Exercise & Health

Mouse and human immune cells have demonstrated that a compound produced by the body when dieting or fasting (β-hydroxybutyrate — BHB) directly inhibits a protein, NLRP3, which is part of a complex set of proteins that drive the inflammatory response in several disorders, including autoimmune diseases, type 2 diabetes, Alzheimer's disease, atherosclerosis, and autoinflammatory disorders.

BHB is produced in response to fasting, high-intensity exercise, caloric restriction, or consumption of the low-carbohydrate ketogenic diet.

The finding helps explain why calorie restriction reduces inflammation.

http://www.eurekalert.org/pub_releases/2015-02/yu-amo021315.php

Youm, Y.-H., Nguyen, K. Y., Grant, R. W., Goldberg, E. L., Bodogai, M., Kim, D., … Dixit, V. D. (2015). The ketone metabolite β-hydroxybutyrate blocks NLRP3 inflammasome-mediated inflammatory disease. Nature Medicine, 21(3), 263–269. http://doi.org/10.1038/nm.3804

A very large British study involving 1.1 million middle-aged women without prior vascular disease has found, over nine or so years, those who performed strenuous physical activity two to three times a week were about 20% less likely to develop heart disease, strokes or blood clots, compared to participants who reported little or no activity. However, those who reported doing strenuous activity daily had higher risk compared to those who only engaged in moderate amounts of activity.

http://www.eurekalert.org/pub_releases/2015-02/aha-waa021115.php

Armstrong, M. E. G., Green, J., Reeves, G. K., Beral, V., & Cairns, B. J. (2015). Frequent Physical Activity May Not Reduce Vascular Disease Risk as Much as Moderate Activity Large Prospective Study of Women in the United Kingdom. Circulation, 131(8), 721–729. http://doi.org/10.1161/CIRCULATIONAHA.114.010296

A small study involving 15 adults with moderate-to-severe obstructive sleep apnea and 19 controls with mild or no sleep apnea has found that predicted peak oxygen uptake (VO2), a measure of aerobic physical fitness, was significantly lower in those people with moderate to severe obstructive sleep apnea. Moreover, the number of times a person stopped breathing, for 10-seconds or more, per hour of sleep, predicted 16% of the variability observed in the group's peak VO2.

People who suffer from apnea are more likely to be obese and thus would be expected to be less fit as well, but even compared to people with similar BMI, the apnea patients had a reduced aerobic fitness. It's suggested that the sleep apnea itself causes structural changes in muscle that contributes to exercise problems.

VO2 max measurements may be an early marker for those who are at higher risk of stroke and heart attack

http://www.eurekalert.org/pub_releases/2014-12/aaos-sls120114.php

http://www.eurekalert.org/pub_releases/2014-11/uoc--sal112414.php

Beitler JR, Awad KM, Bakker JP, Edwards BA, DeYoung P, Djonlagic I, Forman DE, Quan SF, Malhotra A. Obstructive sleep apnea is associated with impaired exercise capacity: a cross-sectional study. J Clin Sleep Med 2014;10(11):1199-1204.

A review of studies investigating lifestyle interventions that can delay or prevent the onset of type 2 diabetes in people with prediabetes and focusing specifically on ones that looked at gender differences, found that both men and women benefited equally from the interventions. The review of 12 studies found that those who received lifestyle interventions (including diet and exercise) were 40% less likely to progress to type 2 diabetes after 1 year, and 37% less likely to progress after 3 years.

People involved in lifestyle interventions also experienced greater weight reductions, and greater reductions of fasting plasma glucose.

http://www.eurekalert.org/pub_releases/2014-11/d-bit112614.php

Glechner, A., Harreiter, J., Gartlehner, G., Rohleder, S., Kautzky, A., Tuomilehto, J., … Kautzky-Willer, A. (2014). Sex-specific differences in diabetes prevention: a systematic review and meta-analysis. Diabetologia, 58(2), 242–254. http://doi.org/10.1007/s00125-014-3439-x

A small study involving 11 non-obese, healthy men aged 20-35, has found that blood flow in leg arteries is significantly impaired after three hours of sitting, but not if they walk for five minutes every hour.

When people sit, slack muscles do not contract to effectively pump blood to the heart. Blood can pool in the legs and affect the endothelial function of arteries, or the ability of blood vessels to expand from increased blood flow. Impaired endothelial function is an early marker of cardiovascular disease.

In the study, participants sat for three hours without moving their legs, while the functionality of the femoral artery was taken at baseline and every hour. This showed that the expansion of the femoral artery as a result of increased blood flow was impaired by as much as 50% after just one hour.

In another session, they again sat for three hours, but also walked on a treadmill for 5 minutes at a speed of 2 mph at the 30-minute mark, 1.5-hour mark and 2.5-hour mark. In this case, arterial function stayed the same throughout the session.

http://www.eurekalert.org/pub_releases/2014-09/iu-tsw090514.php

Thosar, S. S., Bielko, S. L., Mather, K. J., Johnston, J. D., & Wallace, J. P. (2015). Effect of Prolonged Sitting and Breaks in Sitting Time on Endothelial Function: Medicine & Science in Sports & Exercise, 47(4), 843–849. http://doi.org/10.1249/MSS.0000000000000479

A Czech study involving 146 people with mild to moderate risk of cardiovascular disease has found that moderate wine drinking was only protective in people who exercised.

