Does eating enough protein help my immune system as I get older?
Eating enough protein helps your immune system in later life. Aim sustainably for at least 1.0 to 1.2 grams per kilogram of body weight per day, spread across your meals, and preferably obtain this from regular food.
Yes, eating enough protein helps your immune system in later life. The ageing of the immune system is partly worsened by a poor protein status. As a healthy older adult, aim for at least 1.0 to 1.2 grams of protein per kilogram of body weight per day, sustained over time and spread across your meals. With chronic or acute illness that requirement rises to 1.2 to 1.5 grams per kilogram per day; in serious cases of illness or malnutrition it can go as high as 2.0 grams. Always discuss the latter with your doctor.1
In practice, a large proportion of older adults do not reach that threshold. Among Americans over the age of 71, 30% of men and 50% of women fail to meet the recommended amount. Reduced appetite, tooth loss, changes in gut function, financial difficulties and loneliness all play a role. Too little protein increases the risk of frailty and sustains a smouldering, low-grade inflammation.2
Not only the total amount matters, but also how it is distributed throughout the day. Make sure every meal contains a solid portion of protein: for older adults, this is enough to maximise muscle protein synthesis. Ideally, get your protein from regular food: dairy, meat, fish, legumes or a combination. If you do choose a protein powder, check the label for the number of grams of protein per serving and work back to your own daily total. Whether you choose whey, soy or another plant-based source makes no difference for this purpose, as long as the total daily amount is correct.
Individual amino acid supplements are not a safe alternative to protein-rich food. Higher doses can put a strain on the kidneys, increase ammonia production and cause gastrointestinal complaints. In older adults, pregnant women, people with diabetes and those with liver conditions, the risks may be greater. Little research has been done on high doses over the long term.3 A standalone amino acid supplement is not worth your money if you can simply meet the basic amount through your plate.
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 been demonstrated. It has long been used for better sleep, which may be indirectly beneficial for immunity.
Does your immune system really weaken as you get older?
Your immune system demonstrably weakens with age, but vaccinations remain worthwhile and a good diet can limit further decline.
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 get older?
Exercise helps older adults: it lowers mild inflammation in the blood and noticeably reduces the risk of physical frailty. How it works on the deeper ageing of the immune system remains an open question.
Which supplements genuinely support your immune system?
Some supplements genuinely support your immune system, but the effect is greatest when you have a deficiency: so first check whether your vitamin D or zinc levels are adequate, and supplement in a targeted way.
Does your immune system weaken as you get older?
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.