When Anthropology Meets Cardiology

 

When Mount Vesuvius, a volcano near Naples Italy, erupted in 79 AD, it caught the townspeople of nearby Pompeii and Herculaneum by surprise. Many were able to escape, but many died instantly, buried by lava and volcanic ash. Due to the nature of their death, their bodies were well preserved. Recently, scientists were able to study the bodies of these early Mediterranean people and were able to determine what they ate. How does the ancient Mediterranean diet compare to the modern version?  How can the study of ancient peoples give us insight regarding heart healthy diets in today’s world?

 

The Mediterranean basin has been called the cradle of civilization. It stretches from the Nile to Rome and has housed advanced civilizations for thousands of years, including the Egyptian, Assyrian, Babylonian, Persian, Phoenician, Greek and Roman. The Mediterranean diet is linked to the fertile land of the region.  It is more than a diet; it is a way of life and based on traditions linking the land to the preparation, cooking and enjoyment of the food. The key elements of the Mediterranean diet include oil (especially olive oil), whole grains, wine, vegetables, sheep and goat cheese, seafood and very little meat. Whole grains include bread, cereals, couscous, pasta, rice, corn, oats and barley.  The description of the ancient Mediterranean diet comes mainly from written accounts. For example, texts describe the diet of the ancient Greek Olympic athletes starting around 700 BC. The diet was mostly vegetarian, consisting of barley porridge, cheese, fresh vegetables, lentils, beans, seafood, eggs and fresh fruit, mainly figs. Sweets were frowned upon. Initially meat was not a part of the athlete’s diet, but as time went on, meat was incorporated more and more.  Fast forwarding to Pompeii and the modern day, we now have concrete proof of what Roman era Mediterranean people actually ate. Scientists have been able to test the bones of the people frozen in time by the eruption of Mt Vesuvius. Using bioarcheological approaches they determined that the people of Pompeii ate a lot of fish, more than is consumed with the modern Mediterranean diet.  In addition, locally grown fruits and vegetables were eaten. The majority of their food energy came from seafood and cereals, although grain consumption was less than today’s diet. After the fall of Rome, the Mediterranean diet faded during the Middle Ages. It rose again from the ashes and poverty following World War II when meat was scarce and people turned once again to what could be grown locally. The cardiac benefits of the Mediterranean diet were first described in the 1950’s by Ancel Keys, a University of Minnesota researcher who discovered that people in poor towns in southern Italy were healthier than wealthy people in New York City. He conducted the Seven Countries Study and showed that the Mediterranean diet resulted in low levels of cholesterol in the blood as well as low levels of heart artery blockages. 

 

Anthropological data has shown that pre-agricultural hunter-gatherer populations derived a majority of their energy from animal based foods such as meat, fish, birds and eggs. The keto and paleo diets were developed to mimic these eating patterns.  These diets are very low in carbohydrates and high in saturated fat. It is generally believed that hunter-gatherers had low levels of heart disease. Is this true? A recent study performed CT scans on mummies from four regions, including ancient Egypt, Peru, southwest US, the Aleutian Islands and going back 4000 years. Atherosclerosis (calcified plaque in the wall of an artery) was found in 34% of the mummies and was found in all four regions.  In addition, atherosclerosis was present in 60% of the hunter-gatherers.  Atherosclerosis is felt to be a modern disease, but it is clearly present in our ancient ancestors, including hunter-gatherers. 

 

Since atherosclerosis seems to be a fact of human existence, which diets help protect the most against atherosclerotic heart artery disease? In 2021 the American Heart Association outlined its requirements for a heart healthy diet and ranked popular diets on how well they met the criteria. The recommendations included consuming:

Fruits and vegetables

Whole grains (rather than refined grains)

Plant based proteins (such as legumes and nuts)

Fish and seafood

Low-fat or fat-free dairy products

Lean meat or poultry

Plant oils (such as olive oil) 

Minimally processed foods

Minimal added sugar 

Little or no salt

Low amounts of alcohol

The dietary patterns that aligned the most with these criteria included Mediterranean, DASH (Dietary Approaches to Stop Hypertension), pescetarian vegetarian (excludes meat and poultry, includes fish), vegan and low fat. At the bottom of the list were the keto and paleo diets. Is there data, some meat, to back these rankings? One study reviewed all of the literature on seven diets. It found that the Mediterranean diet lowered all deaths, cardiac deaths, stroke and heart attacks. The low fat diet lowered all cause deaths and heart attacks. All of the other diets, including the very low fat Ornish and Pritikin diets, had little or no benefit. Studies on low carbohydrate, high fat “keto-like” diets have not been good. One study had 1220 people and followed them for 12 years. The keto-like diet patients had high levels of LDL cholesterol and were twice as likely to suffer from cardiac events.  Another study of 370,000 people, followed for 23 years, found a higher mortality rate for those on a low carbohydrate diet compared to a low saturated fat diet. 

