An article recently appeared that broadly proclaimed “We may finally know what causes Alzheimer’s Disease and how to stop it!” The author asserted that periodontal disease caused Alzheimer’s Disease and that curing periodontal disease would cure Alzheimer’s Disease. Unfortunately, it is not that simple. The problem with this type of reporting is that the author(s) take a small tidbit of fact and inflate it, make wrong conclusions, and connect dots that are not even in the same book, let alone the same page. Meanwhile, persons living with dementia and their families are battered by waves of false hope that merely wear them down.
Correlation Does NOT Equal Causation
Two things can consistently happen together. This is called “correlation.” There are ways to show “correlation” mathematically, using statistics. But here is where it gets fun. Just because two things tend to happen together, it does not mean one is causing the other. Consider this example. I had a statistics prof who used to show the class an impressive graph comparing national ice cream sales with drownings. Both ice cream sales and drownings steadily increased in April, peaked in July, then slowly dwindled by October. Does this mean that ice cream eaters were more likely to drown than non-ice cream eaters? Nope. Both ice cream sales and drownings occur more frequently in summer months. Neither was related to each other. As my statistics prof was fond of saying, “Correlation does not equal causation.”
AD and Gum Disease Co-exist, But…
So back to gum disease. In some correlation studies, gum disease and Alzheimer’s disease follow the ice cream and drowning pattern. They exist together. I would not argue that AD causes gum disease. HOWEVER, I know from my own research that people with AD and other dementias often stop brushing their teeth. They fight the efforts of others to provide mouth care. Without consistent mouth care, plaque builds up on teeth and along the gum line and pretty soon, gum disease develops. The dementia did NOT cause the gum disease; lack of mouth care caused the gum disease. My team and I have tested a whole slew of ways to get people with dementia to accept mouth care in order to fix this issue. You can click here to read the publication.
There are also some studies, again looking at correlations, that suggest that people with gum disease may be more likely to develop Alzheimer’s disease and other dementias. One has to be careful here. People who develop gum disease usually have other health problems, like heart disease and diabetes. Some scientists have suggested that long-standing gum disease MAY cause heart disease. Other scientists have documented that diabetes and gum disease may aggravate each other. People with diabetes and heart disease are also at greater risk for developing dementia as they age. The bottom line is that these relationships are very complicated. Reporters who push exciting headlines are more interested in getting readers, not explaining the truth.
Beware Claims of Dementia Cures
Dementia is progressive, meaning that it keeps on getting worse. There are all sorts of websites and books claiming that this doctor cured this person. The person probably DID NOT HAVE DEMENTIA in the first place. There are many easily-fixed physical problems that cause memory problems–click here to read that article. Even with a dementia diagnosis, one may be able to slow down the process with healthy lifestyle activities, such as getting a good night’s sleep, exercising, and eating healthy foods.
What about supplements or magical potions? Save your money; supplements have not yet been shown to be helpful. There is so much we are learning about how the nutrients in food work together. I doubt that these supplements can do the same job that fresh fruits and veggies can do.
Lies, Damned Lies, and Statistics
Mark Twain is credited with that quote. Here is why. Some companies will report a finding that is “statistically significant” so that you will buy their product. Statistical significance simply means that I use a mathematical formula to see if there is any change between two groups, and if that change could have happened by accident. Here is a little secret: this mathematical formula is affected by numbers of people. The larger the group, the more likely I am going to get a result that is “statistically significant.”
This is how statistics works. I want to see if my magic pill improves memory. I get 1000 people to volunteer and I divide them into 2 groups of 500 each. They both take a memory test. Then I give the first group pills for 30 days while the other group gets nothing. One month later, both groups take the memory test again. The pill group improves by an average of 2 points on the test. The second group, the one that received nothing, improves by an average of 1 point on the test. Thanks to the magic of statistics, I discover that the difference between the groups “probably” did not happen by chance. I happily make this report:
“The group that received my magic pill had memory scores that were 50% higher than those who took nothing; these findings were statistically significant.”
More Ways to Manipulate Results
If you are scratching your head thinking, “This is bull crap,” welcome to my world. I agree! Is there a real-world difference between 1 and 2 points? Probably not, especially if the scores were on the high end. And it gets even better! Going back to the make-believe experiment, there are ways I could have messed with the outcome. I could have assigned younger and healthier people to the pill group. The pill did not affect their memory; they became familiar with the test and simply did better the second time around. I could have assigned people for whom English was not their primary language to the no-pill group. Their scores were affected by not understanding the test. There are so many ways that this study could have been manipulated to get the results that the manufacturer wanted. Or, the manufacturer could have paid a group of researchers to perform the study. These researchers may have made honest mistakes that affected the results.
Is it Legitimate or Not?
Legitimate research is research that is reviewed by layers of people or organizations with no ties to the group performing the research activity. The National Institute of Health provides money for research studies using strict criteria. The findings of these studies can be found in reputable journals. If you find something in a database like PubMed, it is probably legitimate. If you see a study in ClinicalTrials.gov, it is legitimate. Keep an eye on the web pages of universities with Alzheimer Disease Research Centers and whose faculty are engaged in research. These individuals are excellent resources for figuring out what is real science and what is bull dookie.