Dr. Gary L. Wenk published an article in Psychology Today in which he compares the cognitive effects of obesity versus cannabis use.
In Marijuana or Obesity: Which Is Worse? a respected psychologist gives us a breakdown of the physical and mental effects of both behaviors and answers the question simply…
For the majority of people who read this blog the answer will be obesity.
Elaborating on that he says that the determining factor will be whether you are more genetically predisposed to drug or food addictions. However throughout the rest of his article he provides information showing that obesity leads to cognitive decline while marijuana use can stimulate mental activity.
Today, an overwhelming body of evidence across a wide spectrum of medical disciplines strongly argues that obesity accelerates the aging process, impairs overall cognitive function and, ultimately, is responsible for numerous processes that kill you.
Studies suggest that adults (this argument does not apply to young people) who use low to moderate daily amounts of marijuana show no personality disturbances. During the past few years some sensational studies have been widely featured in the national press; one suggested that daily marijuana use might decreased IQ (Meier et al., PNAS, 2012), the other suggested that daily recreational use caused shrinkage of brain areas that are critical for learning, memory and emotional control (Gilman et al., 2014, J Neurosci). The report by Meier et al. was immediately challenged (Rogeberg, 2013, PNAS) for failing to take into account the confounding effect of socioeconomic status, a factor which has been shown to a significantly impact on IQ score. The results of the second study have now been confronted by a more recent publication (Weiland et al., 2015, J Neurosci) that clearly demonstrated that daily use of marijuana produced no significant changes in the size or shape of brain regions involved in the control of emotion or learning and memory.
Just last month another bit of nonsense derived from poor research methods was published and then debunked (see, https://www.leafly.com/news/health/does-marijuana-cause-alzheimers). Marijuana does not shrink the brain or predispose people to Alzheimer’s disease. Research in my laboratory (copies of publications can be obtained here: http://faculty.psy.ohio-state.edu/wenk/) has demonstrated that stimulating the brain’s marijuana receptors offer protection by reducing brain inflammation. Thus, later in life, marijuana might actually help your brain, rather than harm it. It takes very little marijuana to produce benefits in the older brain. My lab coined the motto “a puff is enough” because it appears as though only a single puff each day is necessary to produce significant benefit.
I often am asked by my students whether smoking marijuana makes it more likely that to develop schizophrenia. Forty years of research has led to the following answer: if you are not genetically vulnerable to schizophrenia then marijuana use will not induce it. It appears as though stimulating endogenous marijuana receptors may be able to unmask underlying symptoms of schizophrenia as well as other mental disorders, such as bipolar disorder, if you inherited the appropriate genes from your parents.
Well, that just killed my munchies!