Cardiovascular Health: Circulation,               Nutrition, and Physical Activity 


                  Health and fitness                 

Cardiovascular disease is the leading cause of death in the United States and throughout the world. Consuming a healthy diet, engaging in regular physical activity, and optimizing metabolic health can significantly reduce the risk of developing cardiovascular disease.

What is Cardiovascular Health?

The cardiovascular system includes the heart and blood vessels, which together circulate blood throughout the body. This system runs continuously in the background, often without any noticeable signs, reaching every cell in the body to deliver oxygen and vital nutrients. Cardiovascular health is largely determined by modifiable lifestyle choices, including diet, exercise, and smoking habits; however, other factors can also contribute.1-4 Social factors including stress, job strain, the built environment of a neighborhood as well as the food environment and the availability of healthy foods can also impact cardiovascular health.5



Activity of the Heart Muscle


The heart is a muscle that pumps blood throughout the body. It consists of four chambers and four valves that ensure the blood flows only in one direction. Blood travels from every corner of the body to the heart where it enters and is pumped to the lungs to exchange carbon dioxide for oxygen. From there, oxygenated blood returns to the heart, which pumps it out into the body’s circulation system to deliver oxygen and nutrients to organs throughout the body.


Healthy Circulation

The heart works as a central pump, and it needs blood vessels to deliver oxygenated blood to cells throughout the body. Blood vessels, including arteries, veins, and capillaries, permeate every system of the body.


Arteries primarily carry blood and fluids to organs in the body.

Veins return depleted blood back to the heart.

Capillaries are microscopic vessels that transport and exchange nutrients, oxygen, and waste products between the blood and various organs of the body.6

Heart activity can change in response to many stimuli. The brain, kidneys, lungs, skeletal muscle, and skin can all signal increased demand for oxygenated blood as well as release metabolites that regulate cardiovascular action.6 For example, in the first few minutes of physical activity, the heart must adapt to the increased demands of skeletal muscle activity and increase the amount of blood and oxygen it is pumping out. The symptoms of this adaptation can often be felt as an intense beating of the heart and rapid breathing as the heart adjusts. Over time, repeated exercise can improve circulation because of the adaptive changes that occur in the heart. Other events that can trigger changes in the output of the heart include pharmaceutical drugs, electrolytes, hormones, nervous system activity, and adrenal gland secretions.6

Cells of the circulatory system

In addition to blood vessels, several specialized cells improve circulation and oxygen exchange within the cardiovascular system. These cells include cardiomyocytes, endothelial cells, vascular smooth muscle cells, and fibroblasts.

Cardiomyocytes are the basic cellular unit of the heart.7 They are involved in the excitation and contraction of the heart, allowing it to beat. Cardiomyocytes are electrically and mechanically connected to each other, allowing direct communication and intercellular signaling.7

Vascular smooth muscle cells are found layered in arteries where they control blood flow and blood pressure by regulating the constriction and dilation of blood vessels.7

Endothelial cells are regulators of the cardiovascular system.7 They are found in arteries and capillaries as well as the heart where they communicate, serve a structural role, and regulate function of other cells in the heart.7

Fibroblasts in the heart and blood vessels respond to stimuli, secreting signaling molecules including growth factors and cytokines that affect other cells in the heart.7

Other important cell types include neuronal cells, which control the structure and function of the heart and blood vessels, macrophages that repair blood vessels after an injury and defend the body from pathogens as part of the immune system, and pericytes that communicate between cells in the heart, stabilize blood vessels, and regulate endothelial cell function.7


Common Heart Diseases for Americans

The term “cardiovascular disease” is used broadly to describe conditions ranging from hypertension to vein diseases.4 Typically, it refers to one of four pathologies:8

Coronary artery disease (or coronary heart disease): the most common heart disease; occurs when the coronary arteries struggle to supply the heart with sufficient blood, oxygen, and nutrients
Cerebrovascular diseases: conditions that affect blood flow and/or blood vessels in the brain

