Alzheimer's Archive

There are currently nine trials of vaccines for Alzheimer's disease under way. All of them are in people with mild Alzheimer's or with the pre-Alzheimer's condition called mild cognitive impairment. All of the vaccines are designed to encourage the immune system to remove protein deposits from the brain. Most experimental vaccines are given by injection; one being tested at Harvard Medical School uses a nasal spray. It will be several years before we know if any of them will work.

Researchers have found that the risk of death due to Alzheimer's disease is markedly lower in taxi and ambulance drivers compared with hundreds of other occupations. And the reason could be that these drivers develop certain structural changes in their brains as they work.

A 2025 study suggested that people who eat higher amounts of processed red meat may be more likely to develop dementia than people who eat very little of it.

In a 2025 Harvard study of more than 133,000 people followed for four decades, those who ate the most red meat each day (a quarter-serving or more) had a 13% higher risk of developing dementia later in life, compared with people who ate the least.

In a 2025 study of about 2,000 people (average age 80) who were followed for seven years, about a third developed dementia or mild cognitive impairment. Being socially active seemed to delay that diagnosis for about five years.

It's fairly common for a medical treatment to cause side effects - but far more rarely, a side effect provides an unexpected benefit. This might be the case for the shingles vaccine, as evidence is mounting that it might also reduce the risk of dementia.

Eating high amounts of processed red meat each day may increase the risk for future cognitive decline and dementia. Switching out processed red meat for nuts, legumes, low-fat dairy, chicken, or fish also may lower the risk.

A 2024 study suggests that older adults who fall for financial scams may have brain changes associated with a higher risk of Alzheimer's disease.

There's no clear-cut answer about whether taking antihistamines for allergies increases dementia risk. Antihistamines have anticholinergic effects, which might increase the risk for dementia by blocking a particular brain neurotransmitter or increasing brain inflammation. But studies on whether there's any link between antihistamines and dementia have produced conflicting findings. Doctors advise taking the lowest antihistamine dose possible or using another medication for symptom relief.