Longevity Briefs: Do We Age Faster Than Hunter-Gatherers?

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Longevity briefs provides a short summary of novel research in biology, medicine, or biotechnology that caught the attention of our researchers in Oxford, due to its potential to improve our health, wellbeing, and longevity.

The problem:

A person born today can expect to live significantly longer than one born even 100 years ago. This is mostly thanks to advances in medicine that allow us to avoid or survive infectious diseases that used to kill us at a young age. By contrast, there is little evidence to suggest that we are ageing much more slowly than our ancestors did – in fact, in some ways, we might be ageing faster. The vast majority of the Earth’s population, whether rich or poor, is exposed to an environment that has not existed for most of human evolution. Many of us consume large quantities of processed foods and refined sugars not accessible to our ancestors, are exposed to man-made environmental pollutants and are not required to undertake physical activity in order to survive.

For these reasons, studying modern hunter-gatherer groups is an interesting way of laying bare the harm inflicted by the lifestyle typical of industrialsied societies. In this study, researchers compare arterial health in US adults to the Tsimane, an indigenous population in Bolivia who live a traditional, physically active lifestyle with a diet rich in complex carbohydrates, fibre and low in saturated fat. Arteries naturally stiffen with age, becoming less elastic. This loss of elasticity is a major driver of cardiovascular disease because it leads to increased blood pressure and damage to the arterial walls. Previous research has hinted that some populations might age exceptionally well, exhibiting low arterial stiffness even in old age.

The discovery:

Researchers compared the Tsimane to two US cohorts: the Multi-Ethnic Study of Atherosclerosis (MESA) and the Framingham Heart Study (FHS) Third Generation. The study used three measures of arterial health:

• Carotid-femoral pulse wave velocity (cfPWV): How fast a pressure wave travels from the neck (carotid artery) to the groin (femoral artery). A faster wave means stiffer arteries.
• C1 (large artery elasticity): Measures the elasticity of the larger arteries, like the aorta.
• C2 (small artery elasticity): Measures the elasticity of smaller arteries.

The researchers measured these metrics in 490 Tsimane adults (mean age 51.2 years) and compared them to data from 6294 MESA participants and 3086 FHS Gen3 participants. The study ran from 2010 to 2012 for the Tsimane data collection.

The Tsimane showed significantly better arterial health than the US participants, with higher elasticity (C1 and C2) and lower stiffness (cfPWV). However, perhaps the most striking finding came when Tsimane individuals with two or more health problems (hypertension, obesity, diabetes) were compared to healthy Americans without these conditions – these Tsimane still had around 25% higher arterial elasticity, on average, than the healthy US participants. The Tsimane’s cfPWV tended to remain low until around age 70, unlike the US cohorts where stiffness increased steadily with age.

The implications:

This research suggests that lifestyle plays a crucial role in maintaining arterial health throughout life. Even the Tsimane who were metabolically unhealthy in spite of their lifestyle showed signs of slower arterial ageing than healthy Americans. This could suggest that being otherwise healthy is not necessarily a defence against the pro-ageing effects of a sedentary lifestyle or certain unhealthy foods. While obesity and diabetes are major risk factors for heart disease and should be avoided, positive lifestyle changes may slow arterial ageing (and most likely other forms of ageing) regardless of whether you have these conditions or not.

This is not the first study to show that the Tsimane appear to age more slowly than those living in industrialised societies. Previous studies report slower onset of neurodegenerative diseases and reduced age-related inflammation, for example. Fortunately, there’s no reasons why we can’t live more like the Tsimane without giving up the benefits of industrialisation. We can, for example, aim for regular, moderate-intensity exercise most days of the week. We can consume a diet that focuses on whole grains, fruits, vegetables, lean protein, and healthy fats while limiting saturated and trans fats, added sugars, and processed foods.

It is important to point out that while the Tsimane might age more slowly than us, they don’t live as long on average. As of the 2000s, Tsimane life expectancy was in the 50s, largely due to preventable and treatable infectious disease. We have still benefited greatly from industrialisation, but we could have the best of both worlds were we to limit the harmful influence of the food industry and encourage more physical activity.