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.
As you age, your immune system declines on multiple fronts. T cells and B cells respond less powerfully, antibodies are produced less effectively, and the innate immune system reacts more slowly. At the same time, a smouldering low-grade inflammation builds within the body, which is linked to age-related diseases such as cardiovascular disease and dementia. This combination of a weakened immune response and chronic inflammation is characteristic of immune ageing.
Large-scale follow-up research involving more than 300 healthy adults shows that these changes begin as early as middle age, not only in people over 70. Memory cells of the immune system gradually shift from an offensive pattern to one that responds less effectively to new threats, such as a flu vaccine. Notably, this appears to be an independent ageing process, separate from inflammation or a prior infection.
The most concrete step you can take right now is to make sure you have no deficiencies in specific nutrients. Deficiencies in vitamin D, B6, B12, C, E, zinc, selenium and folic acid demonstrably impair immune function. Correcting a proven deficiency restores immune performance. An important caveat: this applies to a confirmed deficiency, not to supplementing on top of already normal levels. The study on which this is based was co-authored by researchers with ties to a vitamin manufacturer, so interpret it with caution. Have your levels tested if you are in doubt.
Older adults would be wise to speak with a doctor about tailored vaccines. Standard flu vaccines work less well in older people. Vaccines with a higher dose, or with added components that activate the immune system, show a better response. mRNA vaccines also show promising results, although the response in older adults remains lower than in younger people. Several authors of the research behind this have financial ties to vaccine manufacturers; the finding itself does, however, fit a broader pattern.
Experimental agents such as mTOR inhibitors, certain T-cell growth factors and NAD+ activators are being studied, but are out of reach for now. Safety data for long-term use in humans are largely lacking. These agents currently belong in controlled studies, not on a self-care shelf.
All claims are based on reviews and one non-indexed study; no randomised trials or meta-analyses are included in the source list. Two sources include authors with commercial interests (a vitamin manufacturer, vaccine manufacturers), noted at the relevant points.
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 too little sleep weaken your immune system?
Yes, too little sleep demonstrably weakens your immune system and increases the risk of infections and chronic inflammatory conditions. Seven to nine hours of sleep is the most commonly cited guideline, and vaccinations also work better when you are well rested.
Can air pollution weaken your immune system?
Air pollution disrupts your immune system in several ways at once: a greater chance of allergic reactions, less resistance to viruses. Limit your exposure as much as possible, especially during pregnancy.
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.
Which factors weaken your immune system?
Several factors demonstrably weaken your immune system: deficiencies in vitamin A, zinc and iron are the best supported, but medical treatments, chronic stress and strenuous exercise also play a role. When using high-dose steroids medically or in the case of an HIV infection, it is advisable to involve your doctor in infection prevention.
Can you strengthen your immune system by eating more fibre?
Eating more fibre has a clear biological mechanism, but in healthy people it does not automatically lead to a measurably stronger immune system. Fermented foods appear to work more reliably for your gut microbiome; probiotic supplements are even risky when used alongside immunotherapy.