I didn't say it was. I said "if" it is, there could be many contributing factors.
However, there are many articles on the subject of lifestyle and AD. From the Alzheimer's Association web site, Causes and Risk Factors for Alzheimer's Disease: "Researchers believe there isn't a single cause of Alzheimer's disease. It likely develops from multiple factors, such as genetics, lifestyle and environment. Scientists have identified factors that increase the risk of Alzheimer’s. While some risk factors — age, family history and heredity — can't be changed, emerging evidence suggests there may be other factors we can influence." -
https://www.alz.org/alzheimers-dementia/what-is-alzheimers/causes-and-risk-factors
Lifestyle Changes You Can Make to Help Lower the 19 Risk Factors for Alzheimer’s -
https://www.healthline.com/health-news/alzheimers-risk-factors-lifestyle-changes -“One of the new and most prevalent risk factors to emerge from this report is hyperhomocysteinemia, which is commonly found in those with B12 or folate deficiencies and much more common in those who consume diets high in meat. [This] highlights the relative importance of including a diet higher in plant than meat protein for Alzheimer’s prevention,” McEwen told Healthline...."These new findings are incredibly helpful for clinicians, illuminating the necessity to do a deeper dive into their patients’ medical histories and further blood tests to see if their patients present with any of these risk factors,” she said....“There is more and more evidence that modifiable risk factors play an important role in protecting people from developing cognitive decline as they age, including Alzheimer’s disease,”
Keith Fargo, PhD, director of scientific programs and outreach for the Alzheimer’s Association, told Healthline."
What you can do now: While research is not yet conclusive — partially due to the need for more large-scale studies in diverse populations — certain lifestyle choices, such as physical activity and diet, may help support brain health and prevent Alzheimer's. Many of these lifestyle changes have been shown to lower the risk of other diseases, like heart disease and diabetes, which have been linked to Alzheimer's. With few drawbacks and plenty of known benefits, healthy lifestyle choices can improve your health and possibly protect your brain. -
https://www.alz.org/alzheimers-dementia/research_progress/prevention
I put Alzheimer's and lifestyle into my Google search bar and got 45 million results.