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A new study from the USA has investigated why people who consume alcohol in moderation have a lower risk of heart attacks and strokes than people who abstain from alcohol altogether or drink significantly more. It attributes the main effect not to changes in the blood but in the brain. Study author Dr. Ahmed Tawakol, co-director of the Cardiovascular Imaging Research Center at Massachusetts General Hospital, analysed brain scans of hundreds of participants for this purpose. These showed lower stress reactions in the amygdala, which is involved in emotional reactions in the brain. When over-excited, the amygdala prepares the body for fight-or-flight reactions. This raises blood pressure and certain neurons cause the bone marrow to release more pro-inflammatory cells. Cortisol is released, telling the body to store fat, which increases the risk of diabetes and high blood pressure, and also adrenaline, which further raises blood pressure. The combination of these effects can increase the risk of heart attacks and strokes.
Brain scans of moderate drinkers showed significantly less activity in the amygdala than non-drinkers and heavy drinkers, according to Tawakol. At the same time, he stresses, "For the same amount of alcohol that protects against cardiovascular disease, we found a similar increased risk of cancer, so we are not suggesting that there is a recommended amount of alcohol to improve health," and recommends meditation and exercise to reduce stress.
Some other scientists also warn against focusing on only one aspect in studies on the effect of moderate alcohol consumption. They point out that the study only shows associations, but cannot prove that alcohol is the reason for less stress in the brain.
(al / source: CNN)