When it comes to the mind-robbing disease of Alzheimers, there are very few medications that have been found able to slow its progression.

There also appears to be few medications to effectively treat mild cognitive decline that is not related to Alzheimer’s.

Cognitive enhancers are given to patients who are at a mental decline somewhere between dementia and age-related mental decline. The patient can exist day to day but has some trouble remembering which is noticeable to those close to him.

The latest review of existing data on cognitive enhancement drugs showed benefits that worked short-term on cognitive impairment while delivering a host of side effects including gastrointestinal issues, nausea, headache, vomiting and diarrhea.

The data review was conducted by researchers at St. Michaels Hospital in Toronto. Altogether eight randomized clinical trials look at the efficacy of the four drugs on mild cognitive impairment – Aricept (donepezil), Exelon (rivastigmine), Razadyne (galantamine) and Namenda (memantine).

Nausea and diarrhea were seen more frequently among those patients taking Aricept, Exelon and Razadyne. After a year and a half of treatment any short-term gains were lost, according to researchers.

There are about 4.6 million people with mild cognitive impairment worldwide with up to 17 percent progressing onto dementia.

The same four drugs are prescribed in the U.S. and Canada to treat Alzheimer’s–related dementia. Researchers hoped to determine whether the same drugs used to treat Alzheimer’s patients would be helpful to those experiencing mild cognitive decline, even the decline not related to Alzheimer’s.

The research is published in the Canadian Medical Association Journal.

Theories on Alzheimer’s disease have long taken a look at the role of brain plaques, the gooey substance that coat and kill brain cells, taking with it the ability for a person to retain their memory, personality, cognitive thinking and humanity.

But emerging research is reconsidering whether plaque may actually offer a protective coating to fight off attacks by free-floating bits of toxic protein, amyloid beta.

Newer research indicates there are nine risk factors that may spark early onset dementia that are entirely preventable such as alcohol use, depression, drug use, antipsychotic medication use, a history of stroke and high blood pressure.