New healthy range for blood pressure is lower than thought

Official guidelines dictate doctors treat people who have a blood pressure over 140/90 but a new study suggests otherwise.

Got normal blood pressure and think you are OK? Think again. A startling new study has found blood pressure at a “normal” reading of 120 /80 is too high and could be damaging your brain.

Researchers from the Australian National University have found the optimum blood pressure for a healthy brain is actually much lower – 110/70.

People who had higher blood pressure readings of 135/85, which is still within the normal range, had brains that scans showed were six months older than people who had readings in the optimum range, the study found.

This put them at risk not just of a less healthy brain but at increased risk of heart disease, stroke and dementia, the researchers said.

The damage to the brain from high blood pressure is not just a feature of old age it starts in your 20s.

“This thinking that one’s brain becomes unhealthy because of high blood pressure later in life is not completely true,” Professor Nicolas Cherbuin, Head of the ANU Centre for Research on Ageing, Health and Wellbeing, said.

“It starts earlier and it starts in people who have normal blood pressure,” he said.

Damage to the brain from normal blood pressure could start in your 20s. Picture istock

The study detected brain damage from high blood pressure in people as young as 40.

“By detecting the impact of increased blood pressure on the brain health of people in their 40s and older, we have to assume the effects of elevated blood pressure must build up over many years and could start in their 20s. This means that a young person’s brain is already vulnerable,” Professor Cherbuin said.

The study examined more than 2000 brain scans of 686 healthy individuals aged 44 to 76 and used data from the PATH study, a large longitudinal study featuring around 7500 participants.

The blood pressure of the participants was measured up to four times across a 12-year period and the brain scan and blood pressure data was used to determine a person’s brain age, which is a measure of brain health.

Current guidelines recommend doctors treat people who have blood pressure over 140/90. Which is well above the optimum level identified in this new study.

A recent large international study found the number of people over 30 with high blood pressure has doubled globally.

Professor Nicolas Cherbuin Head, Centre for Research on Ageing, Health and Wellbeing College of Health & Medicine. Picture: Supplied

Cardiologist and co-author of the study, Professor Walter Abhayaratna, said if we maintain optimal blood pressure our brains will remain younger and healthier as we age.

“It’s important we introduce lifestyle and diet changes early on in life to prevent our blood pressure from rising too much, rather than waiting for it to become a problem,” Professor Abhayaratna said.

Research had not yet been done to find out whether people could reverse the brain damage caused by blood pressure if they work to reduce their levels.

“We certainly know that it decreases the risk of further damage happening,” Professor Cherbuin said.

“We’re not saying to people, you have to be extremely worried if it’s over 120 over 80,” he said.

“We also not saying that people who have 120 or 80 should be treated (for hypertension).

“But be aware that a blood pressure of 110 over 70 is better and the further away you stray from it may have an impact on the brain,” he said.

Originally published as New healthy range for blood pressure is lower than thought