Answered questions
Immune system
93 answered questions · 659 studies
All topicsNutrition & preventionMuscles & movementHeart & vesselsBrain & memoryCancerInterventionsSleepAging clocksCells & DNAGut & microbiomeSkinHormonesImmune systemBonesMetabolism
What does ageing of your immune system mean for your health?
Your immune system ages in measurable ways: it responds less effectively to new threats and maintains a smouldering…
Moderate evidence
How does your immune system age and can a blood test measure that?
Your immune system ages in recognisable ways: exhausted immune cells and smouldering inflammation are clearly visible…
Preliminary evidence
How can poor oral health and periodontitis raise your blood pressure?
Gum disease is clearly associated with higher blood pressure, and there is good evidence that it genuinely contributes to it.…
What does regular sauna use do to your immune system?
Regular sauna use produces measurable changes in your immune system, but whether it actually makes you get sick less often has…
Does glyphosate increase your risk of lymph node cancer?
Whether glyphosate causes lymph node cancer remains unresolved after several large analyses. If you are occupationally exposed…
Moderate evidence
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…
Moderate evidence
How does nutrition strengthen your immune system?
Nutrition has a clear influence on the immune system: deficiencies weaken your defences, and correcting a demonstrable…
Moderate evidence
Can a past coronavirus infection weaken your immune system for a long time?
A past coronavirus infection can temporarily disrupt the immune system, and in Long COVID possibly for an extended period. If…
Yes · Moderate evidence
What does the thymus do, and can you rejuvenate that organ?
The thymus is indispensable for a well-functioning immune system, but inevitably shrinks with age. How this can be…
Moderate evidence
Can stem cell therapy slow down or cure rheumatoid arthritis?
Stem cell therapy may be able to slow the symptoms of rheumatoid arthritis, but it does not cure it. The research is still too…
Preliminary evidence
Can mesenchymal stem cells help with frailty in older adults?
Mesenchymal stem cells appear safe in the short term for frail older adults and do reduce certain markers of inflammation in…
Preliminary evidence
Does creatine do anything to your immune system?
Creatine influences immune cells via a specific switch, but whether the outcome is favourable or unfavourable depends strongly…
Preliminary evidence
What do immune cells in your brain do during ageing?
Microglia play an active role in brain ageing through fat build-up and energy shortage, but most of the evidence still comes…
Does quercetin help with hay fever and allergies?
Quercetin has a clear anti-allergic effect in laboratory research, and a small randomised study in humans shows improvement in…
Preliminary evidence
Does covid-19 have a lasting effect on the immune system?
Covid-19 has measurable, lasting effects on the immune system, including in people who do not have Long Covid symptoms. How…
Does long-term antibiotic use weaken your immune system?
Prolonged antibiotic use disrupts gut bacteria, and that disruption can influence your immune system, but how strongly this is…
Moderate evidence
What are the symptoms of a weakened immune system?
The clearest signs of a weakened immune system are recurrent or unusually severe infections, but skin problems, autoimmune…
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…
How does your microbiome influence your health and longevity?
Your gut flora changes over the years and is associated with inflammatory processes, immune function and possibly how long you…
Can you slow down the ageing of your immune system?
The immune system demonstrably ages, and there are promising avenues for slowing that process, but no single approach has been…
Preliminary evidence
What does a disrupted gut barrier do to the rest of your body?
A leaky gut barrier is associated with chronic inflammation and a range of diseases, from diabetes and joint complaints to…
What is the role of chronic inflammation in the development of cancer?
Chronic inflammation is a proven driver of cancer: it promotes every step of tumour formation and makes tumours more resistant…
How harmful are microplastics in your body to your health?
Microplastics are demonstrably present in your body and have been linked in laboratory and animal research to inflammation and…
Is raw milk healthier than pasteurised milk?
Raw milk offers no proven health advantages over pasteurised milk, while its infection risk is considerably higher. For…
No · Preliminary evidence
Do functional mushrooms like reishi and cordyceps actually work?
Medicinal mushrooms such as reishi show promising effects in the lab, but convincing evidence from studies in people is still…
Preliminary evidence
Is colostrum (beestings) a worthwhile supplement?
For now, colostrum has the strongest indications as an aid against respiratory tract infections in athletes; for most other…
Preliminary evidence
Does liposomal vitamin C work better than regular vitamin C?
Liposomal vitamin C reaches higher blood levels than regular vitamin C, but whether that translates into real health benefits…
Moderate evidence
Does chronic inflammation accelerate the ageing of your cells?
