Healthiest human hearts found in the world

 

The healthiest hearts in the world have been found in the Tsimane people in the forests of Bolivia, say researchers.

The healthiest hearts in the world have been found in the Tsimane people in the forests of Bolivia, say researchers.

Barely any Tsimane had signs of clogged up arteries – even well into old age – a study in the Lancet showed. Tsimane is pronounced “chee-may-nay”.

“It’s an incredible population” with radically different diets and ways of living, said the researchers.

They admit the rest of the world cannot revert to a hunter gathering and early farming existence, but said there were lessons for all of us.

There are around 16,000 Tsimane who hunt, fish and farm on the Maniqui River in the Amazon rainforest in the Bolivian lowlands.

 

What is a health heart Tsimane diet?

  • 17% of their diet is game including wild pig, tapir and capybara (the world’s largest rodent)
  • 7% is freshwater fish including piranha and catfish
  • Most of the rest comes from family farms growing rice, maize, manioc root (like sweet potato) and plantains (similar to banana)
  • It is topped up with foraged fruit and nuts

It means:

  • 72% of calories come from carbohydrates compared with 52% in the US
  • 14% from fat compared with 34% in the US, Tsimane also consume much less saturated fat
  • Both Americans and Tsimane have 14% of calories from protein, but Tsimane have more lean meat

How fit are they?

They are also far more physically active with the men averaging 17,000 steps a day and the women 16,000.

Even the over 60s have a step count over 15,000. It makes most people’s struggle to get near 10,000 seem deeply insignificant.

“They achieve a remarkable dose of exercise,” says Dr Gregory Thomas, one of the researchers and from Long Beach Memorial medical centre in California.

How healthy are their hearts?

The scientists looked for coronary artery calcium or “CAC” – which is a sign of clogged up blood vessels and risk of a heart attack.

The scientists scanned 705 people’s hearts in a CT scanner after teaming up with a research group scanning mummified bodies.

At the age of 45, almost no Tsimane had CAC in their arteries while 25% of Americans do.

By the time they reach age 75, two thirds of Tsimane are CAC free compared with the overwhelming majority of Americans (80%) having signs of CAC.

The researchers have been studying this group for a long time so it is not simply a case of the unhealthy Tsimane dying young.

They also smoke a lot less, but they do get more infections which could potentially increase the risk of heart problems by causing inflammation in the body.

One idea is that intestinal worms – which dampen immune reactions – could be more common and this may help protect the heart.

Prof Gurven said: “I would say we need a more holistic approach to physical exercise rather than just at the weekend. Bicycle to work, take the stairs, write your story on a treadmill desk.”

Dr Thomas said: “It could be to maintain health we need to be exercising much more than we do. The modern world is keeping us alive, but urbanisation and the specialisation of the labour force could be new risk factors for an unhealthy heart.

“They also live in small communities, life is very social and they maintain a positive outlook.”

“Simply put, eating a healthy diet very low in saturated fat and full of unprocessed products, not smoking and being active life long, is associated with the lowest risk of having furring up of blood vessels.”

B vitamins may have ‘protective effect’ against air pollution

B vitamins may have ‘protective effect’ against air pollution

B vitamins may have 'protective effect' against air pollution

B vitamins may offer some protection against the impacts of air pollution, a small scale human trial suggests.

Researchers in the US found that high doses of these supplements may “completely offset” the damage caused by very fine particulate matter.

The scientists involved say the effect is real but stress the limitations of their work.

Follow up studies are urgently needed, they say, in heavily polluted cities like Beijing or Mexico.

While the impacts of air pollution on health have become a cause of growing concern to people all around the world, the actual mechanics of exactly how dirty air makes people sick are not clearly understood.

According to the World Health Organization (WHO), over 90% of the world’s population live in areas where air pollution exceeds safety guidelines.

One of the pollutants that is considered the most dangerous is very fine particulate matter, referred to as PM2.5, where particles have a diameter of less than 2.5 micrometres.

These complex particulates come from diesel cars, wood burning stoves and as a by-product of chemical reactions between other polluting gases.

At around 1/30 the width of a human hair, PM2.5 fragments can lodge deep in the human lung and contribute to lung and heart health issues in the young and old.
Image copyright SPL
Image caption Wood burning stoves are also significant sources of particulate matter in the air

Scientists have long suspected that PM2.5 causes what are termed epigenetic changes in our cells that can damage our health.

The genes in our DNA contain the instructions for life, but epigenetics controls how those instructions are used – it’s like the relationship between an mp3 track and the volume control, you can only hear the musical notes (genes) when you dial up the volume (epigenetic changes).

The study shows the very presence of environmental factors like air pollution seems to alter genes in the immune system at the epigenetic level – switching them on or off, and inhibiting our defences.

Researchers had already seen that nutrients could somehow stop this process in animal studies with the chemical Bisphenol A.

Now in this new human trial, an international team of scientists wanted to see if exposure to concentrations of PM2.5 could be mitigated by a daily B vitamin supplement containing 2.5mg of folic acid, 50mg of vitamin B6, and 1mg of vitamin B12.

Ten volunteers were tested initially exposed to clean air while given a placebo to measure their basic responses. The same volunteers were later tested with large doses of B vitamins while exposed to air containing high levels of PM2.5.

The researchers found that a four week B vitamin supplementation limited the PM2.5 effect by between 28-76% at ten gene locations. They found a similar reduction in impact on the mitochondrial DNA, the parts of cells that generate energy.

Where we quantify the effect, it is almost close to a complete offset on the epigenome of the air pollution. On the mitochondrial DNA side, it also offset a big proportion of it.

 

 B vitamins may have 'protective effect' against air pollution

However, the authors caution that their study, while observing a real effect, has many limitations. As well as the small number of participants, there was little information on the size of the B vitamin dose that elicited the response.

Scientists didn’t have different doses and the doses they used were quite high, higher than a normal pregnancy suggested intake. So it is quite high but at the same we did observe this protective effect.

Other scientists in the field, while welcoming the study, agree that caution is needed.

The fact that they find a coherent story in only 10 subjects is promising, but clearly warrants further follow-up in larger populations especially considering the ethnic variability in this study.

While it is great that doing something as easy as taking a vitamin would help protect against air pollution harm, the public health goal still needs to be one of reducing air pollution to a level that is not harmful. The authors acknowledge that this was a pilot study to test a hypothesis and they are not in a position to make any deductions about whether B vitamins could be used in clinical practice as a means of protecting against air pollution.

More and bigger studies are needed – and they need to be done in environments where people have a major exposure to PM2.5.

B vitamins are a likely hope that we can potentially utilise as an individualised treatment to complement the policy regulations to minimise the impacts of air pollution.

A more sophisticated study is urgently needed in Beijing or India or Mexico just to see whether those who are chronically exposed, if the protective effect can still be effective.

The study has been published in the journal Proceedings of the National Academy of Sciences (PNAS).