How Much Cardio Do You Really Need?

Aerobic exercise, or “cardio,” might be the closest thing to a miracle drug that we have. I would humbly add that less intense exercise, such as a brisk walk 30 minutes for 5 days per week can have tremendous value, too.

A growing body of research suggests that when we commit to regular workouts that raise our heart rate and get us moving and sweating for a sustained period of time, magical things happen to our body and brain. We think more clearly, feel better overall, and protect ourselves against some of the cognitive decline that occurs with age.

“Aerobic exercise … has a unique capacity to exhilarate and relax, to provide stimulation and calm, to counter depression and dissipate stress,” the authors of an article in the Harvard Medical School blog “Mind and Mood” wrote.

But how long should you be cycling, swimming, walking, or running to reap these benefits?

Overall, research suggests that the magic happens somewhere in the window of about 30-45 minutes at minimum.

A recent research paper looked at the exercise habits of hundreds of breast cancer survivors who were experiencing symptoms like “chemo brain,” which involves memory loss and trouble focusing. The researchers found that as little as 30 minutes of an aerobic exercise like walking was linked with significantly better performance on cognitive quizzes.

Another study published in May provided some additional support for that research — it found that in adults aged 60-88, walking for 30 minutes four days a week for 12 weeks appeared to strengthen connectivity in a region of the brain where weakened connections have been linked to memory loss.

Similarly, a pilot study in people with severe depression found that just 30 minutes of treadmill walking for 10 consecutive days appeared to be “sufficient to produce a clinically relevant reduction in depression.

Other research suggests it might be better to do cardio for longer. A study in the British Medical Journal found that in adults over 50, the best results for the brain appeared to come from a routine that combined aerobic exercise with resistance training (that is, muscle-building exercises like planks and push-ups) and lasted at least 45 minutes.

Researchers still aren’t sure why this type of exercise appears to provide a boost to the brain, but some studies suggest it has to do with increased blood flow, which provides our minds with fresh energy and oxygen. One recent study in older women who displayed potential symptoms of dementia also found that aerobic exercise was linked with an increase in the size of the hippocampus, a brain area involved in learning and memory. Another reason might have to do with cardio’s ability to help reduce levels of the body’s natural stress hormones, such as adrenaline and cortisol, according to a recent study in the Journal of Physical Therapy Science.

Joe Northey, the lead author of the British study and an exercise scientist at the University of Canberra, said his research suggests that anyone in good health over age 50 should do 45 minutes to an hour of aerobic exercise “on as many days of the week as feasible.”

Explore this blog more here: Wellness

_________________________

I received an undergraduate degree from Harvard, a medical degree from Yale, and completed a residency in radiation oncology at the University of Pennsylvania. I have been blessed to be named a “top doctor” in Seattle Magazine, US News & World Report, Seattle Metropolitan Magazine, 425 Magazine, and WA magazine. Readers of the Kirkland Advertiser have voted me the top doctor (in any field) in the region. I help individuals with cancer at Evergreen Hospital, outside Seattle.

Any information provided herein is not to serve as a substitute for the good judgment of your valued health care provider.

http://www.businessinsider.com/how-long-to-do-cardio-exercise-2017-8

Nighttime Light Exposure: Does It Increase Your Risk of Breast Cancer?

Women who live in areas with higher levels of outdoor light at night may be at higher risk for breast cancer than those living in areas with lower levels, according to a large long-term study from the Harvard T.H. Chan School of Public Health. The link was stronger among women who worked night shifts.

 

Background: Previous studies have suggested that exposure to light at night may lead to decreased levels of the hormone melatonin, which in turn can disrupt circadian rhythms – out internal “clocks” that regulate sleepiness and alertness. As a result, your risk of breast cancer may increase.

The Study: In the most comprehensive study to date (investigating possible links between  outdoor light at night and breast cancer, researchers examined data from nearly 110,000 women enrolled in the Nurses’ Health Study II from 1989-2013. The researchers linked data from satellite images of earth taken at nighttime to residential addresses for each study participant, and also considered the influence of night shift work. The study also factored in detailed information on a variety of health and socioeconomic factors among participants.

