Category: Hypertension

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Fructose – The Role of Fructose in Metabolic Syndrome and Heart Disease

“Mark already ignores me. I think it is because I am in bed and I am a ‘stationary’ object, because once or twice at home when he saw me up and on the way to the toilet he evinced great interest at once. I am absolutely determined to check myself in any tendency to be sad when I see him forgetting and ignoring me, because what matters is that he shall be happy where he is. It is a mercy that he is at an age when ‘now’ is everything. It takes only a day or so to adjust himself completely to new people. I know Bill is right when he says that when I do come back to him he will, within a week, be as though I had never been away.”

 

… I feel hopeful about Mark remembering me again when I come back, because though last time he got quite out of the way of thinking about my being anything but an inanimate object, and used to distress me terribly by crying for someone else if I got him out of his pram or bathed him, yet within a week or so of our being back he was always trying to come to me.

These are the thoughts of a British woman of 32 who was suddenly separated from her husband, Bill, and fifteen-month-old baby, Mark in 1944, an era when those infected with tuberculosis were isolated from society and placed in sanatoriums. Extracts from her diary were published in the Journal of the Royal Society of Medicine in 2004 (1).

Tuberculosis – The Robber of Youth

Tuberculosis is an ancient plague that has flogged humankind throughout history. It has surged in great epidemics and then receded, thus behaving like other infectious diseases, but with a time scale that differs from many other known epidemic cycles.

The disease reached epidemic proportions in Europe and North America during the 18th and 19th centuries, earning the sobriquet, “Captain Among these Men of Death (2).” The bacterial species, Mycobacterium tuberculosis, may have killed more persons than any other microorganism.

Tuberculosis had many nicknames that produced despair and horror; the “great white plague”, “the robber of youth”, and “the graveyard cough”. Therapeutic options were limited, the mainstay of treatment was rest and fresh air.

In the late 19th and early 20th centuries, sanatoria were developed for the treatment of patients with tuberculosis. In 1859 Herman Brehmer opened his Heilenstat in the Silesian Mountain village of Gobersdorf in Germany, emphasizing a regimen of rest, a rich diet, and carefully supervised exercise (3). This facility is considered the first sanatorium devoted to the treatment of tuberculosis.

The first sanatorium in North America was opened in Asheville, North Carolina, by Joseph Gleitsman. Gleitsmann, a German-born and trained doctor, is believed to have selected Asheville because of its optimal combination of barometric pressure, temperature, humidity, and sunlight which he believed to be essential to healing tuberculosis (3).

Although the sanatoriums were supposed to provide treatment and care, they also isolated tuberculosis sufferers not only from those whom they might infect but also from matters of the world they lived in. In his famous novel, The Magic Mountain, Thomas Mann writes about Hans Castorp’s symbolical transport away from the everyday life and mundane obligations he has known, to the rarefied mountain air and introspective little world of the sanatorium

It is hard to comprehend the agony associated with being taken away from your loved ones and isolated from the rest of the world at the same time as realizing that death would be the most likely outcome. Thankfully, tuberculosis is not an epidemic anymore. Although not completely eradicated, it can be prevented and cured. Communicable diseases are no longer the most common cause of death and disability around the world.

Today’s Epidemic – The Metabolic Syndrome

Today’s epidemic is a horse of a different color.  The sanatoriums have been closed. Instead, we are facing a collection of noncommunicable diseases that to a large extent are caused by the way we live our lives, what we eat, whether we smoke, and whether we are couchbound or not.

There is abundant evidence that type-2 diabetes, cardiovascular disease (CVD), non-alcoholic fatty liver disease (NAFLD), hypertension (high blood pressure), and some types of cancer may all be the result of biochemical alterations associated with the modern Western diet. These metabolic changes, collectively known as metabolic syndrome, are characterized by insulin resistance, derangements of glucose metabolism, hypertension, high blood triglycerides, and low blood levels of HDL cholesterol.

Of course, we might easily conclude that the metabolic syndrome is a consequence of the obesity epidemic. In fact, recent evidence shows that the worldwide prevalence of overweight and obesity combined rose by 27.5% for adults and 47.1% for children during the past three decades (4). Interestingly, these increases were seen in both developed and developing countries.

However, although metabolic syndrome often seems to travel with obesity, it occurs in normal-weight people as well. Furthermore, many obese individuals do not have the metabolic abnormalities that characterize the metabolic syndrome. Hence, it has to be assumed that it is not only about body weight and calories. But, if weight gain itself is not the culprit, what is?

For many experts, the answer is obvious (5). It’s added sugar (6), fructose, the silent ‘sweet killer’.

The Silent ‘Sweet Killer’

Fructose is massively used by the food industry due to its very sweet taste and lack of inhibition of satiety compared with other types of sugar (7).

Fructose is a monosaccharide that is found naturally in fruits. It is typically consumed as sucrose (table sugar), a disaccharide composed of equal parts of fructose and glucose, or as a component of high-fructose corn syrup (HFCS). According to US Department of Agriculture (USDA) data, 60% of HFCS used is 55% fructose, and the remainder is typically 42% fructose (8).

For the last few decades, there has been an enormous rise in fructose consumption in the U.S. It is highest among adolescents (12–18 years). The largest source of fructose is sugar-sweetened beverages (30%) followed by grains (22%) and fruit or fruit juice (19%) (9)

There is strong evidence from both experimental and animal studies suggesting that high fructose consumption can lead to insulin resistance, high blood pressure, lipid abnormalities, and NAFLD.

The metabolic effects of fructose are very different from those of glucose. Fructose is metabolized almost exclusively in the liver whereas glucose can be metabolized by most cells of the body.

