nutrition

New evidence on smoking and pregnancy

November 8, 2012 By sh648 2 Comments

It’s no secret that smoking is bad for your health – and, for pregnant women, has serious impacts on the health of their unborn babies. Smoking during pregnancy not only increases the chance for early labor and miscarriage , but also lowers the unborn baby’s heart rate, limits the oxygen he receives, , and increases his risk of lung disease later in life.

Now there is new evidence that provides pregnant mothers with one more reason to avoid smoking: A new systematic review published in the British Medical Journal found that children whose mothers smoked during pregnancy were more likely to be overweight.

The analysis reviewed a total of 30 prospective studies to identify factors during pregnancy and infancy that led to obesity in childhood. Children whose mothers smoked during pregnancy were 47% more likely to be obese.

The review also found that children were significantly more likely to be overweight if their mothers were overweight before giving birth, or if they were fed solids before they were 4 months old.

There were also some factors that seemed to protect against childhood obesity. Breastfed babies were 15 percent less likely to be overweight in childhood. Babies who gained weight more slowly during infancy were also significantly less likely to become overweight as children.

The review offers some solid guidelines for mothers during pregnancy and while caring for young infants. The authors also noted medical professionals could use the findings to develop screening guidelines for pregnant mothers and young babies.

The bottom line: Nutrition and health during pregnancy and infancy has an important impact on a child’s health and well-being.

Filed Under: Evidence-Based Living, Health and Wellness Tagged With: children and youth, food and nutrition, Health and Wellness, nutrition, parenting, research translation

The evidence on super-sized soft drinks

October 26, 2012 By sh648 1 Comment

Next year, New York City residents must say good-bye to their super-sized sodas and Double Big Gulps. Beginning in March, the city will limit to 16 ounces the size of soft drinks sold at restaurants, street carts, movie theaters and sporting venues. The New York City Board of Health passed the proposal last month in an effort to reduce the consumption of sugary drinks thought to contribute to the nation’s obesity epidemic.

But what evidence do we have about sugary soft drinks and weight gain and harm our health? We know that sugar-sweetened drinks account for nearly half of the total added sugars Americans consume and 7 percent of our total calories. But what impact does that have on our health?

New York Times writer Jane Brody also provides an overview of some of the evidence on this topic in her column this week. There are also several systematic reviews that tell the story:

A 2007 meta analysis in the American Journal of Public Health reviewed 88 studies that examined the association between soft drink consumption and nutrition and health outcomes. The analysis found consuming soft drinks led to increased energy intake and body weight, and was associated with lower intakes of milk, calcium, and other nutrients. It also found an association between soda intake and diabetes.
Another systematic review, published in the American Journal of Clinical Nutrition in 2006 – which included 30 cross-sectional, prospective and experimental studies looking at the relationship between sugary soft drink consumption and weight gain – concluded that sugary soft drinks are associated with weight gain and obesity.
A third review published in Cambridge University’s Nutrition Research Reviews in 2008 came up with inconclusive results. The review examined 44 epidemiological studies and interventions and six meta-analyses – all looking at the relationship between sugary soda consumption and obesity. The author concluded that while sugary soft drinks are a source of calories, there is little evidence that they cause more weight gain than other sources of calories. He said the impact of sugary sodas on weight gains depends on variables including how much soda is consumed each day and the formulation of the specific drink. His review also concluded that consuming large amounts of sugary soft drinks on a daily basis is most directly associated with weight gain.

So, did the New York City Board of Health make an evidence-based decision in limiting sugary soft drink sizes? I think the answer is yes. While there is some mixed data on the association of soft drink consumption and weight gain, the evidence makes it abundantly clear that consuming large amounts of soda is the major problem. By limiting soft drinks sizes, the City is essential legislating the old adage, “Moderation in all things.”

Filed Under: Evidence-Based Living, Health and Wellness, In The Media Tagged With: behavior change, evidence-based practice, food and nutrition, Health and Wellness, nutrition, policy

The evidence on arsenic and rice

October 9, 2012 By sh648 2 Comments

The magazine Consumer Reports released a study last month that revealed low levels of arsenic – a chemical element that is toxic when consumed in higher doses – in rice and rice products grown across the world.

