Supporting your immune system isn’t just about dodging colds for the rest of your life – even though that is an inviting prospect. In fact, it’s a vital part of maintaining your overall health, wellbeing and vitality at all life stages.

Your diet plays a crucial role in this, including the proteins you consume. As well as being the building blocks for healthy muscles, did you know that protein is also essential for bolstering your immune defences? (1) This guide will explore the science of protein and its immune-strengthening benefits, helping you make an informed choice about the best protein powder for your individual health goals.

Protein and immune function – what’s the link?

You might already understand the role of protein in supporting muscle health (2), which is perhaps its most well-known function in the body. But protein has a range of other functions in the body, from supporting healthy skin and hair to making sure your immune system works as expected. (3)

Essential amino acids for immune functioning

Proteins and their amino acids play a pivotal role in the proper functioning of your immune system because certain essential amino acids such as arginine, glutamine, and cysteine have direct roles in your body’s immune responses:

• Arginine regulates the function of immune cells like T-cells, which are central to the immune response against pathogens. (4)
• Glutamine serves as fuel for immune cells, including lymphocytes and macrophages, ensuring they function optimally during times of stress or infection. (5)
• Cysteine contributes to the synthesis of glutathione, often referred to as the body’s ‘master antioxidant’. Glutathione plays a critical role in defending against oxidative stress within immune cells. (6)

Ensuring your diet has good sources of these amino acids in particular can help to support your immune health. While whole food sources are the best all-around source of nutrition, a protein powder or supplement is a fantastic way to give your diet a guaranteed protein boost in a simple, measurable, and healthy way.

When it comes to protein powders, choosing the best option for you takes consideration and, sometimes, a bit of trial and error. Much of the time, we’re looking for something that ticks all of our boxes – a quality protein source, easy to digest and, not forgetting, an enjoyable taste and texture.

When it comes to immune support, the most important thing is to make sure you’re getting your recommended daily protein intake – fullstop. That being said, below are some findings that might help you decide whether a particular protein powder is more suited to your goals.

Whey protein and immune function

Research has shown that whey protein is a powerhouse when it comes to supporting your immune health. (7) Given that it is the same protein found in human breast milk, it’s unsurprising that it comes with a whole host of benefits for the optimal functioning of your immune system:

• Bioactive proteins: Whey protein contains several bioactive protein compounds which are important for the body’s immune defence. (8) This includes:

1. Alpha-lactalbumin (α-Lactalbumin) – with prebiotic and antibacterial properties, and potential for improving gastrointestinal health. (9)
2. Beta-lactoglobulin (β-Lactoglobulin) – with the potential for supporting immune function by increasing white blood cell function and production. (10)
3. Immunoglobulin G – our body’s most common antibody, found in the blood and other bodily fluids, with positive effects on immune function, allergies and infections. (11)
4. Lactoferrin – antibacterial and antiviral, with important immunological properties. (12)

• Glutathione production: One of the standout features of whey protein is its ability to increase the body’s antioxidant capacity through the promotion of glutathione. This 'master antioxidant' is crucial in maintaining an effective immune system by protecting cells from oxidative stress and harmful toxins. (13)

Soy protein and immune function

Another protein which has been studied for its impact on immune health is soy. A key plant protein, soy contains all nine essential amino acids in good quantities – one of the only plant-based proteins to do so.

Studies into soy protein have begun exploring benefits for immune functions:

• Isoflavones: Much of the research around the immune benefits of soy protein focuses on isoflavones, which are bioactive compounds called ‘phytochemicals’. There have been studies which have explored their ability to reduce the risk of diseases as well as being antioxidant and anti-inflammatory. (14,15)
  
  However, due to variations in the way this has been studied, there is still some uncertainty around the extent of these benefits (16,17) and the processing methods of some soy protein isolates might actually lower the amount of isoflavones present (18,19) making them less beneficial from an immunity perspective.

Immune benefits of other plant-based proteins

Most of the research on the immune benefits of different proteins has been conducted on whey and soy. However, some other suggested immune benefits of plant-based protein powders include:

• Hemp protein powder: Rich in omega-3 fatty acids and anti-inflammatory, with important immune-regulatory functions. (20) “In our Westernised diet,” says Belle Parrish, registered nutritionist at Balance by Belle, “we tend to have more omega-6 (a pro-inflammatory) in our diets.” So, good sources of anti-inflammatory omegas are vital to balance this out.
• Pea protein powder: A fantastic source of iron (21), which has been shown to play a key role in the regulation of the immune system. (22)

Protein blends with immunity-supporting vitamins & minerals

Some protein powder blends are enriched with vitamins and minerals known to bolster the immune system. Where possible, we’d recommend looking out for blends that are fortified with whole food ingredients that naturally enhance nutritional value with the below:

• Vitamin C: Renowned for its immune-supporting properties, Vitamin C is a potent antioxidant that helps protect cells and keeps the immune system functioning properly. (23)
• Vitamin D: Vitamin D supports immune health and can modulate innate and adaptive immune responses. (24)
• Zinc: This mineral is crucial for normal development and function of cells mediating innate immunity. (25)
• Selenium: A key nutrient that plays a significant role in inflammation and immunity. (26)
• Iron: Necessary for immune cell proliferation and maturation, particularly lymphocytes, which are integral to the immune response. (27)

From whey with its rich array of bioactive compounds to plant-based options blended with essential nutrients, different protein powders can play a pivotal role in improving your immune health as well as supporting your muscles. It’s all about what the best protein powder is for you.

Integrating a high-quality protein powder into a balanced diet enriched with other immune-supporting foods can help to strengthen your body's defences. As you consider your options, prioritise products that align with your health goals and dietary preferences to make sure you both support your immunity and enjoy what you consume.