The entry of fructose into cells is not dependent on insulin and does not promote insulin secretion, unlike glucose. Fructose promotes an increase in blood levels of triglycerides (10). Elevated triglycerides caused by excessive fructose intake may be a precursor of insulin resistance (11).

Fructose-sweetened beverage consumption habits are associated with a central fat distribution and visceral obesity (12). Visceral fat tissue appears much more damaging to health than other types of fat tissue. Obese individuals with excess visceral obesity have a higher risk of diabetes, lipid disorders, and CVD than those with less visceral fat accumulation (13).

However, this may all be circumstantial evidence.  The question remaining is whether fructose plays a causative role in the biochemical abnormalities associated with obesity and metabolic syndrome? Does restricting fructose intake improve these metabolic abnormalities? Will reducing fructose reduce the risk of noncommunicable diseases such as diabetes, CVD, NAFLD, and cancer?

Interestingly, these important questions were addressed recently in a very important paper published by Robert Lustig and colleagues from the University of California (14).

Lustig and coworkers studied 43 obese children (ages 8-19) with metabolic abnormalities typical of the metabolic syndrome. All were high consumers of added sugar in their diets (e.g. soft drinks, juices, pastries, breakfast cereals, salad dressings, etc.).

The children were fed the same calories and percent of each macronutrient as their home diet; but within the carbohydrate fraction, the added sugar was removed, and replaced with starch. For example, pastries were taken out, and bagels put in; yogurt was taken out, baked potato chips were put in; chicken teriyaki was taken out, turkey hot dogs were put in. Whole fruit was allowed. Dietary sugar consumption went from 28% to 10% of calories.

To dissociate the metabolic effects of dietary sugar from its calories and its effects on weight gain, it was important to keep weight constant. If the children were losing weight, they were told to eat more. The goal was to remain weight-stable over the ten days of study. On the final day, the children came back to the hospital for testing on their experimental low-added-sugar diet.

The Bottom Line

According to the World Health Organization (WHO), noncommunicable diseases kill 38 million people each year (15). Sixteen million of those deaths may be considered premature as they occur before the age of 70. CVD account for most of these deaths, followed by cancers, respiratory diseases, and diabetes. According to WHO, tobacco use, physical inactivity, the harmful use of alcohol, and unhealthy diets all increase the risk of premature death from noncommunicable diseases.

A worldwide study published last year suggests that sugary soft drinks kill 184,000 adults every year (16). The study shows that 133,000 deaths from diabetes, 45,000 deaths from CVD, and 6,450 deaths from cancer were caused by fizzy drinks, fruit drinks, energy drinks, and sweetened iced teas in the year 2010.

By now, it should be obvious that sugar-sweetened beverages are a single, modifiable component of our diet that can impact preventable death and disability in adults in high-, middle-, and low-income countries, indicating an urgent need for strong global prevention programs.

The success in preventing and treating communicable diseases like tuberculosis may be considered the biggest achievement in the history of medicine. However, it has left us with another enormous problem of a completely different nature. This time, we are not dealing with a ruthless microorganism but with an environment of our own creation, a culture that manages to encourage unhealthy lifestyle and junk food.

Defining our targets is the first step. It’s about time we realize that added sugar, fructose, in particular, is the silent ‘sweet killer,’ the 21st century’s white plague, today’s robber of youth.




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Added Sugar – Why and How to Avoid It

When it comes to the science of nutrition, everyone seems to have an opinion. Consequently, there is huge disagreement, even among the experts. If we ask for advice, there are likely to be dozen different answers. So, in the era of information overflow, the general population, has become severely confused.

Apart from having to choose between various food products, we are urged to make a choice between different paths, almost like finding a favorite football team or choosing a political party. Your cardiologist will likely recommend the DASH diet or a Mediterranean-type diet. Low carb and Paleo have become very popular but are often condemned by the traditional university academic. Then there is low-fat, vegan, gluten free, raw foodism and much more.

In their search for better health, people spend billions every year on books, DVD’s, meal plans, diet products, and food supplements. Simple plans that promise big results are most popular, but usually, don’t work. Nonetheless, we are continuously hoaxed by marketing and empty promises.

However, in the midst of all the confusion and disagreement, there is a simple measure that if taken seriously may improve our health and lessen the risk of disease more than we might never realize. And, in fact, the academics, the vegans and the low carb, low fat and Paleo enthusiasts might all agree on this one.

Yes, I am talking about avoiding added sugar.

What Is Added Sugar?

The sugar in our diet is either naturally occurring or added. For example, fruit and milk contain naturally occurring sugars (fructose in fruit and lactose in milk).

Added sugar is the sugar that is added to food or drink during preparation or processing. Added sugar may be natural (such as fructose) or processed (such as high-fructose corn syrup).

Added sugar provides no nutritional value. However, it boosts flavor, texture, and color, and extends the shelf-life of foods like bread, breakfast cereals, tinned fruit, and vegetables. No wonder food manufacturers love sugar.

Why We Should Avoid Added Sugar

Because of the lack of nutritional value, foods that are rich in sugar are often described as empty calories. If sugary foods and beverages are a large part of our diet, we are likely to miss out on essential nutrients, vitamins, and minerals.

Added sugar is believed to contribute to obesity.

Sugar promotes tooth decay by optimizing growth conditions for bacteria.

Recent evidence from epidemiological studies suggests that high intake of sugar-sweetened beverages increases the risk for metabolic syndrome, type 2 diabetes, coronary heart disease, and stroke (1).

