Increased Well-Being May Be Associated With Increased Empathy in Medical Trainees By Thea Swenson, MD

Increased Well-Being May Be Associated With Increased Empathy in Medical Trainees By Thea Swenson, MD

Why We Need Exercise: An Evolutionary Perspective

Why We Need Exercise: An Evolutionary Perspective

By Maya Shetty

By now, we have all heard that exercise is good for us. But why is this true? And if it’s so good for us, why is it so hard to get up and do it? The Center for Disease Control (CDC) claims we need 150 minutes of moderate exercise and 2 days of muscle strengthening exercise a week to reduce our risk of chronic disease and other adverse health outcomes. However, nearly 80% of US adults are not meeting these guidelines, and 6 in 10 have one or more preventable chronic diseases. To understand this disconnect, we need to begin by examining the evolutionary perspective of exercise – why did humans evolve to exercise in the first place?  

The first Homo Sapiens emerged around 200,000 years ago and their lives looked very different from our lives in the modern day. While we complain about having to take the escalators instead of the stairs or our food delivery taking too long, our ancient ancestors were running from predators and hunting for prey. Humans subsisted through hunting and gathering for food, and this was the primary way of life for 95% of human history. This means the majority of our evolution was spent living as nomadic hunter-gatherers. Therefore, our body and behavior is primarily adapted for this lifestyle.

An Evolutionary PerspectiveNow, you may be wondering how this translates to exercise in today’s society. Well, as hunter-gatherers, our ancestors’ main advantage was endurance. We are not the strongest or fastest animals out there, so survival was dependent on our ability to outrun our predators and prey. Evolutionarily, we are endurance athletes adapted for consistent, long bouts of physical activity. If this is the case, then why does the average American spend most of their time relatively immobile? This is because we are also adapted for inactivity and energy conservation whenever possible. Thinking again about the hunter-gatherer lifestyle, our ancestors were constantly trying to maintain their energy balance – food intake vs. energy expenditure. It made sense to exercise only when necessary for survival, and conserve energy whenever possible. In today’s society, however, this biological tendency no longer serves us, as our environment has been engineered for an extremely positive energy balance: excess food with little energy expenditure. Now we must go against our biological tendencies and make the decision to exercise, even when our body is telling us not to, in order to maintain good health. 

We can see just how much our physical activity differs from our hunter-gatherer ancestors by studying the few modern day hunter-gatherer communities. These populations are often used as models in public health due to their remarkably low rates of chronic disease and disability with age, a stark difference from modern day America. Researchers analyze the behaviors of these populations to have a better understanding of the evolutionary causes of chronic diseases – Why are they so common now vs. then? The most commonly studied population is the Hadza, a hunter-gatherer population in Tanzania. Decades of research has quantified their daily physical activity and how it changes throughout the lifetime. Most notably, the Hadza people average 15,800 steps, about 6 to 9 miles, per day. Meanwhile, Americans average less than 4,800 steps, about 2 miles, per day – about ⅓ the steps of modern hunter-gatherers. On top of this, the average American reduces the amount of steps they take per day by about half between the ages of 40 to 70. The Hadza people, on the other hand, barely change their physical activity levels with age. These behaviors have measurable effects on our physiology. By the age of 60, most Americans walk 33% slower, have less muscle mass, and their VO2max – an indicator of cardiovascular health – decreases by 25%. These functional losses are seen at a significantly lesser rate, if at all, in hunter-gatherer populations. These findings align with the theory of disuse and aging brought forth by Walter Bortz II, a Professor of Medicine at the Stanford University School of Medicine, and one of America’s most distinguished scientific experts on aging and longevity. Dr. Bortz claims the changes commonly associated with aging, such as loss of muscle mass and decreased maximum oxygen consumption (VO2max), are due to disuse with age, rather than aging itself. The differences in physical capabilities with age seen between the modern American and the Hadza people suggest our sedentary lifestyle may contribute to accelerated aging. By being sedentary, we oppose the evolutionary history encoded in our genes for periodic activity, leading to accelerated physiologic loss with age due to disuse. 

 Regular physical activity stimulates our body to allocate energy toward repair and maintenance, slowing cellular senescence and aging. It has also been seen to have dose dependent effects on the risk of several chronic conditions. 

These include:

-Cardiovascular disease and hypertension

-Type 2 diabetes




-Lung disease

-Many cancers

-Alzheimer’s disease and dementia of any type

Many theories have been suggested about how exercise is able to elicit such powerful health effects. It is widely accepted that many benefits stem from the prevention of excessive weight gain, maintenance of normal blood pressure, decreased levels of unhealthy triglycerides, increased levels of healthy lipoproteins, decreased blood sugar levels, reduced systemic inflammation, and decreased stress levels. However, how these effects come about is still debated. 

Studies have also found that regular physical activity stimulates brain growth and improves cognitive function, counteracting the loss of memory and cognition seen with age. Specifically, running has been shown to stimulate the production of neurotrophic factors, or biomolecules that support the growth and survival of neurons. Brain-derived neurotrophic factor (BDNF), for instance, strengthens neuron synapses, increases the production of new nerve cells, and promotes the growth of dendrites. BDNF expression directly increases in response to exercise and is an exciting example of how exercise attenuates cognitive loss.

