A diet high in protein-rich foods such as meat and legumes reduces the risk of developing Alzheimer’s disease, according to new research from Edith Cowan University (ECU) in Australia.

Researchers from ECU’s School of Medical & Health Sciences examined the diets of 541 Australians and measured the levels of amyloid beta (Aβ), which is a precursor to Alzheimer’s disease. They found that participants with higher levels of protein in their diet were less likely to have high levels of Aβ in their brain, thus reducing their risk of developing Alzheimer’s disease, ECU said.

Brain boost

The participants were divided into three groups based on their protein intake. The researchers found that those with the highest protein consumption -- around 118 g per day -- were 12 times less likely to have high levels of Aβ than those in the lowest consumption group, who ate only 54 g per day.

Joint lead researcher Dr. Binosha Fernando said this was the first-ever study to examine the relationship between protein consumption and Aβ.

“The research clearly demonstrates that the more protein eaten, the lower the chances ... of having a high Aβ burden on the brain, which corresponds to a lower risk of developing Alzheimer’s in the future,” she said.

Fernando said it is still unknown what drives the relationship between high protein intake and low Aβ. “One possibility is that previous studies have shown that a high-protein diet is associated with lower blood pressure,” she said. “High blood pressure is a risk factor for both Alzheimer’s disease and cardiovascular disease. We also know that developing cardiovascular disease increases your risk of developing Alzheimer’s disease.”

Fernando explained that the next step is to further examine what role gender, genetics, age and metabolic factors play in the relationship between protein consumption and Alzheimer’s disease.

Getting enough protein

Protein is found in animal products like beef, pork, lamb, eggs, fish and poultry as well as in plant-based foods like legumes, whole grains, nuts and seeds.

“To get the protective effect that we have demonstrated, you need to be eating about 120 g of protein each day, which isn’t too hard,” Fernando said.

Lifestyle focus

ECU’s Centre for Excellence for Alzheimer’s disease Research & Care recently identified depression and trouble sleeping as other potential risk factors for Alzheimer’s disease.

The center is also currently investigating if a combination of the spice circimun and fish oil can potentially delay the onset of Alzheimer’s disease.

"Associations of Dietary Protein and Fiber Intake with Brain and Blood Amyloid-β" was published recently in the Journal of Alzheimer’s Disease.