Chronic inflammation demonstrably accelerates cellular ageing through a negative spiral that is difficult to break. The best…
Is moderate exercise good or bad for your immune system?
Moderate exercise (sessions up to 45 minutes) is good for your immune system and is associated with fewer infections. Only…
Moderate evidence
Why do older adults become seriously ill from an infection more quickly?
Ageing weakens the immune system in several ways simultaneously, making infections more dangerous. Keep vaccinations up to…
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…
Moderate evidence
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…
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…
Preliminary evidence
Does the flu shot work less well as you get older?
The flu shot demonstrably works less well in older adults than in younger people, but high-dose and other improved vaccines…
Yes · Strong evidence
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 your body age faster after a prolonged period of stress?
Prolonged stress is associated with signs of faster cellular ageing, but whether this is truly causal and applies to everyone…
Can you improve your gut microbiome by picking up bacteria while playing outside?
Playing outside exposes your child to more bacteria, and one small study observed a change in gut microbiome, but whether that…
Preliminary evidence
What is the connection between the thyroid and the immune system?
There is a clear and well-defined connection: autoimmune diseases of the thyroid arise because the immune system attacks the…
Why do cells lose their ability to repair themselves?
Cells lose their capacity for self-repair through a combination of declining energy supplies, impaired DNA repair and the…
Why do you develop thyroid problems after giving birth?
After delivery, the brake on the immune system lifts abruptly, which can trigger inflammation in women with an underlying…
Can your gut microbiome influence inflammation in your body?
Your gut microbiome can influence inflammatory processes throughout your body via the gut wall. Eating more fibre and…
What is the link between high blood pressure and inflammation?
High blood pressure and inflammation reinforce each other, and higher levels of inflammation signals in the blood mean a…
Why do some people develop better protection after vaccination than others?
How well you respond to a vaccine depends on your genetic predisposition, age, the condition of your immune system, and any…
Does sunbathing support your immune system beyond the vitamin D effect?
Sunlight influences your immune system beyond the vitamin D effect, through hormones, neuropeptides, and shifts in immune…
Yes · Moderate evidence
Can smoking permanently damage your immune system?
Smoking structurally damages your immune system and the damage can be lasting, especially with long-term smoking. Quitting…
Yes · Moderate evidence
What are T-cells and why do they decline with age?
T-cells are the conductors of your immune system, and they decline in number and diversity as you age, largely because the…
Does omega-3 from fish oil help with chronic inflammation?
Omega-3 from fish oil lowers inflammation markers in the blood and has the strongest evidence in rheumatoid arthritis. The…
Yes · Moderate evidence
What does chronic sleep deprivation do to your inflammation in the long run?
Chronic sleep deprivation demonstrably raises inflammatory markers in your blood and is linked to diseases such as…
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…
Yes · Moderate evidence
What is apoptosis and why is it a good thing that cells clean themselves up?
Orderly cell death is an essential clean-up mechanism that keeps your body healthy, but balance is everything: too little…
Is the appendix actually useful for your gut microbiome?
The appendix appears to play a real but modest role as a reservoir organ for gut bacteria, particularly in recovery after…
Why do some people experience symptoms for months after an infection?
After an infection, multiple biological processes can continue to smoulder simultaneously, but which mechanism plays the…
Can too little sleep make you more susceptible to infections?
Too little sleep demonstrably makes your immune system more vulnerable, including to infections and vaccinations. Make sure…
Yes · Moderate evidence
Does sauna bathing help against infections?
There are preliminary indications that regular sauna bathing may have a beneficial effect on your immune system, but the…
Preliminary evidence
Can an overactive immune system also be dangerous?
Yes, an overactive immune system can cause serious harm, ranging from chronic autoimmune diseases to life-threatening cytokine…
What does loneliness do to your immune system?
Loneliness disrupts your immune system in multiple ways simultaneously: more inflammation, reduced antiviral defence, and…
What does long-term loneliness do to your brain?
Prolonged loneliness is associated with a higher risk of dementia and persistent low mood, and damages the stress system.…
Does fermented food like kimchi boost your immune system?
Kimchi and other fermented products can improve your gut microbiome and lower inflammatory markers, but whether that actually…
Preliminary evidence
What is the role of inflammation in cellular ageing?
Inflammation and cellular senescence reinforce each other in two vicious cycles, leading to tissue damage and age-related…
Can you test your immune system with a blood test?
A blood test can partially map the immune system, but the results are only meaningful when a doctor interprets them in the…
Yes · Moderate evidence
What does the HPV vaccine do against cervical cancer?
The HPV vaccine provides strong protection against cervical cancer, but works best when received before first sexual contact;…
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…
Preliminary evidence
Why are older adults more susceptible to influenza?