Peripheral artery disease: a condition marked by the narrowing or blockage of blood vessels that carry blood from the heart
Aortic atherosclerosis: a specific type of atherosclerosis involving plaque build-up in the aorta, resulting in conditions such as heart attack, stroke, or sudden loss of blood flow to organs of the body

Atherosclerosis

Atherosclerosis is involved in almost every cardiovascular disease and is heavily influenced by lifestyle factors.8 It is a condition in arteries characterized by plaque formation that can potentially cause cardiovascular disease (CVD) due to decreased or lack of blood flow.8 Blood lipids, immune cells, inflammatory mediators, and dysfunctional endothelial cells initiate the formation of a fatty streak, a visible accumulation of fat in the artery wall that is the first sign of atherosclerosis.8 As cholesterol, fat, blood cells, platelets, macrophages, and other bodily substances aggregate, a plaque forms which limits the amount of blood that can flow through the artery. This narrowing of arteries also limits oxygen delivery to tissues in the body. As layers of plaque form, they secrete chemical messengers that recruit even more cells to the site of “injury” which worsens the condition.8

Significantly reduced blood flow can cause issues in the heart and result in noticeable symptoms; complete blockage of an artery can cause a heart attack. If a plaque bursts, it may result in a blood clot which can travel to other parts of the body and block blood flow. Plaque formation may begin as early as childhood and can eventually lead to an acute cardiovascular event.8

Diagnostics

There are several clinical signs that a healthcare practitioner can evaluate to determine if a patient has an elevated risk for CVD.­8 Blood lipid and metabolic panels, often ordered as part of an annual health screening, measure common risk factors that contribute to CVD development:

  • Low-density lipoprotein (LDL): a lipoprotein that carries cholestrol throughout the body and is commonly referred to as “bad” cholesterol
  • High-density lipoprotein (HDL): a lipoprotein that absorbs cholesterol in the blood and carries it back to the liver where it can be removed from the body; sometimes called “good” cholesterol
  • Triglycerides: the most common type of fat in the body; required by the body in small amounts, but too much can contribute to atherosclerosis
  • Total cholesterol: the sum of all the cholesterol measures (LDL, HDL, and a portion of the triglyceride measure)
  • Blood glucose: an indicator of diabetes or insulin resistance when elevated in the fasted state, which can contribute to poor cardiovascular health

  • Prevalence

  • Cardiovascular diseases are the leading cause of death in the United States and globally, making up approximately one out of every four deaths, which equates to about 600,000 deaths in the United States each year.4,8,9 CVD is also the costliest disease, with a projected annual cost of $368 billion by 2035.8

  • Risk factors

    While there are non-modifiable factors that contribute to CVD risk including age and sex, most are modifiable, up to 90 percent. This means almost anyone can reduce their risk of developing CVD with effort and lifestyle changes.1,8 The major risk factors for CVD are:3

  • High LDL cholesterol (hyperlipidemia)

  • Smoking

  • Hypertension (high blood pressure)

  • Diabetes

  • Abdominal obesity

  • Psychosocial factors

  • Insufficient fruit and vegetable consumption

  • Excessive consumption of alcohol

  • Lack of regular physical activity

  • If all adults in the U.S. attained optimal cardiovascular health, based on the eight recommendations for CVD prevention according to the American Heart Association (AHA), two million CVD events could be prevented each year.10 Even a partial improvement, moving from low to moderate cardiovascular health, could prevent over one million cardiovascular events.10 One estimate suggests that only seven percent of the U.S. population achieves optimal cardiovascular health.10

  • While cardiovascular diseases are diverse and, in some cases, very complex, their strong relationship to modifiable lifestyle factors allows anyone to maximize their cardiovascular health through lifestyle decisions. The AHA recommends eight behaviors to decrease the risk of CVD, coinciding with many of the risk factors for CVD. They advise adults to:

