Lara Zijl 
California, USA: A recent study published in the Journal of Alzheimer’s Disease has identified which diets are effective in lowering the risk of developing Alzheimer’s disease. The research, titled “Diet’s Role in Modifying Risk of Alzheimer’s Disease: History and Present Understanding,” highlights the role of nutrition in reducing the risk of Alzheimer’s.
Extensive studies have shown that plant-based diets, such as the Mediterranean diet and traditional Chinese, Japanese, and Indian cuisines, are effective in lowering the risk of Alzheimer’s disease, especially when compared to the Western diet. As countries transition to the Western diet, Alzheimer’s disease rates have increased. The study identifies several dementia risk factors, including the consumption of saturated fats, red meat (like hamburgers and barbeque), processed meats (like hot dogs), and ultra-processed foods high in sugar and refined grains.
The review explains why certain foods increase or reduce the risk of Alzheimer’s disease. For instance, meat increases dementia risk factors like inflammation, insulin resistance, oxidative stress, saturated fat, advanced glycation end products, and trimethylamine N-oxide. On the other hand, foods that protect against Alzheimer’s include green leafy vegetables, colorful fruits and vegetables, legumes (like beans), nuts, omega-3 fatty acids, and whole grains.
Ultra-processed foods, which can increase the risk of obesity and diabetes, themselves risk factors for Alzheimer’s, lack the anti-inflammatory components and antioxidants found in whole plant foods that help prevent dementia.
Poverty is also a significant driver of Alzheimer’s disease in the US. Ultra-processed foods and meat are cheaper energy sources than fruits, vegetables, whole grains, and other nutritious foods, promoting obesity.
The paper projects that Alzheimer’s disease rates in the US will increase by 50% from 2018 levels by 2038, based on obesity trends. This estimate closely aligns with a 2018 projection by the Alzheimer’s Association of a 56% increase. The study suggests that the rising trend of obesity, due to the consumption of meat and ultra-processed foods, is driving dementia. Although diet can reduce personal risk, those who continue to eat the Western diet will maintain a higher risk.
“Grant and Blake comprehensively review and synthesize the role of dietary factors in Alzheimer’s disease,” said Edward Giovannucci, MD, ScD, Professor of Nutrition and Epidemiology at Harvard University. “Evidence supports that a diet emphasizing fruits, vegetables, legumes, nuts, and whole grains, while de-emphasizing meat, especially red meat, saturated fats, and ultra-processed foods, is associated with a lower risk of Alzheimer’s. Physical inactivity and obesity also contribute to higher risk.”
Giovannucci adds that the dietary and lifestyle patterns associated with higher Alzheimer’s risk also influence mechanisms like inflammation, insulin resistance, and oxidative stress. Further research is needed to better understand these mechanisms, but diet and lifestyle factors linked to diabetes, cardiovascular disease, and some cancers are likely to influence Alzheimer’s risk.
