The tomato effect occurs when effective

therapies A therapy or medical treatment (often abbreviated tx, Tx, or Tx) is the attempted remediation of a health problem, usually following a medical diagnosis. As a rule, each therapy has indications and contraindications. There are many different ...

for a condition are rejected, usually because they do not make sense in the context of the current understanding or theory of the

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

in question. The name refers to the fact that

tomato The tomato is the edible berry of the plant ''Solanum lycopersicum'', commonly known as the tomato plant. The species originated in western South America, Mexico, and Central America. The Mexican Nahuatl word gave rise to the Spanish word ...

es were rejected as a

food Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is inge ...

source by most

North American North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Ca ...

s until the end of the 19th century, because the prevailing belief at the time was that they were

poison Poison is a chemical substance that has a detrimental effect to life. The term is used in a wide range of scientific fields and industries, where it is often specifically defined. It may also be applied colloquially or figuratively, with a broa ...

ous. A parallel concern is

medical reversal Medical reversal refers to when a newer and methodologically superior clinical trial produces results that contradict existing clinical practice and the older trials on which it is based. This leads to an intervention that was widely used falling o ...

which is new clinical information based on new clinical trials or understanding of a disease contradicting clinical practice. Medical reversal implies the original clinical practice failed to achieve success or had harms that outweighed benefits. That is contrasted with the phenomenon of replacement where a useful clinical practice is replaced by one that works better.

Examples

Tomatoes were becoming a staple food in Europe by the 1560s; they were shunned in North America since they were considered poisonous until the 1820s. Similarly, willow tree bark extract was ignored to provide relief of pain and fever, and it was not until the late 1800s with the commercial production of

salicylate Salicylic acid is an organic compound with the formula HOC6H4CO2H. A colorless, bitter-tasting solid, it is a precursor to and a metabolite of aspirin (acetylsalicylic acid). It is a plant hormone, and has been listed by the EPA Toxic Substance ...

(also known as

Aspirin Aspirin, also known as acetylsalicylic acid (ASA), is a nonsteroidal anti-inflammatory drug (NSAID) used to reduce pain, fever, and/or inflammation, and as an antithrombotic. Specific inflammatory conditions which aspirin is used to treat inc ...

) that this treatment was prescribed to patients. In 1753, it was established that

scurvy Scurvy is a disease resulting from a lack of vitamin C (ascorbic acid). Early symptoms of deficiency include weakness, feeling tired and sore arms and legs. Without treatment, decreased red blood cells, gum disease, changes to hair, and bleeding ...

can be treated with

lemon The lemon (''Citrus limon'') is a species of small evergreen trees in the flowering plant family Rutaceae, native to Asia, primarily Northeast India (Assam), Northern Myanmar or China. The tree's ellipsoidal yellow fruit is used for culin ...

juice. Despite this knowledge, it was considered an imbalance of the

humors Humorism, the humoral theory, or humoralism, was a system of medicine detailing a supposed makeup and workings of the human body, adopted by Ancient Greek medicine, Ancient Greek and Medicine in ancient Rome, Roman physicians and Greek philosoph ...

until the mid 1800s.

References

Medical phenomena Psychological effects {{treatment-stub