Sugar (3) – The heart

Introduction:

Patients with cardiovascular disease, or those who are at risk, tend to have impaired glucose tolerance and insulin resistance (1,2,3).

These factors can be worsened with a diet high in sugar (4,5) and reversed when it is removed (5,6), which suggests that the consumption of added sugar is a promoter of cardiovascular disease (7).

Sugar produces the largest insulin spikes (6,8), for this reason, eating large amounts is closely related to insulin resistance and diabetes (6,8,9,10,11,12), while lowering the consumption, produces the opposite effect (13,14).

Considering that high sugar intake is closely related to insulin resistance and that this is undoubtedly a factor that increases the risk of coronary heart disease and mortality from cardiovascular disease, as we have already said, it is not difficult to relate sugar with heart disease.

(Note: There is no black and white in science. The fact that high sugar intake is related to insulin resistance and insulin resistance to heart disease, does not necessarily mean that sugar causes heart attacks. This is a very complex subject and from a very humble place, we will try to shed a little light)

What the glucose tolerance tests tell us:

The glucose tolerance test is used to determine the patient’s response after drinking a solution high in glucose.

In a healthy individual, blood sugar should rise and fall rapidly, but in a patient with insulin resistance, to a lesser or greater extent, glucose will remain in the blood.

More studies:

Insulin levels measured in the fasted state after taking an oral glucose solution of 75 to 90 g, were associated with death from myocardial infarction and coronary heart disease after 5 years (15,16).
In another test of glucose tolerance, patients with atherosclerosis of the cerebral and coronary arteries had an elevated insulin response (17,18).
In a study with 18,403 participants, a relationship was found between blood sugar levels after drinking a glucose tolerance drink, and age-related heart disease after 7.5 years (19).
Insulin levels measured after one hour of ingesting 50 grams of oral glucose were significantly related to the incidence of cardiovascular disease at 6 years and mortality at 12 years in men aged 60 years or older (3,20).

High levels of insulin and glucose, the main protagonists:

High levels of insulin and glucose have the closest relationship.

Diabetics are the most extreme example of this condition, but even in non-diabetic patients, high glucose levels are also associated with an increased risk of coronary heart disease mortality (19). In addition, there are patients with high sugar levels who do not have symptoms. This is called asymptomatic hyperglycemia, and it is also a risk factor for heart disease (21).

More studies:

Feeding rats table sugar makes them glucose intolerant (22).
Future cardiovascular risk can be predicted by insulin resistance (23,24).
High levels of insulin are found in many diseases, including obesity, coronary artery disease, hypertension, peripheral vascular disease and, obviously, in those with hyperglycemia (25).
Hyperinsulinemia (high insulin levels) is an independent risk factor in coronary heart disease (3,20).
A study done to see which marker could predict new cardiovascular events after an acute myocardial infarction found that hyperinsulinism was the most important factor (26).

The severity of myocardial infarction is relative to the degree of insulin resistance (27).
Insulin, linked to excess body fat, is the most important risk factor for heart attacks (28).
Regardless of other markers such as lipids or blood pressure, insulin / glucose ratio has the closest association with cardiovascular disease (29).
One study showed that 73% of patients with a myocardial infarction had abnormal glucose intolerance and that half of them suffered from diabetes (30). Six months after the infarction, 43% still had an abnormal glucose tolerance approximately 3 times higher than that of the control groups.
People with high levels of lipids generally have abnormal carbohydrate metabolism, with high levels of insulin causing the hyperlipidemia (31).
Smoking, which is one of the risk factors for heart disease, appears to induce hyperinsulinism (32). This suggests that when this habit is added to a large consumption of sugar, apart from enhancing hyperinsulinemia, risk factors for both are added, such as inflammation or oxidative stress (33,34).

If high levels of glucose and insulin have the closest relationship, then what is diabetes telling us?

In a survey by the European Society of Cardiology, 75% of people who had had heart attacks and had not been diagnosed as diabetic– had occult diabetes (3).
Diabetics are at increased risk of arterial occlusive disease (25).
Diabetics are at higher risk of dying from myocardial infarction (28).
Diabetics have more coronary atherosclerosis (36,36).
Diabetics have an approximately 3 times higher risk of dying from cardiovascular disease, an increased risk of stroke, coronary heart disease, and peripheral arterial disease (37).
Diabetics are more likely to die after a myocardial infarction (38).

“Those with cardiovascular disease not identified with diabetes… are simply undiagnosed”

Dr. Joseph R. Kraft

Sugar and advanced glycation end products:

Advanced glycation end products, or AGEs, are toxic compounds derived from the glycation of proteins (reaction of sugars with proteins).

AGEs activate the immune response and promote atherosclerosis through inflammation and vascular dysfunctions (39,40).

“Within the vessel wall, collagen-linked AGEs may “trap” plasma proteins, quench nitric oxide (NO) activity and interact with specific receptors to modulate a large number of cellular properties. On plasma low density lipoproteins (LDL), AGEs initiate oxidative reactions that promote the formation of oxidized LDL. Interaction of AGEs with endothelial cells as well as with other cells accumulating within the atherosclerotic plaque, such as mononuclear phagocytes and smooth muscle cells (SMCs), provides a mechanism to augment vascular dysfunction.

Specifically, the interaction of AGEs with vessel wall components increases vascular permeability, the expression of procoagulant activity and the generation of reactive oxygen species (ROS), resulting in increased endothelial expression of endothelial leukocyte adhesion molecules. AGEs potently modulate initiating steps in atherogenesis involving blood-vessel wall interactions, triggering an inflammatory-proliferative process and, furthermore, critically contribute to propagation of inflammation and vascular perturbation in established disease”

Dra Giuseppina Basta (41)

High levels of AGE are related to oxidative stress (42), age-related diseases (43) and other dysfunctions such as kidney failure and premature aging (44).

AGEs can be consumed through food exposed to high temperatures, but they can also be formed endogenously through raising blood sugar and the consequent reaction with proteins.

Hyperglycemia leads to high levels of protein glycation, so people with insulin resistance obviously have the highest risk.

“Driven by hyperglycemia and oxidant stress, AGEs form to a greatly accelerated degree in diabetes“

Dra Giuseppina Basta (41)

(TakeAway: Sugar is related to insulin resistance, which in turn leads to hyperglycemia and hyperinsulinemia. Diabetics have the most direct relationship, but patients without diabetes with vascular disease have an increased level of insulin as well, which suggests that insulin resistance is directly related to heart disease.

Based on the evidence, we could say that the potential to increase the risk of acute myocardial infarction, coronary heart disease and mortality from this disease, is in any factor that worsens glucose tolerance or promotes insulin resistance, such as high consumption of processed foods, especially vegetable seed oils, refined flours and sugar.)

Next blog – Sugar and the immune system