Ever since the Antihypertensive and Lipid-Lowering Treatment to prevent Heart Attack Trial, or ALLHAT, demonstrated in 2002 that low-cost thiazide diuretics performed no worse than an ACE inhibitor or calcium channel blocking drugs (not compared against placebo), thiazide diuretics became regarded as the first choice to reduce blood pressure in people with hypertension. This means that doctors preferentially prescribe drugs such as hydrochlorothiazide, chlorthalidone, indapamide and others before prescribing other drugs such as beta blockers, ACE inhibitors, or ARBs. Less commonly, more powerful “loop” diuretics like furosemide (Lasix) or torsemide (Demadex) are prescribed, especially if congestive heart failure or kidney dysfunction are present. Let’s focus on the much more commonly prescribed thiazide diuretics.
Followers of the Undoctored lifestyle know that you will not find many complimentary comments about the practices of modern healthcare around this neighborhood, but I applaud any effort to save on healthcare costs. Unfortunately, the cost-saving maneuver of preferentially prescribing thiazide diuretics comes with some very serious potential long-term consequences that have not been fully borne out in shorter-term studies. In other words, some of the adverse consequences of taking a daily thiazide diuretic may not show for a decade, effects such as stroke, heart attack, type 2 diabetes, cancer, dementia, and sudden cardiac death. Because thiazide diuretics have been associated with numerous metabolic derangements that lead to such conditions, we should be concerned that short-term reductions in blood pressure, stroke, and heart attack may not necessarily mean that long-term benefits will be experienced.
The list of potential adverse effects of thiazide diuretics is growing. Emerging evidence suggests, for instance, that they:
- May increase risk for a variety of skin cancers, as thiazide diuretics increase photosensitivity, i.e., sensitivity to sunlight. Although the evidence is observational and thereby preliminary, the more than 3-fold increase in squamous cell cancer makes it more likely that this is a genuine association (unlike the much smaller associations seen in dietary observational studies, e.g., 10% increase risk rather than multiples). As is typical in healthcare, rather than just stop the drug and replace with one that does not increase risk for skin cancer or, even better, advise natural methods that are effective for reducing blood pressure, some advocate drugs to reduce skin sensitivity and skin lesions when taking thiazide diuretics.
- Increase insulin resistance that drives risk for multiple diseases including type 2 diabetes, heart disease, cancer, and Alzheimer’s dementia, reflected in higher HbA1c and fasting glucose levels
- Increased activation of the sympathetic nervous system, an effect that has been associated with increased cardiovascular death and other complications. This is actually a sizable effect.
- Increased blood triglycerides and especially liver triglycerides, the process that leads to fatty liver
- Cause urinary loss of potassium and magnesium, not uncommonly to life-threatening levels. Potassium and magnesium therefore need to be monitored and/or supplemented to avoid sudden cardiac death. (Anyone working in emergency rooms, acute care, or coronary care units has seen many such instances, as it is frightfully common, especially among people whose doctors do not monitor such levels.)
- Increased blood levels of uric acid–which can also trigger gout attacks and may increase cardiovascular risk.
- Slow wound healing
There is no question that maintaining healthy blood pressure is a health advantage. Reducing blood pressure with thiazide diuretics has indeed been shown to avoid 2-3 cardiovascular deaths per 100 people over 5 years. But recognize that “placebo” groups consume grains and sugars, fail to correct vitamin D deficiency, do not address magnesium deficiency that is ubiquitous, do not address thyroid status, do not supplement omega-3 fatty acids, and make no effort to cultivate healthy bowel flora that generates the metabolic benefits of butyrate and other bacterial metabolites, i.e., all the basic efforts we make in the Undoctored Wild, Naked, Unwashed program. And, of course, following the Undoctored strategies does not come with increased potential for type 2 diabetes, skin cancer, delayed wound healing or fatty liver, but contributes to reversing these and other conditions including hypertension in the majority.
Also, most of us agree that good hydration is a basic and necessary health practice. How can a dehydrating agent in the form of a diuretic possibly be good for health?