This is how your body shape affects your risk of cancer

You can’t blame Jack Merendino for being nervous during his stress test on the treadmill last year. Just a few months earlier, his brother had undergone heart surgery and his parents had died of heart disease, and his heart’s calcium index, which reflects calcium deposits and plaque clogging arteries, was slightly elevated. Even more worrying: A week ago, he felt pain in his chest.

“I was prepared to receive a diagnosis of heart disease, or at least be told that I wasn’t in good shape,” says Melendino, 64, an endocrinologist in Bethesda, Maryland. To his relief, his overall score, which takes into account heart rate, blood pressure and other measures, placed him in the top five percent of men his age. This means you are less likely to develop heart disease. What he didn’t know, the tests revealed: He might have a lower-than-average risk of cancer.

This is illustrated by recently published results from the Mayo Clinic in Minnesota, USA, which showed a strong relationship between the results of a stress test commonly used to diagnose heart problems and the risk of future cancer.

In the Mayo study, researchers followed 13,382 Minnesota men and women who underwent a 10- to 15-minute treadmill stress test between 1993 and 2010. After starting slowly, one gradually works their way up to the maximum possible intensity. Simultaneously measures blood pressure, aerobic capacity, heart rate and heart rate. The researchers followed the participants for about 13 years after they took the stress test, examining blood pressure and other measurements related to risk of death. They also calculated an “athletic score” by entering the value of each measurement into an equation.

“The interesting finding is that people who performed worst on the test had more than twice the risk of dying from non-cardiovascular causes than people who performed best on the test,” said Thomas G. Allison, professor and senior author of the study. Thomas G. Allison said. in Medicine from the Mayo Clinic Alix School of Medicine in Rochester (also in Minnesota). These “non-cardiovascular diseases” are 14 causes of death, including dementia, stroke and pneumonia. But most important is cancer, which accounts for half of all non-cardiovascular deaths.

Why do stress tests, designed to help diagnose heart disease, predict cancer deaths? “It makes sense to me,” said Emily Lau, a cardiologist and professor at Harvard Medical School who was not involved in the Mayo stress test study, “because cardiovascular disease and certain types of of cancers share some of the same risk factors.”

In research that dovetails with Allison’s new study, Liu and his team reviewed the results of two separate studies that followed 20,305 men who were between the ages of 36 and 64 when the study began. and women’s health. One was conducted in Framingham, Massachusetts (USA) (Framingham Heart Study) and the other was conducted in Groningen, the Netherlands (PREVEND study).

The Framingham and Prevention studies did not conduct stress tests, but instead looked at a number of factors associated with cardiovascular disease, such as blood cholesterol, body mass index (a rough indicator of body fat) and diabetes. They also used the ASCVD (Atherosclerotic Cardiovascular Disease) questionnaire, which showed that people with the highest cardiovascular risk were not only more likely to develop heart disease, but were also less likely to develop cancer by age 15. 3.7 times that of humans. Those who are at lower risk.

The researchers also entered parameters from the Framingham study participants (blood cholesterol, exercise habits and dietary patterns) into the American Heart Association’s risk assessment tool called “Life’s Simple 7.” As with ASCVD, people with lower cardiovascular risk are less likely to develop cancer.

There’s a good reason life is simple 7 Include exercise habits (even specifying the number of minutes you should complete each week); physical activity is closely linked to heart health. Although a stress test cannot tell your doctor how active you are, it is useful for measuring aerobic capacity. “This has important implications for both cardiovascular risk and the risk of certain types of cancer,” Allison said.

In the field of exercise science, “fitness” is technically known as “functional aerobic capacity,” “aerobic fitness,” or “cardiorespiratory fitness”; it is the body’s ability to deliver oxygen to muscle cells during exercise. “The stronger your heart and lungs are, the more oxygen your cells receive, the higher your fitness level, and the more protected you are from heart disease and other cardiovascular diseases,” Allison explains .

Stress testing uses “VO2 max” (the maximum amount of oxygen your body can absorb during maximal exercise) to measure fitness. VO2max in young people and men (because they have a higher proportion of muscle than women). higher. Almost everyone can increase their VO2 max through regular aerobic exercise: walking, running, rowing, biking, or any other activity that increases your heart rate and makes you breathless.

In the Mayo Clinic study, participants whose functional aerobic capacity was just 10 percent below average were 68 percent more likely to die from cardiovascular problems and die from other diseases, primarily cancer) are 42% more likely. And that’s just in terms of physical fitness. If we add functional aerobic capacity, blood pressure, and other stress test measures to the overall “exercise score,” people with the worst scores are more likely to die from heart disease, heart failure, and other cardiovascular problems than those with the lowest scores five times. best result.

“People who are physically healthy are not only less likely to get cancer, but they are also more likely to survive. They are better able to resist almost all illnesses, including falls and fractures. If you can stand up and move, you are more likely to survive. It’s more likely “to go home,” Alison said.

You don’t have to be an athlete to benefit; performing the recommended 150 minutes of moderate-intensity aerobic exercise is enough to reduce the risk of cardiovascular disease by 23 to 40 percent compared with a sedentary lifestyle. Likewise, physical activity can reduce the risk of certain types of cancer by 8 to 25 percent, with breast, colon, endometrial, stomach, and lung cancers at the high end of the range. In addition, it helps prevent chronic diseases such as obesity, type 2 diabetes, and depression.

Exercise works wonders by strengthening your heart muscle while reducing the risk factors for cardiovascular disease and cancer such as obesity, inflammation and high blood sugar.

New research suggests that at least some of the benefits may start in the gut, home to trillions of microorganisms. (Yes, another gap in the gut microbiome!)

“Our study shows that exercise increases levels of bacteria that produce short-chain fatty acids. These acids may protect against colorectal cancer,” says Alexander Boytar, a PhD student in the School of Human Movement and Nutritional Sciences at The University of Queensland (Australia).

“They may even reach other parts of the body and provide protection against other types of cancer,” Boyta wrote in an email. Physical activity also causes intestinal cells to produce more immune cells, which block inflammation. and cancer development.

These microbiome benefits may at least partially explain why people who exercise are less likely to develop certain types of cancer. The evidence is particularly strong for colorectal cancer, the third most diagnosed type and second leading cause of cancer death in the world. People who exercise regularly have a 24% lower risk of developing this type of cancer than those who sit for long periods of time.

“It’s not just about preventing cancer: The gut microbiome can also enhance the effectiveness of chemotherapy and immunotherapy,” said Beutard.

How much exercise? “Thirty to 90 minutes of aerobic exercise three or more times per week for eight weeks can tip the balance of the gut microbiome in our favor,” says Boytar.

While exercise is powerful, it’s not everything. “I recommend following the American Heart Association’s 8 Essential Recommendations, which detail not only specific recommendations for exercise, but also how to improve your diet and develop other healthy habits,” Liu advises. In his research, he used the version available at the time called “Life’s Simple 7.” Since then, the American Heart Association has added an eighth heart-protecting habit: getting enough sleep. Although more research is needed, research suggests sleep disorders can increase cancer risk by disrupting circadian rhythms and increasing inflammation.

Jack Merendino is taking note. “Even with a good stress score, I don’t take my heart health for granted. Before the test, I would often stay up late or get only five hours of sleep. I knew the link between sleep deprivation and heart disease, and now I’m discovering it Probably cancer-related, I had another reason to turn off the lights early,” he said.