Does eating enough protein help my immune system as I get older?
Eating enough protein helps your immune system in later life. Aim for at least 1.0-1.2 grams per kilogram of body weight per day, spread across your meals, and preferably obtain this from ordinary food rather than supplements.
Eating enough protein helps your immune system in later life. Multiple human studies support the view that older adults need at least 1.0 to 1.2 grams of protein per kilogram of body weight per day. This helps slow the ageing of the immune system. In chronic illness that requirement rises to 1.2-1.5 grams per kilogram, and in serious illness or malnutrition to as much as 2.0 grams.1
In practice, a large proportion of older adults eat too little protein. Among Americans over the age of 71, 30% of men and 50% of women fail to reach the recommended amount. Reduced appetite, tooth loss, changes in gut function, financial difficulties and loneliness all play a role. A poor nutritional status increases the risk of frailty and sustains low-grade, chronic inflammation.2
Not only the total daily amount matters, but also how you spread it throughout the day. Around 25-30 grams of protein per meal is enough for older adults to maximise muscle protein synthesis. Those who want to optimise this further can eat an additional 40 grams just before going to sleep; this improves amino acid utilisation slightly.
Individual amino acid supplements are not a safe substitute for ordinary protein-rich food. Higher doses can put a strain on the kidneys, increase ammonia production and cause gastrointestinal complaints. In people with diabetes or liver conditions the risks may be greater. Research into the long-term consequences of high doses is still at an early stage.3
All claims are based on PMID 40806046 (guidelines and population data on protein intake in older adults), PMID 35219904 (nutritional status and immunity/frailty) and PMID 35043647 (risks of amino acid supplements). No large independent trials that directly measure the immune effect were provided; the strength of evidence for most claims is 'moderate'.
Does melatonin support your immune system in later life?
Melatonin has clear effects on the immune system in animal and laboratory research, but whether supplements genuinely improve immune function in older people has not yet been demonstrated. It has long been used for better sleep, which may be indirectly beneficial.
Does your immune system really weaken as you get older?
Your immune system does indeed weaken as you get older, but how quickly that happens varies considerably from person to person. Lifestyle factors play a role in this, although little has yet been proven specifically for humans.
Does spending more time outdoors help your immune system as you get older?
Spending more time outdoors may support your immune system as you get older, mainly through improved vitamin D production, but whether this actually leads to less illness has not yet been conclusively demonstrated. How polluted the outdoor air is also matters: in areas with serious air pollution, being outside can in fact be detrimental.
Does exercise help your immune system as you age?
Regular, moderate exercise helps your immune system by reducing smouldering inflammation. Suddenly training very hard without a gradual build-up can actually temporarily lower your immune defences.
Does your immune system really weaken as you get older, and can you do anything about it?
Your immune system demonstrably weakens with age, but eating healthily and exercising can reduce the smouldering inflammation that accompanies it. It is still too early to rely on drugs targeting senescent cells.
How do I strengthen my weakening immune system?
You can partly support your immune system by correcting measured deficiencies in vitamins and minerals and by making use of vaccines specifically tailored for older adults. More far-reaching options such as experimental inhibitors are not yet safe enough for daily use outside of studies.