Dr Anna Phillips, University of Birmingham
Its remarkably common for elderly people - who were previously healthy - to die soon after their spouse. We usually say theyíve died of a ďbroken heart.Ē But why? Could there actually be a medical reason?
Ginny Smith caught up with Dr Anna Phillips from the University of Birmingham who has evidence that itís down to the immune system not working so well at times of stress...
Anna - The study that has just come out is looking at the stress of bereavement which is a chronic stress because itís enduring and we wanted to see whether it could have a negative effect on particular parts of the immune system that are very key for fighting off diseases like pneumonia. There's a lot of anecdotal evidence - people are always saying how they had a relative who died suddenly and then in a very short time afterwards, the spouse of that person also died and they had been previously healthy. And weíre interested in finding out why that might be. Are they dying of a broken heart or is something going on in the immune system? Is the stress of bereavement accelerating their own mortality?
Ginny - So, how did you go about studying that?
Anna - We had some great collaborators at St. Maryís Hospice who gave out our information to the friends and family who had lost people who have been staying in a hospice. These individuals were able to decide if they wanted to take part in our study and if they did, we would give them a questionnaire and also take a blood sample so that we could look at immune function.
Ginny - And what were you looking for in that blood sample?
Anna - We were particularly interested in a cell called the neutrophil. So, itís an immune system cell. There's a lot of them and they're very important if you're fighting off pneumonia. So, they're very important for older people because pneumonia is a big killer of older people. What the neutrophil does is it engulfs bacteria or 'eats' them and then it produces a lot of chemicals such as reactive oxygen species that actually eradicate the bacteria. So, we particularly wanted to look at this cell because this is the one that if itís not working, an older person is going to be susceptible to infection and death from pneumonia.
Ginny - And what did you find? Was there a difference in these cells for the people whoíve been bereaved?
Anna - When we compared bereaved old adults to a control group, so these are people who are non-bereaved, relatively healthy, older people, we found that the bereaved people had poorer neutrophil function. So, while their neutrophils were still able to engulf bacteria, they just couldnít kill it effectively. They werenít producing as much of these reactive oxygen species. And the interesting thing was that we compared this to a younger group. And although the younger bereaved group also had high levels of stress having suffered bereavement and had high anxiety and depression, their immune cell function was fine. Their neutrophils were working the same level as a young control group. So, itís the older bereaved people that were susceptible to poor neutrophil function.
Ginny - So, what do we think is going on here? Why is it having more of an impact in the older people than in the younger people?
Anna - As you age, your immune system ages as well and itís what we call immunosenescence and there are changes to various parts of the system and also, to the function and numbers of different immune cells. So, by the time you're 65, your immune system isnít working as effectively. Thatís why we see things like poor responses to vaccination in older people and higher levels of infections. When you add a chronic stressor on top of that, something like bereavement, thatís when we expect to see that older people would be even more vulnerable because their immune system is already not working as efficiently as it was when they were younger.
Ginny - And do we know what it is in the body thatís controlling this change in the immune system after a stressor?
Anna - We think that one of the key mechanisms that might be having this impact are stress hormones, so for example the stress hormone cortisol, which can be a good thing because itís anti-inflammatory, but also can be a bad thing because it can supress the function of some parts of the immune system. When you have a chronic stressor, you have more cortisol generally in circulation, but you'll also have a drop in the opposite hormone which is dehydroepiandrosterone or DHEA. Now, this also decreases with age. So, by the time that you're over 65, you donít have the same levels that you had when you were younger. And the interesting thing is the ratio between the stress hormone cortisol and the other one, DHEA, because DHEA is immuno-enhancing whereas cortisol can supress immunity. And what we found is that the bereaved people in our study, the bereaved older adults, had a higher ratio of cortisol to DHEA.
Ginny - Is that having an impact on them? Are they more likely to feel sick because of that?
Anna - Certainly. If youíve got a high cortisol to DHEA ratio, thatís been related in other older groups to having an increased risk of infection and also, mortality from infection. So, we believe that the changes weíre seeing here will have real knock-on effects. If you're not able to combat pneumonia for example then yes, thatís going to have a big impact on your health.
Ginny - So now we know this, what can we do to help people who are vulnerable to these kind of effects?
Anna - We could try and correct the hormone balance which hasnít been done yet, but we are considering looking into whether a supplement, such as trying to get peopleís DHEA levels back up to where they were. Just for a short time, it might actually help them, but there are lots of simple ways as well. So for example, one of the ways that you can boost your immune function and boost your DHEA levels is by exercising, even if itís just moderate physical activity. And also social support. Itís really important at times of stress like bereavement, to have a social network that you mobilise. Donít be socially isolated because you'll be at more risk.
Kat - Birmingham scientist Anna Phillips speaking with Ginny Smith about the work she published this week in the journal Immunity and Ageing.