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Category: cardiovascular health

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Interesting to think of bacteria and biofilms (bacterial communities resistant to treatment) involved in stress related heart attacks. From Science Daily:

Bacteria help explain why stress, fear trigger heart attacks

Scientists believe they have an explanation for the axiom that stress, emotional shock, or overexertion may trigger heart attacks in vulnerable people. Hormones released during these events appear to cause bacterial biofilms on arterial walls to disperse, allowing plaque deposits to rupture into the bloodstream, according to research published in published in mBio®, the online open-access journal of the American Society for Microbiology.

"Our hypothesis fitted with the observation that heart attack and stroke often occur following an event where elevated levels of catecholamine hormones are released into the blood and tissues, such as occurs during sudden emotional shock or stress, sudden exertion or over-exertion" said David Davies of Binghamton University, Binghamton, New York, an author on the study.

Davies and his colleagues isolated and cultured different species of bacteria from diseased carotid arteries that had been removed from patients with atherosclerosis. Their results showed multiple bacterial species living as biofilms in the walls of every atherosclerotic (plaque-covered) carotid artery tested.

In normal conditions, biofilms are adherent microbial communities that are resistant to antibiotic treatment and clearance by the immune system. However, upon receiving a molecular signal, biofilms undergo dispersion, releasing enzymes to digest the scaffolding that maintains the bacteria within the biofilm. These enzymes have the potential to digest the nearby tissues that prevent the arterial plaque deposit from rupturing into the bloodstream. According to Davies, this could provide a scientific explanation for the long-held belief that heart attacks can be triggered by a stress, a sudden shock, or overexertion.

To test this theory they added norepinephrine, at a level that would be found in the body following stress or exertion, to biofilms formed on the inner walls of silicone tubing."At least one species of bacteria -- Pseudomonas aeruginosa -- commonly associated with carotid arteries in our studies, was able to undergo a biofilm dispersion response when exposed to norepinephrine, a hormone responsible for the fight-or-flight response in humans," said Davies. Because the biofilms are closely bound to arterial plaques, the dispersal of a biofilm could cause the sudden release of the surrounding arterial plaque, triggering a heart attack.

To their knowledge, this is the first direct observation of biofilm bacteria within a carotid arterial plaque deposit, says Davies. This research suggests that bacteria should be considered to be part of the overall pathology of atherosclerosis and management of bacteria within an arterial plaque lesion may be as important as managing cholesterol.

Note the red biofilm bacterial colonies within the diseased arterial wall:

Bacteria stained with a fluorescent bacterial DNA probe show up as red biofilm microcolonies within the green tissues of a diseased carotid arterial wall.

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Moderate levels of exercise seems to have tremendous benefits for everyone, but there are downsides to being an extreme exerciser.  From Science Daily:

Elderly men with high blood pressure lower death risk with moderate fitness

Elderly men with high blood pressure can lower their risk of death with even moderate levels of fitness. "This level of fitness is achievable by most elderly individuals engaging in a brisk walk of 20 to 40 minutes, most days of the week," said Charles Faselis, M.D., lead author of the study.

For the study, researchers assessed the fitness status of 2,153 men, aged 70 years and older with high blood pressure by a standard treadmill exercise test. Researchers applied the international units used to measure fitness, called metabolic equivalents (METs), to determine the men's peak fitness levels. After an average follow-up of nine years, researchers found that the risk of death was 11 percent lower for every one-MET increase in exercise capacity.

"For every 100 people who died in the least-fit category, 82 died in the low-fit, 64 in the moderate-fit and 52 in the high-fit categories," Kokkinos said. "The death rate is cut in half for those in the highest fitness category."

Too much exercise also has negatives for men. From Medical Xpress:

Too much prolonged high-intensity exercise risks heart health

Overdosing on high intensity exercise may actually increase the risk of death from a heart attack or stroke in those with existing heart disease, suggests German research published online in the journal Heart.

Similarly, a second Swedish study in the journal suggests that young men undertaking endurance exercise for more than five hours a week may increase their risk of developing an irregular heart rhythm in later life.

Both sets of findings indicate a J-shaped curve for the health benefits of exercise... And they describe "a similar U-shaped or reverse J-shaped pattern for the dose-response effect of exercise: maximum cardiovascular benefits are obtained if performed at moderate doses, while these benefits are lost with (very high) intensity and prolonged efforts."

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It seems that research showing benefits of exercise is multiplying. This study only looked at men, and if you look at the "after age 40 group", their average age of starting endurance training was 48. From Science Daily:

Forty not too old or too late to start endurance training

A study of healthy senior men has found that "relatively intensive" endurance exercise confers benefits on the heart irrespective of the age at which they began training. The benefits were evident and comparable in those who had started training before the age of 30 or after the age of 40. As a result, said the investigators, 40 is not too old to start endurance training.