Studies show that sugar-sweetened beverages increase accumulation of fat in the liver, muscle, and the visceral fat depot. Most of the studies support the fact that fructose is the main driver of these metabolic aberrations because it drives fat production and fat release from the liver (2).

A large survey published 2014 showed a significant relationship between added sugar consumption and risk of death from cardiovascular disease (3). Individuals who reported more of their total calorie intake as added sugar had a significantly increased risk of dying from cardiovascular disease.

A recently published paper addressed the link between sugar intake and risk factors for heart disease (4). The study tested the effects of consuming beverages sweetened with different doses of high fructose corn syrup on blood lipids (fats). The results showed that blood levels of LDL-cholesterol, non-HDL cholesterol, and apolipoprotein B, and triglycerides increased in a dose-dependent manner within two weeks following consumption of different doses of high-fructose corn syrup. The authors believe their findings provide a possible link to the increased risk of death from heart disease associated with increased intake of added sugar.

Sugar intake may have negative effects on blood pressure. A meta-analysis of randomized controlled trials showed high intake of sugar to be associated with elevated blood pressure (5).

What Are The Main Sources of Added Sugar?

To avoid added sugar, we have to know where to find it.

The figure below is based on data from NHANES showing the sources of added sugars in the diet of the US population 2005-2006.

Sources of added sugars in the diets of the U.S. population ages 2 years and older. National Health and Nutrition Examination Survey, 2005-2006

The figure shows that soda drinks, energy drinks, and sports drinks provide more than a third of added sugars consumed by Americans. If we add fruit drinks to this number, it becomes evident that more than 46.1 percent of added sugar consumed comes from sugar-sweetened beverages.

Other important sources of added sugar are grain-based desserts, dairy desserts, candy, ready-to-eat cereals, sugars and honey, tea and yeast bread.

Why It’s So Hard to Avoid Sugar

Because sugar is such a popular food additive, we can expect to find it where we least expect it. Food we think of as healthy may contain high amounts of added sugar, such as low-fat yogurt, fruit juice and sauces (e.g. tomato ketchup and sweet and sour sauce).

The Nutrition Facts label contains information about the amount of sugar per serving. The size of the serving (53 g in this case) has to be taken into account. Here the amount of total sugar is 24.5g per 100g (100/53 x 13g) which is very high.

Finding out how much-added sugar is in our food may be confusing. The Nutrition Facts label may be misleading because it contains information about the amount of sugar per serving. So, to interpret this information, the size of the serving has to be taken into account.

The only reliable way is to look at the ingredient list. However, food manufacturers are not required to separate added sugars from naturally occurring sugars. Nonetheless, if you find sugar is listed among the first few ingredients, the product is likely to contain a high amount of added sugar.

A rule of thumb is that more than 15g of total sugars per 100g means that sugar content is high, and less than 5g of total sugars means that sugar content is low.

Another problem is that sugar goes by many different names. The chemical name for sugar has the ending “ose” like fructose, sucrose, glucose, and maltose. So, watch out for the “ose” ending.

The biggest obstacle, however, is that humans seem to love sugar and for most of us the love affair lasts a lifetime. Love is not easily conquered by practical reasoning and rational common sense.

Furthermore, there is evidence that sugar consumption can induce behavior and neurochemical changes that resemble the effects of a substance of abuse. In other words, similar to drugs such as opiates, sugar may be addictive (6).

The Bottom Line

A worldwide study published earlier this year suggests that sugary soft drinks kill 184,000 adults every year (7). The study shows that 133,000 deaths from diabetes, 45,000 deaths from cardiovascular disease and 6,450 deaths from cancer were caused by fizzy drinks, fruit drinks, energy drinks, and sweetened iced teas in the year 2010.

Furthermore, the same study suggests that sugar-sweetened beverages significantly increase disability from diabetes, heart disease, and cancers.

The authors of the paper pin-point sugar-sweetened beverages as a single, modifiable component of diet that can impact preventable death and disability in adults in high-, middle-, and low-income countries, indicating an urgent need for strong global prevention programs.

Thus, taking actions to reduce the intake of added sugar is one of the biggest challenges facing public health authorities worldwide. Due to their potential commercial significance, effective measures will undoubtedly be followed by severe repercussion from parts of the food industry. But, if better health is our aim, confrontations are inevitable.

However, for us, individuals and mortal human beings the message is simple; few lifestyle measures are likely to be more useful than avoiding added sugar whenever possible.

So, what are you waiting for?



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Atrial Fibrillation and Atrial Flutter – AFib Explained

Estimated reading time: 11 minutes

Arrhythmia is a term that is used to describe disorders of heart rhythm. It may be an irregular rhythm, or rapid or slow beating of the heart.

Although most arrhythmias are completely innocent, some may need medical attention, and a few are life-threatening.

The term palpitations describes an awareness of heart muscle contractions in the chest. These are often described as hard beats, fast beats, irregular beats, skipped beats or “flip-flopping”.

Palpitations are most often caused by premature contraction of the upper or lower chambers of the heart. Such symptoms are very common, and in most cases, they are completely benign.

Atrial fibrillation (AFib) is the most common arrhythmia needing medical attention. During the last few years, the prevalence of atrial fibrillation has increased rapidly (1).

The Electrical System of the Heart

The heart has its physiological pacemaker, the sinus node (SA node), in the upper right chamber of the heart, right atrium. The sinus node emits more than 2.5 billion electric pulses during a lifetime.

Although a normal resting pulse may vary between 40 to 100 per minute, the sinus node, influenced by signals from the nervous system and endocrine organs, adjusts the heart rate to meet demands such as during physical exercise.

