Category: Longevity & Health

A major new study by researchers at the University of Edinburgh, indicates that maintaining a healthy weight and continuing in further education, are two of the best behaviours to adopt to extend our lifespan. Data was drawn from 25 separate population studies mainly across Europe, Australia and North America. For each year spent studying beyond school, 11 months was added to lifespan. Giving up smoking and being open to new experiences also seem helpful. However, for people who are overweight, each extra kilogramme of body weight is associated with two months off their lifespan. The study identified two new DNA differences which affect lifespan: a gene linked to the immune system adds around half a year to life expectancy whilst one linked to blood cholesterol levels shortens it by around eight months.

Dr Peter Joshi, Chancellor’s Fellow at the University of Edinburgh’s Usher Institute, said: “Our study has estimated the causal effect of lifestyle choices. We found that, on average, smoking a pack a day reduces lifespan by seven years, whilst losing one kilogram of weight will increase your lifespan by two months.”

(Genome-wide meta-analysis associates HLA-DQA1/DRB1 and LPA and lifestyle factors with human longevity. Nature Communications, on-line 13 October 2017.)

In NGS National Gardens and Health Week, it seems appropriate to survey what we now know about how gardening and access to green spaces, impacts on our well being. Much of what is “discovered” in scientific research into this topic, will come as no surprise to keen gardeners or those who know them.

In the UK, 87% of households have a garden, and half the adult population in England report gardening as a free time activity: homing in on age ranges, this figure is 40% in the 25-44 age group and 70% for those aged 65-74. Increasing numbers of younger adults would like to grow food. As an indicator of the direction in which gardeners’ interests overall are moving, sales of vegetable seeds have recently exceeded those of flower seeds for the first time since the Second World War.

It has been established that time spent in green spaces is linked to a long-term reduction in reported health problems. This includes heart disease, cancer, musculoskeletal problems, obesity, depression and anxiety. School gardening is linked with a significant increase in fruit and vegetable intake by children. Allotment gardening improves mood and self-esteem, and reduces cortisol levels (a measure of stress) in subjects compared with their matched controls. Studies in Holland, Japan and Canada indicate that for every 10% increase in exposure to green space, people enjoy health equivalent to that of someone five years younger. Living in areas with green spaces is associated with significantly less income-related health inequality.

As we get older, gardening becomes relatively more important as a physical activity. There is emerging evidence of a link with prevention of falls, dementia and cognitive decline.

The NHS is beginning to use social prescribing and community referral, having recognised that social and economic factors play a role in underpinning health: Lambeth GP Food Co-op covers eleven practices where patients with long-term conditions work together to grow food. Horatio’s Garden creates and maintains gardens in NHS spinal injury centres.

So in addition to spending time in your own garden, consider visiting others in the south-west which are open this week under the NGS scheme

(Gardens and health: Implications for policy and practice. The King’s Fund, May 2016.)

A meta-analysis of 25 double-blind, randomised, controlled trials covering 11 000 participants, has concluded that vitamin D supplementation is both safe and can help provide protection against acute respiratory tract infections.
Participants ranged in age up to 95, and data on a host of factors was assessed, including incidence of infections, their requirement for antibiotics, and number of days off school or work. Trials had taken place in 14 countries across 4 continents. Protective effects were strongest in those who already had profound vitamin D deficiency at baseline.

There were no serious adverse events associated with taking vitamin D. Concerns normally centre around raised blood calcium levels and kidney stones; these were no higher in the vitamin D groups compared to the control groups.

The researchers say their results add to the body of evidence supporting the introduction of public health measures such as food fortification, to improve vitamin D status, particularly in settings where profound vitamin D deficiency is common.

Public Health England recommended in 2016 that everyone needs vitamin D equivalent to an average daily intake of 10 micrograms, although this is intended to protect bone and muscle health.

(Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data. British Medical Journal, online 15 February 2017.)

A study carried out at the University of Eastern Finland, suggests that frequent saunas are associated with significantly reduced risk of dementia in men.

The effects of sauna use on the risk of Alzheimer’s disease and other forms of dementia were studied in the Kuopio Ischaemic Heart Disease Risk Factor Study (KIHD), which gathered data for 20 years on more than 2000 middle-aged men living in eastern Finland. Based on their sauna useage, participants were divided into three groups: those taking a sauna once a week; those taking one 2–3 times a week; those taking one 4–7 times a week.

The more frequently saunas were taken, the lower was the risk of dementia. Among those taking a sauna 4–7 times a week, the risk of any form of dementia was 66% lower and the risk of Alzheimer’s disease 65% lower than among those taking a sauna just once a week.

Previous results from the KIHD study have shown that frequent sauna bathing also significantly reduces the risk of sudden cardiac death, the risk of death due to coronary artery disease and other cardiac events, as well as overall mortality. According to Professor Jari Laukkanen, the study leader, saunas may protect both the heart and memory to some extent via similar, still poorly known mechanisms. The sense of well-being and relaxation may also play a role.

(University of Eastern Finland, online news, accessed 4 January 2017.)

There is one supplement you should consider taking from this point in the year: vitamin D. Last summer, Public Health England issued new advice that all adults, and children over the age of one, should get at least 10 micrograms of vitamin D per day. Vitamin D is found in oily fish eg salmon, red meat, liver and egg yolks. It can also be found in fortified foods such as breakfast cereals. It’s difficult however to get the recommended amount of vitamin D from diet alone, and our main source is from the action of sunlight on our skin. From October to the end of March, sunshine in the UK is too weak to achieve this, and we are largely covered up and/or indoors anyway, so these are the months in which it is particularly important to consider a supplement.

It’s relatively cheap too: checking today, you can buy 3 months supply in Exeter High Street for £3-59.

It is accepted that vitamin D is needed for healthy bones, teeth and muscle. There may also be associations (although causality has not been established) between low vitamin D status and a host of other conditions such as dementia, cancer, cardiovascular disease, and autoimmune disorders such as multiple sclerosis, rheumatoid arthritis and some thyroid problems. This year, two separate studies from Australia have linked vitamin D deficiency in pregnancy with autism, and deficiency in childhood with allergic disorders such as asthma and eczema. It is a vitamin about which we still have much to learn.