A high-fat diet can carry health risks, but for mothers-to-be, it may make all the difference when it comes to Alzheimer’s disease prevention for their children.
In a new study, researchers found for the first time that eating a high-fat diet during pregnancy protects offspring against changes in the brain that are characteristic of late-onset Alzheimer’s disease.
The research was conducted by a team from the Lewis Katz School of Medicine at Temple University.
In humans, it has been known that individuals whose mothers develop Alzheimer’s disease after age 65 are at increased risk of also developing the disease around the same age
Genetic factors transmitted by mothers to their offspring seem like an obvious explanation behind this phenomenon, but so far no genes have been identified that could explain the maternal transmission of Alzheimer’s disease.
This fact would suggest that environmental factors, such as lifestyle and diet, adopted during the gestation period, a time in which mother and baby are in tight interaction, could significantly influence the offspring’s risk of developing the disease later in life.
Diet is of particular interest as a risk factor, especially a diet rich in animal fat and cholesterol.
High-fat intake previously has been shown in young/adult mice to directly exacerbate the types of changes in brain function that ultimately may contribute to Alzheimer’s disease.
In the study, the team focused on the unique link between maternal Alzheimer’s disease and risk in her offspring.
They looked at maternal fat intake specifically during the gestation period in mice engineered to develop Alzheimer’s disease.
Pregnant mice were fed a high-fat diet from the beginning until the end of gestation.
The moment offspring were born, mothers were switched to a regular diet, which was maintained during the lactation period.
Offspring of these mothers were always kept at the same regular, or standard, diet throughout their life.
At 11 months of age, offspring underwent behavioral tests to assess learning ability and memory.
The team found that animals from mothers fed a high-fat diet during gestation had better learning and memory skills than their counterparts born to mothers fed a regular diet during gestation.
The observed improvements in memory and learning were associated with the maintenance of good synaptic integrity.
In fact, offspring from mothers exposed to a high-fat diet had a big improvement of synapse function when compared with offspring from mothers on a regular diet.
Synapses, the places where neurons come together to relay information, play a vital role in learning and memory formation.
In addition, compared to animals born to mothers fed a regular diet, offspring from mothers on a high-fat diet had lower levels of amyloid-beta, an abnormal protein that builds up in neurons, contributing to nerve cell dysfunction and eventually significant impairments in memory and learning.
The team then discovered that offspring from mothers fed a high-fat diet exhibited reduced levels of three important genes involved in Alzheimer’s disease: beta-secretase, tau, and the pathological tau-regulating gene CDK5.
The three genes were effectively switched off in offspring because the high-fat diet had increased activity of a protein called FOXP2.
They demonstrated that the repressive activity of FOXP2 on these genes ultimately protected offspring from later declines in brain function and Alzheimer’s disease development.
The findings suggest that to be effective, Alzheimer’s disease prevention probably needs to start very early in life, during gestation.
Diet at this specific life stage can have critical, but underestimated, long-term impacts on brain health.
The team plans next to compare the effects of a high-fat diet to those of other diets, including diets high in sugar and protein and diets resembling the Mediterranean diet in humans.
The lead author of the study is Domenico Praticò, MD, Scott Richards North Star Foundation Chair for Alzheimer’s Research.
The study is published in the journal Molecular Psychiatry.
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