Alternatives to animal testing
Alternatives to animal tests are often cheaper, quicker and more effective
Replacing animal tests does not mean putting human patients at risk. It also does not mean halting medical progress. Instead, replacing animal testing will improve the quality as well as the humaneness of our science.
Thankfully, the development of alternative methods is growing. Due to innovations in science, animal tests are being replaced in areas such as toxicity testing, neuroscience and drug development. But much more needs to be done.
The reasons why animal testing persists are often not scientific. Instead it can be due to conservatism within the scientific establishment – it is easier and more comfortable to simply do what has always been done. Test results on animals can be easily compared to earlier tests on animals to give confidence to scientists. Regulators can adopt a ‘tick box’ approach, divorced from the needs of the real world.
Once new alternatives have been developed, there are also massive bureaucratic hurdles to implementing and enforcing their use. One of the most important jobs the Cruelty Free International science team does is encourage regulators to accept and promote alternative methods to animal testing.
This device, which is the size of a smartphone, is known as a human-on-a-chip. So far, cells from four different organs have been linked together on one chip to mimic the human body. © Photo by TissUse - www.tissuse.com.
Reconstituted human skin models can be used to replace the notorious Draize skin irritation tests in rabbits and have proven to be more effective at predicting human reactions. © Photo by Philippe Gotteland at Episkin – www.episkin.com.
This innovative little device is a lung-on-a-chip. It is lined with human lung cells and can be used instead of animals to study lung disease processes and screen potential drugs. © Photo by Wyss Institute at Harvard University.
Types of alternatives
Cell cultures
Almost every type of human and animal cell can be grown in the laboratory. Scientists have even managed to coax cells to grow into 3D structures, such as miniature human organs, which can provide a more realistic way to test new therapies.
Human cells have been used to create innovative little devices called ‘organs-on-chips’. These can be used instead of animals to study biological and disease processes, as well as drug metabolism. Devices have already been produced that accurately mimic the lung, heart, kidney and gut. The ultimate goal is to use these chips to create a whole ‘human-on-a-chip’.
Cell cultures have been central to key developments in areas such as cancers, sepsis, kidney disease and AIDS, and are routinely used in chemical safety testing, vaccine production and drug development.
Human tissues
Both healthy and diseased tissues donated from human volunteers can provide a more relevant way of studying human biology and disease than animal testing.
Human tissue can be donated from surgery (e.g. biopsies, cosmetic surgery and transplants). For example, skin and eye models made from reconstituted human skin and other tissues have been developed and are used to replace the cruel rabbit irritation tests. Companies such as Episkin, Mattek and CellSystems GmbH now produce these tests in easy to use kits for companies to use to test their cosmetics and other substances.
Human tissue can also be used after a person has died (e.g. post-mortems). Post-mortem brain tissue has provided important leads to understanding brain regeneration and the effects of Multiple Sclerosis and Parkinson’s disease.
Computer models
With the growing sophistication of computers, the ability to ‘model’ or replicate aspects of the human body is ever more possible.
Computer models of the heart, lungs, kidneys, skin, digestive and musculoskeletal systems already exist. They can be used to conduct virtual experiments based on existing information and mathematical data.
Volunteer studies
Rapid advances in technology have allowed for the development of sophisticated scanning machines and recording techniques that can be used to safely study human volunteers.
Brain imaging machines that can ‘see’ inside the brain can be used to monitor the progression and treatment of brain disease. They can help researchers understand the causes by comparing with healthy volunteers.
An innovative technique called microdosing can also be used in volunteers to measure how very small doses of potential new drugs behave in the human body. These microdoses are radio-labelled, injected into human volunteers and measured (usually in blood samples) using a very sensitive measuring device called an accelerator mass spectrometer.
Less high-tech studies for nutrition, drug addiction and pain can also be carried out on consenting humans in the interest of advancing medical science. These studies can help replace animal tests.
Human medical breakthroughs
- We are told that insulin therapy would not have been discovered unless animal researchers had removed the pancreas from dogs in the 1920s. But like other areas of medical research, the important clues actually came much earlier from observations of human patients.
- Brain surgery in Parkinson’s patients identified the best place for Deep Brain Stimulation electrodes to be placed in the brain to improve symptoms, decades before a claimed ‘discovery’ in monkeys.
- Alois Alzheimer first described the main features of Alzheimer’s disease in 1906 by studying brain segments from patients after they had died.
- Human population studies led to the discovery that smoking causes cancer. Smoking does not cause cancer in mice and rats.
- An Australian doctor used himself in an experiment to discover the main cause of stomach ulcers. He drank a culture of bacteria and became sick before curing his symptoms with antibiotics.
- A German chemist tested the effects of aspirin on himself after an accidental discovery that it helped relieve pain in a patient with toothache.
- The anaesthetic effect of laughing gas was discovered when someone accidentally cut their leg while under the influence of the gas. An American dentist then confirmed the effects on himself while having a tooth removed.
Alternatives are better
- Crude skin allergy tests in guinea pigs only predict human reactions 72% of the time. But a combination of chemistry and cell-based alternative methods has been shown to accurately predict human reactions90% of the time.
- The notorious Draize skin irritation test in rabbits can only predict human skin reactions 60% of the time. But using reconstituted human skin is up to 86% accurate.
- The standard test on pregnant rats to find out if chemicals or drugs may harm the developing baby can only detect 60% of dangerous substances. But a cell-based alternative (EST) has 100% accuracy at detecting very toxic chemicals.
- The cruel and unreliable shellfish toxin testing on live mice has now been fully replaced with a far superior analytical chemistry method that is better at protecting humans.
The science relating to animal experiments can be extremely complicated and views often differ. What appears on this website represents Cruelty Free International expert opinion, based on a thorough assessment of the evidence.