The study tested 223 types of rice and rice products – such as rice-based cereals and rice milk – purchased in the United States in April, May and August of this year. It found arsenic in every product it tested, and dangerous levels of inorganic arsenic in dozens of products. Consumer Reports the story points out that their study is “a spot check of the market and “too limited to offer general conclusions about arsenic levels in specific brands within/across rice product categories.” Nevertheless, their article raises some surprising questions about toxins in our food supply.

Following the Consumer Reports study, the U.S. Food and Drug Administration released some preliminary results of a long-term study on arsenic levels in our food supply. Their study found levels of arsenic in rice similar to the Consumer Reports study.

So, what’s a rice-lover to do? Consumer Reports recommends limiting consumption of rice and rice products, while the FDA is not recommending any limits on rice consumption.

Since the FDA and Consumers Reports found the same level of arsenic in food, the question in my mind is: Exactly how dangerous is low-level exposure to arsenic? A search of systematic reviews yielded some interesting results.

One meta-analysis found consuming arsenic in drinking water is associated with a higher risk of lung cancer.
Another analysis found chronic arsenic exposure can lead to mental retardation and developmental disabilities such as physical, cognitive, psychological, sensory and speech impairments – although in higher levels that measured in the rice products tested by Consumer Reports and the FDA.
Other analyses found inconclusive results on the relationship between arsenic exposure and diabetes and arsenic exposure and cardiovascular disease – although both of these reviews identified limitations in the study methodology and called for additional research.

My plan is to think more carefully about the rice products my family consumes. I’m not going to throw out the brown rice in my pantry, and we will still enjoy stir fry and sushi on a regular basis. But I certainly plan to steer way from rice cereals and other rice products at the grocery store.

Filed Under: Evidence-Based Living, Health and Wellness, policy Tagged With: agriculture, evidence-based practice, food and nutrition, Health and Wellness, nutrition, policy, research translation, science in the media

What we know – and what we don’t – about Omega-3 fatty acids

October 4, 2012 By sh648 2 Comments

Over the past four decades, there have been thousands of studies examining the health benefits of Omega-3 fatty acids – building blocks our bodies use to create cell membranes and maintain the connections between brain cells.

The medical community’s excitement over this nutrient began when observational studies of non-western diets – in Japan and among Eskimos in Greenland, for example – found significantly lower rates of heart disease and other chronic medical conditions. (Humans can’t produce omega-3 fatty acids, so we must get them by eating fish, walnuts, flaxseed and green vegetables.)

Dozens have studies have identified these types of correlations. But earlier this year, a meta-analysis published in the Journal of the American Medical Association, which included 20 clinical trials involving nearly 70,000 people, concluded omega-3 fatty acids did not prevent heart attacks, strokes or deaths from heart disease.

Proponents of omega-3s point out that the authors of the JAMA analysis used the an especially strict standard to determine statistical significance. (Using the typical standard would have found a 9 percent reduction in cardiac deaths.)

But other systematic reviews – like this one by the Cochrane Collaboration – found it unclear whether omega-3 supplements reduce the risk of cardiac deaths.

So, what’s the bottom line? This is one case where the evidence is truly unclear. One challenge is that longitudinal diet studies are difficult to perform because there are so many variables in what people eat over long periods of time. The it can be tough to differentiate between omega-3s consumed as part of a diet versus those taken in a supplement. It is clear that foods like salmon, tuna and green vegetables are good for us – and including them in our diets is a step in the right direction. But we need more evidence to determine their exact effects, and to establish whether it’s worthwhile to take omega-3 supplements.

Filed Under: Cornell Cooperative Extension, Evidence-Based Living, Health and Wellness Tagged With: evidence-based practice, food and nutrition, Health and Wellness, nutrition, research methods

Slimming it down? New evidence on low-calorie diets

September 4, 2012 By sh648 5 Comments

Over the past few years, you may have heard the buzz about the potential for a low-calorie diet to prolong life and prevent chronic medical conditions like heart disease and cancer.