Normal heart rhythm originating from the sinus node is termed sinus rhythm.

The electrical signal from the sinus node spreads through the two upper chambers of the heart, the atria, causing them to contract and eject blood into the left and right ventricles.

Next, the signals travel to the area that connects the atria with the the lower chambers of the heart (the ventricles), the atrioventricular node (AV node) and from there through an area called the AV bundle, or the bundle of His.

The bundle of His splits into thinner branches (right and left bundle branches) that extend to the right and left ventricles. Finally, the signals reach the muscle cells of the ventricles, causing them to contract.

The Electrical Characteristics of AFib

The term tachycardia is used to describe rapid beating of the heart while the term bradycardia describes slow heart rate.

Tachycardias originating in the atria are usually far better tolerated than those originating in the ventricles (ventricular tachycardia).

Atrial fibrillation is characterized by a chaotic electrical activity of the atria leading to rapid, irregular heart rhythm. The atria discharge at a very fast rate, exceeding 300 per minute or faster. But, fortunately, these rapid electrical impulses cannot reach the ventricles without traversing the AV node.

The AV node reduces the impulses reaching the ventricles by about two-thirds. While the resulting heart rate is rapid and irregular, it can often be tolerated for long periods.

Epidemiology and Underlying Causes of AFib

Despite many years of research and recent advances, the precise mechanisms underlying atrial fibrillation are not exactly understood. Changes in the electrical characteristics of atrial cells are believed to be important.

Atrial fibrillation is more common in men than women and its prevalence increases with age (2). Atrial fibrillation’s growing prevalence is partly explained by the aging of the population.

Many patients with atrial fibrillation have underlying disorders that increase their risk of arrhythmias such as congenital heart disease, high blood pressure, valvular heart disease, coronary artery disease or obstructive sleep apnea. Rheumatic heart disease, although now uncommon in developed countries, is associated with increased risk of atrial fibrillation.

The use of non-steroidal anti-inflammatory drugs (NSAID) has been associated with increased risk of atrial fibrillation (3)

Having a family history of atrial fibrillation increases the risk of the disorder.

Classification of AFib

The clinical picture of atrial fibrillation varies. Some people only experience a few short periods of atrial fibrillation throughout their lifetime, and in some, atrial fibrillation is constantly present.

Paroxysmal atrial fibrillation is defined as atrial fibrillation that terminates spontaneously or because of specific treatment within seven days of onset. It is sometimes called occasional, self-terminating or intermittent atrial fibrillation.

Persistent atrial fibrillation is defined as atrial fibrillation that persists for more than seven days.

Permanent atrial fibrillation is defined as persistent atrial fibrillation where a clinical decision has been made to not aim at restoring normal sinus rhythm.

Lone atrial fibrillation is a term that was often used in the past to describe atrial fibrillation that occurred in people without underlying heart disease (4). This distinction was believed to be important because when there is a known underlying cause for the arrhythmia, such as heart surgery, heart attack, thyroid dysfunction or lung disease, treatment is directed toward the underlying disease as well as the atrial fibrillation itself.

Lone atrial fibrillation identifies a group of individuals with low risk of complications. Affected individuals are often younger than those with underlying heart disease and more likely to be males. It accounts for between 25-45 percent of cases of paroxysmal atrial fibrillation (5).

History and Diagnostic Evaluation

The diagnosis of atrial fibrillation is based on history, physical examination, and an electrocardiogram (ECG). Further evaluation aims at identifying or excluding underlying heart disease.

History

Patients with atrial fibrillation commonly experience palpitations, such as fast and irregular heart beat. Some experience breathlessness or reduced exercise tolerance. Fatigue, dizziness, light-headedness and increased urination may also be present.

Holter registration may help to identify intermittent atrial fibrillation

However, not all patients with atrial fibrillation are symptomatic. In these cases, atrial fibrillation is often incidentally discovered on physical examination or by an electrocardiogram.

Sometimes atrial fibrillation is preceded by physical exercise, emotional stress or alcohol.

Diagnostic Evaluation

An electrocardiogram (ECG) is used to verify the presence of atrial fibrillation.

Further testing aims at identifying risk factors and excluding the presence of underlying heart disease.

An ultrasound of the heart (echocardiogram) is usually recommended. It provides information about the condition of the heart valves, the size of the atria and the function of the left and right ventricle.

Exercise testing is sometimes performed if coronary heart disease is suspected.

Holter monitors or event recorders are small devices that the patients may carry with them for long-term registration of heart rhythm. They may help to identify episodes of intermittent atrial fibrillation.

Atrial fibrillation is sometimes associated with disorders of the thyroid gland. Therefore, a blood test for analysis of thyroid-stimulating hormone (TSH) and free T4 levels is usually recommended.

Treatment of AFib

Two important management issues have to be addressed when treating atrial fibrillation.

Firstly, atrial fibrillation is associated with increased risk of stroke. The chaotic heart rhythm and absence of atrial contraction may cause blood to pool in the left atrium and form blood clots. These clots can dislodge and travel with the arterial blood stream to the brain or other organs.

Therefore assessment of stroke risk is important, and blood thinning medications (antithrombotic drugs) should be administered when indicated.

Secondly, the rhythm disturbance itself has to be dealt with. There are two options. The first is to strive to restore sinus rhythm; the second is to accept that atrial fibrillation has become permanent and aim treatment at maintaining acceptable heart rate. The former approach is often termed “rhythm control” while the latter approach is called “rate control”.

