Wednesday, September 28, 2016

How statins aid the immune system




Statins protect against cardiovascular disease in more ways than previously thought. In a study, researchers from Karolinska Institutet are able to show the immunological effects of statins, and present a new hypothesis on why statins are effective at preventing heart attacks. The study is published in The Journal of the American Heart Association.

Atherosclerosis can lead to a number of serious medical conditions, such as heart attack, stroke and intermittent claudication. These and other cardiovascular diseases are on the increase around the world, and are the leading causes of death in the west. Johan Frostegård, professor at KI's Institute of Environmental Medicine, has had a long-standing interest in atherosclerosis and the possible underlying causes of this chronic inflammation. Atherosclerosis is visible on the blood vessel walls as plaque consisting of accumulated dead cells and oxidised (rancid) LDL cholesterol (the so-called "bad" cholesterol) and two types of immune cell, T cells and dendritic cells, which are the key players in this chronic inflammation.

Statins are a common class of drug often used to prevent cardiac arrest and other such conditions. Even though it has long been known that statins are anti-inflammatory, it is unclear whether the immune system is more specifically affected, the assumption having been that statins are so effective because they reduce levels of cholesterol in the blood.

"We can show how statins can protect against cardiovascular disease through a new, specific immunological mechanism, and I believe that this can explain much of their beneficial effect," says Johan Frostegård, professor of medicine at Karolinska Institutet's Institute of Environmental Medicine and consultant at Karolinska University Hospital's Emergency Clinic. "For the first time, we're able to show that an immunological treatment for atherosclerosis can actually work."

The researchers studied the interaction between the two most important immune cells in this context, T cells and dendritic cells. By looking at atherosclerotic plaque sourced direct from operations on human patients, they found that oxidised LDL-cholesterol activates inflammatory T cells from plaque via the dendritic cells. The statins block the T cells and stimulate the production of anti-inflammatory T cells (T regulatory cells). The dendritic cells are also affected in a way that renders them anti-inflammatory.

When the side-effects of statins are discussed, their possible carcinogenic properties are sometimes addressed. While large-scale metastudies have shown that there is a reduction in most kinds of tumour, in this study it was discovered that statins repress gene activators (microRNA), including a certain kind called let7c, which normally helps to inhibit tumour growth. In this study, let7c was involved in oxidized LDL-induced T cell activation.

"Statins severely repressed let7c," says Professor Frostegård. "If a patient has a tumour in which let7c plays an important part, the statin effect could be adverse. At the same time, statins reduce inflammation and that can lower the risk of cancer, and large metastudies show no general increase in cancer risk."


Interval exercise training improves blood vessel function in older adults


Resistance-based interval exercise helps improve endothelial function -- including blood flow and blood vessel dilation -- both in older adults with type 2 diabetes and in age-matched non-exercisers and regular exercisers, according to new research published in the American Journal of Physiology -- Heart and Circulatory Physiology. The results suggest that increasingly popular interval exercise plans could be used to treat endothelial dysfunction in older adults.

"The endothelium plays a pivotal role regulating the many factors that determine vascular tone, tissue perfusion, coagulation and inflammation. Endothelial dysfunction is an early manifestation in many chronic diseases, including diabetes, and contributes to the [approximately two- to four-fold] greater risk of cardiovascular disease in type 2 diabetes," the researchers wrote. For the estimated 28 million people with type 2 diabetes in the U.S., endothelial problems can impair blood flow and lead to nerve damage and other complications.

Interval training alternates periods of high- and low-intensity exercise. Many people find interval training appealing because of the relatively short time commitment required and because rest periods are built into the exercise time. In this study, researchers compared resistance (using weighted leg resistance exercises) and cardiovascular (using a stationary bicycle) interval training to see how the exercise regimens affected endothelial function. Thirty-five volunteers (average age 56) were assigned to three groups: people with type 2 diabetes (T2D), non-exercisers without diabetes (UN-NG) and regular exercisers without diabetes (TR-NG). Each group performed the same 20-minute exercise regimen: three-minute warm up; seven one-minute (resistance or cardio) interval workout with a one-minute rest between each interval; three-minute cool down. The researchers measured blood flow in the brachial artery in the upper arm before and immediately following interval training and at one and two hours post-exercise.