Results: Women exposed to the highest levels of outdoor light at night — those in the top fifth — had an estimated 1.14-times increased risk of breast cancer during the study period, as compared with women in the bottom fifth of exposure. As levels of outdoor light at night increased, so did breast cancer rates. The association between outdoor light at night and breast cancer was found only among women who were premenopausal and those who were current or past smokers. In addition, the link was stronger among women who worked night shifts, suggesting that exposure to light at night and night shift work contribute jointly to breast cancer risk, possibly through mechanisms involving circadian disruption.

 

My Take: While provocative and consistent with historic studies, there are many potential variables for which the investigators did not control. Still, while we need confirmatory studies, this may be a caution regarding night exposure. For my patients, this typically means limiting blue light exposure in the hour before bedtime. Watch out for those computer screens, cell phones, and televisions! I’m Dr. Michael Hunter.

_________________________

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

And, one more thing: NEW free apps for Android and iOS (Apple): In apps, search My Breast Cancer by Michael Hunter.

_________________________

Reference: Peter James, Kimberly A. Bertrand, Jaime E. Hart, Eva Schernhammer, Rulla M. Tamimi, Francine Laden. Outdoor Light at Night and Breast Cancer Incidence in the Nurses’ Health Study II. Environmental Health Perspectives, 2017 DOI: 10.1289/EHP935

 

Aerobic, resistance exercise combo boost brain power

A combination of aerobic and resistance exercises can significantly boost the brain power of the over 50s, according to the most comprehensive review of the available evidence to date.

 

Background: Physical exercise for older adults appears to be a very promising way to ward off (or perhaps halt) a decline in brain health and cognitive abilities. Unfortunately, the evidence is not yet high-level. In the current study, researchers systematically reviewed 39 relevant studies published up to the end of 2016 to assess the potential impact of varying types, intensities, and durations of exercise on the brain health of the over 50s. They analyzed the impact of aerobic exercise, resistance training (such as weights), multi-component exercise (containing elements of both aerobic and resistance training), tai chi, and yoga.

Results: Pooled analysis of the data showed that exercise improves the brain power of the over 50s, irrespective of the starting state of their brain health. Aerobic exercise significantly enhanced cognitive abilities, while resistance training had a profound effect on executive function, memory, and working memory. Tai chi also improved cognitive abilities, but the authors note that this analysis was based on just a few studies.

My Take: How much, and how often? The analysis points to a session lasting 45 to 60 minutes, of moderate to vigorous intensity, and of any frequency as good for brain health. While we need a large clinical trial to confirm the tai chi benefits, it is nice to know that such exercises may help those unable to perform more challenging forms of physical activity. I’m Dr. Michael Hunter.

_________________________

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

And, one more thing: NEW free apps for Android and iOS (Apple): In apps, search My Breast Cancer by Michael Hunter.

_________________________

Reference: Hsu, CL et al. Aerobic exercise promotes executive functions and impacts functional neural activity among older adults with vascular cognitive impairment. British Journal of Sports Medicine, 2017; bjsports-2016-096846 DOI: 10.1136/bjs-ports-2016-096846

Yoga reduces symptoms of depression

A multi-week regimen of yoga may be an effective complement to traditional therapy for depression, multiple studies suggest.

 

Individuals who suffer from depression may want to look to yoga as a complement to traditional therapies as the practice may lessen symptoms, according to studies presented at the 125th Annual Convention of the American Psychological Association.

 

Study #1: Lindsey Hopkins (San Francisco Veterans Affairs Medical Center) focused on the acceptability and antidepressant effects of hatha yoga, the branch of yoga that emphasizes physical exercises, along with meditative and breathing exercises, to enhance well-being. She examined outcomes for 23 male veterans who participated in twice-weekly yoga classes for eight weeks. On a 1-10 scale, the average enjoyment rating for the yoga classes for these veterans was 9.4. All participants said they would recommend the program to other veterans. More importantly, participants with elevated depression scores before the yoga program had a significant reduction in depression symptoms after the eight weeks.

 

Study #2: Nyer and Nauphal presented data from a pilot study of 29 adults that also showed eight weeks of at least twice-weekly Bikram yoga significantly reduced symptoms of depression and improved other secondary measures including quality of life, optimism, and cognitive and physical functioning.

“The more the participants attended yoga classes, the lower their depressive symptoms at the end of the study,” said Nyer, who currently has funding from the National Center for Complementary and Integrative Health to conduct a randomized controlled trial of Bikram yoga for individuals with depression.