 

Clearly no randomized controlled trials were done in ancient times to see if any of the diets conferred benefit from heart disease. This was due to a lack of scientific knowledge as well as the fact that our ancestors succumbed at early ages due to infectious disease, famine, the tip of the sword from an enemy or volcanic ash, well before heart disease became manifest.  What is clear from the study of mummies is that high fat diets, keto or paleo, did not protect against atherosclerosis. In addition, our modern studies show that these diets are detrimental to heart health. Heart patients should avoid these types of diets.  On the other hand, the Mediterranean diet is a sustainable, lifelong eating plan that continues to sit atop Agamemnon’s throne as the king of the heart healthy diets. The Mediterranean diet, along with DASH, vegetarian, vegan and low fat diets should continue as staples for the heart patient. 

 

 

Can Congestive Heart Failure Be Cured By Walking With Friends?

Congestive heart failure (CHF) is the inability of the heart to pump blood to meet the requirements of the body. CHF is classified into two groups based on ejection fraction. Ejection fraction (EF) is the percentage of blood ejected by the heart with each heartbeat. Normal EF is greater than 55%. CHF with reduced EF includes patients with EF less than 40% while patients with CHF with preserved EF have EF greater than 50%. CHF is an enormous global problem affecting more than 60 million people worldwide. CHF is the number one reason for hospitalization in the US and associated with frequent hospitalization, high healthcare use and cost. Symptoms of CHF include shortness of breath, trouble breathing with exertion or laying flat in bed, severe exercise intolerance, easy fatigability, and swelling. In 2021, a universal definition of CHF stated that CHF is a clinical syndrome with symptoms caused by a structural heart problem plus either an elevation in the blood of natriuretic peptides or objective evidence of congestion (by physical examination or chest X-ray). Natriuretic peptides are released when the heart is stretched or stressed, as in CHF. There are two natriuretic peptides; BNP and pro-BNP. CHF is present when BNP is greater than 35pg/ml or pro-BNP is greater than 125 pg/ml.

 

CHF with preserved EF affects half of all CHF patients. It affects women more than men and it is increasing in prevalence compared to CHF with reduced EF.  CHF with preserved EF is associated with and may be caused by hypertension, obesity, diabetes, heart artery disease, sleep apnea, kidney dysfunction and advanced age. Treating CHF preserved EF is difficult and frequent hospitalizations often result. A recent guideline recommends SGLT2 inhibitors as first line therapy. These medications, Jardiance and Farxiga, relieve congestion and promote weight loss. In addition, diuretics such as furosemide (Lasix) and spironolactone help in the treatment of fluid overload. The next line of recommended medications include Entresto, valsartan or losartan. Beyond medication, what else can be done? Recent information postulates that CHF preserved EF is an exercise deficiency and a social isolation problem. Addressing those issues could go a long way to treating the disease.

 

CHF preserved EF is a syndrome of exercise deficiency.

An intriguing article hypothesizes a spectrum of shortness of breath with exertion. At one end is the patient with CHF preserved EF. With exercise, such as climbing the stairs, there is insufficient cardiac output to meet the demands of the muscles, pressure goes up in the heart, and breathlessness ensues. The same series of events happens with an elite athlete. The difference is the workload; the CHF patient just walks up the stairs, the athlete has run 26 miles. The athlete has larger cardiac chambers, more heart muscle mass and a compliant heart that can handle high volumes and work loads. The patient with CHF preserved EF has a small, stiff, less compliant heart that cannot handle increased volumes with exertion.  Normal aging results in a smaller heart size, higher filling pressures during exertion and a greater potential for CHF. Being sedentary over the course of a lifetime exacerbates the effects of aging.  For adults who sit many hours each day the cumulative effects of a sedentary lifestyle plus the effects of aging plus other factors (for example, high blood pressure, smoking, diabetes) combine to cause CHF preserved EF. On the other hand, adults who have spent a lifetime exercising regularly can stave off the cardiac stiffness that occurs with age and can avoid CHF. Fortunately, for patients with CHF preserved EF the adverse cardiac effects can be reversed with physical training. For this reason, the American Heart Association recommends structured exercise for patients with CHF preserved EF. Structured exercise, or cardiac rehab, has been shown to reduce hospitalizations and reduce cardiac events. Not all those with CHF preserved EF fall into the category of exercise deficiency; it is reserved for the subset of patients with habitually low levels of physical exertion.

 

CHF preserved EF is a syndrome of social isolation and loneliness.

Social factors are a well-known contributor to heart disease. A recent study followed more than 400,000 people for more than 12 years to see if social isolation or loneliness were associated with CHF. Social isolation was defined as objectively being alone or having few social connections. Loneliness was defined as a painful feeling resulting from a desire for more social connections. Those with social isolation or loneliness were more likely to be men and to have unhealthy lifestyles (smoking, diabetes, obesity, physical inactivity). The study found that both social isolation and loneliness increased the risk for CHF by 15-20%. 

 

So, if you have CHF, or are at risk for CHF, grab a friend, talk a walk, eat, sleep, repeat.