The researchers found that all of the exercisers -- with or without diabetes, trained or untrained -- saw an improvement of flow-mediated dilation (FMD%, a measure of endothelial function) after resistance-based interval training. This was especially true in the T2D group, which experienced FMD% improvement at each measurement period. Cardiovascular interval training led to FMD% changes after one hour in the T2D group and after two hours in the regular exercise group but did not cause any improvement in the non-exercising group.

"This study shows that resistance-based interval exercise is a time-efficient and effective exercise method to acutely improve endothelial function in T2D, age-matched UN-NG and TR-NG participants," the researchers wrote. "These findings warrant the examination of the long-term impact of [resistance-based interval exercise] on vascular function."


Monday, September 26, 2016

Eating raw apple or lettuce may help reduce garlic breath


Garlic -- consumers either love or hate the taste, but one thing is for certain, no one likes it when the scent of it sticks around on their breath. Now, garlic lovers may have a new solution to their halitosis problem. A study published in the September issue of the Journal of Food Science found that eating raw apple or lettuce may help reduce garlic breath.

Researchers from the Ohio State University gave participants three grams of softneck garlic cloves to chew for 25 seconds, and then water (control), raw, juiced or heated apple, raw or heated lettuce, raw or juiced mint leaves, or green tea were consumed immediately. The volatiles responsible for garlic breath include diallyl disulfide, allyl mercaptan, allyl methyl disulfide, and allyl methyl sulfide. The levels of volatiles on the breath after consumption were analyzed by selected ion flow tube mass spectrometry.

Raw apple and raw lettuce and decreased the concentration of volatiles in breath by 50 percent or more compared to the control for the first 30 minutes. Mint leaves had a higher deodorization level compared to raw apple and raw lettuce for all volatile compounds measured. Apple juice and mint juice reduced the levels of volatiles, but not as effectively as chewing raw apple or raw mint. Both heated apple and lettuce produced a significant reduction of volatiles. Green tea had no deodorizing effect on the garlic compounds.

According to the researchers, foods deodorize garlic breath through two mechanisms. First, enzymes in the raw foods help to destroy the odors, and then, phenolic compounds in both the raw and cooked foods destroy the volatiles. This is why raw foods were generally more effective because they contain both the enzymes and the phenolic compounds.


Yoga may not count toward 30 minutes of daily physical activity, but may have other benefits


Hatha yoga is an increasingly popular form of physical activity and meditative practice in the U.S. It is important to understand the calorie cost and intensity of yoga in relation to the national physical activity guidelines, such as those recommended by the American College of Sports Medicine (ACSM) and the American Heart Association (AHA). These guidelines encourage 30 minutes of moderate-intensity physical activity on most days of the week.

This study was a systematic review that evaluated published research investigations that have directly measured the calorie cost of yoga and calculated the metabolic intensity (METS) of individual yoga poses including a popular sequence called "sun salutations."

Based on ACSM/AHA classification, the intensity of holding most poses and of full yoga sessions ranged from light (less than 3 METS) to moderate-intensity (3-6 METS), with the majority classified as light-intensity.

A few sequences/poses, including the sun salutations, met the criteria for moderate-intensity activity. The health benefits of yoga, however, should not be discounted. The regular practice of yoga may also increase strength, balance and flexibility, calm the mind and reduce stress.

Physical activity lowers the risk of urinary tract infections



The risk of viral infections is known to be affected by physical activity, but little information is available regarding the more serious infections caused by bacteria.


In this study, the investigators examined the relationship between leisure-time physical activity and suspected bacterial infections during a one-year follow up.

Suspected bacterial infections were determined based on prescriptions for antibiotics. Via the use of Denmark's unique civil registration number (an identification number assigned to all citizens at birth), it was possible to link health survey information with information from nationwide registries.

Results showed that compared with sedentary behavior, low leisure-time physical activity was associated with a 10 percent lower risk of any suspected bacterial infection.

Further, low and moderate levels of leisure-time physical activity were associated with a 21 percent and 32 percent reduction of suspected cystitis (urinary tract bacterial infections), respectively -- compared with individuals classified as sedentary. Suspected respiratory tract bacterial infections, however, were not associated with physical activity level.


