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Why Using Animals for Alzheimer’s Disease Research Isn’t Helping Humans or Science

Why Using Animals for Alzheimer’s Disease Research Isn’t Helping Humans or Science


 

Research into lifesaving treatments and cures is always a sensitive topic, especially when the research is on such a common disease like Alzheimer’s Disease (AD). Sadly, around 70,000 Kiwi’s are living with dementia today (Alzheimer’s is the most common form of dementia and accounts for around 60-80% of all cases), and it’s estimated that at least 170,000 people will be living with dementia by 20501.

If you do know someone affected by this progressive neurodegenerative disease then you, like us will presumably have a strong emotional connection with wanting to ensure that the best possible research is being conducted. This is both admirable and understandable as it means that you care and that you want the best for your loved ones.

It is therefore vital that people all around the world are aware that 99.6% of Alzheimer’s drugs that test successfully in animals fail in human trials2and that in the last decade, zero new drugs have been developed that can treat Alzheimer’s effectively3.

Animals can’t reliably predict how humans will response and this is the fundamental issue with a vast majority of AD research happening in NZ and around the world. 

There are viable methods of AD research that don’t involve the use of animals. These include:

The table above was provided by the Physicians Committee for Responsible Medicine (PCRM).

 

In honour of World Alzheimer's Day, which is on the 21 September every year, Dr Andre Menache has written the article below for NZAVS to highlight the failure of the animal model in AD research.

As you read his article, we hope that it becomes apparent that the only type of AD research that should be supported, is human-relevant and non-animal based.

Photo provided by Tara Swan — Chocolate Mouse Photography 

During World Alzheimer's Month (September) you will probably be approached by various charities and research organisations asking for funding. For the sake of the countless animals who suffer globally in the name of AD research, the many suffering humans who are patiently waiting for treatments and cures and for the future of science and finding out applicable and useful knowledge – please refuse to donate to animal-based research.

Always make sure that you are funding viable research, if you are unsure if a charity partakes in animal experimentation then refuse to donate and ask NZAVS for help in finding out! Better yet, donate to NZAVS and help educate many more people on this important issue. Together we have the power to change the face of AD research and ultimately end animal experimentation for animals, people and science!  


Why Using Animals for Alzheimer’s Disease Research Isn’t Helping Humans or Science

Written by Dr Andre Menache, BSc (Zoology), BSc(Hons), BVSc, Dip ECAWBM (AWSEL) MRCVS

The general public largely considers animal research to be a necessary evil in the quest to find cures for human disease. This “message of hope” is regularly reinforced in the mind of the public by media headlines promising us medical breakthroughs just around the corner. Few people actually read the articles, and fewer still have the necessary science background to judge the quality of the research. However, animal researchers and the media have profited enormously from this clever formula for decades because it often provides increased funding for the former and plenty of exciting headlines for the latter. But how many of these bold headlines actually lead to medical breakthroughs in general and for Alzheimer’s disease (AD) in particular? 

Until recently, animal researchers managed to keep their heads down and thus largely avoid the scrutiny of evidence-based science. Finally, some honest researchers realized that the quality of most animal studies was so poor that it was shaming the scientific community. In fact, as much as 87.5 percent of biomedical research may be wasteful and inefficient, according to Yale University professor Michael Bracken4. Professor Bracken notes that for every 100 research projects, only half lead to published findings. Of those 50, half have significant design flaws, making their results unreliable. And of those 25, half are redundant or unnecessary because of previous work. Fortunately for the animal researchers, the taxpayer has been totally in the dark concerning these disturbing statistics. Not anymore.

The use of animals to study AD is no exception. In fact, the spectacular failure of animal experiments to produce results relevant to people has led one of the world’s largest pharmaceutical companies (Pfizer) to end research for new AD drugs5. This is not surprising since AD is a uniquely human disease. The ‘experimental Alzheimer's Disease’ that researchers produce in animals is emphatically not the same as the human version.  By far the most popular ‘laboratory models’ have been transgenic mice, whose genetic make-up has been altered. Yet the public would be shocked if it found out that some of the strongest criticisms of these mouse models come from the animal researchers themselves:

 

Transgenic mouse models exist that mimic a range of AD–related pathologies, although none of the models fully replicate all pathological features of the human disease (Birch et al., 2014).

Drugs developed using these mouse models have failed in phase III clinical trials (Mangialasche et al., 2010; Braidy et al., 2012; Saraceno et al., 2013).

These failures question not only our accurate understanding of the disease (Castellani and Perry, 2012) but also the validity of the animal models upon which the drug discovery efforts are rooted (Windisch, 2014; Nazem et al., 2015)6.

 

Interestingly, the author of the above passage also happens to collaborate with an industry-funded lobby group that fully supports animal experiments (Understanding Animal Research - UAR).

