The best protein supplements of 2024 – but do they work?
Protein supplements are not only for young men looking to bulk up in the gym. Emerging research suggests that they may hold benefits for midlifers and older adults, as our protein requirements increase with age.
To combat the steady loss of muscle, which occurs with age, nutritional experts have suggested that we should increase the amount of protein we consume in a day.
The current daily protein recommendation for UK adults is 0.75 grams per kilo of body weight, according to the British Heart Foundation.
“The British Association of Sport and Exercise Sciences are suggesting that older people do require more,” says Dr Colleen Deane, a lecturer in muscle cell biology at the University of Southampton. “They probably need about 1 to 1.2 grams, which I would agree with.”
But in practice, this isn’t as easy as it seems. For a woman weighing 60 kilograms (9st 6lb), that means going from 45 grams of protein per day to 72 grams, an intake that, Deane says, equates to approximately two-and-a-half chicken breasts (100 grams of chicken contains around 30 grams of protein).
“The issue is that as we get older, we also lose our willingness or ability to eat as much,” she says. “So things like supplements can help with taking on protein and maintaining muscle.”
How do protein supplements work?
Protein supplements, which typically come in the form of powders to be mixed into water or milk, are designed to be both highly convenient and easily digestible.
If you’re looking to build muscle tissue, you need to both exercise and consume sufficient quantities of protein to stimulate a biological process known as muscle synthesis. “You can’t just eat protein and grow muscle,” says Deane. “And exercise alone also does not put your body in a growth-promoting state.”
Abigail Green, senior health and wellbeing physiologist at Nuffield Health, describes the main benefits of these supplements as being quick and easy, cost-efficient and versatile.
“Protein powders are dynamic and can be added to cakes, cookies, oats, breads, smoothies, porridge and much more,” she says. “It’s a quick and convenient way of increasing your intake after a workout. You might feel like eating a full plate of chicken and rice at 10pm, whereas a shake sits easier on the stomach before bed.”
However, she emphasises that they should always be viewed as supplements to protein in your diet, and that they are not necessary for maintaining or building muscle.
If you’re already meeting your daily protein requirements, any excess from supplements will just end up being broken down into amino acids which circulate in the bloodstream. As a result, Deane says, scientists are still trying to figure out whether too much protein might even be bad for our health.
“For some people, just eating a meal high in protein does the same thing,” says Green. “Most people don’t need to supplement their diet with protein powder.”
When it comes to choosing a protein supplement, there are an abundance of different options. Here are some of the most popular choices and what to use them for:
Whey protein
Whey protein is by far the most widely studied protein supplement, with Deane describing it as “the bedrock” of all protein supplement research.
Whey is a dairy product, being the liquid that is left over when milk is processed into cheese. As an animal product, it has the advantage of naturally containing all nine essential amino acids, the building blocks of protein that our body requires for tissue growth.
It typically comes in two forms:
Whey concentrate, which is cheaper and contains a mix of protein, carbohydrate and fat.
Whey isolate powder, which is more expensive and has been processed so that the powder is more than 90 per cent protein. It also has a lower lactose content which makes it a better choice for anyone who is lactose-intolerant.
According to Dr Swrajit Sarkar, a senior lecturer in nutrition at City, University of London, various studies have found that whey protein is capable of increasing skeletal muscle mass, overall muscle strength and even gait speed in older adults who combined the supplements with resistance training. The effect was more profound in those who consumed whey isolate.
“If they’re healthy and they take it alongside doing lower or upper body exercise, it definitely will make a difference,” says Sarkar.
Casein
Like whey, casein also originates from milk. In fact, it is the casein protein that gives milk its white colour. Studies have also suggested that casein can be effective in building muscle, but the main difference compared with whey is that it is slower to digest. Sarkar suggests that this could make it less appealing to older individuals who do not digest things as easily.
However, it has made casein popular with both amateur and professional athletes, as casein is thought to encourage muscle repair over a more prolonged period of time, for example during sleep.
“People who are very physically active might take casein before going to bed,” says Sarkar.
Leucine
Leucine is thought to be especially potent in driving muscle growth.
Last year, a study in the European Journal of Clinical Nutrition found that when leucine supplements were given to 37 adults aged between 20 and 65, all of whom were on a calorie-restricted diet to lose weight, it helped to preserve their muscle tissue.
Deane says that one of the advantages of leucine is that it offers benefits even in relatively low doses. “It’s a really potent essential amino acid as it really stimulates a growth response in muscle,” she says. “As you can still do this with low quantities of leucine, it’s a promising supplement for people with less appetite, such as older adults.”
While leucine can be consumed through either leucine capsules or leucine-enriched protein supplements, Sarkar says that consumers buying the latter should look for products containing at least 40 per cent leucine.
“If it contains 40 per cent leucine that can increase both lean body mass and muscle function,” he says. “And one thing you want to do is to improve both so you can do more physical activity.”
Creatine
Creatine, a compound that is stored in muscle tissue and the brain, has attracted growing interest for its ability to rapidly regenerate adenosine triphosphate (ATP), a chemical that cells use as energy.
As a result, creatine supplements are thought to be potentially valuable for muscle performance and providing bursts of energy during workouts.
While people who eat a high-protein diet will already have more than enough creatine in their muscles, as the substance is commonly found in seafood and red meat, some studies have suggested that people who eat a plant-based diet, or those who are relatively new to exercising, may benefit from creatine supplements.
