Skip to content

Tag: physical activity

Published on

Nice summary of cancer prevention advice. What it boils down to is that there is no magic bullet for cancer prevention (maybe the closest thing is to NOT smoke), but it's a lot of little things adding up (your lifestyle) that lowers the risk of cancer. From The Washington Post:

Looking for that fruit or vegetable that might prevent cancer?

Blueberries. Green tea. Tomatoes. And, oh, that cruciferous cauliflower. All make the lists of super foods that might help prevent cancer. Then there are the foods such as smoked meat and fried foods that supposedly might cause cancer. Such information is standard fare for TV doctors and Web sites, but most of us don’t know how to judge such claims. What sounds authoritative may not be. Only about half of the recommendations on two internationally syndicated TV medical talk shows were supported by scientific evidence, according to a recent study in the journal BMJ.

Of course, the blueberries we eat today are good for us. But nutrition’s role in cancer prevention is much more complex than a single dietary component: Evidence has mounted, for example, that lifestyle — diet, weight control and exercise — is vital in helping reduce risk. For now, experts endorse general dietary advice that is healthful for a variety of chronic diseases and conditions, rather than reductionist thinking that focuses on single foods or nutrients.

When you hear that a certain food helps prevent cancer, ask: Which cancer? “Cancer is multiple diseases,” said Marian Neuhouser, a nutritional epidemiologist at the Fred Hutchinson Cancer Research Center in Seattle. Whereas cardiovascular disease might be broken down into several types, including myocardial infarction, stroke and peripheral vascular disease, she said, “for cancer, it’s really over 100 different diseases.” “Cancer is a very complex, very challenging disease to study whether you’re looking at it on the cell level or the clinical level or the epidemiologic and preventive level,” Willett said.

Researchers caution about overreacting to a single study. New findings come out every week, but “we never take any one study to be the answer to anything,” said Nancy Potischman, a nutritional epidemiologist at the National Cancer Institute. Only if the same results come up in multiple studies across multiple populations, “then you might think that, yes, this food might be important,” she said.

Tobacco use remains the leading preventable cause of cancer incidence and death worldwide. After tobacco, the lifestyle trio of diet, weight control and exercise may be linked to one-third to two-thirds of cancers. “They’re inseparable,” Neuhouser said. “You can have a great diet and you can have a healthy weight, but if you’re extremely sedentary then there’s a risk.”And there’s a strong link between excess weight and several kinds of cancer, including the esophagus, breast (after menopause), endometrium, colon and rectum, kidney, pancreas, thyroid, gallbladder, according to the NCI. 

Evidence mounts about how lifestyle may affect risk of cancer. In the largest study of its kind, nearly half a million Americans were evaluated for adherence to American Cancer Society cancer prevention guidelines that include smoking avoidance; a healthful, consistent weight; physical activity; limiting alcohol; and a diet emphasizing plants.

Those who followed the guidelines most closely had lowered risk of developing cancer (10 percent for men, 19 percent for women) and dying from cancer (25 percent for men, 24 percent for women) compared with those whose habits were least in line with the guidelines. Most striking was the reduction of overall risk of dying: 26 percent for men, 33 percent for women during the 14-year study period.

Fourteen types of cancer seemed affected by lifestyle behavior, most particularly gallbladder, endometrial, liver and colorectal. For men and women, a healthful weight and physical activity were the top factors in reduced deaths overall. Albert Einstein College of Medicine Researchers published this analysis online in January in the American Journal of Clinical Nutrition, based on data from a National Institutes of Health/AARP study.

Another approach to cancer and nutrition considers dietary patterns. “What we eat on any one day is not going to change our cancer risk, but it’s the pattern over the long term.” Neuhouser said. Several diets that emphasized fruit, vegetables, whole grains and plants or plant-based proteins were analyzed against information collected over more than 12 years from nearly 64,000 post-menopausal women in the Women’s Health Initiative Observational Study. Consuming a high-quality diet was associated with lower death rates from chronic diseases including cancer, as reported last year in the American Journal of Epidemiology.