Friday, September 23, 2016

Low concentration of fish oil in the blood and lack of physical activity contribute to the high levels of depressed mood


Low concentration of fish oil in the blood and lack of physical activity may contribute to the high levels of depressed mood among soldiers returning from combat, according to researchers, including a Texas A&M University professor and his former doctoral student.

In a study titled "Fatty Acid Blood Levels, Vitamin D Status, Physical Performance, Activity and Resiliency: A Novel Potential Screening Tool for Depressed Mood in Active Duty Soldiers," researchers worked with 100 soldiers at Fort Hood to identify which factors affected moods in returning soldiers.

The research was conducted by Major Nicholas Barringer when he was a Texas A&M doctoral student under the direction of Health & Kinesiology Professor and Department Head Richard Kreider, in collaboration with several current and former members of the U.S. Army, and colleagues at Texas A&M.

"We looked at how physical activity levels and performance measures were related to mood state and resiliency," Kreider says. "What we found was the decrease in physical activity and the concentration of fish oil and Omega-3s in the blood were all associated with resiliency and mood."

Kreider says fish oil contains Omega-3 fatty acids that help to boost brain function. He says studies also show that fish oil acts as an anti-inflammatory within the body -- helping athletes and soldiers manage intense training better. Fish oil content is especially important for soldiers due to the consistent training and physical regiments performed in and out of combat and risk to traumatic brain injury.

The study originated from research conducted by Colonel Mike Lewis, M.D. who examined Omega-3 fatty acid levels of soldiers who committed suicide compared to non-suicide control and found lower Omega-3 levels in the blood were associated with increased risk of being in the suicide group.

Barringer says he believes these findings to be significant toward addressing some of the issues many soldiers face.

"The mental health of our service members is a serious concern and it is exciting to consider that appropriate diet and exercise might have a direct impact on improving resiliency," Barringer notes.

In order to properly measure soldiers physically, Kreider and Barringer developed a formula they say has the potential to assist in effectively screening soldiers with potential PTSD ahead of time. The formula measures a number of factors including: fitness and psychometric assessments, physical activity, and additional analysis.

"By improving resiliency in service members, we can potentially decrease the risk of mental health issues," Barringer says. "Early identification can potentially decrease the risk of negative outcomes for our active service members as well as our separated and retired military veterans."

"The military is using some of our exercise, nutrition, and performance-related work and the findings may help identify soldiers at risk for depression when they return from combat tours," Kreider notes. He says that by working to identify such high-risk issues faced by soldiers, it can set a precedent that will benefit not only military leadership, but also the general public.

"The public must realize that our soldiers need support before, during, and after their service," Kreider explains. "There needs to be a time for soldiers to transition, become re-engaged within a community, and stay engaged in that community."


Tuesday, September 20, 2016

Early menopause: increased risk of coronary heart disease, cardiovascular disease mortality, all-cause mortality



In a study published online by JAMA Cardiology, Taulant Muka, M.D., Ph.D., of Erasmus University Medical Center, Rotterdam, the Netherlands, and colleagues evaluated the effect of age at onset of menopause and duration since onset of menopause on certain cardiovascular disease (CVD) outcomes and all-cause mortality.


As many as 10 percent of women experience natural menopause by the age of 45 years. If confirmed, an increased risk of CVD and all-cause mortality associated with premature and early-onset menopause could be an important factor affecting risk of disease and mortality among middle-aged and older women. To examine this issue, the researchers conducted a systematic review and meta-analysis of 32 studies (310,329 women) that met criteria for inclusion in the study.

Outcomes were compared between women who experienced menopause younger than 45 years and women 45 years or older at onset. The researchers found that overall, women who experienced premature or early-onset menopause appeared to have a greater risk of coronary heart disease (CHD), CVD mortality, and all-cause mortality but no association with stroke risk. Women between 50 and 54 years at onset of menopause had a decreased risk of fatal CHD compared with women younger than 50 years at onset.

Time since onset of menopause in relation to risk of developing intermediate cardiovascular traits or CVD outcomes was reported in 4 observational studies with inconsistent results.

"The findings of this review indicate a higher risk of CHD, cardiovascular mortality, and overall mortality in women who experience premature or early-onset menopause when younger than 45 years. However, this review also highlights important gaps in the existing literature and calls for further research to reliably establish whether cardiovascular risk varies in relation to the time since onset of menopause and the mechanisms leading early menopause to cardiovascular outcomes and mortality," the authors write.