Poor vascular health accelerates brain aging

血管健康状况差会加速大脑衰老

Using an AI tool, researchers at Karolinska Institutet have analysed brain images from 70-year-olds and estimated their brains' biological age. They found that factors detrimental to vascular health, such as inflammation and high glucose levels, are associated with an older-looking brain, while healthy lifestyles were linked to brains with a younger appearance.

Every year, over 20,000 people in Sweden develop some form of dementia, with Alzheimer's disease accounting for approximately two-thirds of cases. However, the speed at which the brain ages is affected by various risk and health factors.

"Despite the recent introduction of new Alzheimer's drugs, they will not work for everyone with dementia, so we want to study what can boost the brain's resilience against pathological ageing processes" says the study's lead author Anna Marseglia, researcher at the Department of Neurobiology, Care Sciences and Society, Karolinska Institutet.

AI-derived brain age

The study involved 739 cognitively healthy 70-year-olds, 389 of whom were female, recruited from Gothenburg's H70 cohort in Sweden. The researchers took MRI scans of their brains and then estimated the age of the resulting brain images using their own AI-based algorithm.

"The algorithm is both accurate and robust, yet easy to use," says principal investigator Eric Westman, professor of Neurogeriatrics at the same department. "It's a research tool that still needs further evaluation, but our aim is for it also to be of clinical use in the future, such as in dementia investigations."

The brain images were complemented with blood samples for measuring lipids, glucose, and inflammation. The participants also carried out cognitive testing. Data on lifestyle factors such as exercise and medical conditions were also available.

Brains with an older appearance

The AI tool estimated the brain age for both sexes to be on average 71 years. The researchers then looked at the "brain age gap" by subtracting the participants' estimated biological brain age from their chronological age.

The researchers found that diabetes, stroke, cerebral small vessel disease, and inflammation were linked to brains with an older appearance, whereas a healthy lifestyle involving regular exercise could be linked to brains of a younger appearance.

"A take-home from the study is that factors that adversely affect the blood vessels can also be related to older-looking brains, which shows how important it is to keep your blood vessels healthy, to protect your brain, by making sure, for instance, that your blood glucose level is kept stable," says Anna Marseglia.

Studies of sex differences next

The brains of women and men seem to differ in terms of factors linked to older- and younger-looking brains, meaning that women and men may differ in how they build resilience, a phenomenon that the researchers now plan to investigate by looking not only at biological determinants such as hormones but also at sociocultural influences.

"Next year, we'll launch a study to understand how social health -- including social engagement, connectedness, and support -- in middle and older age, along with sleep and stress, influence brain resilience, with a focus on women's health factors," says Anna Marseglia.

1. detrimental [ˌdɛtrɪˈmɛntəl] adj. 有害的，不利的

2. vascular [ˈvæskjʊlər] adj. 血管的，脉管的

3. glucose [ˈɡluːkoʊs] n. 葡萄糖

4. dementia [dɪˈmɛnʃə] n. 痴呆，脑力衰退

5. resilience [rɪˈzɪljəns] n. 恢复力，适应力

6. accurate [ˈækjərət] adj. 精确的，准确的

7. robust [roʊˈbʌst] adj. 强健的，结实的

8. complement [ˈkɒmplɪmənt] n. 补充物，补足物；v. 补充

9. sample [ˈsæmpl] n. 样本，样品；v. 取样

10. chronological [ˌkrɒnəˈlɒdʒɪkl] adj. 按时间顺序的

11. adversely [ˈædvɜːrsli] adv. 不利地，反面地

12. hormone [ˈhɔːrmoʊn] n. 荷尔蒙，激素