Several systematic reviews have been conducted on animal use for AD research. One of the most significant of these was conducted by a group of researchers who are specialists in evaluating animal studies. The group identified several weaknesses in the articles published where mouse models were used to study AD. A major criticism was the poor quality of the studies and therefore the weak data7. It is important to note that even if the mouse studies had been performed to a high standard, the information obtained would be relevant only to mice and not human patients8.

By far the most common animal used in AD research is the mouse, although rats, dogs, worms, fruit flies and non-human primates have also been used. The mice used are genetically altered, for example by inserting a human gene implicated in human AD. The mice are then subjected to various observational studies that measure normal behaviour (e.g. burrowing) or else memory. 

 

Above: Example of a Morris Water Maize experiment. The image source can be found here. Note this is a link to a video that may upset some people.  

 

A common memory test is the Morris water maze (pictured above): 

The Morris water maze is widely used to study spatial memory and learning. Animals are placed in a pool of water that is coloured opaque with powdered non-fat milk or non-toxic tempera paint, where they must swim to a hidden escape platform. Because they are in opaque water, the animals cannot see the platform, and cannot rely on scent to find the escape route. Instead, they must rely on external/extra-maze cues. As the animals become more familiar with the task, they are able to find the platform more quickly. Developed by Richard G. Morris in 1984, this paradigm has become one of the "gold standards" of behavioural neuroscience9.

For the record, AD is the most common form of dementia in humans and accounts for 60–80% of all cases. It is a progressive neurodegenerative disease, currently considered to be irreversible and causing a large socioeconomic burden. Some of the known risk factors include mental inactivity, physical inactivity and poor diet. Epidemiological studies have shown that physical activity has a beneficial effect on brain health10. In addition to a common-sense approach to maintaining good health in terms of helping to prevent AD, some researchers are turning their attention to studying people, not animals.

In a frank interview, Lawrence Hansen, professor of neuropathology in California, has said the following about the use of animals to study AD: 

 

Setting aside the ethical dimensions (which we should never do) of inflicting pain and suffering on any animal, even mice and rats, the amoral scientific problem with using rodents as models for neurodegenerative diseases is that rodents do not naturally develop Alzheimer disease (AD) or Parkinson`s disease(PD). The only way to get what looks even a little like AD or PD pathology in rats and mice is to make them transgenic — that is, to insert human disease-causing genes into the rodents. This does create a Frankenstein-like mutant model with some expression of AD or PD pathology which can be manipulated to make it go away. But reversing artificially induced AD or PD changes in animals that never naturally develop them is a far cry from curing the human diseases. The “cures” that work in the rodents have never worked when applied to humans11.

 

It should be clear by now that if we are serious about looking for a treatment for AD, then we need to focus our energy and resources on studying people and human data, not animals. Imagine how much farther we might have progressed towards finding a treatment for people if researchers had not squandered billions of dollars going down the blind alley of animal research? This question, in turn, raises concerns about who controls research budgets and who decides where the bulk of the money should be spent. The current trend in biomedical research is to use animals. That paradigm, which is rooted in 19th-century science, has got to change. It is society as a whole, and not the elitist club of animal researchers, who should decide how our tax dollars should be spent. For too long, animal researchers have kept their work shrouded in secrecy and considered the average person incapable of understanding the science that underpins the research. That view no longer holds water in the era of internet access and public accountability.

Although there is currently no cure for AD and conventional drugs appear to have very limited success (as well as unpleasant side effects), some success has been shown using less conventional methods, e.g. consuming coconut oil. It appears that AD brain cells have difficulty using glucose for energy but are able to obtain energy from coconut oil12. In addition, activities that improve cognitive function (memory games, puzzles, crosswords) can all help to slow down the onset or progression of AD. Physical exercise is also very important. Tai Chi is a physical activity that incorporates cognitive, meditative and social components to the exercise program. All of these activities are evidence-based. Animal research is not.

 

 


1.http://www.alzheimers.org.nz/our-voice/new-zealand-data  

2.https://alzres.biomedcentral.com/articles/10.1186/alzrt269#B13

3.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4000701

4.https://nihrecord.nih.gov/newsletters/2016/07_01_2016/story3.htm

5.https://www.reuters.com/article/us-pfizer-alzheimers/pfizer-ends-research-for-new-alzheimers-parkinsons-drugs-idUSKBN1EW0TN

6.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5357652/

7.https://onlinelibrary.wiley.com/doi/full/10.1002/ebm2.15

8.http://www.medsci.org/v10p0206.htm 

9.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2872979/  

10.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5596480/

11.http://antidote-europe.org/en/professor-larry-hansen-on-ethical-dilemmas/

12.https://www.ncbi.nlm.nih.gov/pubmed/28421789


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