 

Study #3: Another and more specific version of hatha yoga commonly practiced in the West is Bikram yoga, also known as heated yoga. Sarah Shallit, MA, (Alliant University, San Francisco) investigated Bikram yoga in 52 women, age 25-45. Just over half were assigned to participate in twice-weekly classes for eight weeks. The rest were told they were wait-listed and used as a control condition. All participants were tested for depression levels at the beginning of the study, as well as at weeks three, six and nine. Shallit and her co-author Hopkins found that eight weeks of Bikram yoga significantly reduced symptoms of depression compared with the control group.

 

Study #4: Nina Vollbehr MS (Center for Integrative Psychiatry, the Netherlands) presented data from two studies on the potential for yoga to address chronic and/or treatment-resistant depression. In the first study, 12 patients who had experienced depression for an average of 11 years participated in nine weekly yoga sessions of approximately 2.5 hours each. The researchers measured participants’ levels of depression, anxiety, stress, rumination and worry before the yoga sessions, directly after the nine weeks and four months later. Scores for depression, anxiety and stress decreased throughout the program, a benefit that persisted four months after the training. Rumination and worry did not change immediately after the treatment, but at follow up rumination and worry were decreased for the participants.

 

Study #5:  Among 74 mildly depressed university students, Vollbehr and her colleagues compared yoga to a relaxation technique. Individuals received 30 minutes of live instruction on either yoga or relaxation and were asked to perform the same exercise at home for eight days using a 15-minute instructional video. While results taken immediately after the treatment showed yoga and relaxation were equally effective at reducing symptoms, two months later, the participants in the yoga group had significantly lower scores for depression, anxiety and stress than the relaxation group.

 

My Take: While yoga is not a cure-all (and recognizing the the results are suggestive of benefit, but not yet definitive) for depression , low-level evidence points to a lot of potential. If you are considering incorporating it into standard management, please check with a valued health care provider. I’m Dr. Michael Hunter.

_________________________

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

And, one more thing: NEW free apps for Android and iOS (Apple): In apps, search My Breast Cancer by Michael Hunter.


References:
American Psychological Association (APA). “Yoga effective at reducing symptoms of depression.” ScienceDaily. ScienceDaily, 3 August 2017. <www.sciencedaily.com/releases/2017/08/170803152917.htm>.

Can Mediterranean Diet Reduce Your Chances of Becoming Blind?

Better adherence to a Mediterranean diet reduces the risk of developing age-related macular degeneration, according to a study reported in 2016 in Ophthalmology.

 

Background: Macular degeneration is the leading cause of vision loss, affecting more than 10 million Americans – more than cataracts and glaucoma combined. At present, it is considered incurable. One can compared the human eye to a camera, with the macula the central and most sensitive area of the so-called film. When it is working properly the macula collects highly detailed images at the center of your field of vision and sends the information up the optic nerve to the brain, where we interpret the signals as sight. When the cells of the macula deteriorate, images are not received correctly. While early macular degeneration may not affect your vision, as the disease progresses, you may experience wavy or blurred vision. If the condition continues to worsen, central vision may be completely lost (although peripheral vision may be retained). A Mediterranean diet has been inversely associated with heart attack, stroke, cancer, and mortality. But what about eye health, including macular degeneration?

The Study: Researchers evaluated 5060 patients aged 65 years or older, chosen randomly from centers in Norway, Estonia, the United Kingdom, France, Italy, Greece, and Spain between 2001 and 2002. Dietary intake during the previous 12 months was evaluated, which captured information about consumption of items such as olive oil, fish, wine, fruit, legumes, and meat/meat products. All patients had eye exams, including digital retinal photographs, and blood samples were collected to evaluate antioxidant levels (including lutein, zeaxanthin, carotene, and lycopene). In addition, information was collected regarding smoking and alcohol use and environmental exposure. The mean age among participants was 73.6 years, and 55% were women.

Results: The researchers found that, among the 4753 participants with full dietary data, individuals with a high adherence to a Mediterranean diet had the lowest odds of neovascular advanced macular degeneration, dropping their risk by about half.

My Take:  We cannot establish causality between consuming a Mediterranean diet and the risk of macular degeneration. In addition, self-reporting of dietary information may lead to bias. Still, given the good effects of the diet on the risk of heart attack stroke, and cancer, I am gonna go have some Italian food! I’m Dr. Michael Hunter.

New: Free apps for Android and iOS (Apple): Search My Breast Cancer by Michael Hunter. Please let me know what you think!