While the concept of restricting calories has been around for decades, a longitudinal study of monkeys published in 2009 seemed to provide definitive evidence that eating less was good for you. The study by researchers at the University of Wisconsin found a diet of moderate caloric restrictions over 20 years lowered the incidence of aging-related deaths and reduced the incidence of diabetes, cancer, cardiovascular disease, and brain atrophy.

But last week, a new longitudinal study of different species of monkey raised questions about the idea of restricting calories to improve health. The study included 121 monkeys split into two groups. The experimental group was fed 30 percent fewer calories than the control group.

In the study published last week, which was sponsored by the National Institute on Aging, the monkeys on restricted diets did not live any longer than those with normal diets. Rates of cancer and heart disease were the same for monkeys on restricted diets and normal diets. While some groups of monkeys on restricted diets had lower levels of cholesterol, blood sugar and triglycerides, they still did not live longer than the monkeys who ate normally.

The study is interesting from a health perspective because it raises questions about the notion of restricting calories to improve health. But it’s also a prime example of why it’s important to collect data from more than one study.

“This shows the importance of replication in science,” Steven Austad, interim director of the Barshop Institute for Longevity and Aging Studies at the University of Texas Health Science Center, told the New York Times. Austad, who was not involved in either study, also explained that the first study was not as conclusive as portrayed in the media.

The take home message: It’s important to collect evidence from multiple studies before drawing conclusions, even when the data seems extremely convincing.

Filed Under: Evidence-Based Living, Health and Wellness Tagged With: alternative treatments, food and nutrition, Health and Wellness, nutrition, research methods, science in the media

New evidence: Vitamin D helps prevent falls

August 9, 2012 By sh648 1 Comment

Vitamin D is one of those supplements that makes it into the news media frequently. Here on EBL, we’ve written before about the U.S. Institute of Medicine’s recommendations on Vitamin D intake.

Now there is a new recommendation that taking Vitamin D supplements can help prevent falls in people over 65 years old with a higher risk of falling.

In a review of nine separate studies, the United States Preventative Services Task Force came to the conclusion a daily dose of 800 international units reduced the risk of falling by about 17 percent, compared with those who did not take the vitamin.

“The exact mechanism is not known, but it seems to help muscle strength and balance,” Dr. Al Siu, vice chairman of the task force and chairman of the geriatrics and palliative medicine department at Mount Sinai School of Medicine, told the New York Times.

The panel also made two other recommendations. Doctors should do a comprehensive assessment of patients’ risk of falling – including asking about falling history and observing patients stand up and walk – to identify those at higher risk. And patients’ should exercise to improve strength and balance.

Falls are the leading cause of injury in adults 65 and older. While there’s no sure-fire way to prevent them, we have evidence that some interventions do work. That’s important information for all of us to know.

Filed Under: Evidence-Based Living, Health and Wellness, policy Tagged With: aging, alternative treatments, evidence-based practice, food and nutrition, Health and Wellness, nutrition

Evidence-based Olympics, Part II: The facts on fitness products

August 7, 2012 By sh648 Leave a Comment

We’ve all seen the advertisements of the sweaty, exhausted athlete pausing to take a sip of a brightly-colored drink and then going on to score the winning goal or set a personal record. Magazines and web sites – especially in these days when Olympic athletes dominate the news – are filled with fitness products that supposedly make you perform better or recovery more quickly. But are any of those claims true?

A group of researchers at the University of Oxford set out to answer that exact question. They analyzed magazine advertisements and web sites of 104 different fitness products looking for real evidence behind their claims. Then they wrote to manufacturers of fitness products asking for references to research that backed up their claims.

But their study did not find much credible evidence. More than half of the web sites they reviewed did not provide any references. They did find a total of 146 specific references to study, but they were only able to find 76 studies to review.

None of the studies they found were systematic reviews. Eighty-four percent were judged to be of high risk-bias, and only 58 percent used randomization. In total, only three of the studies were judged to be high quality.

The study was thoroughly reported on in the New York Times, along with responses from beverage manufacturers and from health and nutrition experts not involved in the study.

Politics aside, there is a clear lack of evidence about whether performance-enhancing products really work.