  • Avoid smoking

  • Be physically active

  • Eat a heart healthy diet

  • Get adequate sleep

  • Maintain healthy body weight

  • Control cholesterol levels

  • Manage blood pressure in healthy range

  • Achieve blood glucose levels in healthy range4,8,11

  • In addition to these eight recommendations, maintaining a diverse gut microbiome may positively affect both blood pressure and CVD risk.2,12

  • Antioxidant Activity for Cardiovascular Health

  • Oxidative stress is a major underlying pathway that contributes to the development of atherosclerosis and cardiovascular diseases.4 Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are a normal byproduct of cellular process. However, elevated ROS and RNS can lead to oxidative stress, DNA damage, endothelial dysfunction, and increased oxidized LDL particles, which stick to plaques in the arteries,
  • exacerbating plaque formation.4 ROS also negatively affect blood vessels, promoting hypertension, and can impair normal heart function.13 Chronic elevation of ROS can contribute to inflammation, which contributes to the development of cardiovascular diseases.4,13
  • Antionxidant in the body convert ROS to more stable, less harmful compounds, helping to lessen or prevent oxidative stress. Several nutrients and bioactive compounds possess antioxidant activity including vitamin C, vitamin E, vitamin A, and plant polyphenols. Within the vitamin A family, carotenoids, including beta-carotene and lycopene, combat oxidative stress and protect against CVD.3 Carotenoids are natural compounds found in fresh fruits and vegetables, often in the red and orange category.3 Consuming naturally occurring dietary sources of carotenoids can protect the heart and reduce the risk of developing CVD.14-16 However, clinical trials investigating whether supplementation with isolated carotenoids can deliver the same benefits have not yet found any benefit.3,17

  • Best Foods for Cardiovascular Health

  • Diet is one of the most modifiable and consequential lifestyle factors that can positively or negatively impact cardiovascular health. A heart healthy diet can reduce the risk of CVD, and in some cases reverse heart disease.4 It also plays a role in reducing other risk factors that contribute to CVD including obesity, hypertension, diabetes, and hyperlipidemia.4 Following a healthy dietary pattern rich in essential nutrients and whole foods can have a significant impact on cardiovascular health.

B vitamins

Vegetables like spinach, kale, and sweet potatoes are good for cardiovascular health due to the presence of certain B vitamins involved in protecting the heart. Riboflavin (B2), pyridoxine (B6), folate (B9), and cobalamin (B12) are involved in the synthesis and degradation of the amino acid homocysteine. Elevated plasma homocysteine is associated with various vascular diseases, especially in women.3 Maintaining adequate levels of these B vitamins keeps homocysteine levels in a normal range because if any of are in short supply, it can impair enzyme function, leading to a build-up of homocysteine which negatively affects vascular health.

Clinical studies investigating the role of B vitamin supplementation in managing homocysteine levels have produced positive findings. Supplementation with folic acid and vitamin B12 was effective at lowering homocysteine when used together compared to vitamin B6 alone.18 Additionally, supplementation with folic acid, vitamin B12, and vitamin B6 slowed the progression of atherosclerosis in healthy individuals with elevated homocysteine.19 While B vitamin supplementation may help keep homocysteine levels in a healthy range, clinical trials investigating the relationship to cardiovascular diseases have had mixed results. Because of this, supplementation with B vitamins to prevent CVD is considered safe but not routinely recommended. Instead, a balanced diet rich in fruits and vegetables will provide sufficient B vitamins in addition to many other heart healthy nutrients.

The B vitamin niacin (B3) also supports cardiovascular health. It can inhibit inflammatory genes in vascular cells, reduce oxidative stress, and lower cytokines involved in atherosclerosis, improving overall vascular health.3 A supplement form of niacin, nicotinic acid, can raise HDL, lower triglycerides, and, at high doses, lower LDL cholesterol, improving cardiovascular health.20 Niacin can affect blood glucose levels, so it is important to monitor glucose in individuals with diabetes or metabolic syndrome when high doses of niacin are administered.3???