The bacteria, viruses and other organisms that live in and on humans seem to play a bigger role in health and disease than was previously understood, Freudenheim said. How the countless microbes in such areas as the gut and the mouth might contribute to or prevent cancers is one of the open questions in the new area of study of the microbiome, which refers to the many organisms in the body, 10 percent of which are human and 90 percent nonhuman.

Published on

Exercise is the Fountain of Youth? Note that they could not come up with a biomarker of aging in these active people. From Medical Xpress;

Exercise allows you to age optimally

Staying active allows you to age optimally, according to a study by King's College London and the University of Birmingham. The study of amateur older cyclists found that many had levels of physiological function that would place them at a much younger age compared to the general population; debunking the common assumption that ageing automatically makes you more frail.

The study, published in The Journal of Physiology, recruited 84 male and 41 female cycling enthusiasts aged 55 to 79 to explore how the ageing process affects the human body, and whether specific physiological markers can be used to determine your age.

Cyclists were recruited to exclude the effects of a sedentary lifestyle, which can aggravate health problems and cause changes in the body, which might appear to be due to the ageing process. Men and women had to be able to cycle 100 km in under 6.5 hours and 60 km in 5.5 hours, respectively, to be included in the study...Participants underwent two days of laboratory testing at King's. For each participant, a physiological profile was established which included measures of cardiovascular, respiratory, neuromuscular, metabolic, endocrine and cognitive functions, bone strength, and health and well-being. Volunteers' reflexes, muscle strength, oxygen uptake during exercise and peak explosive cycling power were determined.

The results of the study showed that in these individuals, the effects of ageing were far from obvious. Indeed, people of different ages could have similar levels of function such as muscle strength, lung power and exercise capacity. The maximum rate of oxygen consumption showed the closest association with age, but even this marker could not identify with any degree of accuracy the age of any given individual, which would be the requirement for any useful biomarker of ageing.

In a basic, but important test of function in older people, the time taken to stand from a chair, walk three metres, turn, walk back and sit down was also measured. Taking more than 15 seconds to complete the task generally indicates a high risk of falling. Even the oldest participants in the present study fell well below these levels, fitting well within the norm for healthy young adults.

Overall, the study concluded that ageing is likely to be a highly individualist phenomenon...The main problem facing health research is that in modern societies the majority of the population is inactive. A sedentary lifestyle causes physiological problems at any age. Hence the confusion as to how much the decline in bodily functions is due to the natural ageing process and how much is due to the combined effects of ageing and inactivity."

"In many models of ageing lifespan is the primary measure, but in human beings this is arguably less important than the consequences of deterioration in health. Healthy life expectancy - our healthspan - is not keeping pace with the average lifespan, and the years we spend with poor health and disabilities in old age are growing."

Emeritus Professor Norman Lazarus, a member of the King's team and also a cyclist, said: "Inevitably, our bodies will experience some decline with age, but staying physically active can buy you extra years of function compared to sedentary people. Cycling not only keeps you mentally alert, but requires the vigorous use of many of the body's key systems, such as your muscles, heart and lungs which you need for maintaining health and for reducing the risks associated with numerous diseases."

Published on

The bottom line: for better health be physically active at least is 2.5 hours of week. Note that HbA1c is a measure of glycated hemoglobin which identifies average plasma glucose concentration (and lower is better). From Medscape:

Exercise Tied to Cardiometabolic Markers in Clinic Patients 

Healthy, middle-aged outpatients who were physically active for at least 2.5 hours a week had better blood pressure and blood glucose levels than their sedentary peers in a large cross-sectional study in California. The differences were especially notable in women, in this study published online December 18, 2014 in Preventing Chronic Disease.

Men and women who were consistently physically active—defined as performing moderate to vigorous activity such as brisk walking for at least 150 minutes a week, as self-reported at all three outpatient visits in a 33-month period—had lower diastolic blood pressure, glucose, and HbA1c levels than patients not reporting exercise at that level.

Moreover, on a population level, the observed associations "were comparable to those needed to reduce the risk of coronary heart disease, stroke, and diabetes," they continue. "If healthcare providers would routinely assess the physical activity of their patients and refer those who are physically inactive to effective physical-activity programs, it may reduce the burden of future chronic diseases."

