What are ACE inhibitors?
Angiotensin-converting enzyme inhibitors, commonly known as ACE inhibitors, are a class of drugs primarily used in the treatment of hypertension and heart failure.
ACE inhibitors block an angiotensin-converting enzyme, which helps produce an angiotensin II hormone. This hormone tightens blood vessels and causes the body to hold more fluid. By reducing angiotensin II, ACE inhibitors allow blood vessels to relax and widen, lower fluid buildup, and ease the heart's workload. [1, 2].
Uses of ACE Inhibitors
Treating Hypertension: ACE inhibitors have been proven effective in managing essential hypertension and various forms of secondary hypertension. They help normalise blood pressure in almost all patients and have favourable effects on hemodynamics and regional blood flow distribution [2].
Treating Heart failure: Besides treating high blood pressure, ACE inhibitors are also used alongside other treatments for systolic heart failure. They are recommended to help prevent heart failure in people with a reduced ejection fraction (a measure of heart function) who have previously had a heart attack and to treat patients already dealing with heart failure and reduced ejection fraction. [3].
ACE inhibitors not only reduce the risk of death in individuals with congestive heart failure and left ventricular dysfunction after a heart attack, but they also slow the progression of kidney and nerve damage in diabetes. Moreover, they may provide protective effects in memory-related disorders and certain cancers.[4].
Side effects of ACE inhibitors
ACE inhibitors, like all medications, can cause several side effects.
Common Side Effects: One of ACE inhibitors' most common side effects is a dry, hacking cough, which can occur in 10% to 20% of patients [3]. This is due to increased bradykinin levels, a molecule associated with cough and inflammation [5].
Hypotension, or low blood pressure, is another common side effect in 7% to 11% of patients [6]. ACE inhibitors help widen blood vessels, lowering the overall resistance in the bloodstream and reducing the pressure the heart has to work against, known as afterload. [3].
Hyperkalemia, an increase in blood potassium levels, can occur in 2% to 6% of patients [6]. ACE inhibitors can reduce potassium excretion from the kidney, leading to a buildup of potassium in the blood [3].
ACE inhibitors can also cause dizziness, experienced by 12% to 19% of patients [6]. This is often related to the hypotensive effects of the medication.
Rare side effects: In rare cases, ACE inhibitors can lead to angioedema—a severe and potentially life-threatening swelling of the face and airways. This occurs in about 0.7% of patients and is linked to higher levels of bradykinin, which can increase blood vessel permeability and cause fluid buildup [7, 8].
Uncommon Side effects: Uncommon side effects include fatigue, rash, decreased ability to taste, fainting, and renal insufficiency [9, 10]. ACE inhibitors can also cause cholestatic jaundice, a condition where bile cannot flow from the liver to the duodenum, and hypersensitivity reactions [10].
Pinto beans as ACE inhibitors
Pinto beans, a variety of Phaseolus vulgaris, have been found to contain peptides that exhibit angiotensin-converting enzyme (ACE) inhibitory activities.
In a study by Donna M. Winham and colleagues, consuming half a cup of pinto beans daily for eight weeks significantly lowered total cholesterol and low-density lipoprotein (LDL) cholesterol levels. These cholesterol types are known risk factors for coronary heart disease [11].
Another study identified five pinto bean peptides with ACE inhibitory activities. These peptides were found to bind to the ACE enzyme's catalytic and substrate binding sites, inhibiting its activity.
In conclusion, pinto beans contain peptides that have been shown to inhibit ACE activity, which is potentially beneficial in managing hypertension and heart disease. However, more research is needed to fully understand the potential health benefits and determine the optimal intake of pinto beans for these effects.