Researchers have long known that obesity increases the risk of heart disease by raising blood pressure and unhealthy cholesterol levels.
People living with obesity are also more likely to develop type 2 diabetes, heart failure, stroke, and other long-term health problems. For many years, doctors expected older adults with obesity to have much worse blood pressure and cholesterol than people of a healthy weight.
However, a large new international study has found that this difference has become much smaller over the past 30 years in several wealthy countries.
The research, published in The Lancet, was led by Professor Majid Ezzati and colleagues from Imperial College London. The team examined information from 110 health surveys involving almost one million adults between 1990 and 2024.
Participants came from seven high-income regions: England, the United States, Japan, South Korea, Taiwan, Thailand, and Finland. The researchers compared people with obesity, overweight, and normal body weight to see how blood pressure and unhealthy cholesterol changed over time.
Blood pressure is the force of blood pushing against artery walls. If it stays too high for many years, it damages blood vessels and increases the risk of heart attacks, strokes, kidney disease, and heart failure. Cholesterol is a fatty substance needed by the body, but too much LDL or non-HDL cholesterol can build up inside arteries and block blood flow.
The study found that during the 1990s, adults with obesity usually had much higher blood pressure and unhealthy cholesterol than adults with a normal body mass index. Over time, however, this gap became much smaller among adults aged 40 to 79 in most of the countries studied.
The biggest improvements occurred among people aged 60 to 79. In England and the United States, older adults with obesity, especially severe obesity, eventually had blood pressure and cholesterol levels that were similar to, or even lower than, those of older adults with normal weight.
The researchers believe the main reason is not that obesity has become less harmful, but that many more people with obesity are now receiving effective treatment. During the past three decades, doctors have increasingly prescribed statins and blood pressure medicines to older adults with obesity because they are at higher cardiovascular risk.
By the early 2020s, around seven out of ten older men with severe obesity in England and the United States were taking cholesterol-lowering medicines, compared with fewer than half of older men with normal weight.
The picture was different for younger adults under 40. In this group, there was little improvement in the gap between obesity and normal weight. Blood pressure and unhealthy cholesterol remained higher in younger people with obesity, and far fewer of them were taking medicines to control these risk factors.
The findings suggest that younger adults may benefit from earlier screening, healthier lifestyles, and medical treatment when appropriate before permanent damage develops.
The researchers also noted that the study only included seven high-income countries. Results may be very different in lower-income countries where access to cholesterol and blood pressure medicines is more limited. In addition, the study could not examine differences in medication doses or long-term treatment patterns.
Overall, the findings highlight an important public health success. Modern medicines appear to have greatly reduced two major cardiovascular risk factors among many older adults with obesity. However, this does not mean obesity is harmless.
Excess body weight still affects many organs and increases the risk of diabetes, liver disease, arthritis, sleep apnea, and several cancers. As Dr. Yuan Lu of Yale School of Medicine pointed out in an accompanying commentary, better blood pressure and cholesterol should not be mistaken for the complete removal of obesity-related health risks.
This study provides strong evidence that widespread access to statins and blood pressure medicines has improved heart health for many older adults with obesity. At the same time, it shows that prevention should begin much earlier.
Healthy eating, regular physical activity, weight management, early health checks, and appropriate medications remain the best combination for reducing long-term cardiovascular risk.
Future research should examine whether similar improvements can be achieved in lower-income countries and whether new weight-loss medicines provide additional protection alongside traditional heart medications.
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Source: Imperial College London.