They analyzed electronic records from over 622,000 adults covered by Kaiser Permanente Southern California healthcare insurance who made at least three clinic visits between April 2010 and December 2012 and were not being treated for diabetes or hypertension.

The consistently active women had systolic and diastolic blood pressures that were 4.60-mm-Hg lower and 3.28-mm-Hg lower, respectively, than inactive women. Perhaps surprisingly, somewhat active women had slightly better blood-pressure values than the more active group.

Published on

Interesting term "actively sedentary", which may describe many of us. From Medscape:

Walking Is the Superfood of Fitness, Experts Say

NEW YORK (Reuters) - Walking may never become as trendy as CrossFit, as sexy as mud runs or as ego-boosting as Ironman races but for fitness experts who stress daily movement over workouts and an active lifestyle over weekends of warrior games, walking is a super star.

For author and scientist Katy Bowman, walking is a biological imperative like eating. In her book, "Move Your DNA: Restore Your Health Through Natural Movement," she suggests there are movement nutrients, just like dietary nutrients, that the body needs. "Walking is a superfood. It's the defining movement of a human," said Bowman, a biomechanist based in Ventura, California. 

Researchers say emerging evidence suggests that combined physical activity and inactivity may be more important for chronic disease risk than physical activity alone. "Actively sedentary is a new category of people who are fit for one hour but sitting around the rest of the day," Bowman said. "You can't offset 10 hours of stillness with one hour of exercise."

She added that a small study of non-obese men published in the journal Medicine & Science in Sports and Exercise by scientists at Indiana University suggests that three five-minute walks done throughout three hours of prolonged sitting reverses the harmful effects of prolonged sitting on arteries in the legs.

Three miles (5 kilometers) per hour is a good beginning, gradually working to 4 miles per hour, she said about walking.

Published on

Two related stories that look at children, exercise, and academic performance. Boys, in general, have higher activity levels than girls, and they need exercise and recess to be able to get through the rest of the school day. Sitting quietly in class and doing classwork is hard when one has lots of excess energy. In fact, sitting still for hours on end is NOT healthy in any way for anyone! Fidget, fidget, fidget... From Science Daily:

High levels of physical activity linked to better academic performance in boys

Higher levels of physical activity are related to better academic achievement during the first three school years, particularly in boys, research shows. For instance, boys with higher levels of physical activity, and especially walking and bicycling to and from school, had better reading skills than less active boys....The findings of the present study highlight the potential of physical activity during recess and participation in organized sports in the improvement of academic achievement in children. 

 Instead of medicine, why aren't doctors prescibing exercise? From The Atlantic:

Exercise Is ADHD Medication

Physical movement improves mental focus, memory, and cognitive flexibility; new research shows just how critical it is to academic performance.

...More insipid but also more clearly critical to addressing what's being called the ADHD epidemic is plain old physical activity.

This morning the medical journal Pediatrics published research that found kids who took part in a regular physical activity program showed important enhancement of cognitive performance and brain function. The findings, according to University of Illinois professor Charles Hillman and colleagues, "demonstrate a causal effect of a physical program on executive control, and provide support for physical activity for improving childhood cognition and brain health." If it seems odd that this is something that still needs support, that's because it is odd, yes. Physical activity is clearly a high, high-yield investment for all kids, but especially those attentive or hyperactive. This brand of research is still published and written about as though it were a novel finding, in part because exercise programs for kids remain underfunded and underprioritized in many school curricula, even though exercise is clearly integral to maximizing the utility of time spent in class.

Earlier this month, another study found that a 12-week exercise program improved math and reading test scores in all kids, but especially in those with signs of ADHD.

Last year a very similar study in the Journal of Attention Disorders found that just 26 minutes of daily physical activity for eight weeks significantly allayed ADHD symptoms in grade-school kids. The modest conclusion of the study was that "physical activity shows promise for addressing ADHD symptoms in young children." 

