Your Blood Pressure Is High. Your Genes May Be Why.

ACE is an enzyme that converts angiotensin I into angiotensin II, a powerful hormone that makes blood vessels constrict and narrows the arteries. This is a normal biological process. When blood pressure drops, your body releases angiotensin to tighten vessels and restore pressure. When blood pressure rises, ACE activity should decrease. This delicate balance keeps your cardiovascular system in equilibrium.

Here’s the problem: the ACE I/D polymorphism determines how much ACE enzyme your body produces. People who carry the D/D genotype, found in roughly 25% of people with European ancestry, produce significantly more ACE enzyme. This means your blood vessels get the constriction signal more aggressively and more frequently. Higher ACE activity leads to sustained elevation of angiotensin II, persistent blood vessel constriction, and baseline elevation of blood pressure. The D allele is directly associated with higher resting blood pressure and increased risk of cardiac hypertrophy, where your heart muscle thickens from working against sustained pressure.

If you carry the D/D genotype, your blood vessels are more responsive to the hormone that makes them narrow. This means salt restriction helps you more than it helps others, because you’re already starting from a higher baseline of vessel constriction. This also means ACE inhibitor medications often work remarkably well for you, because they directly block the enzyme you’re overproducing. Your genetics aren’t a life sentence; they’re a diagnostic clue that points to a specific intervention.

Nitric oxide is the opposite of angiotensin II. While angiotensin II makes blood vessels constrict, nitric oxide makes them relax and dilate. This vasodilation is essential for blood flow and blood pressure regulation. Every time blood vessels need to open wider to allow more blood through, nitric oxide is doing the work. Your endothelial cells (the cells lining your blood vessels) produce nitric oxide continuously to maintain healthy vascular tone.

The NOS3 Glu298Asp variant, carried by roughly 30-40% of people, reduces the production of functional nitric oxide synthase. With less nitric oxide production, your blood vessels lose their ability to dilate properly, creating a chronic state of vascular stiffness and narrowing. This is the opposite problem from ACE. While too much ACE constricts vessels, too little NOS3 activity prevents dilation when it’s needed. The result is elevated baseline blood pressure, reduced blood flow to tissues, and increased atherosclerosis risk because stiff vessels develop plaque more easily.

If you carry the Asp298 variant, your blood vessels are stiffer and less responsive to signals telling them to relax. This is why people with this variant often respond well to vasodilating interventions: nitrate-containing foods (beets, leafy greens), exercise (which increases nitric oxide production), and L-arginine or citrulline supplementation (which provides raw material for nitric oxide synthesis). You’re not being lazy or non-compliant if medications alone aren’t enough; you’re genetically predisposed to need direct support for nitric oxide production.

Angiotensinogen is the starting material for the entire angiotensin system. Your liver produces angiotensinogen, which circulates in your blood. When blood pressure drops, an enzyme called renin cleaves angiotensinogen into angiotensin I. Then ACE converts angiotensin I to angiotensin II, the powerful vasoconstrictor. This is the renin-angiotensin-aldosterone system (RAAS), and it’s essential for blood pressure regulation. But like any system, it can be overactive.

The AGT M235T variant, carried by roughly 40% of the population, increases the amount of angiotensinogen your liver produces. More angiotensinogen means more substrate available to be converted into angiotensin II. People with the T235 allele have higher circulating angiotensin II levels and elevated baseline blood pressure. This effect is amplified by salt intake; people with this variant are more salt-sensitive, meaning their blood pressure rises more dramatically when sodium intake increases. The variant also promotes sodium retention in the kidneys, creating a double hit: more angiotensin II constriction plus more sodium in the bloodstream.

If you carry the T235 allele, you are genetically more sensitive to dietary salt than people without this variant. This is not about willpower or discipline. Your kidneys are coded to hold onto sodium more aggressively. This is also why you may see dramatic blood pressure improvements when you reduce salt intake, whereas your friend sees almost no change. You’re not overresponding to a low-sodium diet; your genetics make you one of the people who responds most strongly to salt restriction.