In some cases, research has shown it can improve the amount of weight people can lift by up to 32 per cent and increase muscle mass by 7.2 per cent, particularly in the upper body.
One review paper from 2021 indicated that creatine may be especially effective for women when used in combination with resistance exercises. Because some creatine is stored in the brain, the review also suggested that it could help boost mood and cognitive function.
Soy
For vegetarians and vegans, animal-derived supplements such as whey protein and casein may be off-limits. Dr David Rogerson, a researcher in the Academy of Sport and Physical Activity at Sheffield Hallam University, also points out that these supplements may not be suitable for people with certain allergies.
“Some people experience issues with dairy products in terms of their tolerability,” he says. “Whey and casein can aggravate that, and so they might find a plant-based source easier to consume.”
Soy is arguably the most heavily researched alternative to animal protein supplements, and last year a review paper found that in some cases, soy can be just as good at promoting muscle growth as whey protein.
Rogerson feels that for the majority of people, the differences between animal and plant-based protein supplements are likely to be relatively negligible. “Whether whey protein, for example, is better than another type of protein, it’s marginal at best,” he says. “So what someone chooses to use really comes down to personal preference.”
Pea protein
Along with soy, pea protein is another popular plant-based protein supplement. Sarkar describes it as being quite easily digestible, while Deane says that it does contain the same nine essential amino acids as whey protein and casein, but in smaller quantities.
“You would need to have a lot more of it to get the same response as something like whey,” says Deane. “This means it might cost more for people, because they’re having to take larger amounts, and with older people who don’t want to eat as much, they might not adhere to that.”
Collagen
Collagen, a type of protein, is present in astonishing abundance in our skin, cartilage and other connective tissues. Nearly a third of all the proteins in the human body are various types of collagen, but from our 20s onwards, our ability to produce them ourselves dwindles, making us progressively wrinklier and stiffer.
This has created an enormous market for collagen supplements, many of which are targeted at skin health. While the jury is still out on whether these supplements can really help retain youthful skin tone and elasticity, scientists are interested in whether they can help prevent frailty. Researchers at Liverpool John Moores University are currently examining whether they can make older adults less vulnerable to tripping and falling.
“Collagen is a poor source of the nine essential amino acids, so it isn’t as efficacious for helping to maintain or grow muscle as things like whey or pea protein for example,” says Deane. “But it’s rich in the other 11 amino acids so there may be benefits in these other areas.”
Blended protein powders
Rogerson says that blended protein powders, sometimes containing a mixture of whey, casein and egg proteins or different plant-based proteins, are becoming increasingly popular.
One of the best-known blended brands is Huel, but as with many other blends, Rogerson says he would categorise the product as more of a high-protein meal replacement than a supplement.
“Different blends of proteins have been around for a while now, and they’re often higher in calories because they contain carbohydrates and fat,” he says. “Some of the benefits are that they’re processed to be easy to consume, super convenient and they contain things like fibre and other nutrients. But if you’re not careful, they can really increase your calorie intake if you’re having them on top of meals. They should also be an occasional choice rather than a full replacement for a proper meal.”
What to watch out for with protein supplements: calories, chemicals, kidney issues
While supplements are a good way of boosting your protein intake, Rogerson urges consumers to always check the ingredient list carefully as many manufacturers will add in extra sugars to increase the palatability of their product.
“You don’t want these extras that are adding calories,” he says. “If you’re not careful, some of these supplements can be quite high in carbohydrates.”
Two years ago, a report from a US-based non-profit organisation called the Clean Label Project drew attention to the issue of contamination within protein supplements. After screening 134 different products, it found that many supplements contained heavy metals such as lead, arsenic, cadmium and mercury, a chemical found in plastics called bisphenol-A (BPA), pesticides or other known carcinogens. The levels of these contaminants was often dangerously high, with one particular protein powder containing 25 times the allowed limit of BPA.
“This created a bit of controversy,” says Rogerson. “But my perception is if you’re buying quality products, you probably don’t need to worry about it as much.”
The other consideration, particularly for older adults with underlying kidney problems, is to be careful of consuming higher amounts of protein without careful consultation with a doctor or dietitian. This is because removing the waste products from protein is stressful for the kidneys and forces them to work harder, and so people with chronic kidney disease are often encouraged to eat a low-protein diet.
“We need to be really cautious about recommending higher amounts of protein to older people if they have kidney problems,” says Rogerson.
Are there any other benefits in protein supplements?
Increasing the amount of protein in your diet can also have other benefits for your health, other than muscle mass and function.
“There is a little bit of evidence that suggests having protein supplements before a meal could help with things like blood glucose regulation,” says Rogerson. “Some pieces of research have looked at whether this can help curb appetite in people who are overweight or obese. Protein in general, as a nutrient, we do know that it’s helpful in a weight loss context, because it’s a really complex thing to digest and absorb. So it tends to make people feel fuller for longer.”
Verdict
While supplements can be a useful option, overall experts feel that consumers are best advised to try to get their protein requirements from their diet. “In general, I would say that you can get all the proteins that you’re looking for from a natural diet,” says Sarkar. “And as your requirements rise with age, you just increase the amount of protein that you’re eating to around half of your plate.”
Recommended
What your 'healthy' protein bar is really doing to your body
