A water ionizer (also known as an alkaline ionizer) is a

home appliance A home appliance, also referred to as a domestic appliance, an electric appliance or a household appliance, is a machine which assists in household functions such as cooking, cleaning and food preservation. The domestic application attached to ...

which claims to raise the pH of drinking water by using

electrolysis In chemistry and manufacturing, electrolysis is a technique that uses Direct current, direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of c ...

to separate the incoming water stream into

acidic An acid is a molecule or ion capable of either donating a proton (i.e. hydrogen cation, H+), known as a Brønsted–Lowry acid, or forming a covalent bond with an electron pair, known as a Lewis acid. The first category of acids are the ...

and

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

components. The treated water is called alkaline water. Proponents claim that consumption of alkaline water results in a variety of health benefits, making it similar to the alternative health practice of

alkaline diet Alkaline diet (also known as the alkaline ash diet, alkaline acid diet, acid ash diet, and acid alkaline diet) describes a group of loosely related diets based on the misconception that different types of food can affect the pH balance of the bo ...

s. Such claims violate basic principles of

chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a physical science within the natural sciences that studies the chemical elements that make up matter and chemical compound, compounds made of atoms, molecules a ...

and

physiology Physiology (; ) is the science, scientific study of function (biology), functions and mechanism (biology), mechanisms in a life, living system. As a branches of science, subdiscipline of biology, physiology focuses on how organisms, organ syst ...

. There is no medical evidence for any health benefits of alkaline water. Extensive

scientific evidence Scientific evidence is evidence that serves to either support or counter a scientific theory or hypothesis, although scientists also use evidence in other ways, such as when applying theories to practical problems. "Discussions about empirical ev ...

has completely debunked these claims, leaving such claims in the

pseudoscientific Pseudoscience consists of statements, beliefs, or practices that claim to be both scientific and factual but are incompatible with the scientific method. Pseudoscience is often characterized by contradictory, exaggerated or unfalsifiable cl ...

realm. The machines originally became popular in

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and other East Asian countries before becoming available in the U.S. and Europe.

Health claims

Water ionizers are marketed on the basis of

health claim A health claim on a food label and in food marketing is a claim by a manufacturer of food products that their food will reduce the risk of developing a disease or condition. For example, it is claimed by the manufacturers of oat cereals that oa ...

s which are focused on their ability to make water more

. A wide variety of benefits have been claimed, including the ability to slow

aging Ageing (or aging in American English) is the process of becoming Old age, older until death. The term refers mainly to humans, many other animals, and fungi; whereas for example, bacteria, perennial plants and some simple animals are potentiall ...

, prevent

disease A disease is a particular abnormal condition that adversely affects the structure or function (biology), function of all or part of an organism and is not immediately due to any external injury. Diseases are often known to be medical condi ...

, give the body more energy, and offset alleged effects of acidic foods. Some claims include it being twice as hydrating after exercise. There is no empirical evidence to support these claims, nor the claims that drinking ionized water will have a noticeable effect on the body. Drinking ionized water or alkaline water does not alter the body's pH due to acid-base homeostasis. Additionally, marketers have inaccurately claimed that the process of electrolysis changes the structure of water from large non-bioavailable water clusters to small bioavailable water clusters, called "micro clusters". Some proponents of alkaline water and the alkaline diet as a whole claim a link between alkaline intake and

cancer prevention Cancer prevention is the practice of taking active measures to decrease the incidence of cancer and mortality. The practice of prevention depends on both individual efforts to improve lifestyle and seek preventive screening, and socioeconomic ...

; no scientific evidence exists for such a connection, and as such, several cancer societies have denounced this claim.

Operation

Despite being described as 'water ionizers', the machines are designed to work as water electrolyzers. This is an

electrochemical Electrochemistry is the branch of physical chemistry concerned with the relationship between electrical potential difference and identifiable chemical change. These reactions involve electrons moving via an electronically conducting phase (typi ...

process in which water is split to form

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

and

oxygen Oxygen is a chemical element; it has chemical symbol, symbol O and atomic number 8. It is a member of the chalcogen group (periodic table), group in the periodic table, a highly reactivity (chemistry), reactive nonmetal (chemistry), non ...

by an

electric current An electric current is a flow of charged particles, such as electrons or ions, moving through an electrical conductor or space. It is defined as the net rate of flow of electric charge through a surface. The moving particles are called charge c ...

. In some machines, the process produces

calcium hydroxide Calcium hydroxide (traditionally called slaked lime) is an inorganic compound with the chemical formula Ca( OH)2. It is a colorless crystal or white powder and is produced when quicklime ( calcium oxide) is mixed with water. Annually, approxim ...

and

hydrochloric acid Hydrochloric acid, also known as muriatic acid or spirits of salt, is an aqueous solution of hydrogen chloride (HCl). It is a colorless solution with a distinctive pungency, pungent smell. It is classified as a acid strength, strong acid. It is ...

through the use of an

ion-exchange membrane An ion-exchange membrane is a semi-permeable membrane that transports certain dissolved ions, while blocking other ions or neutral molecules. Ion-exchange membranes are therefore electrically conductive. They are often used in desalination and ...

. The effectiveness of the process is debatable because electrolysis requires significant amounts of time and power; hence, the amount of hydroxide that could be generated in a fast-moving stream of water such as a running tap would be minimal at best. Additionally, the process of reversing the reaction requires much less energy, so if the area between the alkaline and acidic water is at least semi-

permeable Permeability, permeable, and semipermeable may refer to: Chemistry *Drug permeability *Semipermeable membrane, a membrane which will allow certain molecules or ions to pass through it by diffusion *Vascular permeability, the movement of fluids a ...

, the water will undergo another reaction that just leaves neutral water.

References

External links

* {{DEFAULTSORT:Water Ionizer Alternative medical treatments Drinking water Fad diets Pseudoscience

Health claims

Operation

See also

References

External links