The study was performed in 40 healthy men (without cardiovascular risk factors) aged between 55 and 70 years who were divided for assessment according to the level of exercise they took and the ages at which they began. Thus, 10 of the men had never exercised for more than 2 hours a week throughout their lives, and 30 had exercised for at least 7 hours a week for over five years.

The regular exercise they took was either running or cycling. Those beginning before the age of 30 had been training for an average of 39 years (since the age of 22) and those starting at 40 for 18 years (since the age of 48).

First, resting heart rate was found to be similar between the two exercise groups (T30 56.8 bpm, T40 58.1 bpm), but significantly faster in the non-exercising men (69.7 bpm). Maximal oxygen uptake was also similar between the T30 (47.3 ml/min/kg) and T40 groups (44.6 ml/min/kg), but significantly lower in the non-exercising men (33.0 ml/min/kg).

The study also found no difference between T30 and T40 in cardiac echocardiography tests. "Thus," said Matelot, "despite biological changes with age, the heart still seems -- even at the age of 40 -- amenable to modification by endurance training. Starting at the age of 40 does not seem to impair the cardiac benefits.

Matelot pointed out that aging is associated with adverse structural and functional changes to the cardiovascular system. And, while physical activity is unable to prevent these changes, it is able to slow them down.

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Once again research shows problems with physical inactivity: this time heart disease risk in women. From Science Daily:

From age 30 onwards, inactivity has greatest impact on women's lifetime heart disease risk

From the age of 30 onwards, physical inactivity exerts a greater impact on a woman's lifetime risk of developing heart disease than the other well-known risk factors, suggests research published online in the British Journal of Sports Medicine. This includes overweight. the findings show, prompting the researchers to suggest that greater effort needs to be made to promote exercise.

The researchers wanted to quantify the changing contribution made to a woman's likelihood of developing heart disease across her lifetime for each of the known top four risk factors in Australia: excess weight (high BMI); smoking; high blood pressure; and physical inactivity. Together, these four risk factors account for over half the global prevalence of heart disease, which remains the leading cause of death in high income countries.

They based their calculations on estimates of the prevalence of the four risk factors among 32,154 participants in the Australian Longitudinal Study on Women's Health, which has been tracking the long term health of women born in 1921-6, 1946-51, and 1973-8, since 1996.

Combining the prevalence and relative risk data, the researchers found that up to the age of 30, smoking was the most important contributor to heart disease, with a PAR of 59%. But from age 30 until the late 80s, low physical activity levels were responsible for higher levels of population risk than any of the other risk factors.

The researchers estimate that if every woman between the ages of 30 and 90 were able to reach the recommended weekly exercise quota -- 150 minutes of at least moderate intensity physical activity -- then the lives of more than 2000 middle aged and older women could be saved each year in Australia alone.

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The numbers are so staggering that at first I thought it was a joke (it being April 1). But no, these are the real study results. From Science Daily:

Eating seven or more portions of fruit and vegetables a day reduces your risk of death by 42 percent

Eating seven or more portions of fruit and vegetables a day reduces your risk of death at any point in time by 42% compared to eating less than one portion, reports a new UCL study.

Researchers used the Health Survey for England to study the eating habits of 65,226 people representative of the English population between 2001 and 2013, and found that the more fruit and vegetables they ate, the less likely they were to die at any age. Eating seven or more portions reduces the specific risks of death by cancer and heart disease by 25% and 31% respectively. The research also showed that vegetables have significantly higher health benefits than fruit.

Compared to eating less than one portion of fruit and vegetables, the risk of death by any cause is reduced by 14% by eating one to three portions, 29% for three to five portions, 36% for five to seven portions and 42% for seven or more. These figures are adjusted for sex, age, cigarette smoking, social class, Body Mass Index, education, physical activity and alcohol intake, and exclude deaths within a year of the food survey.

The study, published in the Journal of Epidemiology & Community Health, found that fresh vegetables had the strongest protective effect, with each daily portion reducing overall risk of death by 16%. Salad contributed to a 13% risk reduction per portion, and each portion of fresh fruit was associated with a smaller but still significant 4% reduction.

"We all know that eating fruit and vegetables is healthy, but the size of the effect is staggering," says Dr Oyinlola Oyebode of UCL's Department of Epidemiology & Public Health, lead author of the study. "The clear message here is that the more fruit and vegetables you eat, the less likely you are to die at any age. Vegetables have a larger effect than fruit, but fruit still makes a real difference. If you're happy to snack on carrots or other vegetables, then that is a great choice but if you fancy something sweeter, a banana or any fruit will also do you good."