"If physical activity is established as an effective intervention for ADHD," they continued, "it will also be important to address possible complementary effects of physical activity and existing treatment strategies ..." Which is a kind of phenomenal degree of reservation compared to the haste with which millions of kids have been introduced to amphetamines and other stimulants to address said ADHD. The number of prescriptions increased from 34.8 to 48.4 million between 2007 and 2011 alone. The pharmaceutical market around the disorder has grown to several billion dollars in recent years while school exercise initiatives have enjoyed no such spoils of entrepreneurialism. 

Over all, the pandemic of physical inactivity, as Hillman and colleagues put it in their Pediatrics journal article today, is "a serious threat to global health" responsible for around 10 percent of premature deaths from noncommincable diseases. 

John Ratey, an associate professor of psychiatry at Harvard, suggests that people think of exercise as medication for ADHD. Even very light physical activity improves mood and cognitive performance by triggering the brain to release dopamine and serotonin, similar to the way that stimulant medications like Adderall do. 

Published on

Well DUH ! Of course children need to run, run, run or somehow exercise to get rid of excess energy. That's why recess is so important (but unfortunately so many schools are eliminating it). It is incredibly hard for children to quietly sit for many, many hours straight like little robots working tirelessly on schoolwork, especially those with high energy levels to start with. From Medscape:

Before-School Exercise May Reduce ADHD Symptoms

Moderate to vigorous aerobic exercise in the morning may reduce symptoms of attention-deficit/hyperactivity disorder (ADHD) in young children at risk for the illness, new research suggests.

A randomized study of 202 kindergarteners, 1st graders, and 2nd graders showed that those who completed 12 weeks of before-school physical activity had significantly higher reductions in inattention and moodiness than those who completed a sedentary classroom-based intervention.In addition, the subgroup of children with elevated ADHD symptoms who went through the before-school exercise program showed reduced impairment associated with ADHD risk in both their school and home settings.

"We need more studies to replicate the results, but I think the take-home message is that aerobic exercise is a health-producing activity ― and there are really no negative side effects from it," added Dr. Hoza.

Past research has shown some positive effects from exercise on patients with ADHD, providing evidence that it may be "a viable strategy for improving symptoms, behavior, achievement, inhibitory control, and neurocognitive function in youth with elevated ADHD symptoms," write the investigators.

In the current study, the researchers enrolled 94 children at risk for ADHD and 108 children deemed "typically developing" to act as their control group....The physical activity involved continuous movement requiring children to breathe hard and included a variety of age-appropriate activities and games.

"Although our findings indicated that all participants showed improvements, children with ADHD risk receiving exercise benefited across a broader range of outcomes than those receiving the sedentary activities," said coinvestigator Alan Smith, PhD, chair of the Department of Kinesiology at Michigan State University in East Lansing, in a release.

Published on

Several more articles on the benefits of exercise. From Science Daily:

Train your heart to protect your mind

Exercising to improve our cardiovascular strength may protect us from cognitive impairment as we age, according to a new study. "Our body's arteries stiffen with age, and the vessel hardening is believed to begin in the aorta, the main vessel coming out of the heart, before reaching the brain. Indeed, the hardening may contribute to cognitive changes that occur during a similar time frame," explained the first author of the study. "We found that older adults whose aortas were in a better condition and who had greater aerobic fitness performed better on a cognitive test. We therefore think that the preservation of vessel elasticity may be one of the mechanisms that enables exercise to slow cognitive aging."

The researchers worked with 31 young people between the ages of 18 and 30 and 54 older participants aged between 55 and 75. This enabled the team to compare the older participants within their peer group and against the younger group who obviously have not begun the aging processes in question. None of the participants had physical or mental health issues that might influence the study outcome.

The results demonstrated age-related declines in executive function, aortic elasticity and cardiorespiratory fitness, a link between vascular health and brain function, and a positive association between aerobic fitness and brain function. "Although the impact of fitness on cerebral vasculature may however involve other, more complex mechanisms, overall these results support the hypothesis that lifestyle helps maintain the elasticity of arteries, thereby preventing downstream cerebrovascular damage and resulting in preserved cognitive abilities in later life."