The World Health Organization suggests that about 150 minutes per week of moderate exercise or 75 minutes per week of vigorous exercise reduces the risk of all-cause of mortality by ~50% in otherwise sedentary individuals (1). Aside from reducing risk of mortality, regular physical activity has been shown to improve functionality, cognition, mood, and healthspan – the amount of time spent in good health- without the functional losses of aging. Despite the extensive benefits of exercise, most of us do not routinely exercise and spend the majority of the day sedentary. Our drive to not exercise, however, is as encoded into our genes as our necessity to exercise.  As difficult as it is to find the time and energy to exercise, we as humans are genetically selected for lifelong physical activity and, because of this, regular exercise is synonymous with good health. Our world has been engineered for our convenience, not our health, and for this reason we need to make the personal decision each day to walk more, sit less, and make physical activity a regular habit. Something is better than nothing, so find something that brings you joy! Identify activities that you like and can see yourself consistently doing throughout your life. When you are short on time, taking the stairs instead of the elevator or a short walk after a stressful day can still have tremendous benefits.  Whether it be running, dancing, boxing, walking, pilates, biking, etc., just remember to find joy in it and be proud of yourself for putting in the effort. Your health will thank you later.

Navigating the Difficult World of Supplements

The Impact of Supplements on Sports Performance for the Trained Athlete: A Critical Analysis


Study Suggests the Benefits of Prebiotic Supplements Were Dependent on Dietary Fiber Intake

This small proof-of-concept study found something for further exploration: the high dietary fiber vs low dietary fiber interaction with different prebiotic supplements. The  study found that the supplements only affected those who weren’t taking in dietary fiber, thus taking prebiotic supplements may be ineffective if you already consume the recommended amounts of dietary fiber. The study included a very wide age range so the findings shouldn’t be printed on t-short quite yet, however it brings to light an interesting interaction. Ironically it’s often the people who already have a healthy diet that lean towards supplement intake even though they don’t need it!

By: Marily Oppezzo, PhD, MS, Head of Lifestyle Medicine Nutrition Pillar


Journal Reference:

  1. Holmes ZC, Villa MM, Durand HK, Jiang S, Dallow EP, Petrone BL, Silverman JD, Lin PH, David LA. Microbiota responses to different prebiotics are conserved within individuals and associated with habitual fiber intake. Microbiome. 2022 Jul 29;10(1):114. doi: 10.1186/s40168-022-01307-x. PMID: 35902900; PMCID: PMC9336045.



Lifestyle May Be More Important Than Age in Determining Risk of Cognitive Decline

A great part of who were are is composed of the memories we have. With a growing interest in preventing the loss of memories, researchers have turned to preventative approaches – to address the lack of disease-modifying treatment for dementia. 

A recent study found that lifestyle may be more important than age in determining the risk of dementia and cognitive health. The study included data from over 22,000 participants between the ages of 18 – 89  and found that, for all ages, lifestyle is a more important risk factor for cognitive decline than age. The risk factors that were examined range from early-life factors to late-life factors. They include low education, traumatic brain injury, hypertension, smoking, diabetes, and depression. 

In the study, participants with no risk factors for dementia had similar brain health to people 10-20 years younger than them! Additionally, the study found that each risk factor for dementia reduced cognitive abilities by the equivalent of 3 years of aging, and each additional risk factor added to this decline. 

For the risk factors that are modifiable with nutrition, exercise, and stress management, this study suggests it is never too early to start caring for your brain health. Maintaining healthy lifestyle habits can prevent the loss of memory and shape the life you live.

By: Helena Zhang, BS & Maya Shetty, BS

Journal Reference:

  1. LaPlume AA, McKetton L, Levine B, Troyer AK, Anderson ND. The adverse effect of modifiable dementia risk factors on cognition amplifies across the adult lifespan. Alzheimers Dement (Amst). 2022 Jul 13;14(1):e12337. doi: 10.1002/dad2.12337. PMID: 35845262; PMCID: PMC9277708.
Research Suggets Whole Food Diets Improve Mood and Quality of Life

Research Suggets Whole Food Diets Improve Mood and Quality of Life

When the substance of food culture is composed of highly processed goods and advertisements of snacks, alcohol and soda as avenues of happiness, the poor food choices that arise are unsurprising. However, sugar-laden and high-fat consumption are associated with rising mortality rates, increased prevalence of chronic diseases, and soaring rates of addiction and mental health crises.  

In a first of its kind study, Francis et al randomly assigned 76 young adults to either eat a healthy Mediterranean diet, that is rich in fruit, vegetables, fish, and lean meat, or to continue eating a diet high in processed foods, saturated fats, and refined sugars. After a brief educational video and a $60 incentive to purchase Mediterranean foods, the Med diet group reported decreasing their intake of refined sugar and saturated fat. After only three weeks, the Med diet group showed significantly lower levels of depressive symptoms. On the other hand, young adults in the control group, who consumed a diet high in processed foods, saturated fats, and refined sugars, experienced no change in depression symptoms. 

With diet as a modifiable risk factor for depression, education on healthy eating habits, diet changes, and interventions are more important than ever as we face a world of increased stress and anxiety from the pandemic and saturation with social media and virtual technology. In the study, the diet intervention consisted of vegetables, omega-3 fatty acids, wholegrain cereals, protein from poultry to eggs and legumes, nuts and seeds, olive oil, and spices such as turmeric and cinnamon. In addition to following a Mediterranean style diet, the recommendations provided in this study included avoiding foods that come in a package with multiple ingredients, foods with more than 10g sugar per 100g, soft drinks, chocolates, sweets, and fried take away foods.  

 There is no doubt that what we eat affects us from our head to toe. Therefore, eating healthy, whole foods, is a promising way to improve our mood and the quality of our life.  

By: Helena Zhang, BS and Marily Oppezzo, PhD, MS

Journal Reference:

  1. Francis HM, Stevenson RJ, Chambers JR, Gupta D, Newey B, Lim CK. A brief diet intervention can reduce symptoms of depression in young adults – A randomised controlled trial. PLoS One. 2019 Oct 9;14(10):e0222768. doi: 10.1371/journal.pone.0222768. PMID: 31596866; PMCID: PMC6784975.