Participants were randomly assigned to one year of moderate consumption of red wine (Pinot Noir) or white wine (Chardonnay-Pinot) from the same year and wine region of the Czech Republic. They had to keep a logbook on their consumption of wine and other alcoholic beverages, medication use, and amount and type of exercise. They were required to return the corks from the wine bottles to confirm that they had drank the wine rather than sold it.

The study was looking for a rise in HDL cholesterol, indicating a protective effect against cardiovascular disease. However, there was no change in HDL cholesterol levels by the end of the study in either the red or white wine groups. Nor did it appreciably affect blood glucose, triglycerides, or levels of inflammatory markers like C-reactive protein, although LDL cholesterol was lower in both groups while total cholesterol was lower only in the red wine group.

However, those participants who engaged in regular exercise at least twice a week did show an increase in HDL cholesterol, as well as a decrease in LDL and total cholesterol. This occurred in both red and white wine groups.

Of course, the study didn't include a control group of people engaging in regular exercise who didn't drink, so all we can really say (and it's certainly worth saying) is that moderate wine drinking doesn't seem to help protect against cardiovascular disease, and that despite all the hype around red wine, with its greater antioxidants and resveratol, there's no evidence it's any healthier than white wine.

http://www.eurekalert.org/pub_releases/2014-08/esoc-wop082614.php

http://www.theatlantic.com/health/archive/2014/09/working-with-the-wine-not-against-it/379504/

Taborsky M, Ostadal P, Petrek M. A pilot randomized trial comparing long-term effects of red and white wines on biomarkers of atherosclerosis (in vino veritas: IVV trial). Bratisl Lek Listy. 2012;113(3):156-158.

A study looking at the workout habits of more than 55,000 individuals for 15 years has concluded that running can reduce a person’s all-cause mortality rate by 30% and cardiovascular mortality rate by 45%. This equated to a difference of about three years of life.

But the really exciting news is that people who ran less than an hour each week showed the same mortality benefits compared to those who ran more than three hours in each week. Note that this is more about running, say, ten minutes every day, than only running once a week for a longer time! You don't have to run fast, either. Those running more slowly (< 6 miles/hour) got the same benefits.

Not running had about the same negative effect on life expectancy as having hypertension.

Around 24% of the participants did some running. The average age was 44.

http://www.futurity.org/even-short-slow-running-can-extend-lifespan/

Lee D, Pate RR, Lavie CJ, Sui X, Church TS, Blair SN. Leisure-Time Running Reduces All-Cause and Cardiovascular Mortality Risk. J Am Coll Cardiol. 2014;64(5):472-481. doi:10.1016/j.jacc.2014.04.058.

Telomeres are the protective caps at the ends of chromosomes that affect how quickly cells age. With age, they shorten, and as their structural integrity weakens, the cells age and die quicker. Telomere length thus is a biomarker of cellular age. Stress is also thought to shorten telomere length.

A year-long study that looked at the effects of three healthy behaviors in 239 post-menopausal, non-smoking women has found that women who engaged in lower levels of healthy behaviors showed a significantly greater telomere shortening for every major life stressor that occurred. However, stress didn't lead to greater shortening in those women who maintained active lifestyles, healthy diets, and good quality sleep.

Shorter telomeres have become associated with a broad range of aging-related diseases, including stroke, vascular dementia, cardiovascular disease, obesity, osteoporosis diabetes, and many forms of cancer.

http://www.eurekalert.org/pub_releases/2014-07/uoc--hlm072414.php

Puterman, E., Lin, J., Krauss, J., Blackburn, E. H., & Epel, E. S. (2015). Determinants of telomere attrition over 1 year in healthy older women: stress and health behaviors matter. Molecular Psychiatry, 20(4), 529–535. http://doi.org/10.1038/mp.2014.70

A Canadian study comparing neighborhoods that varied in “walkability” found that people living in neighborhoods with greater walkability had an average 13% lower likelihood of developing type 2 diabetes over 10 years, compared to those living in less walkable neighborhoods. However, walkability was only protective in those who were younger and middle aged; those who were age 65 or older saw no benefit from living in a walkable neighborhood.

Over the ten years of the study, the incidence of diabetes fell 7% in the most walkable neighborhoods, but rose 6% in the least walkable neighborhoods. Similarly, the incidence of excess weight (being overweight or obese) fell by 9% in the most walkable neighborhoods and rose 13% in the least walkable neighborhoods.

People who lived in the most walkable neighborhoods were three times more likely to walk or bicycle and half as likely to drive as a means of transportation.

The study was presented at the American Diabetes Association's 74th Scientific Session.

http://www.eurekalert.org/pub_releases/2014-06/ada-dn060214.php

A Canadian study involving 129 sedentary adults (aged 18-64) found that they tended to underestimate how hard they should be working to achieve levels of moderate and vigorous intensity while moving on a treadmill. This is despite being given commonly used exercise intensity descriptors.

The finding suggests that, while considerable thought has been given in developing physical activity guidelines, most people don't understand them well enough to use them.

For adults to achieve a moderate intensity, their heart rates should be within the range of 64-76% of their maximum heart rate and between 77-83% for vigorous intensity, according to the Canadian and global physical activity guidelines.

http://www.eurekalert.org/pub_releases/2014-06/yu-moe061614.php

Canning KL, Brown RE, Jamnik VK, Salmon A, Ardern CI, Kuk JL (2014) Individuals Underestimate Moderate and Vigorous Intensity Physical Activity. PLoS ONE 9(5): e97927. doi:10.1371/journal.pone.0097927