Category: Longevity & Health

Researchers at Pennsylvania State University looking at walnuts and the gut biome, have found that eating walnuts daily as part of a healthy diet, leads to increases in certain beneficial gut bacteria associated with improvements in some risk factors for heart disease. Forty-two adults aged 30 to 65 and already identified as at risk from cardiovascular disease, were put on randomised, crossover diet trials. For the first fortnight, they consumed a standard western diet. There then followed three different six week diets to test the effects of walnuts. The walnut diet included 57 to 99 grams per day of whole walnuts. Faecal samples were collected to analyse gut bacteria.

The team found that after the walnut diet, there were significant associations between changes in gut bacteria and risk factors for heart disease. Eubacterium eligens was inversely associated with changes in several different measures of blood pressure, suggesting that an increase in Eubacterium eligens was associated with reductions in those risk factors. Additionally, greater numbers of Lachnospiraceae were associated with reductions in blood pressure, total cholesterol, and non-HDL cholesterol.

Kristina Petersen, assistant research professor, said “Replacing your usual snack, especially if it’s an unhealthy snack, with walnuts is a small change you can make to improve your diet. Substantial evidence shows that small improvements in diet greatly benefit health. Eating two to three ounces of walnuts a day as part of a healthy diet could be a good way to improve gut health and reduce the risk of heart disease.”

(Walnuts and Vegetable Oils Containing Oleic Acid Differentially Affect the Gut Microbiota and Associations with Cardiovascular Risk Factors: Follow-up of a Randomized, Controlled, Feeding Trial in Adults at Risk for Cardiovascular Disease. The Journal of Nutrition, 18 December 2019.)

The headline above is unlikely to surprise you. However, researchers at University College London, found that just six months of training for a first marathon, resulted in an aorta (the main artery from the heart) with a flexibility equivalent to that of someone four years younger. The greatest benefits were reaped by older, slower, male marathon runners with higher baseline blood pressure.

The researchers selected 138 healthy, first-time marathon runners, mean age 37, from the 2016 and 2017 London Marathon. They examined the participants before training and after marathon completion to determine whether age-related aortic stiffening would be reversible with real-world exercise training. Assessments included blood pressure, and aortic stiffness by cardiovascular MRI. Training schedules equated to between 6 and 13 miles per week.

Training decreased systolic and diastolic blood pressure by 4 and 3 mmHg respectively. Aortic stiffness reduced with training, with increases in distensibility of up to 9%. This amounted to the equivalent of an almost four-year reduction in ‘aortic age’. Older patients had greater changes, with males and those running slower marathon times deriving greatest benefit.

Dr Charlotte Manisty of the UCL Institute of Cardiovascular Science & Barts Heart Centre said, “Our study shows it is possible to reverse the consequences of aging on our blood vessels with real-world exercise in just six months. These benefits were observed in overall healthy individuals across a broad age range and their marathon times are suggestive of achievable exercise training in novice participants.”

(Marathon running makes arteries younger and lowers blood pressure. UCL News, accessed online 8 January 2020.
Training for a First-Time Marathon Reverses Age-Related Aortic Stiffening. Journal of the American College of Cardiology, January 2020.)

As we slip into the season of colds and flu, what are some of the steps we can take to improve our chances of evading them? Firstly, ensure your immune system is provided with all the essential nutrients. Here are some useful foods.

Beginning with breakfast, have an oat-based cereal eg museli, or make some oat porridge: oats contain a type of fibre known as beta-glucan which stimulates the white blood cells and macrophage cells of our immune system. This is also an opportunity to get some extra zinc by sprinkling a small palmful of pumpkin seeds over your cereal: in the laboratory, zinc has been shown to stop the cold virus multiplying, but studies also suggest it can shorten the duration of a cold (NHS Choices). Another ingredient you might like to include with breakfast, is a probiotic preparation, such as live or bio yoghurt, kefir, Yakult or Actimel. Probiotics appear to be useful in preventing upper respiratory tract infections (Cochrane Commentary). Finally, as regular intake of vitamin C appears to slightly shorten the duration and severity of a cold in some individuals (Cochrane Library), you could slice a kiwi or other citrus fruit over your cereal. A laboratory study suggests blueberries might also hold promise as an immune system aid (Oregon State University).

Having followed all that breakfast advice, we could turn to a mid-morning cup of tea. Black, green and white tea all contain catechins which seem according to a study in Japan, to reduce the likelihood of catching flu.

