Ask the Expert—Dr. Izzy Lira


Q: I’m thinking of supplementing my diet with protein drinks. Can you provide some insight into the different types?

A: The types of protein used in protein powders can be divided into two categories: protein from animals and protein from vegetables. Animal proteins include milk protein derivatives like whey and casein, goat’s milk, and egg white protein. Vegetable proteins include soy, rice, pea, and hemp proteins.

Nutritionally and taste-wise, animal proteins are superior to vegetable proteins and far more popular, especially whey protein. Before whey gained popularity, egg white protein was the favored form of protein supplement because it’s very low in fat and carbs. Egg white protein is cholesterol-free and an excellent choice for those who wish to avoid dairy products. Whey protein, derived from milk, is also the most commonly taken form of protein and is easily found on any shelf of any grocery or supplement store. Whey protein products can be made from whey concentrate, whey isolate, or a blend of both. Some people may find though that they have a hard time digesting the concentrates and can sometimes end up feeling a little gassy and bloated.

protein_powderCasein protein is also derived from milk protein. The key difference between whey and casein is that whey is absorbed in the digestive system quickly, whereas casein is absorbed slowly and steadily. Casein takes anywhere from 5-7 hours to fully break down, which keeps your body absorbing and utilizing the nutrients even while you sleep. People also use casein after a workout or during the day to help stay full and to keep a constant supply of protein in the body in order to supply muscles with proper nutrition for hours after drinking the shake.

woman_drinking_protein_mixOf the vegetable protein types, soy is the most popular. Most people using vegetable protein powders do so as part of a vegetarian or vegan lifestyle, although many people take soy protein for its heart-health and/or hormone-balancing benefits.Soy supports a healthy cholesterol profile due to the isoflavones, which are very similar to the hormone estrogen. Some fear that eating too much soy could potentially have harmful effects on men. Too much estrogen could theoretically affect fertility, or sexual function, and studies have in fact found that giving large amounts of phytoestrogens to animals can indeed do so. Keep in mind, however, that men have been eating soy, and plenty of it, for centuries in Asia and have not experienced population-wide fertility issues. Soy has also been found to boost thyroid hormone output. By doing so, it speeds up the metabolism, which aids in fat loss.

The most common concerns people raise after looking at protein powders and reading labels are allergies to protein components such as lactose, soy, casein, eggs, or gluten. Other common concerns relate to artificial ingredients, which you may wish to avoid. In both cases, there are plenty of alternatives from which to choose. And as always, see your chiropractor or doctor for more tips!

A Doctor of Chiropractic, Izzy Lira is also a strength and conditioning specialist.

Follow him on Twitter:
Find him on Facebook:

Photos, from top: Richard Salas. Stock photography from

1 Star2 Stars3 Stars4 Stars5 Stars (No Ratings Yet)