The researchers found no evidence of significant benefit from fruit juice, and canned and frozen fruit appeared to increase risk of death by 17% per portion. The survey did not distinguish between canned and frozen fruit so this finding is difficult to interpret. Canned fruit products are almost four times more popular than frozen fruit in Europe*, so it is likely that canned fruit dominated this effect.

"Most canned fruit contains high sugar levels and cheaper varieties are packed in syrup rather than fruit juice," explains Dr Oyebode. "The negative health impacts of the sugar may well outweigh any benefits. Another possibility is that there are confounding factors that we could not control for, such as poor access to fresh groceries among people who have pre-existing health conditions, hectic lifestyles or who live in deprived areas."

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From Medscape:

Allergic Rhinitis Patients Live Longer

Their runny noses might drive them crazy, but people with allergic rhinitis are likely to outlive the rest of us, a new study suggests.

"We found that allergic rhinitis patients had a decreased risk of heart attack, a decreased risk of stroke and, most strikingly, a decreased risk of all-cause mortality," said lead investigator Angelina Crans Yoon, MD, from the Department of Allergy and Clinical Immunology at the Kaiser Permanente Los Angeles Medical Center.

"They were basically half as likely to die during the study period," she told Medscape Medical News. 

Researchers studying data from the National Health and Nutrition Examination Survey (NHANES) found that people who tested positive for allergies were less likely to suffer cardiovascular events.

To explore the issue further, Dr. Crans Yoon and her team looked at a database of Southern California patients.The cohort consisted of 109,229 patients with allergic rhinitis and 109,229 people without allergic rhinitis who were matched for age, sex, and ethnicity. It also consisted of 92,775 patients with asthma who were matched with a similar group without asthma.

Risk for acute myocardial infarction was 25% lower in patients with allergic rhinitis than in those without, risk for a cerebrovascular event was 19% lower, and risk for all-cause mortality was 49% lower. Risk for all cardiovascular events was similar in the allergic rhinitis and control groups.

In contrast, risk for all cardiovascular events was 36% higher in patients with asthma than in those without, whereas risk for cerebrovascular disease and all-cause mortality were similar.

This could be the result of a difference in phenotypes in asthma patients, said Dr. Crans Yoon. People whose asthma is caused by allergies could be at less risk for cardiovascular events than people whose asthma has other causes.

Why should allergic rhinitis decrease someone's risk for death? 

Another explanation could be that the immune systems of patients with allergic rhinitis are hyperalert, aggressively fighting off disease, as well as causing symptoms, when it is not necessary. More work is needed to evaluate that.

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From the Feb. 6, 2014 Science Daily:

Whole diet approach to lower cardiovascular risk has more evidence than low-fat diets

A study published in The American Journal of Medicine reveals that a whole diet approach, which focuses on increased intake of fruits, vegetables, nuts, and fish, has more evidence for reducing cardiovascular risk than strategies that focus exclusively on reduced dietary fat.

This new study explains that while strictly low-fat diets have the ability to lower cholesterol, they are not as conclusive in reducing cardiac deaths. By analyzing major diet and heart disease studies conducted over the last several decades, investigators found that participants directed to adopt a whole diet approach instead of limiting fat intake had a greater reduction in cardiovascular death and non-fatal myocardial infarction.

"Nearly all clinical trials in the 1960s, 70s and 80s compared usual diets to those characterized by low total fat, low saturated fat, low dietary cholesterol, and increased polyunsaturated fats," says study co-author James E. Dalen, MD, MPH, Weil Foundation, and University of Arizona College of Medicine. "These diets did reduce cholesterol levels. However they did not reduce the incidence of myocardial infarction or coronary heart disease deaths."

Carefully analyzing studies and trials from 1957 to the present, investigators found that the whole diet approach, and specifically Mediterranean-style diets, are effective in preventing heart disease, even though they may not lower total serum or LDL cholesterol. The Mediterranean-style diet is low in animal products and saturated fat, and encourages intake of monounsaturated fats found in nuts and olive oil. In particular, the diet emphasizes consumption of vegetables, fruit, legumes, whole grains, and fish.

"The potency of combining individual cardioprotective foods is substantial -- and perhaps even stronger than many of the medications and procedures that have been the focus of modern cardiology," explains co-author Stephen Devries, MD, FACC.

More evidence in support of Mediterranean style diet. From the Feb. 4, 2014 Science Daily:

Mediterranean diet linked with lower risk of heart disease among young U.S. workers

Among a large group of Midwestern firefighters, greater adherence to Mediterranean-style diet was associated with lower risk factors for cardiovascular disease (CVD), according to a new study led by researchers from Harvard School of Public Health (HSPH) and Cambridge Health Alliance (CHA). The study is the first to assess the effects of Mediterranean-style diet among a group of young, working U.S. adults.

The researchers analyzed medical and lifestyle data, including dietary habits, from an existing cohort of 780 male firefighters in the Midwest. They developed a modified Mediterranean diet score (mMDS) to assess the participants' dietary patterns.