Blood Thinning Treatment (Antithrombotic Therapy) in AFib

Every patient with atrial fibrillation should be evaluated for the need of antithrombotic therapy. This is usually based on the CHADS2 risk score or the CHA2DS2-VASc score. These scores address risk factors such as age, gender, history of hypertension or vascular disease, heart failure, and diabetes.

Patients with a CHA2DS2-VASc score of zero usually don’t need antithrombotic therapy. Those with a score of one should be considered for treatment, and those with a score of two or more should be treated with antithrombotic drugs, unless there are contraindications such as high bleeding risk.

For many years, warfarin has been the most used drug to reduce the risk of stroke in people with atrial fibrillation. Regular blood samples for measurements of INR (International Normalized Ratio) are required for proper dosing of the drug.

Today, several newer medications that don’t require monitoring are available. Examples are dabigatran (Pradaxa), rivaroxaban (Xarelto) and apixaban (Eliquis).

All these drugs increase the risk of bleeding.

Rhythm Control in AFib

Rhythm control describes a treatment strategy that aims at restoring and maintaining sinus rhythm.

The word “cardioversion” describes the process of converting an arrhythmia to normal sinus rhythm.

Electrical conversion is the most commonly used method to restore sinus rhythm in patients with atrial fibrillation. It is a brief procedure, usually performed under general anesthesia or sedation where an electrical shock is delivered to the heart through paddles placed on the chest.

Sometimes, cardioversion may be achieved by drug treatment.

Before cardioversion, antithrombotic treatment is recommended for several weeks to reduce the risk of blood clots. This therapy is usually continued for at least four weeks after cardioversion unless the episode of atrial fibrillation has lasted less than 48 hours.

Once sinus rhythm is restored, antiarrhythmic drug therapy may be needed to maintain sinus rhythm. Examples of drugs used for this purpose are flecainide (Tambocor), propafenone (Rythmol), amiodarone (Cordarone, Pacerone) and dofetilide (Tikosyn).

Rate Control in AFib

Although there are exceptions, most people with atrial fibrillation have fast heartbeats that may eventually exhaust the heart muscle and lead to heart failure. Therefore, control of heart rate is of key importance when treating this arrhythmia.

In many patients, maintaining sinus rhythm may be a difficult task. In these cases, accepting that atrial fibrillation has become permanent may be a better option than continuing to strive for maintenance of sinus rhythm.

Heart rate slowing drugs are used to control heart rate. Examples of such drugs are beta blockers, calcium channel blockers, and digoxin.

Studies have suggested that rhythm control and rate control strategies are associated with similar risks of mortality and complications such as stroke. The rhythm control strategy is more often used for younger patients and if symptoms are severe.

Catheter and Surgical Procedures

Maintaining sinus rhythm may sometimes be a difficult task. Accepting a rate control strategy may also be problematic if the patient is very symptomatic. In those cases, catheter ablation or surgical procedures may be an option.

Catheter Ablation for AFib

In this procedure, long thin tubes (catheters) are inserted, usually into the groin and guided through a vein to the heart. Special techniques are used to map out the area or “hot spots” that trigger the arrhythmia. These are usually located in the left atrium, close to the origins of the pulmonary veins. By using radiofrequency energy through electrodes at the catheter tips to induce scarring, the abnormal electric signals may be blocked.

Surgical Procedures

The maze procedure has been used to treat atrial fibrillation. It is performed during open heart surgery by creating several incisions in the atria. This leads to the formation of scar tissue that may help block the abnormal electrical signal causing the atrial fibrillation.

Because the surgical maze procedure requires open heart surgery it is usually reserved for individuals with severe symptoms who don’t respond to other types of therapy.

Lifestyle and AFib

Smoking and a sedentary lifestyle are known risk factors for heart disease.

Obesity is associated with an increased risk of atrial fibrillation (6).

A recent study found that general weight management reduced the burden of atrial fibrillation in overweight and obese patients with symptomatic atrial fibrillation (7). Therefore, maintaining a healthy weight is important.

Not smoking is of key importance.

Regular physical exercise is associated with lower incidence of atrial fibrillation (8).

A diet low in salt and rich in fruits, vegetables, and whole grains may be beneficial if high blood pressure is present (9)

Excessive alcohol intake is associated with increased risk of atrial fibrillation (10).

Atrial Flutter

Atrial flutter is an arrhythmia with many similar characteristics as atrial fibrillation, but they differ somewhat with regards to underlying mechanisms and management. Both arrhythmias are associated with increased risk of blood clotting. Some patients have both atrial fibrillation and atrial flutter.

Atrial flutter is not as common as atrial fibrillation. The use of anti-thrombotic, antiarrhythmic and heart rate slowing drugs is similar for atrial flutter and atrial fibrillation.

Electrical cardioversion is often used to restore sinus rhythm in atrial flutter, and catheter ablation may be useful.

The Take-Home Message

Atrial fibrillation is the most common arrhythmia needing medical attention. It is associated with increased risk of stroke.

Atrial fibrillation is an independent risk factor for mortality in both men and women (11). However, many specialists believe that the atrial fibrillation itself is not causal. In other words, the increased risk of mortality may be due to other factors associated with the arrhythmia, such as high blood pressure and coronary heart disease.

Many patients with atrial fibrillation need long-term treatment with blood thinners (antithrombotic therapy) to reduce the risk of stroke.

Electrical cardioversion is often used to restore normal heart rhythm in patients with atrial fibrillation.

Further treatment aims at maintaining sinus rhythm and/or controlling heart rate if atrial fibrillation is persistent. Antiarrhythmic drugs and drugs that slow heart rate are usually administered for this purpose.