Filed Under: Evidence-Based Living, Health and Wellness, In The Media Tagged With: evidence-based practice, Health and Wellness, nutrition, science in the media

Bodyfat facts: Real evidence on the consequences of obesity

June 14, 2012 By sh648 2 Comments

We often hear in the media – this blog included – that obesity is an epidemic in the United States, and move straight to discussing solutions to the problem. But lately I’ve found myself wondering, what exactly are the health consequences of being overweight or obese?

So, of course, I went on a hunt to find some evidence. It turns out there are many. The Harvard School of Public Health provides a great summary of the health risks of obesity with references – many of them systematic reviews.

Their summary finds obesity associated most strongly with the diabetes and cardiovascular disease. Meta-analyses have found significantly greater risks of developing coronary artery disease, stroke and cardiovascular death.

While the link between obesity and cancer is less clear, there is certainly still ample evidence that shows obesity is a risk factor for developing cancers. A major review of the data by the World Cancer Research Fund and the American Institute for Cancer Research found evidence of an association between obesity and cancers of the esophagus, pancreas, colon and rectum, breast, endometrium, and kidney, and a probable association between obesity and gallbladder cancer. Since the report was released in 2007, the group is providing continuous updates about the evidence on diet, physical activity, body fatness and cancer.

There are other serious risks that come along with obesity: depression, dementia, infertility, asthma and arthritis.

I have to say that, personally, I was astounded by the sheer volume of evidence out there on the consequences of obesity. I know my fair share of people who are overweight. Reviewing the evidence bring their struggles into a whole new light for me. It doesn’t seem like you can live with obesity without some health consequence.

I did find one silver lining though. There is some pretty clear evidence in this report from the National Heart Blood and Lung Institute that losing some weight – even without reaching an ideal weight – offers some health benefits for adults who are obese. The clear take-home message here is to do what you can – eat more fruits and veggies, go for a walk, cut out junk food – to move toward a healthier weight.

Filed Under: Evidence-Based Living, Health and Wellness Tagged With: behavior change, Health and Wellness, nutrition

Disney takes its cues from the evidence

June 11, 2012 By sh648 Leave a Comment

In major news this week, the Walt Disney Co. banned the advertising of junk foods from its television, radio and Internet programming. Under the new guidelines, advertisers who want to promote food and beverages on Disney programming for children must meet guidelines on serving size, calories, and fat and sugar content.

While it’s inspiring that such a large company is interested in promoting health among kids, I was even more inspired that Disney created a policy based on real evidence. Because, in fact, there is a growing body of evidence that links media consumption – and specifically advertisements – with negative health outcomes for children.

This systematic review, for example, looked at 173 studies examining the relationship between media consumption and health outcomes among children. In 80 percent of the studies, more media exposure was associated with a negative health outcome, and childhood obesity had the strongest correlation. This analysis considered the quantity of media that children watched, but not the content.

Another meta-analysis found a significant association between the proportion of children overweight and the number commercials per hour on children’s television, especially ads that promoting junk foods. The study used data from surveys of advertising on children’s television and estimates of the prevalence of overweight among children, in the U.S., Australia and eight European countries. It concluded the quantity and content of advertising on children’s television programs has a specific effect on children.

It’s great to see a major company taking cues from the evidence in an effort to improve the health of children!

Filed Under: Evidence-Based Living, Health and Wellness, policy Tagged With: children and youth, food and nutrition, Health and Wellness, nutrition, policy, science in the media

The buzz on red meat

March 20, 2012 By sh648 3 Comments

Last week, the headlines on meat consumption were inflammatory to say the least.

The Los Angeles Times: All red meat is bad for you, study finds Fox News: Red meat linked to premature death, research finds
The BBC: More Red Meat, More Mortality
The New York Times: Red Meat Increases Death, Cancer and Heart Risk

The researchers, from the Harvard School of Public Health, followed the diets and health outcomes of 37,000 men and 83,000 women over more than two decades. The found those who ate protein sources other than red meat were more likely to live longer. But what’s really at work here?

I found several systematic reviews on red meat consumption that give a broader look at this issue.

