A Healthy Lifestyle Can Compensate for Genetic Risk of Heart Attack
We can control many of the factors that increase our chance of having a heart attack, such as smoking, physical fitness and diet. But genetic predisposition is a major risk factor that we tend to think of as fixed. Researchers at Massachusetts General Hospital looked at whether that predisposition can be mitigated by our lifestyle choices or if the risk in our DNA is set in stone.
Analyzing data from four major studies, the researchers found that participants’ genetic predispositions for heart attack and coronary artery disease could increase their risk of a cardiac event by up to 90%. They assessed the participants’ lifestyles in terms of smoking, body mass index, physical activity level and diet to generate a general health score. This score was matched to the genetic risk profile and compared with the incidence of those adverse cardiac events over the long term.
It was clear that these events happened more often in participants with a high genetic risk. However, having a healthier lifestyle score was associated with up to a 50% decrease in this risk. As Sekar Kathiresan, MD, a lead researcher of the study, commented, “Some people may feel they cannot escape a genetically determined risk for heart attack, but our findings indicate that following a healthy lifestyle can powerfully reduce genetic risk.”
A New Understanding of How Stress Can Lead to Heart Disease
We know that stress can contribute to heart attacks and stroke, but exactly how remains an open question. Now for the first time in humans, researchers have tied that relationship to a specific part of the brain. In a study published in The Lancet, a team at Harvard Medical School found that increased activity in the amygdala is associated with higher risk of heart attack and stroke.
It was already known that people with post-traumatic stress disorder, anxiety and depression show increased function in the amygdala, a brain structure that plays a key role in generating sympathetic nervous system responses to emotional stressors. The Harvard researchers took a closer look at the relationship between stimulation of the amygdala and the development of cardiovascular events. Among the nearly 300 individuals observed for about 3.5 years, those with heightened amygdala activity experienced more events such as stroke and heart attack than those with lower levels of activity.
They found that these individuals also experienced elevated bone marrow activity and blood vessel inflammation, suggesting a possible explanation for the observed cardiovascular events. When bone marrow is overactive, this results in the increased production of white blood cells, an inflammatory response which can spur the development of plaques that clog blood vessels. The resting activity levels in the amygdala predicted cardiovascular disease independently of other known risk factors. The new findings point to avenues for future research to understand the impact of stress through both the sympathetic nervous system and inflammation.
E-cigarettes Tied to Increased Risk of Heart Disease
E-cigarettes are marketed as a safe alternative to smoking tobacco cigarettes, but a recent study from the University of California, Los Angeles has found evidence that this may not be the case. E-cigarette devices work by vaporizing a liquid mixture containing nicotine, which is in turn inhaled by the smoker. The big advantage over regular cigarettes is that they work without the use of fire and avoid the consumption of some harmful byproducts such as carbon monoxide and tar. Despite these benefits, the study suggests that e-cigarette users may not escape possible adverse cardiovascular effects.
Because nicotine is a strong stimulant, it leads to an excitatory response in the body that can be hazardous in the long term. The researchers found that routine e-cigarette smokers experience increased heart rate as well as more oxidative stress, compared with non-users. These conditions can actually lead to cardiovascular disease, making them a significant health concern.
Little is known conclusively about the physiological changes in e-cigarette users over the course of their lifetime. A spokesperson for the European Society of Cardiology commenting on the study indicated that further studies are needed to better understand the effects of e-cigarettes and that using these devices to treat nicotine addiction is not as effective as gum or patches and may instead extend the addiction.