One of the largest studies conducted on the effects of cardiovascular disease (CVD) on cognitive function, published in the Journal of the American College of Cardiology (JACC), followed over 7,800 people with no previous or existing cognitive impairment (CI) or heart disease. At the end of a twelve-year period, 5.6 percent of those in the group had experienced heart attack or angina. Over the course of those twelve years, three sets of cognitive tests were administered at different times, and it had been determined that none of the participants had risk factors or were likely candidates for impaired brain health or cognitive function. However, researchers found that those who had suffered a heart attack or angina were at a much higher risk for cognitive decline.
In another study reported in JACC, 1,588 dementia-free patients were followed for 21 years and assessed annually. This study examined the impact of cardiovascular risk on “cognitive decline and structural brain differences”. The conclusion was that cardiovascular risk factors such as diabetes, obesity, hypertension, and smoking may not only predict cognitive decline but are also “associated with neurodegeneration and vascular lesions in the brain.”
Until recently, most of the studies regarding cognitive decline have focused on circulation problems caused by events such as stroke, which affects blood supply to the brain. However, more attention is now being paid to the connection between heart function and brain decline through the lens of vascular health. And with the World Health Organization projecting that by the year 2030, a projected 82 million people are projected to develop dementia (an increase of 32 million since 2017), unless we can develop new tools for identifying risk factors, especially since there is no available cure.
The National Institutes of Health published an Expert Opinion paper stating that “cognitive decline is a prevalent condition…in patients with heart failure.” The research they compiled showed that between 39 percent and 80 percent of patients hospitalized for heart failure experienced CI, with the highest percentage accounting for patients with acute decompensation (a sudden worsening of heart failure typically marked by swelling of the legs or feet, fatigue, or difficulty breathing). Because of the prevalence of CI in these patients, these researchers recommended that cognitive assessments become part of the routine examinations for heart failure patients.
Beyond risk factors for heart disease, cognitive assessments lead to higher early identification of CI
There are a number of factors that contribute to cognitive problems in patients with heart failure, including:
- atrial fibrillation
- impaired blood flow
- poor nutrition
- metabolic abnormalities
- co-morbidities including diabetes, anemia, and artherosclerosis
Cognitive impairment due to heart failure, which typically fits the parameters for vascular dementia or vascular cognitive impairment, can range from mild or moderate symptoms to advanced dementia; even mild symptoms can negatively impact independence and self-care. The cognitive areas typically affected include:
- visual-spatial function
- short-term memory
- task processing speed (coordination, accuracy, smoothness)
- executive functions (decision-making, problem solving, planning, social abilities, adaptation)
- reaction time
- difficulty recalling personal memories
Interestingly, research has shown that some of the same risk factors for CVD—diabetes, obesity, and high blood pressure—are also associated with impaired cognition. Risk factors for both CVD and CI increase greatly with age, and because cognitive decline is considered a “normal” part of the aging process, CVD is frequently overlooked as the cause of CI in older patients.
Vascular research provides fresh perspective about cholesterol and fats as cardio- and brain protective
According to the American Heart Association, 121.5 million American adults—over 48 percent—have some form of cardiovascular disease. With so much attention paid by conventional medicine to heart disease over the past several decades, why have the numbers increased so much? This is one major area where functional medicine parts ways with certain conventional medicine recommendations:
Conventional medicine advocates for low- to no-fat diets and makes a generally sweeping claim that fats clog arteries and cholesterol is the enemy, while functional medicine has embraced a multitude of studies that continue to prove that healthy fats and cholesterol are necessary for their anti-inflammatory properties and improvements to arterial flexibility, blood and nerve flow and vascularity.
For example, a study published by the National Institutes of Health followed more than 347,700 participants over a span of 5 to 23 years. Of those participants, 11,006 suffered a stroke or coronary heart disease (CHD) during that time period. However, a thorough analysis concluded that saturated fat intake “was not associated with an increased risk of CHD, stroke, or CVD.”
While a number of studies have reached the same conclusion, there are no one-size-fits-all solutions. Every individual’s genetics and lifestyle need to be taken into consideration before recommendations for optimal health and wellness can be made. However, other risk factors (and this is not a conclusive list) are much more concerning, including metabolic syndrome, insulin resistance (which is rarely, if ever, tested for in conventional medicine), sedentary lifestyles, processed and refined foods, and diets high in carbohydrates and sugars.
In general, a good balance can be found in the Mediterranean diet that uses high amounts of olive oil and fish, but as important are sufficient fruits, vegetables, meats and healthy fats for each person’s specific brain and heart health needs. A fast-food hamburger with its heavy sodium content and low-quality meat does not offer the same health benefits as a homemade grass-fed beef hamburger. Frozen vegetables processed with chemical-laden cheese sauces are not the equivalent of fresh vegetables lightly cooked with grass-fed butter or eaten raw. And sweetened fruit juices or juice drinks don’t replace fresh fruits.
If we are to lower our risk of cognitive impairment brought on by cardiovascular disease, we must first understand our own medical risk factors such as history of heart attack, hypertension and stroke and replace outdated therapeutics and “wait and see” approaches with better tools of inquiry such as brain health functional assessments that include cognitive reasoning. There is ample evidence of diet and lifestyle, along with rigorous attention to cardiometabolic activity, can improve vascular health and lower the risk for heart and brain problems.