Beta blockers are a group of medicines prescribed as a preventive medication for, among other things, heart attacks, high blood pressure and anxiety. While they may slow down metabolism, there is no evidence suggesting that they by themselves have any significant effect on weight loss. The main effect on weight loss may come from the anti-anxiety effects of certain beta blockers. A person with less anxiety and stress may be less active overall. But treating anxiety could also have the opposite effect on a person's activity level.
Adrenaline and Beta Blockers
The adrenal glands that sit atop of the kidneys produce adrenaline, noradrenaline and cortisol in response to internal or external stressors. These stress chemicals prepare the body for a fight-or-flight reaction by increasing heartbeat, increasing oxygen flow to the bronchia and lungs, and making energy sources available for the main muscle groups. While this reaction is beneficial to survival, it can be dangerous for heart patients, because the quickening of the heartbeat can increase the risk of heart attacks or heart failure. Beta blockers are sometimes prescribed to prevent this reaction. They block adrenaline receptors on the heart, thereby preventing adrenaline in the bloodstream from causing an increased heartbeat.
Beta Blockers as an Anti-Anxiety Medication
Although beta blockers are not FDA-approved as anti-anxiety medications, doctors sometimes prescribe the beta blocker propranolol as an anti-anxiety medication. It doesn't reduce fear or the secretion of stress chemicals but it reduces some of the symptoms of anxiety, including a rapid heartbeat and shaky hands and legs. Because beta blockers do not treat anxiety, it is best suited as a medication for situational anxiety, such as fear of public speaking, stage fright and test anxiety. It can also be beneficial for individuals who work in jobs that require precise hand and finger movements, such as high-performing musicians and surgeons.
Weight Loss and Stress
Weight loss occurs when the intake of calories is less than the calories used for body maintenance and to support movement. The daily calories needed to maintain body weight depend on a number of factors, including body weight, muscle mass, gender and daily activity level. The more active you are, the more calories you need. People who go through stressful periods of their lives may experience unintentional weight loss. Part of the reason for this can be a tendency to move around more or forgetting to eat.
The Effect of Beta Blockers on Weight Loss
When you take beta blockers for a heart condition or anxiety, you slow down heartbeat, respiration, sweating and other effects of stress chemicals being secreted into the bloodstream. This internal hyperactivity may increase your metabolism in theory. But there is not yet any scientific evidence to support this theory. When beta blockers slow weight loss, the main reason typically is that the lack of stress makes people less fidgety. However, as anxiety can also result in a depression-like state, treating the symptoms of anxiety can also make people more active. This could result in a weight loss.
References
- MayoClinic.com: Beta Blockers
- Preventive Cardiology: Beta-blockers by Skye Schulte, MS, MPH and Rebecca J. Stahl, MA
- National Institutes of Health: Your Guide to Lowering Blood Pressure
- Weight Loss Resources.co.uk: How to Make Your Body Burn More Calories
- MayoClinic.com: Stress Basics
- Healthy Place: Beta-Blockers for Treatment of Anxiety and Panic Attacks