From Science Daily:

Physically fit kids have beefier brain white matter than their less-fit peers

A new study of 9- and 10-year-olds finds that those who are more aerobically fit have more fibrous and compact white-matter tracts in the brain than their peers who are less fit. 'White matter' describes the bundles of axons that carry nerve signals from one brain region to another. More compact white matter is associated with faster and more efficient nerve activity.

The analysis revealed significant fitness-related differences in the integrity of several white-matter tracts in the brain: the corpus callosum, which connects the brain's left and right hemispheres; the superior longitudinal fasciculus, a pair of structures that connect the frontal and parietal lobes; and the superior corona radiata, which connect the cerebral cortex to the brain stem."All of these tracts have been found to play a role in attention and memory," Chaddock-Heyman said. 

From Science Daily:

Exercise may protect older women from irregular heartbeat

Increasing the amount or intensity of physical activity can cut the chances of older women developing a life-threatening irregular heartbeat, according to new research. Researchers found that post-menopausal women who were the most physically active had a 10 percent lower risk of developing atrial fibrillation (AF), compared to women with low levels of physical activity, even if they were obese. Obesity is an important risk factor for atrial fibrillation.

Published on

This is Part 2 on how lifestyle influences aging. Many recent research reports tell of a link between our lifestyle and how we'll age - whether we'll be active and healthy well into our 80s or in terrible shape and dying young. Mind you, these are not "definites" because nothing can give you a guarantee, but they are ways we can improve our odds in living the long and healthy life that we want. From February 2014 Medscape:

Cancers Caused by Lifestyle Behaviors: Experts Urge Action

In launching the World Cancer Report 2014 earlier this week, the editors emphasized the need for prevention and highlighted lifestyle behaviors that lead to cancer, including smoking tobacco, drinking alcohol, overweight/obesity, and lack of exercise. The report, issued by the International Agency for Research on Cancer (IACR), contains contributions from more than 250 scientists worldwide, many of them leading experts in their fields. 

In the United States, 1 in 3 cancer deaths is related to obesity, poor nutrition, or physical inactivity, and the problem will only increase as more countries and regions adopt the diet and lifestyles of more economically developed economies."

Tobacco, both smoked and smokeless, remains the world's leading cause of cancer morbidity and mortality, the report notes. The IACR and also the US Surgeon General have concluded that the relationship with smoking is causal for cancers of the nasal and oral cavities, hypopharynx, larynx, trachea, esophagus, lung, bronchus, bone marrow (leukemia), stomach, kidney, pancreas, ureter, uterus, bladder, and cervix. The IACR expands this list to also include paranasal sinuses, liver, colon, rectum, and ovary (mucinous), but says it is unclear if there is a link with breast cancer.

Still under-recognized, and not acted on, is the association between drinking alcohol and cancer. The agency says cancers caused by drinking alcoholic beverages include those of the oral cavity, pharynx, larynx, esophagus, liver, colorectum, and female breast.

Excess body fat increases the risk for cancers of the esophagus, colon, pancreas, endometrium, and kidney, as well as postmenopausal breast cancer. The evidence for obesity increasing the risk for these cancers is "convincing," the agency comments, and there is a dose–response relationship, so being overweight is less risky than being obese.

Regular physical activity reduces the risk for multiple cancers by contributing to weight control, and also reduces the risk for colorectal and breast cancer by additional mechanisms. The general consensus among researchers is that exercise should be of moderate intensity and average at least an hour each day.

High consumption of red meat, especially processed meat, is associated with a risk for colorectal cancer. "A diet high in fruit and vegetables and whole grains does not appear to be as strongly protective against cancer as initially believed," the report notes. "However, this dietary pattern is still advisable because of the benefits for diabetes and cardiovascular diseases, and some possible reductions in cancer incidence."

From Science Daily:

Watching too much TV may increase risk of early death: Three hours a day linked to premature death from any cause

Adults who watch TV three hours or more a day may double their risk of premature death from any cause. Researchers suggest adults should consider getting regular exercise, avoiding long sedentary periods and reducing TV viewing to one to two hours a day.

