Alzheimer's

A study by Italian researchers has tested a treatment administered as a nasal spray to slow down early-stage Alzheimer's disease. Administered in mice, the treatment inhibits an enzyme linked to the disease and to insulin resistance. According to the researchers, who publish the work in the journal PNAS, application of the spray to the animals “can counteract the accumulation of harmful proteins in neurons and delay the onset and progression of cognitive decline”. 

Less than four months after the European Medicines Agency recommended in July not to grant marketing authorisation for Leqembi™ (lecanemab) for the treatment of Alzheimer's disease, the EMA's Committee for Medicinal Products for Human Use (CHMP) has reassessed the available evidence to conclude that the benefits outweigh the risks.

Men and women could develop Alzheimer’s disease through different mechanisms. Understanding these differences is essential to design specific interventions and to treat the disease effectively. In an article published in Alzheimer’s and Dementia: The Journal of the Alzheimer’s Association, a group of researchers, including myself, have highlighted the urgency of adding a sex and gender approach to the studies on this pathology.

Mice with Alzheimer's disease are more resistant to the development of colorectal tumors, a study shows. An inverse relationship between Alzheimer's and cancer has already been shown in epidemiological studies in humans. An imbalance in certain intestinal bacteria contributes to this negative correlation in mice, adds the article published in PNAS.

The European Medicines Agency (EMA) has recommended not granting marketing authorization for Leqembi™ (lecanemab) for the treatment of Alzheimer's disease. The EMA's Committee for Medicinal Products for Human Use (CHMP) considers that its effect in delaying cognitive decline does not outweigh the risk of serious side effects associated with the drug, in particular swelling and possible bleeding in patients' brains. Leqembi™ was approved in 2023 in the United States.

Hormonal therapy to treat breast cancer is associated with a lower risk of Alzheimer's disease and dementia in women over 65, a study says. The retrospective analysis is based on data from more than 18,000 women with breast cancer in the US: two-thirds of them had received hormone therapy and one-third had not. The "protective effect" of hormone therapy declines with age and varies by ethnicity, adds the article published in JAMA Network Open. 

A family of more than 1,000 members with origins in Colombia has a mutation called "paisa" that leads to the development of Alzheimer's disease. In 2019, an added mutation in the apoE gene called "Christchurch" was described as conferring strong protection to an individual carrying two copies of it. Now, a study has found that 27 family members carry a single copy and that it is also associated with some degree of protection. According to the authors, who publish their findings in the journal NEJM, the discovery could be used to develop new treatments for the disease. 

Genetic forms of Alzheimer's are considered to be those in which certain variants of a gene inevitably lead to the disease over time. Until now, only rare alterations in three genes were considered as such. A group of researchers led by the Hospital de Sant Pau in Barcelona has proposed a new, much more frequent form. After analysing data from more than three thousand donated brains and clinical data from more than ten thousand patients, they found that almost all people who carry two copies of the ApoE4 variant in the ApoE gene, which was previously only considered a risk factor, also end up developing the disease.They publish the results in the journal Nature Medicine.  

Drugs to treat erectile dysfunction may be associated with a reduced risk of Alzheimer's disease, according to an observational study of nearly 270,000 men, published in Neurology. The research does not prove that these drugs reduce the risk of Alzheimer's, but only shows an association.

Researchers have described five cases of people in the UK who developed Alzheimer's-like dementia after being treated as children with growth hormone from cadavers. The treatment was administered between 60 and 40 years ago. This suggests that the disease could be transmitted. However, the authors point out that this is a very rare occurrence and could have been caused by repeated exposure to a type of hormone that is no longer used. The results are published in the journal Nature Medicine.