Angiotensin II does nothing by itself. It must bind to a receptor on the surface of blood vessel cells to trigger constriction. AGTR1 encodes the angiotensin II receptor type 1, the primary sensor that responds to angiotensin II and initiates the cascade of vascular constriction. When angiotensin II binds to AGTR1, blood vessels tighten. The strength of this response depends partly on how many receptors your blood vessel cells have and how efficiently they respond.

The AGTR1 A1166C variant, with the C allele carried by roughly 30% of people, creates receptors that are more sensitive to angiotensin II signaling. Blood vessels with the C1166 variant respond more aggressively to angiotensin II, constricting more forcefully and remaining constricted longer. This means that even normal levels of circulating angiotensin II trigger an exaggerated blood pressure response. If you also carry variants in ACE or AGT that increase angiotensin II levels, the C1166 allele amplifies the problem: more hormone plus more sensitive receptors equals significant blood pressure elevation.

If you carry the C1166 allele, your blood vessels are unusually responsive to the constricting signal. This is why ARB medications (which block AGTR1 directly) often work particularly well for you. It’s also why reducing stress and managing anything that activates the sympathetic nervous system helps more for you than for others; you’re reducing the signals that trigger your already-sensitive receptors. You’re not weak or deficient if standard lifestyle changes don’t fully control your blood pressure; your receptors are simply more trigger-happy.

Alpha-adducin is a protein in your kidneys that controls how much sodium is reabsorbed and recycled back into your blood versus excreted in urine. Your kidneys filter sodium constantly. Most of it is reabsorbed because your body needs sodium for nerve signaling, muscle contraction, and blood pressure regulation. Alpha-adducin sits on the surface of kidney tubule cells and regulates this reabsorption process. When the body needs to hold onto sodium, alpha-adducin becomes more active. When sodium levels are adequate, it relaxes and more sodium is excreted.

The ADD1 G460W variant, with the W allele present in roughly 25% of people, impairs alpha-adducin function and reduces its ability to regulate sodium reabsorption properly. Kidneys carrying the W460 allele retain more sodium regardless of how much salt you consume. This is a genetic predisposition toward salt sensitivity. You can eat a low-sodium diet and your kidneys still hold onto sodium because they’re coded to do so. This leads to expansion of blood volume and elevation of baseline blood pressure. The effect is stronger in people of African ancestry, where this variant is more common and salt sensitivity is more pronounced.

If you carry the W460 allele, you are genetically coded to be salt-sensitive. Your kidneys don’t respond normally to signals that tell them to excrete excess sodium. This is not a mineral deficiency or a weakness in your willpower around salt restriction. This is a biological difference in how your kidneys are wired. It’s also why salt restriction can be dramatically effective for you; reducing the amount of sodium entering your system directly counters your kidney’s tendency to retain it.

Aldosterone is a hormone produced by your adrenal glands that tells your kidneys to retain sodium and excrete potassium. This is essential when blood volume is low or electrolytes are imbalanced. But when aldosterone production is too high, your kidneys hold onto too much sodium and your blood pressure rises. CYP11B2 is the enzyme that synthesizes aldosterone. The more active your CYP11B2, the more aldosterone your body produces.

The CYP11B2 -344C>T variant, with the T allele present in roughly 40% of people, increases the activity of the aldosterone synthase enzyme. People carrying the T allele produce more aldosterone, leading to greater sodium retention, higher blood volume, and elevated blood pressure. This effect is independent of how much salt you eat. Your body is simply coded to produce more of the hormone that tells kidneys to hold onto sodium. The T allele is also associated with greater blood pressure responsiveness to salt intake; when you add salt to your diet, blood pressure rises more steeply because you’re already producing more aldosterone.

If you carry the T allele at CYP11B2, your adrenal glands are overproducing aldosterone relative to your actual sodium needs. This is why you see such dramatic benefits from sodium restriction; you’re reducing the raw material for a hormone-driven retention system. This is also why potassium supplementation or potassium-sparing diuretics can be particularly effective for you. Aldosterone tells kidneys to excrete potassium; blocking that signal with a potassium-sparing diuretic (spironolactone, amiloride) directly counteracts your overactive aldosterone system.