To Delay Death, Lift Weights

Strength training is good for you. Photo from Studio Firma/Stocksy.






Two relatively new papers offer some eye-opening insights into the benefits of strength training, even for people who consistently blow the aerobic exercise guidelines out of the water.

The first is an analysis of the link between strength, muscle mass, and mortality, from a team at Indiana University using data from the National Health and Nutrition Examination Survey. The design was pretty straightforward: They assessed 4,440 adults ages 50 or up who had their strength and muscle mass assessed between 1999 and 2002. The researchers checked back in 2011 to see who had died.

For muscle mass, they used a DEXA scanner to determine that 23 percent of the subjects met one definition of “low muscle mass,” with total muscle in the arms and legs adding up to less than 43.5 pounds in men or 33 pounds in women. For strength, they used a device that measures maximum force of the knee extensors (the muscles that allow you to straighten your knee) and found that 19 percent of the subjects had low muscle strength.

The results, published in Medicine and Science in Sports and Exercise, found that those with low muscle strength were more than twice as likely to have died during the follow-up period than those with normal muscle strength. In contrast, having low muscle mass didn’t seem to matter as much

The message here? Function matters more than what you look like. That doesn’t mean you can afford to let your muscle melt away as you age; having a good reserve of muscle mass may be important, for example, if you end up having to spend time in the hospital at some point. But it’s good news for those of us who struggle to put on muscle but persist in slogging through a reasonable number of pull-ups and other strength exercises.

The other study took aim at the perception that strength training is an afterthought in public health guidelines. Most of us remember that we’re supposed to get at least 150 minutes of moderate exercise or 75 minutes of vigorous exercise per week. Reams of data support the beneficial health effects of hitting this goal.

But the guidelines also suggest doing “strength-promoting exercise” at least twice a week—a clause that’s often forgotten and the benefits of which are usually framed in terms of avoiding frailty and improving quality of life, rather than actually extending it.

Researchers in Australia analyzed data from 80,000 adults in England and Scotland who completed surveys about their physical activity patterns starting in the 1990s. The headline result was that those who reported doing any strength training were 23 percent less likely to die during the study period and 31 percent less likely to die of cancer. Meeting the guidelines by strength training twice a week offered a little extra benefit.

One interesting (and, for me, reassuring) detail: Strength training in a gym and doing body weight exercises seemed to confer roughly equivalent benefits. So you don’t necessarily need to heave around large quantities of iron.

There’s some evidence that strength training may reduce blood pressure but increase artery stiffness, effectively canceling out the heart benefits. This study can’t answer that question, but the findings do suggest that ditching aerobic exercise entirely may not be optimal. And indeed, the best outcomes of all—a 29 percent reduction in mortality risk during the study—accrued to those who met both the aerobic and strength-training guidelines.

So, in summary, strength training is good for you. Does that really tell you anything you didn’t know? Perhaps not.

Read the complete article in Outside here.

















Obesity, a wider understanding


All calories do not seem to be created equal, and the way the body processes the same calories may vary dramatically from one person to the next.

This is the intriguing suggestion from the latest research into metabolic syndrome, the nasty clique that includes high blood pressure, high blood sugar, unbalanced cholesterol and, of course, obesity. This uniquely modern scourge has swept across America, where obesity rates are notoriously high. But it is also doing damage from Mexico to South Africa and India, raising levels of disease and pushing up health costs.

A study published in Nature Communications by Richard Johnson, of the University of Colorado, explains that glucose may do its harm, in part, through its conversion to fructose.

Dr. Johnson and his colleagues administered a diet of water and glucose to three types of mice. One group acted as a control and two others lacked enzymes that help the body process fructose. The normal mice developed a fatty liver and became resistant to insulin. The others were protected. The body’s conversion of glucose to fructose, therefore, seems to help spur metabolic woes.

Jeffrey Gordon, of Washington University in St Louis, found four pairs of human twins, with one twin obese and the other lean. He collected their stool, then transferred the twins’ bacteria to sets of mice. Fed an identical diet, the mice with bacteria from an obese twin became obese, whereas mice with bacteria from a thin twin remained lean.

Dr. Gordon then tested what would happen when mice with different bacteria were housed together—mouse droppings help to transfer bacteria. Bacteria from the lean mice made their way to the mice with the obese twin’s bacteria, preventing those mice from gaining weight and developing other metabolic abnormalities. But the phenomenon did not work in reverse, probably due to Dr. Gordon’s theory on the microbiota’s job vacancies. Interestingly, the invasion did not occur, and obesity was not prevented, when the mice ate a diet high in fat and low in fruits and vegetables. The transfer of helpful bacteria therefore seems to depend on diet.

Read the full article on The Economist.

Most Canadians not informed about GMOs, experts say


Trinity, 4, holds up an anti-genetically modified alfalfa during a demonstration outside the St. Lawrence Market in Toronto. While farmers and other interest groups rally against genetically modified organisms, does the average Canadian consumer really care what’s in their food? (John Rieti/CBC)

Thousands of products in Canada’s food chain contain some form of a genetically modified item or GMO’s — and because there are no mandatory labelling requirements, it’s difficult for consumers to know which ones do.

Ottawa has approved over 80 types of GM crops, including corn, canola, soybeans and wheat. Products that contain any of these items, including most processed and packaged foods, likely contain genetically modified ingredients. Many meats are also affected, since animals are often fed GM crops.

In fact, a survey conducted last year by the B.C. Growers’ Association found that 76 per cent of Canadians feel that the federal government hasn’t given them enough information on GM foods. Another nine per cent said they’d never even heard of GM foods.

Registered dietitian Christy Brissette, is working on a masters in nutrition at the University of Toronto.

“I think a lot of people have seen what happened in Europe, with a lot of lobbying to European governments demanding that these foods be labelled so that consumers can then make educated choices,” Brissette says. “I think Canadians want that same kind of transparency.”

In 2002 Canadians were cautioned about GMO’s. In an attempt to quell the growing public concern over GM food, the federal government commissioned a report from the Royal Society of Canada, the country’s top scientific body. A year later their report is out and the CBC’s Bob McDonald talked to Brian Ellis, the associate director of University of British Columbia’s Biotechnology Laboratory and co-chair of the report. The society blasts Canada’s approach to regulating GM food, concluding that government’s assumption that GM food is the same as conventional food is scientifically unsound.

• The Royal Society of Canada’s report, Regulation of Food Biotechnology of Canada, made over 50 recommendations. Some of the key suggestions include:
– testing of GM foods should be conducted in a transparent and open environment
– the outcome of all tests are to be monitored by an independent expert panel who report to the public
– clearer definitions of the types of toxicological studies required to ensure the safety of GM foods.

• The Royal Society of Canada was founded in 1882 to promote learning and research in the arts and sciences. The society has 1,700 distinguished Canadian scientists and scholars who have been recognized by their peers for their outstanding contributions.

• A 2004 study, authored by Dr. Peter Andrée of Trent University and the Polaris Institute, concluded that the Canadian government has failed to respond seriously to the 58 recommendations made by the Royal Society of Canada. The study accused the Canadian government of dawdling and being unwilling to butt heads with the powerful biotech industry.

Link to CBC News articles: 1, 2, 3, 4. Place mouse over number to see article subject.