Potential Benefits of Caffeine Alone or in Combination with Nitrate Supplementation in Blood Pressure Control in the Elderly

Abstract

The elderly population is characterized by its susceptibility in their cardiovascular system and thus likely to developing cardiovascular diseases as well as related events associated to the aging process (e.g. to psychiatric disorders). The elderly population consumes high amounts of substances containing caffeine. If on one hand the chronic consumption of caffeine-containing substances (in particular coffee) may be beneficial, on the other hand acute consumption might be harmful to the cardiovascular system (e.g. by increased blood pressure). Acute caffeine consumption also promotes other benefits to elderly population such as to increase physical performance and aids in the treatment of symptoms related to psychiatric disorders. A potential substance that could inhibit the acute effects of caffeine on the cardiovascular system is inorganic dietary nitrate. Inorganic dietary nitrate supplementation has been show to be an effective hypertensive substance (through nitric oxide production via the nitrate-nitrite-no pathway) with no apparent adverse effects. The aim of this review was to highlight, with data published in the literature, the effects of caffeine and dietary nitrate, isolated and in association on blood pressure modulation in the elderly population. Whilst they have been studied independently in the elderly, they have only been studied in combination in young healthy adults. MOJ Gerontology & Geriatrics Reserach Article Open AccessPotential benefits of caffeine alone or in combination with nitrate supplementation in blood pressure control in the elderly 8 Interestingly, several complications such as atherosclerosis, stroke and especially hypertension, are associated with reduced NO bioavailability, or even a deficiency in its production. 17,18 Nitrate is available for consumption in two main forms, as organic nitrate or inorganic nitrate. Inorganic nitrate can be found in several natural sources and it is considered healthy and therefore has no side effects presented so far.15−20 Inorganic nitrate (instead of organic nitrate) has been chosen as the most used option for nitrate supplementation due to its salivary regulation (which prevents NO spurt).20 Inorganic nitrate it is present, mainly, in vegetables, and is encountered in larger concentration in arugula, spinach, lettuce, celery and beetroot. 20The inorganic nitrate pharmacokinetics that results in NO bioavailability starts in the mouth, where anaerobic bacteria (located in the tongue) transforms nitrate in nitrite. After this modification, nitrite arrives in the stomach, where it is converted to NO and is absorbed; it enters the bloodstream and is distributed throughout the body. 21Once in its action site, NO stimulates cyclic guano sine monophosphate (cGMP) production which in high concentration reduces calcium entrance in the sarcolemma and reduces calcium release of its storage sites promoting vasodilatation. 22 Furthermore, the increase of NO production reduces the Ang II activity in the renal tubules (inhibiting renal vasoconstric...