Older adults are more susceptible to influenza due to a combination of an ageing immune system, chronic diseases, and…
What does excess weight do to your inflammation levels?
Excess weight structurally raises your inflammation levels through multiple biological pathways. Exercise, and strength…
Can too much sugar weaken your immune system?
Consistently eating too much sugar disrupts the gut barrier, drives chronic inflammation, and locks immune cells into a state…
Yes · Moderate evidence
Does your immune system age at a different rate than your heart?
Yes, your immune system and heart age at measurably different rates, and an ageing immune system is more strongly linked to a…
Does beta-glucan help strengthen your immune system?
Beta-glucan demonstrably activates parts of the immune system, but the evidence that a supplement genuinely protects healthy…
Moderate evidence
What is a cytokine storm?
A cytokine storm is a life-threatening syndrome in which the immune system reinforces itself in a spiral of inflammation that…
Does green tea help against infections?
For flu there is reasonable evidence that green tea catechins help; for most other infections the evidence is still limited to…
Moderate evidence
What does smoking do to your biological age?
Smoking measurably accelerates the biological ageing of lung cells, the immune system, and the reproductive system. Stopping…
Why do you get sick more often when you are on a diet?
A low-calorie diet can weaken your immune system through deficiencies in minerals such as magnesium, disrupted gut bacteria…
Does cold showering boost your immune system?
Cold showering does not demonstrably strengthen your immune system in the short term, but people who do it regularly do report…
Moderate evidence
What does alcohol do to your immune system?
Chronic excessive alcohol use weakens your immune system on multiple fronts simultaneously and increases the risk of serious…
Can anyone take rapamycin?
Rapamycin is a powerful drug with serious side effects, including reduced immune function and blood sugar disturbances, and is…
No · Moderate evidence
Does fasting reset your immune system?
Fasting lowers inflammatory markers and has measurable effects on the gut microbiome that appear to be beneficial for the…
Yes · Moderate evidence
Does vitamin C actually help against a cold?
Taking vitamin C daily does not protect most people against colds, but does make a cold somewhat shorter and milder. Intensive…
No · Strong evidence
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…
Yes · Moderate evidence
Does stress really lower your immune system?
Prolonged stress demonstrably lowers your immune system: fewer active immune cells, a weaker response to vaccines and a…
Does regular exercise help against that creeping chronic inflammation?
Regular, moderate exercise demonstrably lowers inflammatory markers such as CRP and IL-6; training too intensely can reverse…
Yes · Moderate evidence
Does leaky gut actually exist?
Leaky gut is a recognised biological phenomenon that is associated with various diseases, but whether it also causes those…
Can long-term inflammation in your body cause cancer?
Prolonged inflammation is one of the most robustly supported risk factors for cancer. Well-known causes such as smoking,…
Does vitamin D help your immune system, or is that overrated?
Vitamin D genuinely helps your immune system, but the benefit of taking extra only really applies if you are deficient. If…
Moderate evidence
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…
Yes · Strong evidence
Can a disrupted gut microbiome weaken your immune system?
A disrupted gut microbiome demonstrably throws your immune system off balance and increases the risk of chronic inflammation.…
Yes · Moderate evidence
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…
Yes · Moderate evidence
What does sleep deprivation do to your immune system?
Sleep deprivation demonstrably weakens your immune system: sleeping fewer than six hours significantly increases your…
Does low-dose naltrexone (LDN) work against inflammation?
LDN shows positive signals as an anti-inflammatory agent in small studies and cell research, but the evidence in humans is…
Preliminary evidence
Is taking extra vitamin C worthwhile?
Extra vitamin C offers little benefit for most people. Intensive athletes and people following a carnivore diet do have a good…
Moderate evidence
Which vaccinations belong to healthy ageing?
For healthy ageing, the flu vaccine (high dose), the pneumococcal vaccine, the shingles vaccine, and the RSV vaccine are well…
Moderate evidence
Is zinc useful for my immune system?
Zinc is useful for your immune system if you have a deficiency or belong to a risk group, such as older adults or severely…
Yes · Moderate evidence
Does turmeric help against inflammation?
Curcumin has a biologically plausible anti-inflammatory effect, but the clinical results are mixed. If you want to try it,…
Moderate evidence
What is inflammaging?
Inflammaging is a smouldering, chronic inflammation that increases with age and is associated with frailty, muscle loss and…
How can I strengthen my weakening immune system?
Correcting vitamin and mineral deficiencies is the best-supported step for maintaining immune function. For more far-reaching…
Moderate evidence