflammation. The study enlisted 4,255 participants who underwent cardiac magnetic resonance imaging to measure left ventricular volume (structure) and left ventricular ejection fraction (function). Annual average exposure to PM2.5 was calculated based on home address. The investigators found direct relationships between ambient PM2.5 levels and heart structure and function. Every 5 micrograms-per-cubic-meter increase in exposure was associated with a 4 to 8% increase in left ventricular volume and a 2% decrease in left ventricular ejection fraction. In other words, as diesel pollution rises, the heart gets larger, and its performance decreases; this indicates increased morbidity and mortality from heart disease as a result of pollution.
The researchers suggested that reducing PM2.5 emission should be an urgent public health priority and the worst offenders such as diesel vehicles should be addressed with policy measures. This research was presented May 26, 2017 in Prague at EuroCMR 2017, the Cardiovascular Magnetic Resonance conference, but has not yet been published.
OMEGA-3 DEFICIENCY IN ADOLESCENCE MAY CAUSE MENTAL HEALTH PROBLEMS IN ADULTHOOD
Scientists have found that a diet lacking omega-3 fatty acids fed to mice during adolescence may result in anxiety-like behaviour and worse performance on a memory task. The study suggests that adequate nutrition in adolescence may be important for refinement of the human adult brain and behaviour. The structure and function of the brain continue to change throughout adolescence, at the same time that teenagers gain increasing independence and begin to make their own food choices. Teenagers may opt for foods that lack key nutrients important for brain health such as omega-3 essential fatty acids, called “essential” because they cannot be produced by the human body and must be obtained from foods such as fish and vegetables.
Researchers fed mice a balanced diet until early adolescence, when some were switched to a diet lacking omega-3 fatty acids. Mice fed the poor diet during adolescence had reduced levels of omega-3 in certain brain areas when they reached adulthood, compared to control mice. The low-quality diet impaired the ability to fine-tune connections between neurons in these regions. This study was published June 19, 2017 in the Journal of Neuroscience. The full report is available at https://tinyurl.com/ya7doe9z for a fee.
TAI CHI REDUCES SYMPTOMS OF DEPRESSION
Psychiatric researchers have found that a 12-week program of instruction and practice of the martial art known as tai chi can reduce symptoms of depression in Chinese Americans. The pilot study enrolled exclusively Chinese-American individuals who had mild to moderate depression and who were fluent in Cantonese or Mandarin, but who had no experience with tai chi or any other mind-body interventions and were not being treated by any psychiatric treatments. They were assessed in interviews for health and depression symptoms.
Participants were randomized into three groups: one that received the tai chi intervention; an active control group that participated in sessions that included discussions on stress, mental health and depression; and a passive control group that returned for repeat assessments during and after the study period but received no active intervention. The tai chi intervention involved twice weekly sessions for 12 weeks, in which participants were taught traditional tai chi movements and then practice at home three times a week. The education group also met twice weekly for 12 weeks, and sessions for both groups were offered in Cantonese or Mandarin. The tai chi group had significantly greater improvement in depression symptoms than members of either other group. Follow-up assessment at 24 weeks showed sustained improvement among the tai chi group. This study was recently published online by the Journal of Clinical Psychiatry. The full report can be accessed at https://tinyurl.com/yd3uv6nl for a fee.
YOGA, MEDITATION REVERSE THE HARMFUL DNA REACTIONS TO STRESS
Scientists have found that mind-body interventions (MBIs) such as meditation, yoga, and tai chi do more than simply enable relaxation; they can reverse the molecular reactions in our DNA that cause stress, ill-health, and depression. When exposed to a stressful event, the sympathetic nervous system of each individual is triggered to increase production of a molecule that causes genes to produce cytokines, which cause inflammation at the cellular level. This inflammation is important for reacting quickly to threatening situations (fight-or-flight) and blocking infections. But when the inflammation persists too long, it increases the risks of cancer, accelerated aging, and psychiatric disorders such as depression.
After reviewing 18 studies, the researchers found that people who use mind-body interventions exhibit the opposite effect: a decrease in production of NF-kB and cytokines, leading to a reversal of the pro-inflammatory gene expression pattern and a reduction in the risk of inflammation-related diseases and conditions. In other words, these mind-body activities leave a molecular signature in our cells that reverses the effect that stress or anxiety would have had on the body by changing how our genes are activated, steering our DNA processes down a path that improves well-being.
This study was published online June 16, 2017 at the site of the journal Frontiers in Immunology.The full report is now available at https://tinyurl.com/yasphj2q free of charge.