Why Protein Matters More Than Ever as We Age

Dr Max Gowland, biochemist and longevity expert explains the importance of ageing with grace from within

When most people think about healthy ageing, they tend to focus on their heart, their cholesterol, their blood pressure, or perhaps their memory. Yet there is another part of the body that is just as important, and it is often overlooked. And that is muscle.

In fact, growing scientific evidence suggests that muscle mass and muscle strength are actually among the strongest predictors of healthy ageing, independence, and even longevity. Put simply, maintaining muscle may be one of the most important things we can do to remain active, capable and healthy as we get older.

Unfortunately, muscle loss is a natural part of ageing. But the good news is that it is not inevitable, and one of the most powerful tools we have to slow it down is surprisingly simple: eating enough protein.

The Silent Loss of Muscle

From around the age of 40, most adults begin to lose muscle mass gradually. This process accelerates with age and can reach 1–3% per year in later life, which means that by 65, you could have lost a quarter of your muscle mass!

This age-related loss of muscle is known as ‘sarcopenia’. While it is not considered a disease, it is one of the major causes of frailty, weakness, loss of mobility and reduced quality of life in older adults. Many people assume that muscle loss simply means becoming a little weaker, but in reality, the consequences can be far greater.

Reduced muscle mass is associated with poorer balance, increased risk of falls, slower recovery after illness or surgery, loss of independence, and a higher risk of many chronic diseases. Studies have also shown that people with greater muscle mass and strength tend to live longer than those with less. That makes muscle one of the most important tissues in the body to protect as we age.

Muscle is Built from Protein

Muscle is made primarily of water, but protein is the second largest component.

Proteins themselves are built from smaller units called ‘amino acids’, which are often described as the building blocks of life. Without protein, there would be no muscle, but protein is also needed for much more than that.

Protein is required to make:

• Skin and connective tissues
• Cartilage and tendons
• Bone matrix
• Hormones
• Enzymes
• Haemoglobin, which carries oxygen around the body
• Immune cells and antibodies
• New cells and tissues throughout the body

Every day, proteins are continually broken down and rebuilt and this of course includes muscle too, which is in a constant state of repair and renewal. This means that our bodies need a regular supply of dietary protein simply to maintain what we already have. However, when muscle loss outpaces muscle repair, a slow but relentless decline begins. Strength falls, physical function deteriorates and the risk of frailty, falls and loss of independence increases.

Why Older Adults Need More Protein

One of the biggest misconceptions in nutrition is that protein requirements remain the same throughout life. Not true. For many years, the recommended daily intake of protein was set at 0.8 grams per kilogram of body weight. For a 75 kg adult, that equates to around 60 grams of protein per day. However, many scientists in the field now believe that this recommendation is outdated.

The original recommendations were based largely on ‘nitrogen balance’ studies, which measured protein intake against protein losses, using nitrogen as the main marker. More recent research however has looked directly at actual clinical outcomes such as muscle mass, strength and physical function, providing a more realistic picture of what older adults actually need.

Today, many leading researchers suggest that older adults should consume between 1.0 and 1.2 grams of protein per kilogram of body weight daily, with some recommending up to 1.5 grams per kilogram in certain circumstances, such as illness, recovery from surgery, or periods of inactivity.

For a 75 kg person, that could mean aiming for around 90–110 grams of protein per day. But what does that actually mean in real life? Well, it is roughly the equivalent of four medium chicken breasts or eighteen eggs. Most of us are not going to eat either of those in a day, which highlights just how difficult it can be for older adults to consume enough protein consistently. This is one reason why protein supplementation can be a sensible option, not as a replacement for a healthy diet, but as a practical way of helping to achieve these higher protein targets.

Most Older Adults Are Not Eating Enough Protein

This is where the problem begins.

Data from the UK National Diet and Nutrition Survey (NDNS) suggests that the vast majority of older adults are failing to meet these newer protein targets. In fact, around 80% of older adults do not achieve the recommended intake of 1.2 grams per kilogram of body weight per day, according to this data.

Many people assume they are eating plenty of protein because they have some meat with dinner or milk on their cereal. Yet when total daily intake is calculated, it often falls well short of what is required to support healthy ageing. This shortfall may be one of the reasons why muscle loss is so common in older adults.