On to lunch or dinner, oily fish such as salmon, herring or mackerel offers you the benefits of omega-3 oils. Work done at Michigan State University suggests that the DHA in fish oil may enhance the activity of B-cells (specialised white blood cells) in your immune system. So consider a smoked salmon sandwich for lunch, or for a hot meal, have a salmon steak with which you could include sweet potato and carrots; these are rich in beta-carotene which the body converts to vitamin A and which performs a wide range of functions in the immune system. The salmon is also providing you with vitamin D, which like vitamin A, enables an array of immune system processes. Your breakfast milk and yoghurt will have contained vitamin D too.

If you are looking for a light evening meal, try a mushroom omelette: the eggs and mushrooms offer more vitamin D, whilst the protein contains the essential amino acid building blocks for our immune system cells. (You can significantly enhance the vitamin D content of your mushrooms by leaving them gills upwards in sunshine for an hour after buying them.) There are other ingredients in mushrooms which further support immune function. If it’s to your taste, add some garlic: a study published in 2014 suggested that people who took garlic supplements over a three month period, had fewer colds than those who took a placebo.

Secondly, following diet, try to get sufficient sleep, avoid overwork, and keep stress levels down.

Finally, attend to basic personal hygiene. Wash your hands at intervals eg at work where colleagues are touching the same door handles, office equipment etc, or after shopping when you have handled a supermarket trolley, petrol pumps etc.

These steps combined cannot completely eliminate the risk of a cold, but should give you a better chance of avoiding one as you are optimising defences on so many levels.

Authors from the Universities of Exeter, Uppsala in Sweden and Michigan in the US, have collaborated to examine the effects of time spent in nature, on health and wellbeing.

Nearly 20 000 people were asked to report on their recreational nature contact. Compared to no nature contact, the likelihood of reporting good health or high wellbeing became significantly greater when contact exceeded a threshold of 120 minutes. Positive associations peaked between 200 and 300 minutes per week. This pattern was consistent across groups including older adults and those with long-term health issues. It also did not matter whether the 120 minutes was achieved in one long or several shorter blocks.

The researchers say one explanation for their findings may be that time spent in nature is a proxy for physical activity, and it is this which is driving the relationship, rather than nature contact itself. Although they tried to control for this by asking participants about physical activity, they were unable to completely separate one effect from another. Experimental research however, indicates that some benefits cannot be due solely to physical activity. Research into shinrin-yoku (Japanese “forest bathing”), suggests that various psycho-physiological benefits can be gained from merely sitting passively in natural settings.

(Spending at least 120 minutes a week in nature is associated with good health and wellbeing. Scientific Reports, online 13 June 2019.)

A new study on cycling and health undertaken across seven European cities reveals that it is the mode of transport associated with the greatest health benefits. Cyclists experience better self-perceived general health and better mental health.

The study was carried out in Antwerp, Barcelona, London, Örebro, Rome, Vienna and Zurich. A baseline questionnaire was completed by more than 8800 people, 3500 of whom also completed a final survey, on transport modes and perceptions of general health. The survey included questions on anxiety, depression, loss of emotional control, psychological well-being, vitality and perceived stress. The transport modes assessed were car, motorbike, public transport, bicycle, electric bicycle and walking.

The findings were that cycling yielded the best results in every analysis. Bicycles were associated with better self-perceived general health, better mental health, greater vitality, lower self-perceived stress and fewer feelings of loneliness. The second most beneficial transport mode, walking, was associated with good self-perceived general health, greater vitality, and more contact with friends and/or family.

Research in 2016 looked at the impact of cycling for commuting and recreation, on the risk of developing type 2 diabetes. In this cohort study of Danish adults aged 50 to 65, those who reported higher weekly cycling mileages were less likely to develop diabetes; the effect was more pronounced in those who cycled to work.

Perhaps most interesting though was that those who took up cycling after the study began, also had a lower risk of developing diabetes than those who did not cycle. This suggests that it is not too late to access the benefits of cycling, even in the years approaching retirement.

(Barcelona Institute for Global Health, 13 August 2018.

Associations between Recreational and Commuter Cycling, Changes in Cycling, and Type 2 Diabetes Risk: A Cohort Study of Danish Men and Women. PLOS Medicine, 12 July 2016.)