Catheter ablation or surgical therapy is reserved for highly symptomatic patients who don’t respond to other types of therapy.

Lifestyle factors such as regular exercise, not smoking, healthy diet and maintaining a healthy weight are all important therapeutic measures.




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Health Benefits of Jogging

Since the 1970’s jogging has become an increasingly popular form of exercise.

Jogging means running at a gentle pace. Going at a pace of less than 6 miles per hour (10 km per hour) is usually defined as jogging, while running is defined as anything faster than 6 miles per hour.

There are many reasons why jogging has become so popular. Firstly, it is easily accessible and relatively inexpensive. Secondly, it usually makes people feel good. Thirdly, we believe jogging to be associated with good health and increased life expectancy.

However, there have also been concerns about possible harmful effect of jogging. We’ve all heard of people dying while jogging and it is often suggested that it might be too strenuous for ordinary middle-aged people.

James Fuller (“Jim” Fixx) was an American, who wrote the 1977 best-selling book The Complete Book of Running. His enthusiasm and believe in the role of exercise helped spark America’s fitness revolution, and he blew the lid off the alleged health benefits of running and jogging.

James Fixx (1932-1984)

Fixx started running in 1967, then 35 years old. At that time, he weighed 240 pounds (110 kg) and smoked two packs of cigarettes every day. Ten years later, at the time of the publication of his book, he had lost 60 pounds (27 kg) and had quit smoking.

He firmly believed in the benefits of physical exercise and boosted the belief that regular jogging and running would increase average life expectancy.

Sadly, Fixx died of a heart attack while jogging, at the age of 52. The autopsy revealed severe coronary artery disease.

Fixx’s sudden passing sent waves of shock through the community. Lawrence K. Altman MD wrote for The New York Times

THE first symptom of heart disease is sometimes sudden death. Never was that fact made clearer than in the ironic death last week of James Fixx, whose best-selling book ”The Complete Book of Running” led tens of thousands to take up jogging and made him a guru of the running world. Mr. Fixx, whose transition from a heavy young man who smoked two packs of cigarettes a day into a trimmer, middle-aged nonsmoking athlete seemed to insure a healthy life, died at the age of 52 while jogging in Vermont…”

Fred Lebow, then president of the New York Road Runners Club, and the guiding light of the New York City Marathon said

”What I’m concerned about now is all those people who talk about the danger of running. What does this prove to them? Sure, we have people dying in Central Park, one or two a year while running. But I’m sure more people die on the golf course or watching the Yankees play baseball. Maybe if Jim Fixx didn’t run, he’d have died five years ago.”

Of course, it must be acknowledged that Fixx had a family history of heart disease, and there were several lifestyle issues that may have increased his risk. His father had a heart attack at the 35; Fixx was a heavy smoker before he took up running, and he had a stressful occupation.

In 2013, the number of US joggers was estimated to be 54 million. This number has increased 20-fold in 35 years. Therefore, studies on the health effects of running and jogging may have important implications for public health.

Health Benefits of Jogging

In 1953, British researchers found that drivers of London’s double-decker buses were more likely to die from heart attack than the more physically active conductors

In 1953, British researchers found that drivers of London’s double-decker buses were more likely to die from heart attack than the more physically active conductors (1). Another study published five years later found that government clerks suffered more fatal heart attacks than postmen (2).

These studies laid the foundation for the hypothesis that men in physically active jobs were at lower risk of heart disease than men in physically inactive jobs. In other words, it was proposed that a sedentary lifestyle was a risk factor for heart disease.

The Honolulu Heart Study followed physically capable elderly men aged 71 to 93 years (3). The results published 1999 showed that men who walked less than 0.25 mile a day had a two-fold increased risk of coronary heart disease compared to those who walked more than 1.5 miles a day. The researchers concluded that the risk of coronary heart disease decreases with increases in distance walked.

The Copenhagen City Heart Study kicked off in the 1970’s. It is a prospective population study of cardiovascular disease of around 20,000 men and women aged 20 years and over. The study makes use of the Copenhagen Population Register.

Data from this study published 2000 showed significantly lower mortality among male joggers compared with men that did not jog (4).

In a paper published by the same group in 2013, regular jogging was associated with longevity among both men and women. The age-adjusted increase in survival with jogging was 6.2 years for men and 5.6 years for women.

How Much Jogging Will Improve Health

Despite the association between jogging and longevity, the optimal intensity, frequency, and duration of physical activity have yet to be established. However, two recent papers may shed some light on these issues.

A recent paper from the Copenhagen City Heart Study addresses the association between the dose of regular jogging and longevity in 10,89 healthy joggers (5).

Firstly, the study found that jogging, even less than one hour a week or once per week is associated with a significant reduction in mortality risk compared with sedentary non-joggers.

Secondly, 1 to 2.4 hours of jogging per week with a frequency of 2-3 times per week, at slow average pace is most strongly associated with a reduction in mortality risk.

Thirdly, higher jogging times (more than 2.5 hours per week), higher frequencies (more than three times per week), and faster paces were not associated with better survival compared with sedentary non-joggers.

These findings are supported by another recently published paper from The Aerobics Center Longitudinal Study, which is based in Dallas, Texas (6).

The study addressed 55,000 adults between 18 and 100 years of age who were followed for 15 years.

Runners as compared with non-runners had a 30% and 45% lower risk of all-cause and cardiovascular mortality, respectively.

Maximal benefits on cardiovascular mortality risk were found with moderate doses of running (specifically 6-12 miles per week), running durations of 50-120 minutes per week, a running frequency of approximately three times a week and a modest pace of approximately 6-7 miles per hour.

