Metabolic syndrome is a big risk factor for early dementia, and what you do makes a difference, study suggests

How you manage a cluster of health conditions known as metabolic syndrome could have a big impact on whether you develop dementia at a young age, according to a new study. To be diagnosed with metabolic syndrome, a person must have three of the following conditions: a large waistline, high blood pressure, high blood sugar, high blood triglycerides, and low levels of high-density lipoprotein cholesterol, also known as HDL or “good” cholesterol. People who had metabolic syndrome, or a combination of those components, were 24% more likely to develop dementia at a young age, the data showed. “The key takeaway (of the study) is that metabolic syndrome significantly increases the risk of developing young-onset dementia,” which is dementia before age 65, said principal study investigator Dr. Minwoo Lee, in an email. “Our findings highlight the importance of managing metabolic health early to potentially prevent dementia and maintain brain health.” The study analyzed data of nearly 2 million people from the Korean National Health Insurance Service who underwent health checkups. Researchers analyzed the markers of metabolic syndrome and who developed young-onset dementia between 2009 and the end of 2020, according to the study published Wednesday in the journal Neurology. “Each component — such as elevated blood pressure, high blood sugar, obesity, abnormal cholesterol levels — is individually linked to higher dementia risk,” said Lee, assistant professor in the department of neurology at Hallym University Sacred Heart Hospital in South Korea. The finding suggests an increased risk for much of the US population, as about 1 in 3 adults in the United States have metabolic syndrome, according to the National Heart, Lung, and Blood Institute. “Dementia is among our most feared diseases, and developing dementia at an early age is even more worrisome,” said Dr. Richard Isaacson, a preventive neurologist and director of research at the Institute for Neurodegenerative Diseases in Boca Raton, Florida. He was not involved in the new study. “People of all ages –– from the 20s, 30s, 40s, 50s and beyond –– should be empowered to make brain-healthy choices early on,” Isaacson said. “I think this study gives us more evidence to suggest that these brain-healthy choices may lead to better brain outcomes over time.” Causation vs. correlation It is important to note that the study was observational, which means that researchers can’t say that metabolic syndrome caused dementia, only that there was a correlation between the two, Isaacson said. “I don’t really think that vascular risk factors and metabolic syndrome causes Alzheimer’s disease, but I think it can fast-forward someone towards it,” he said. More research will need to be done to determine whether treating metabolic syndrome actually delays the onset of dementia or reduces the number of cases, Isaacson said. Researchers will also need to look into more populations to see if the results from South Korea can be broadly applied. But the latest study does give hope that there are actions people can take to combat young-onset dementia, he said. “Some people say young onset-dementia, you can’t do anything about that –– it’s preordained, but I don’t agree with that. These lifestyle factors are nontrivial,” he added. Lee believes people can influence their odds. “My advice is to proactively manage metabolic health by maintaining a balanced diet, regular physical activity, and routine medical check-ups,” he said. “Addressing metabolic syndrome early can substantially reduce the risk of dementia later in life.” The connection between vascular and brain health The conditions that make up metabolic syndrome may not seem immediately connected to dementia risk, but there are a few ways that vascular health can impact cognitive decline, Isaacson said. Metabolic syndrome can lead to inflammation, and “when someone has inflammation in the body and in the brain, it can fast-forward aging,” Isaacson said. “And when you have inflammation in the brain, things don’t work as well.” Your blood vessels working efficiently is also important to cognitive health to keep enough oxygen flowing to the brain, he added. And finally, he noted that metabolic syndrome may affect the brain’s ability to metabolize energy, which may lead to cognitive impairment. The different conditions that make up metabolic syndrome tend to happen together because they have similar causes and impact one another, he added. “When a person is physically inactive and has an unhealthy diet … and someone is not sleeping and just kind of burning the candle at both ends … poor activity, low exercise: These are the medical or clinical manifestations of that sort of thing,” Isaacson said. “That’s why these risk factors often flock together — because they really are interrelated.” People can take steps to get healthy Because both genetic and lifestyle factors contribute to dementia cases, some people can do everything their doctor suggests and still get dementia, Isaacson said. But making healthy lifestyle changes and addressing metabolic syndrome may still prevent or delay dementia in many people, he added. Treatment for metabolic syndrome, which can also increase the risk of diabetes and cardiovascular conditions, starts with lifestyle changes, said Dr. Pam Taub, a preventive cardiologist and professor of medicine at the University of California San Diego. She was not involved in the research. “In general, the lifestyle recommendations that we recommend are really having a balanced Mediterranean diet, a diet that is balanced in terms of proteins, carbohydrates, and fiber, and also limiting the amount of calorie intake,” she added. Some of Taub’s research into metabolic syndrome shows that time-restricted eating can help manage the conditions, she said. Maintaining regular physical activity is key, though the amount and the proportion of strength, cardio and flexibility training may be specific to you and discussed with your doctor, she said. Getting enough sleep and handling stress are also essential in managing almost every chronic condition, she added. “Of course, we can’t control the stress that’s thrown at us, but it’s how we modulate our response that is important,” Taub said. But lifestyle changes alone may not solve the problem completely, she said. Your doctor may recommend medications to help with blood pressure, blood sugar, insulin resistance, lipid lowering and weight management. “It’s really not one or the other,” Taub said. “You have to synergize both lifestyle and pharmacology.”