Common Interventions That Slow Immune Ageing

With advancing age, the immune system gets progressively less effective at fulfilling a variety of different roles. There’s a decline in the number and effectiveness of pathogen-hunting T cells and antibody-producing B cells, as well as a rise in the presence of chronic inflammation. This doesn’t just make the immune system worse at dealing with infections, but also contributes to the development of age-related diseases like cancer and cardiovascular disease. This gradual deterioration of the immune system with age is called immunosenescence. Fortunately, it looks as though lifestyle interventions can slow immunosenescence down. This review article discusses what we know so far and provides some insights into how we might optimise factors like exercise and diet to keep the immune system healthy. Here is a summary of their findings:

Physical Activity: 

Regular moderate-intensity exercise appears to improve multiple aspects of immune function, even in older adults. This includes enhanced T cell division and improved ability of white blood cells to seek out and  kill pathogen-infected cells. Exercise has also been shown to reduce chronic inflammation. 

The quantity and type of exercise necessary to produce significant benefits is still under investigation. For now, the guidelines of 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity aerobic activity per week, plus muscle-strengthening activities is likely to significantly enhance immune function, reducing infection risk and improving vaccine efficacy. A combination of aerobic and resistance training may be optimal. Prolonged high-intensity activity, on the other hand, appears to be detrimental to immune function, resulting in increased risk of infections. Extremes of intensity have even been shown to correlate with increased mortality, resulting in the J-shaped relationship: increasing levels of activity result in benefits up to a point, but then start to become detrimental to health.

Diet:

Research suggests that a diet to support the immune system is one typically referred to as the Mediterranean diet, being rich in fruits, vegetables, whole grains, legumes, nuts, and olive oil, with moderate fish and poultry consumption and limited red meat and processed foods. This diet provides omega-3 fatty acids (anti-inflammatory), antioxidants (protect against oxidative stress), and potentially zinc and vitamin D (both necessary for immune function). Incorporating zinc-rich foods and ensuring adequate vitamin D (through sun exposure or supplementation if needed) are also suggested.

Fermented foods are also highlighted as a natural source of probiotics that may benefit the immune system by improving gut health. Certain strains of gut bacteria like Lactobacillus and Bifidobacterium have been shown to enhance white blood cell activity, potentially boosting immune function.

Other lifestyle interventions:

Beyond diet and exercise, the review emphasizes the importance of:

• Stress Management: Techniques like meditation and deep breathing may help reduce stress and its negative impact on immune function. 
• Adequate Sleep: Aiming for 7–9 hours of quality sleep per night appears to be important for immune health, as less sleep than this has been shown to correlate with increased risk of infection.
• Social Connections: Strong social ties are correlated with reduced inflammation and improved overall health.
• Smoking Cessation: Quitting smoking significantly improves immune function.
• Moderate Alcohol Consumption: Limiting alcohol intake or abstaining altogether is recommended.
• Vaccination: Staying up-to-date with recommended vaccinations helps to compensate for natural immune decline in old age.
• Weight Management: Obesity is associated with increased chronic inflammation, which accelerates immune ageing.

So, it seems as though there are plenty of opportunities for slowing down immune ageing through simple lifestyle interventions. Recent advances have improved our understanding of the underlying biological processes behind immunosenescence, including things like changes in key molecular signalling pathways and dysfunction of the mitochondria, the power plants of the cell. We may one day be able to fix these problems with targeted therapies, but in the meantime lifestyle changes are the most effective way to preserve immune function in old age, and in turn extend healthy lifespan.