Hazard ratios (HRs) of all-cause and cardiovascular mortality by running characteristic (weekly running time, distance, frequency, total amount, and speed). Data from The Aerobics Center Longitudinal Study. J Am Coll Cardiol. 2014;64(5):472-481. doi:10.1016/j.jacc.2014.04.058

Why Should We Jog?

Regular jogging may have several health benefits. Beneficial effects on blood pressure, HDL cholesterol, bone health, and mental health have been reported.

Furthermore, observational studies have consistently found an association between regular jogging and reduced mortality risk as compared to sedentary behavior. Maximal health benefits in terms of longevity may be achieved with light or moderate exercise.

However, case-control studies such as these can’t prove causality. The results tell us that people who jog are likely to live longer than those who don’t. However, they don’t prove that jogging prolongs life.

George Sheehan (1918-1993)

The late Dr. George Sheehan was a respected cardiologist, an accomplished runner, and author of eight books. Similar to Jim Fixx he was one of the pioneers of the fitness boom of the 1970’s. He was a popular lecturer and traveled the world to teach about the importance of exercise and sport and promote the “athletic life”.

Sheehan was very passionate about running. He had a very competitive personality and was always looking for ways to improve. For him, the feel-good factor was probably more important than anything else.

In his book Running and Being Sheehan writes

A daily jogger has written to me in frustration because medical science has failed to come up with conclusive proof that jogging will prevent heart disease. Why jog, he asks, if there is not definite evidence that jogging will thwart a heart attack?

The answer, it seems to me, is that we should do so for more important and urgent and compelling reasons. We jog, play tennis, cycle, swim, hike, hunt, ride horses or whatever because they have to do with the quality of our lives rather than the quantity.

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Benefits of Coffee – Caffeine Benefits Explained

It’s been almost forty years since Bob Dylan and Emmylou Harris sang about the guy who left his gypsy girl for a journey “to the valley below”. His final cup of coffee became a classic.

One more cup of coffee for the road
One more cup of coffee ‘fore I go
To the valley below

– Bob Dylan 1976

Coffee, second to water, is the most widely consumed beverage in the US (1). However, the US doesn’t reach the world’s top ten when it comes to coffee consumption per capita. Consumption is higher in Scandinavia and many other European countries (2).

About two-thirds of Americans drink coffee daily. Given its widespread popularity, small benefits or harms associated with coffee may have important implications for public health.

Caffeine is the best-known compound in coffee. However, coffee contains more than 1.000 substances, among them, are diterpene alcohols and chlorogenic acid.

Caffeine is known for its stimulating effects on the central nervous system; diterpene alcohols have been associated with elevation of cholesterol (3) and chlorogenic acid and flavonoids in coffee have antioxidant and anti-inflammatory effects.

Caffeine is the most widely used stimulant in the world and one of few that is socially accepted. In most cases, exposure to caffeine continues for many years, often throughout life. It is estimated that 80-90 percent of adults in the world consume coffee daily.

Habitual coffee consumption often leads to mild physical dependence. Withdrawal symptoms such as irritability, headache, fatigue, anxiety and depressed mood are common if consumption is stopped abruptly.

Most of the data on the health effects of coffee are derived from observational studies. Unfortunately, such studies can’t prove a causative relationship between habitual coffee consumption and different health issues. However, currently available evidence suggests that habitual coffee consumption may have important effects on health and wellbeing.

 

How Much Coffee is Safe?

The average US adult drinks about two cups of coffee per day which is equivalent to approximately 280 mg of caffeine. However, this depends on the caffeine content of the coffee that varies greatly.

Consuming high amounts of caffeine may cause palpitations, anxiety, tremors and sweating. Very high doses may even be lethal.

Men consume more coffee than women; smokers drink more than nonsmokers and coffee consumption is lower in the black than in the white population in the US (4).

For most adults, consumption of up to 400 mg of caffeine a day appears safe (5).

It is important to keep in mind that soft drinks and energy drinks are also a common source of caffeine.

Coffee and Cardiovascular Risk Factors

Habitual coffee consumption may affect risk factors for cardiovascular disease such as blood lipids and blood pressure. In theory, this may influence health, quality of life and risk of developing coronary heart disease or stroke.

Coffee and Cholesterol

Cafestol and kahweol are examples of diterpenes in coffee beans that may raise blood cholesterol and triglycerides (6).

The highest amounts of cafestol are found in unfiltered coffee drinks such as French press coffee or Turkish/Greek coffee. Kahweol is a similar molecule, typically found in Coffea Arabica.

Diterpenes are extracted from coffee by prolonged contact with hot water. When coffee is filtered, diterpenes are retained in the filter paper, and the coffee has much shorter contact with hot water. Consequently, boiled coffee has higher concentration of diterpenes than brewed/filtered coffee.

A meta-analysis of 14 randomized controlled trials showed a significant increase in total and LDL cholesterol following regular consumption of boiled coffee compared to filtered coffee (7).

Coffee and Blood Pressure

High blood pressure (hypertension) is a strong risk factor for coronary heart disease and stroke.

Coffee consumption may be associated with acute, short-term increase in blood pressure that may last for up to three hours. However, long-term blood pressure does not seem to be significantly affected by habitual coffee consumption (8).

A 2012 meta-analysis did not show any significant effect of coffee consumption on blood pressure or the risk of hypertension (9). However, the authors of the paper conclude that the quality of currently available evidence is low, and therefore “no recommendation can be made for or against coffee consumption as it relates to blood pressure and hypertension“.

In other words, scientific evidence has not shown an association between coffee consumption and the risk of developing hypertension. However, such a relationship can’t be ruled out.