Results of a large study published in the Mayo Clinic Proceedings. From Science Daily:

Large waist linked to poor health, even among those in healthy body mass index ranges

Having a big belly has consequences beyond trouble squeezing into your pants. It’s detrimental to your health, even if you have a healthy body mass index (BMI), a new international collaborative study has found. Men and women with large waist circumferences were more likely to die younger, and were more likely to die from illnesses such as heart disease, respiratory problems, and cancer after accounting for body mass index, smoking, alcohol use and physical activity.

Some good news for those who have to sit for long periods every day at work - being physically fit may help. From Science Daily:

Physical fitness associated with less pronounced effect of sedentary behavior

Physical fitness may buffer some of the adverse health effects of too much sitting, according to a new study. Sedentary behavior has been linked to an increase risk of obesity, metabolic syndrome, type 2 diabetes mellitus, cardiovascular disease, some cancers, and premature death. But previous studies of the association have not taken into account the protective impact of fitness, a strong predictor of cardiovascular disease incidence and mortality.

Published on

It seems that research showing benefits of exercise is multiplying. This study only looked at men, and if you look at the "after age 40 group", their average age of starting endurance training was 48. From Science Daily:

Forty not too old or too late to start endurance training

A study of healthy senior men has found that "relatively intensive" endurance exercise confers benefits on the heart irrespective of the age at which they began training. The benefits were evident and comparable in those who had started training before the age of 30 or after the age of 40. As a result, said the investigators, 40 is not too old to start endurance training.

The study was performed in 40 healthy men (without cardiovascular risk factors) aged between 55 and 70 years who were divided for assessment according to the level of exercise they took and the ages at which they began. Thus, 10 of the men had never exercised for more than 2 hours a week throughout their lives, and 30 had exercised for at least 7 hours a week for over five years.

The regular exercise they took was either running or cycling. Those beginning before the age of 30 had been training for an average of 39 years (since the age of 22) and those starting at 40 for 18 years (since the age of 48).

First, resting heart rate was found to be similar between the two exercise groups (T30 56.8 bpm, T40 58.1 bpm), but significantly faster in the non-exercising men (69.7 bpm). Maximal oxygen uptake was also similar between the T30 (47.3 ml/min/kg) and T40 groups (44.6 ml/min/kg), but significantly lower in the non-exercising men (33.0 ml/min/kg).

The study also found no difference between T30 and T40 in cardiac echocardiography tests. "Thus," said Matelot, "despite biological changes with age, the heart still seems -- even at the age of 40 -- amenable to modification by endurance training. Starting at the age of 40 does not seem to impair the cardiac benefits.

Matelot pointed out that aging is associated with adverse structural and functional changes to the cardiovascular system. And, while physical activity is unable to prevent these changes, it is able to slow them down.

Published on

More studies on the amazing benefits of exercise, or activity, even light activity.  From Science Daily:

Simple tests of physical capability in midlife linked with survival

Low levels of physical capability (in particular weak grip strength, slow chair rise speed and poor standing balance performance) in midlife can indicate poorer chances of survival over the next 13 years, while greater time spent in light intensity physical activity each day is linked to a reduced risk of developing disability in adults with or at risk of developing knee osteoarthritis, suggest two papers published on bmj.com today.

The researchers conclude that there are "robust associations of standing balance time, chair rise speed and grip strength at age 53 with all-cause mortality rates over 13 years of follow-up." They suggest there is value in using these simple tests to assess physical capability in midlife to identify those people who are less likely to achieve a "long and healthy life."

In a linked paper, a team of US researchers set out to investigate whether time spent in light intensity physical activity is related to a reduced risk of developing disability and disability progression.

Their study involved 1,680 men and women aged 49-83 years free of disability, but with or at high risk for developing knee osteoarthritis, a major disability risk factor. The primary outcome was the development of disability at a two-year follow up visit. In total, participants averaged 245 minutes/day of non-sedentary activity, of which the vast majority was light intensity activities (229 minutes/day).

The results show a "significant and consistent relationship between greater time spent in light intensity activity and a reduced risk of developing disability or progression in disability," say the authors.

More details on the second study. From Science Daily:

Light activity every day keeps disability at bay