The firefighter group with greatest adherence to Mediterranean-style diet showed a 35% decreased risk in metabolic syndrome, a condition with risk factors that include a large waistline, high triglyceride level, low HDL ("good") cholesterol level, high blood pressure, and high blood sugar. The group with the highest mMDS also had a 43% lower risk of weight gain compared with the lowest mMDS group. Additionally, greater adherence to a Mediterranean-style diet was significantly associated with higher HDL cholesterol and lower LDL ("bad") cholesterol. Consistent with previous investigations, obese participants in the firefighter study reported a higher intake of both fast foods and sugary drinks.

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From the Medical Daily:

High Blood Pressure In Teens, Young Adults A Sign Of Hardened Arteries Down The Road

Your blood pressure during your teens and early twenties, though often naturally low due to youth, may have something to do with your cardiovascular health in later years, according to new research from Northwestern University Feinberg School of Medicine. In the new study, which was published in JAMA, researchers found that having higher blood pressure during your teens and twenties was actually linked to hardened arteries at age 40.

The study, led by epidemiologist Norrina Allen, points out the significance of maintaining cardiovascular health at a young age.

The study reviewed 4,600 men and women throughout several different states and followed them for 25 years. They found that 19 percent of them had blood pressure that was much higher than their peers, and that another 5 percent started with high blood pressure that gradually rose. Though these blood pressure readings fell within “normal” range for their age, it was higher than average and thus they were more likely to develop hypertension by age 40. Hypertension is also known as high blood pressure or arterial hypertension.

“While you wouldn’t prescribe medications for this group, you might have conversations with those individuals about ways they can improve their diet or increase physical activity,” Allen told NPR. She notes that “many of these cardiovascular risk factors are cumulative,” meaning they often occur over a long period of time and are a combination of things, from smoking to living a sedentary lifestyle.

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Exposing skin to sunlight may help to reduce blood pressure and thus cut the risk of heart attack and stroke.

From the January 17, 2014 Science Daily: Here Comes the Sun to Lower Your Blood Pressure

Exposing skin to sunlight may help to reduce blood pressure and thus cut the risk of heart attack and stroke, a study published in the Journal of Investigative Dermatology suggests.

Research carried out at the Universities of Southampton and Edinburgh shows that sunlight alters levels of the small messenger molecule, nitric oxide (NO) in the skin and blood, reducing blood pressure... "NO along with its breakdown products, known to be abundant in skin, is involved in the regulation of blood pressure. When exposed to sunlight, small amounts of NO are transferred from the skin to the circulation, lowering blood vessel tone; as blood pressure drops, so does the risk of heart attack and stroke."

While limiting sunlight exposure is important to prevent skin cancer, the authors of the study, including Dr Richard Weller of the University of Edinburgh, suggest that minimising exposure may be disadvantageous by increasing the risk of prevalent conditions related to cardiovascular disease.

Cardiovascular disease, often associated with high blood pressure, accounts for 30 per cent of deaths globally each year. Blood pressure and cardiovascular disease are known to vary according to season and latitude, with higher levels observed in winter and in countries further from the equator, where ultraviolet radiation from the sun is lower.

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According to a new report, exercise can be as effective as many frequently prescribed drugs in treating some of the leading causes of death. This is a major finding! From the Dec.11, 2013 NY Times:

Exercise as Potent Medicine

For the study, which was published in October in BMJ, researchers compared how well various drugs and exercise succeed in reducing deaths among people who have been diagnosed with several common and serious conditions, including heart disease and diabetes.

They ended up with data covering 305 past experiments that, collectively, involved almost 340,000 participants, which is an impressive total. But most of the volunteers had received drugs. Only 57 of the experiments, involving 14,716 volunteers, had examined the impact of exercise as a treatment.The researchers compared mortality risks for people following any of the treatment options.

The results consistently showed that drugs and exercise produced almost exactly the same results. People with heart disease, for instance, who exercised but did not use commonly prescribed medications, including statins, angiotensin-converting-enzyme inhibitors or antiplatelet drugs, had the same risk of dying from — or surviving — heart disease as patients taking those drugs. Similarly, people with diabetes who exercised had the same relative risk of dying from the condition as those taking the most commonly prescribed drugs.

On the other hand, people who once had suffered a stroke had significantly less risk of dying from that condition if they exercised than if they used medications — although the study authors note that stroke patients who can exercise may have been unusually healthy to start with.

Only in chronic heart failure were drugs noticeably more effective than exercise. Diuretics staved off mortality better than did exercise.

Over all, Dr. Ioannidis said, “our results suggest that exercise can be quite potent” in treating heart disease and the other conditions, equaling the lifesaving benefits available from most of the commonly prescribed drugs, including statins.