What you need to know about different sources of proteins. By Joyce Teo
Proteins on their own are not good or bad. It is the saturated fats that animal proteins come with that are problematic. Photo: belchonock / 123rf.com
The human body needs protein to repair and maintain itself. Protein is thus called the building block of the body. Our hair, skin, eyes, muscles and organs are made from protein.
Protein comprises 20 amino acids, of which nine are considered essential and can be obtained only from food. The other 11 can be made by the body if needed.
These can come from red or white meat and dairy products, and are more easily absorbed by the body than plant proteins.
Good sources of proteins are milk, eggs, fish and soya as they contain complete protein, or all nine essential amino acids, said Ms Fiona Chia, director of nutrition consultancy Health Can Be Fun.
Proteins on their own are not good or bad. It is the saturated fats that animal proteins come with that are problematic, she said.
Animal proteins can provide all the essential amino acids a person needs, but red meat has fat nestled within the protein tissue that can be harmful when taken in large amounts, she added.
Professor Koh Woon Puay from the Duke-NUS Medical School and NUS Saw Swee Hock School of Public Health said red meat is eaten for the richness of its protein, iron and vitamin B.
“There are other minerals such as zinc and other nutrients that are good for the body,” she said.
However, apart from containing fat and cholesterol, red meat is most commonly eaten in processed form or cooked at high temperatures, both of which can lead to the formation of potentially cancer-causing chemicals, she said.
Red meats such as beef, lamb and pork have more cholesterol and saturated fat than chicken, fish and plant proteins such as beans, according to the American Heart Association.
“Cholesterol and saturated fat can raise your blood cholesterol and make heart disease worse,” it said.
Fortunately, Prof Koh said, dietary items can be substituted. “No single food item is really indispensable.”
She added: “Once you eat a variety of foods, you won’t likely overeat any one type of food.”
These can come from beans, lentils, peas, nuts and nut butters, seeds and some grains like quinoa.
The local study linking red meat to kidney failure observed that eating soya and other legumes could reduce the risk of kidney failure.
With the exception of soya beans and soyabean products such as tofu, tau huay and bean curd, plant foods are incomplete proteins.
This is because they lack significant amounts of certain essential amino acids.
So plant proteins, such as peas, should be eaten with other food items such as rice and beans, said Ms Chia.
“Vegetarians will need to combine various sources of plant proteins to get the nine essential amino acids their body needs,” she said.
A version of this article appeared in the print edition of The Straits Times on July 26, 2016, with the headline ‘Moderate intake of red meat is fine’.