Key Considerations to Support Immune Health in the Elderly

• Senior adults do not respond to immune challenges as robustly as younger generations, making them a vulnerable population group that is more susceptible to infection and disease. But what are the reasons behind this increased risk and what role does nutrition have to play?
  
• In the second session of our ‘Supporting Immunity in Elder Care’ webinar series, our panel of experts – Dr. Ulrich Suchner, Prof. Philip Calder and Aniza Sheikh – explored the reasons for low immune health in the elderly, the latest nutritional science and what practical steps caregivers can follow to optimize nutritional care in older populations.
  
• In this blog, we share a roundup of the key takeaways for medical directors, portfolio managers, R&D and innovation managers, to help inspire the development of appealing and effective medical nutrition solutions that will help to support immune health in the elderly – from prevention to rehabilitation.
  

An effective, fully functioning immune system is essential for protection against pathogenic organisms, like bacteria, viruses, fungi and parasites, and safeguarding the body from disease and infection. However, the efficacy of the immune system declines with age – a phenomenon known as immunosenescence. This decline in immune function is marked by the increased vulnerability of older individuals to infections like influenza, poorer response to vaccinations and increased antibiotic use.^1,2,3 The impact that this has on the older community is evident when you consider the higher frequency, spread and severity of infection in long-term care facilities for the elderly.⁴ As well as impacting health and recovery, which can lead to longer hospital stays and increased healthcare costs, low immune function can also impact quality of life and increase their risk of death.⁵

Optimal dietary management helps to build a resilient immune system. However, ensuring older individuals receive the right nutritional care can be challenging due to a number of physical, psychological and social factors. Medical nutrition products targeted towards immune health are one way to support the elderly in staying healthier for longer. But to develop effective and appealing products and optimize nutritional care, a deep understanding of the barriers to consumption and the factors affecting immunity in the elderly is critical.  Below we outline four key insights from our webinar, ‘Optimal Nutritional Management for Elderly: from Prevention to Rehabilitation’. 

Below we outline four key insights from our webinar, ‘Optimal Nutritional Management for Elderly: from Prevention to Rehabilitation’. 

Aging impacts both the innate and adaptive immune systems.⁶ Immunosenescence happens because of a number of factors, including cell senescence (irreversible arrest of cell growth), mitochondrial dysfunction and oxidative stress.^7,8,9 Activation of the immune system also appears to be compromised in old age, but even when it does respond it is less efficient – meaning insufficient protection from infection.⁹ This is because immunosenescence also impacts important immune cells – like T lymphocytes and macrophages – so that they do not function as well, or work slower to fight infection.
At the same time though, inflammaging is common in older people.² This describes the chronic low-grade inflammation and resulting tissue damage that develops with advancing age.

This imbalance in the immune system is thought to speed up biological aging and can induce a number of non-communicable diseases (NCDs) that may further negatively affect immune function. It can also lead to increased risk of developing age-related conditions, like sarcopenia and cognitive dysfunction, which in turn can lead to increased frailty in older people which leads to additional vulnerability and the inability to cope with everyday acute stressors, like infection. Addressing and reestablishing the balance in the immune system is therefore critical to supporting immunity in older people.

Nutrition is closely linked to immune health, supporting the immune system in several ways including working as antioxidants to protect healthy cells, influencing the activity of immune cells, producing antibodies and helping to resolve inflammation. Dr. Suchner explained that malnutrition is a special risk factor for the elderly which can increase the risk of, or exacerbate, conditions like sarcopenia.¹⁰ Nutrient deficiency is more prevalent in older people because of factors including morbidity, decreased food intake, low physical activity and disease treatment. As well as causing weight and muscle loss, low intake and status of nutrients appears to play a role in immune decline (immunosenescence) and inflammaging; delaying wound healing, increasing length of stay in hospital and reducing overall quality of life. To support immune health in the elderly and therefore help to delay the onset or severity of resulting diseases, like sarcopenia, dietary management of age-related functional decline is essential.

There is considerable research exploring the role of nutrition in immunity, which is driving new innovations and developments in the nutrition and medical communities. A number of important vitamins and trace elements are well-known to support immune health, with some influencing immunosenescence, and others impacting inflammaging. During the symposium, Prof. Calder highlighted a few key ingredients including vitamin D, vitamin E, zinc, selenium and omega-3 fatty acids EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) and explained the latest science behind them.

Vitamin D – also known as the ‘sunshine vitamin’ – is thought to reduce the risk of respiratory tract infections (RTIs), a common illness that can have a significant impact on an individual’s health and quality of life. The number of RTI cases increase in the winter months when vitamin D status is low, for instance, but research shows that there is a relationship between low vitamin D status and increased susceptibility to RTIs irrespective of season.¹¹ A recent meta-analysis evaluating the results of more than 25 trials reported that daily or weekly vitamin D supplementation protected against acute RTIs in all individuals, including those that were older.¹² The benefits were greatest in people with low vitamin D status at baseline.

Vitamin E acts mainly as an anti-inflammatory agent in the body – positively influencing different aspects of the immune response. Like vitamin D, it is also proven to reduce the risk of RTIs in older people, especially upper RTIs and the common cold.¹³ Other important nutrients include zinc^14,15,16 and selenium^17,18, as well as the omega-3 fatty acids EPA and DHA. Nutritional lipids EPA and DHA help to optimize the immune system by enhancing the function of immune cells, while their anti-inflammatory and inflammation resolving properties also contribute to normal immune function.¹⁶ Because they help to control low grade inflammation, omega-3 fatty acids are predicted to be extremely important in medical nutrition products for the elderly.

As malnutrition in older individuals is complex and multi-factorial, the medical community has struggled to find efficient, evidence-based approaches for its prevention and treatment. Nutritional management in retirement homes is especially challenging, since many elderly people have particularly complex and specific nutritional needs that require a targeted approach to manage. Due to the importance of good nutrition and the risk of malnutrition in the elderly, Aniza Sheikh explained that a multidisciplinary approach to nutritional care of these individuals is essential. This involves early and routine nutritional screening – i.e. the assessment of nutrient status – in older people to understand their morbidities better and recognize which factors are affecting their food intake. Treatment of malnutrition can then be tailored to individuals with the help of targeted medical nutrition products. Sheikh concluded it is critical that exercise is also included in the treatment plan, as it plays just as significant a role in combatting nutrient deficiency and slowing the development of conditions, like sarcopenia, as optimal nutrition.