Proteins as nutritional tools

Unlocking the potential of peptides to improve human health

High blood pressure is a leading risk factor for heart disease and affects close to one in four Canadian adults. Cancer causes around a quarter of deaths annually. Alzheimer’s disease and other forms of dementia affect over 650,000 Canadians, a number that is expected to almost triple by 2050.

What do these three diseases have in common? For Rotimi Aluko, U of M professor in the faculty of agricultural and food sciences, they are the targets of research aimed at using proteins as nutritional tools to improve health outcomes.

Whether it is found in a hamburger or soybeans, proteins are large biological molecules made up of units called amino acids that are needed for the body to function properly.

“What we do is very special,” Aluko said. “We deconstruct nature’s assembly of proteins. How do we do that? We simply add enzymes.”

Enzymes, Aluko explained, are the biological equivalent of scissors. Adding an enzyme to a protein allows it to cut the protein at certain points, resulting in fragments. These fragments of protein, called peptides, are studied for their potential health implications.

“You eat it and you can actually benefit in terms of improved health,” he said.

One component of Aluko’s work examined the ability of these peptides to treat high blood pressure, a “silent killer,” in which the heart works harder to pump blood and the force of blood straining the artery walls is abnormally high

By performing customized cutting of certain proteins identified in terms of their function, a group of specialized peptides are produced with the ability to reduce blood pressure. While these peptides act similarly to anti-hypertensive drugs, which also lower blood pressure, they are consumed as constituent s with food.

Aluko highlighted that, when fed to rats, these peptides were shown to reduce blood pressure. Following the trial on rats, similar findings were observed on a study of human volunteers in Winnipeg.

“That is something that we’re very proud of,” Aluko said, “the fact that we can eat food and not just benefit in terms of normal body growth for your muscles, but actually in terms of being able to have lower blood pressure.”

He emphasized the potential of peptides as an alternative or additional nutritional tool for patients who might otherwise be heavily medicated.

“Another thing we looked at is the potential for peptides grow excessively,” Aluko said.

This excessive growth, he noted, is cancer.

Cancer occurs when mutations in cells cause them to bypass apoptosis, the normal, healthy process of cell death. Cancerous cells grow and divide uncontrollably, using up the body’s oxygen and nutrient resources and impairing normal bodily functions, like the immune system. Cancer is the leading cause of death in Canada and is experienced by nearly half of Canadians during their lifetime.

“The peptides that we generated from food can actually bind to one of the principal molecules in a cell that encourages the cell to grow too much,” Aluko explained. “Our peptide combines with it and then can prevent the cell from getting the signal to go.”

Beyond high blood pressure and cancer, Aluko’s team is also working to use customized peptide sequences to prevent the memory loss associated with Alzheimer’s disease.

Alzheimer’s disease is a disorder of the brain that causes slow deterioration of the memory and cognitive skills, as well as behaviour and personality changes. While the causes of Alzheimer’s disease are not fully understood, they may include changes in the brain such as shrinking, inflammation and a loss of neurons.

“Some of the peptides that we were able to produce are also able to bind to the principal enzyme in the brain that basically causes the loss of memory,” Aluko said. “They help by binding to this enzyme in the brain and then can keep the enzyme at bay and prevent the enzyme from causing reactions that lead to memory loss.”

The objective of Aluko’s work is for the practical applications of proteins as nutritional tools to be recognized.

“I would love to really see our inventions eventually translated into products in the market that anybody can just go, and buy and use it to improve their health,” Aluko said. “That will be my ultimate goal.”