Ageing Creates “Anabolic Resistance”

Another challenge is that ageing muscles become less responsive to protein. Scientists refer to this as ‘anabolic resistance’. In younger adults, a moderate amount of protein can stimulate muscle protein synthesis quite effectively, but in older adults, the same amount produces a weaker response. In simple terms, older muscles need a stronger growth signal to maintain themselves.

This means two things become increasingly important:

1. Eating enough high-quality protein.
2. Regular resistance exercise.

Protein provides the building materials for muscle, while exercise tells the body where those materials are needed. And neither works as effectively without the other.

Not All Protein Sources Are Equal

All protein foods provide amino acids, the building blocks used to build and repair muscle. However, some proteins are richer in the so called ‘essential amino acids’ that the body cannot make for itself. These essential amino acids are especially important for preserving muscle mass and strength as we get older. One amino acid deserves special attention and that is ‘leucine’. Leucine acts almost like a switch that turns on muscle protein synthesis, meaning that foods rich in leucine will be especially effective at stimulating muscle repair and growth. Just what we need.

Good protein sources include:

• Fish
• Poultry
• Lean meat
• Eggs
• Dairy products
• Whey protein
• Soy products
• Beans and pulses

Plant proteins can certainly contribute to overall protein intake, but they are generally less concentrated and often contain lower levels of some of these essential amino acids. This does not mean plant proteins are inferior, but it may mean that larger quantities are required to achieve the same protein target.

The key message is simple: focus on total daily protein intake and ensure that protein is included at every meal.

Muscle Matters for More Than Strength

Maintaining muscle is not simply about looking fit or being able to lift heavier weights. Muscle plays a vital role in overall health. In fact, healthy muscle helps regulate blood sugar, supports metabolic health, improves mobility, protects joints, and contributes to better balance and coordination.

Another issue with low protein intake and muscle loss is the risk of falling. In fact, around one in three older adults experiences a serious fall each year. Falls like this can lead to fractures, hospital admissions, loss of independence and, in some cases, death. Hip fractures are particularly concerning. For example, in the UK, around 100,000 hip fractures occur each year, most commonly in older adults. Perhaps the most sobering statistic is that around one in four hip fracture patients will not survive beyond twelve months following the fall and subsequent surgery. This highlights just how important it is to preserve muscle strength, balance and mobility as we age.

Muscle health also becomes critically important during periods of illness or recovery. A hospital stay, surgery, or even a prolonged period of bed rest can trigger what researchers call a ‘catabolic crisis’, a rapid loss of muscle mass and strength over a relatively short period of time. Unfortunately, once muscle has been lost, rebuilding it can be extremely challenging for older adults. In most cases, they never fully regain their previous strength, mobility or confidence, which can accelerate the progression towards early frailty and loss of independence. By contrast, individuals who enter these situations with greater muscle reserves are often much more resilient and better able to recover, highlighting the importance of maintaining muscle throughout later life.

The Simple Formula for Healthy Muscle Ageing

The science around muscle health is extensive, but the practical message is quite straightforward. If you want to maintain muscle as you age:

• Stay physically active every day.
• Include resistance or strength exercise two or three times each week.
• Aim for at least 1.2 grams of protein per kilogram of body weight daily.
• Spread protein intake across the day rather than eating most of it at one meal.
• Ensure adequate intake of key nutrients such as vitamin D, calcium and magnesium.
• Get enough sleep and allow time for recovery.

The Bottom Line

Ageing is inevitable. Frailty is not.

One of the most important factors that determines how well we age is how much muscle we retain throughout life. Protein is not just a nutrient for bodybuilders. Far from it.  It is the raw material used to build and repair muscle, maintain tissues, support immunity, produce hormones and enzymes, and keep the body functioning properly. Yet many older adults are simply not consuming enough.

By combining adequate protein intake with regular resistance exercise, it is possible to slow the progression of sarcopenia, maintain strength and independence, reduce the risk of falls, and improve both lifespan and healthspan in general.

The goal is not merely to live longer. The goal is to remain strong, active and capable for as many of those years as possible.