_________________________

The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.

References: Ophthalmology. Published online November 5, 2016; https://www.macular.org/what-macular-degeneration

Gum Disease and Cancer Risk

dental exam oral cavity white male head and neck oropharynx

New data supports the need to further investigate an association between periodontal disease and cancer risk.

Background: Previous studies have found periodontal disease is a risk factor for breast, oral, and esophageal cancers. Case-control studies have shown a link between tooth loss and the risk for esophagus and stomach cancers.

The Study: Investigators examined periodontal disease information in 65,869 women ages 54 to 86 at 40 centers in the USA. Mean age 68 years. Most were non-Hispanic whites with some college education. Participants answered this question: “Has a dentist or dental hygienist ever told you that you had periodontal or gum disease?”

The Results: This large prospective cohort study shows that postmenopausal women with a history of periodontal disease, including those who have never smoked, are at significantly increased overall risk for cancer as well as site-specific cancers, including lung, breast, esophageal, gall bladder, and melanoma skin cancers.Although periodontal disease and cancer share important risk factors (such as increased risk with increasing age and increased in smokers), this study showed that after adjustment for age, the risk of periodontal disease history and cancer persists regardless of smoking history.

My Take: This study adds to a growing body of evidence from smaller studies that link periodontal disease to total cancer risk. Oral hygiene is important not only in preventing tooth loss, but may have important implications for prevention of systemic diseases, including cancer. I’m Dr. Michael Hunter.

Cancer Epidemiol Biomark Prev. Published online 01 Aug 2017.

Available Today: Your Breast Cancer app on Android (in Search, type Michael Hunter Your Breast Cancer … and voila!)

Is Walking as Good as Running?

People who do equivalent amounts of running and walking have the same degree of benefit in terms of blood pressure, cholesterol, diabetes, and heart disease.

Background: According to CDC classification, running is a “vigorous” exercise, because runners usually end up sweaty and short of breath. They burn about eight times more energy than they would sitting on the couch. Meanwhile walking is “moderate” exercise that involves 3.8 times more energy than sitting.

 

The Study: When the 33,000 participants in the National Runners’ Health Study were compared to the 15,000 participants in the National Walkers’ Health Study, the runners appeared to have much better heart health than the walkers. Their risk of hypertension, high cholesterol, and diabetes was reduced by 38, 36, and 71 percent, respectively, regardless of how much running they reported doing. So running is not only sweatier, it’s also healthier, right?

Researchers took the data from the walkers’ and runners’ health study, and controlled for how much energy the exercisers were expending. By looking at it this way, they were attempting to compare the inherent benefits of each form of exercise. The participants, who ranged in age from 18 to 80, all reported their height, weight, diet, and the miles per week they spent walking or running. They were followed for about 6 years, during which time the researchers tracked all health problems.

Results:Regardless of whether exercise was vigorous (running) or not (walking), as long as participants used the same amount of energy, they saw more or less equivalent health benefits. Runners saw a reduced risk of hypertension, high cholesterol, diabetes, and coronary artery disease by 4.2, 4.3, 12.1, and 4.5 percent, respectively. The walkers’ risk reduction for each condition was 7.2, 7, 12.3, and 9.3 percent — amounts that didn’t differ significantly from the runners’ results. The more energy walkers and runners used, the more their cardiovascular health improved.

What Does This Mean? The key to improved cardiovascular health, according to this study, is calorie expenditure, regardless of how it’s expended. Runners aren’t healthier by virtue of being runners — they’re just more efficient in their exercising. If you prefer walking, you can be just as well off, health-wise. “Assuming a slow jogging speed of a 12 minute mile, compared to a walking speed of 17 minute miles, you would need to walk about 50 percent further to expend the same energy as running,” lead author Paul Williams explains. In terms of time, “you would need to walk for about twice as long.”

 

I’m Dr. Michael Hunter. Of course, the disclaimer: Do not begin an exercise program without input from an appropriate medical professional. Many can simply start with a brisk walk for 30 minutes daily, 5 days per week. Have a wonderful day!

References:

  1. https://www.theatlantic.com/health/archive/2013/04/study-walking-can-be-as-good-as-running/274738/?utm_source=atlfb
  2. Walking Versus Running for Hypertension, Cholesterol, and Diabetes Mellitus Risk Reduction” is published in Arteriosclerosis, Thrombosis, and Vascular Biology.