Coffee, Insulin Resistance, and Diabetes

Habitual coffee consumption is associated with reduced risk of diabetes (10).

Drinking coffee, both caffeinated and decaffeinated was associated with lower risk of diabetes according to a recent analysis of a huge epidemiological database from the Nurse’s Health Study (11). A four to eight percent risk reduction in incident type-2 diabetes may be expected for every one cup increment in coffee consumption.

Several mechanisms have been proposed to explain the protective effects of coffee on the risk of developing diabetes. Coffee is rich in chlorogenic acid, an antioxidant that may improve glucose metabolism and insulin sensitivity (12).

Another study found that consumption of 5 cups of coffee per day increased adiponectin levels and decreased insulin resistance (13).

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Coffee and Cardiovascular Disease

Caffeine has diverse effects on the cardiovascular system. It has been associated with increased heart rate, palpitations and elevated blood pressure, in particular among non-habitual coffee drinkers.

Coffee and Coronary Heart Disease

Studies performed in the 1970s suggested that habitual coffee consumption was associated increased risk of heart attack (myocardial infarction) (14,15). Today it is believed that confounding factors such as smoking, alcohol use, and physical activity may have flawed those early studies.

Since then, many observational studies have addressed the association between habitual coffee consumption and coronary heart disease. Most of these studies have shown neutral effects.

A 2009 meta-analysis of prospective cohort studies showed that moderate coffee consumption was associated with lower risk of coronary heart disease (16).

A recent Korean study showed  that middle-aged individuals who drank 4-5 cups of coffee a day had less calcification in their coronary arteries compared to those who drank less coffee (17). Coronary artery calcium score is  a known risk factor for developing clinical coronary heart disease.

Coffee and Arrhythmia (Irregular Heartbeat)

There is widespread belief that habitual coffee consumption is associated with heart palpitations and irregular heartbeat. However, data linking coffee consumption to arrhythmia is inconsistent.

Atrial fibrillation is a common arrhythmia and has sometimes been associated with habitual coffee consumption. However, a 2013 meta-analysis suggests that caffeine exposure is not associated with increased risk of atrial fibrillation (18).

Recent studies suggest that coffee does not cause arrhythmia. In fact, one large study suggests that  people who drank four cups of coffee per day were less likely to be hospitalized for arrhythmias (19). Therefore it is unlikely that moderate caffeine intake increases the risk of clinically significant arrhythmia.

Coffee and Stroke

A recent meta-analysis of prospective studies that have examined coffee consumption and risk of cardiovascular events in a general population found that moderate intake is associated with a decreased risk of stroke (20).

In the Swedish Mammography Cohort, coffee consumption was associated with lower risk of stroke among 34,670 women without a history of cardiovascular disease or cancer (21). The authors of the paper concluded that low or no coffee consumption is associated with an increased risk of stroke in women.

Data from the large Nurses’ Health Study showed an association between coffee consumption and decreased risk of stroke in a large cohort of women (22). The authors of the paper concluded that coffee consumption may modestly reduce the risk of stroke.

Coffee and Cancer

Caffeine has not been shown to cause any type of cancer (23).

The relationship between caffeine consumption and breast cancer is uncertain. Some studies have found coffee consumption to be associated with lower risk of breast cancer while others have not (24).

Some studies suggest that coffee consumption is associated with increased risk of lung cancer (25). However, this association became only marginally significant when the analysis was stratified by smoking status. Smokers, in general drink more coffee than non-smokers. Therefore, these results have to be interpreted with caution.

Observational studies have suggested that coffee consumption is associated with a decreased risk of some cancers of the gastrointestinal tract, particularly cancer of the mouth and throat (oropharyngeal cancer)(26) and cancer of the liver.

The relationship between coffee consumption and bowel cancer (colorectal cancer) is unclear (27). Although some studies suggested an association between coffee consumption and decreased risk of colorectal cancer, other studies have not supported this finding.

Habitual coffee consumption is associated with reduced risk of prostate cancer according to a number os studies (28). It has been suggested that this effect is related to other components of coffee than caffeine as a similar level of protection was found for those drinking caffeinated and decaffeinated coffee (29).

Other Health Benefits of Coffee

Studies have shown habitual coffee consumption to be associated with decreased rate of depression in women. This effect seems to be largely related to the caffeine content because similar association was not found for decaffeinated coffee (30)

Coffee is associated with reduced risks of Alzheimer’s disease (31) and Parkinson’s disease (32).

According to some studies coffee may increase the risk of bone loss. This may partly be offset by daily milk consumption (33).

Numerous observational studies have shown a relationship between coffee consumption and decreased all-cause mortality, suggesting that drinking coffee may prolong life (34,35,36).

Two prospective cohorts studies published 2015 showed that habitual intake of coffee was with lower risk of total mortality and less mortality from heart disease, cerebrovascular disease, respiratory disease, diabetes and influenza (37,38).

Health Benefits of Coffee – The Take Home Message

The association between habitual coffee consumption and health is mainly based on observational studies. Although such studies can’t prove a causative relationship, currently available evidence does not suggest that moderate coffee consumption is associated with health risks or increased risk of cardiovascular disease or cancer.

There is an association between habitual coffee consumption and decreased risk of diabetes, coronary heart disease, stroke and some cancers. However, the possibility that coffee consumption is a surrogate marker for other lifestyle factors can’t be ruled out.

Current evidence suggests that habitual coffee consumption can be a part of a healthy lifestyle, and there is no reason to advise individuals with established cardiovascular disease to abstain from moderate coffee consumption.

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