Alzheimer’s and Offspring Part 1
Writer: Prahalad Srinivasan
Editor: Brianna Viets and Vijaya Varadarajan
When parents begin to grow old and develop symptoms of Alzheimer’s disease, one of their first questions is often: “Does this mean my child will also suffer from the condition?” The answer to this question is complicated, and a direct answer is difficult to find. However, thanks to the work of researchers and genetic technology, we have a widely accepted theory regarding the nature of Alzheimer’s disease and its association with genetics.
Scientists have determined that two primary influences can lead to the development of Alzheimer’s in a human: environmental factors and genetic factors. Environmental factors refer to the overall lifestyle of a person, including their dietary choices and their physical activity. Genetic factors refer to mutations in genes that could increase the risk of Alzheimer’s. Both of these factors must be considered when determining how likely one is to develop Alzheimer’s in the future.
In this week’s edition of the AFA blog, we will examine the effects of environmental factors on Alzheimer’s and how these factors could affect the passing down of the condition.
Environmental Factors
As mentioned before, environmental factors refer to lifestyle choices made in one’s life, which are often influenced by their surroundings, primarily diet and exercise. To understand the indirect connection between lifestyle factors and Alzheimer’s, one must first understand the foundation of this connection: the gut-brain axis.
The gut-brain axis is the link between the digestive tract and the central nervous system caused by microbiota* residing in the stomach. These microbiota are responsible for interacting with the intestinal barrier, as shown in the image below. The intestinal barrier controls inflammation throughout the body, and if interacted with by specific types of microbiota, could lead to chronic inflammation in the brain. This chronic inflammation is often connected to Alzheimer’s, with those experiencing it demonstrating common symptoms of the condition.
Figure 1: Gut microbiota influences the intestinal barrier, in turn affecting the Gut-Brain axis (ScienceDirect)
However, this still leaves a major question unanswered: “How can we maintain a healthy disposition of gut microbiota?” This is where maintaining a healthy diet and exercise routine comes into play. When humans consume and digest food, the nutrients they receive from the food primarily determine what types of microbiota thrive in their gut. Eating a wide variety of healthy foods, primarily fruits and vegetables, allows for a diverse and healthy disposition of gut bacteria. This further promotes healthy interactions with the intestinal barrier. Similarly, exercise can also play a major role in the diversity and healthiness of the gut microbiota. According to the National Library of Medicine, exercising moderately for about 1 hour multiple times a week will likely produce significant changes in the gut microbiota as soon as 8 weeks. Just like maintaining a healthy diet, regular exercise also allows certain healthy types of microbacteria to thrive in the gut, allowing for healthy interactions with the brain.
Figures 2 & 3: A balanced diet and exercise routine: both factors that can prevent Alzheimer’s (ripe, NASM)
Connection to offspring
As mentioned earlier, exercise and physical diet are both factors often influenced by parents; children are likely to follow similar patterns to their parents. This means that while these factors affecting Alzheimer’s are not directly inherited, they can often be controlled by parents. Parents with healthy lifestyle choices are more likely to pass these traits along to their offspring and vice versa. These findings can also explain why Alzheimer’s is likely to run in families, but to find out about how specific genetic factors can influence the inheritance of Alzheimer’s, tune in to next week’s blog which dives into how genetic mutations can lead to the development of the condition.
Our journey goes on... join us for our Alzheimer’s and Offspring Part 2 shortly!
Glossary:
microbiota: the microorganisms of a particular site, habitat, or geological period.
Bibliography:
“Is Alzheimer’s Genetic?” Alzheimer’s Disease and Dementia, www.alz.org/alzheimers-dementia/what-is-alzheimers/causes-and-risk-factors/genetics. Accessed 9 Dec. 2023.
Jinyue Zhou, et al. “Diet and Physical Activity Influence the Composition of Gut Microbiota, Benefit on Alzheimer’s Disease.” Food Science and Human Wellness, Elsevier, 25 Oct. 2023,
Boytar, Alexander N, et al. “The Effect of Exercise Prescription on the Human Gut Microbiota and Comparison between Clinical and Apparently Healthy Populations: A Systematic Review.” Nutrients, U.S. National Library of Medicine, 22 Mar. 2023, www.ncbi.nlm.nih.gov/pmc/articles/PMC10054511/#:~:text=The%20 findings%20show%20that%20 participation,both%20clinical%20 and%20 healthy%20 populations.
Comments