One published in the journal Circulation found 20 case-controlled studies and randomized controlled trials that assessed the effect of red meat consumption on health and concluded that eating processed meats, but not red meat, is associated with higher incidence of heart disease and diabetes.

Another review looked at the link between red meat consumption and colorectal cancer, and found eating red meat on a daily basis is associated with an increased risk of colorectal cancer and eating processed meats regularly is associated with an even higher risk of colorectal cancer.

And a third review found little evidence available on the links between red meat consumption and stroke risk.

As much as I love a good burger or juicy steak, the available evidence shows that eating red meat regularly is bad for your health. It is worth noting ,though, that in each study, the conclusions were drawn based on participants consuming red meat every day.

Personally, I’m going to stick with my motto of everything in moderation, and still enjoy a nice cut of beef once in a while.

Filed Under: Evidence-Based Living, In The Media Tagged With: evidence-based practice, food and nutrition, Health and Wellness, nutrition, research translation, science in the media

The body of evidence on chocolate and heart disease

March 15, 2012 By sh648 2 Comments

If you regularly read any health or wellness publications, you’ve likely heard the assertion that chocolate is good for you – usually phrased something like this: “Thinking about skipping dessert? Think again. A new study shows that chocolate is actually heart-healthy.”

But what does all of the evidence say about chocolate? Is it really good for your health? A systematic review published in the Journal of Nutrition has found that, yes, chocolate is really good for your health.

The review looked at the effect of flavonoid-rich cocoa on all cardiovascular risk factors such as blood pressure, cholesterol and insulin sensitivity. It also evaluated the dose-response relationships between cocoa and cardiovascular risk factors.

The review included a total of twenty-four studies with 1,106 participants. It found that chocolate had positive effects on a number of cardiovascular risk factors – blood pressure, insulin resistance, lipid profiles and cholesterol.

While that’s good news for dessert-lovers far and wide, there was a limitation of the available evidence – the studies only looked at benefits over the short-term – days or weeks. The review concluded with a call for long-term investigations into effects of cocoa on the heart.

In the meantime, you can still pass the chocolate to me.

Filed Under: Evidence-Based Living, Health and Wellness Tagged With: evidence-based practice, food and nutrition, Health and Wellness, nutrition, science in the media

How your working environment impacts your health

March 6, 2012 By sh648 Leave a Comment

Adopting a healthy lifestyle can be tough these days, especially for parents working hard to make ends meet. Yes, there are gyms and organic grocery stores, on-demand yoga and healthy cooking magazines. But for working parents, long hours and irregular schedules make can make it difficult to eat healthily and exercise.

A cadre of researchers are Cornell’s College of Human Ecology are working on this problem, conducting the research and pulling together the best evidence to help families exercise more and eat healthier.

Among them is nutritional sciences professor Carole Devine, who has created and evaluated a program that helps change workplace environments to support physical activity and healthy eating.

The program, called Small Steps are Easier Together, is an active collaboration between Cornell faculty, Cooperative Extension educators and worksite leadership teams across New York. Pilot studies have been conducted in 23 sites since 2006. It involves worksites creating wellness leadership teams, who work with Cornell researchers to implement evidence-based strategies – like creating walking groups, posting maps, and offering more fruit and vegetable options in the cafeteria – to increase walking and promote healthier eating.

The most recent analysis of the program included 188 participants in 10 rural worksites. It found the percentage of sedentary women had declined to from 42 percent to 26 percent. A total of 35 percent of the women moved to a higher activity level.

Devine is also pulling together the evidence on how working conditions impact food decisions for families at home and on the job.

Her research has found that the stress of a busy job impacts parents’ ability to serve healthy meals, leading them to serve quicker and less healthy meals, such as fast food. She’s investigated a variety of coping strategies such as negotiating a more flexible work schedule and teaming up with a neighbor to take turns preparing meals.

Devine’s work highlights the connections between work environments and health, and provide some evidence-based strategies to improve public health.

Filed Under: Cornell Cooperative Extension, Evidence-Based Living, Health and Wellness Tagged With: behavior change, Cooperative Extension programs, environment, evidence-based programs, food and nutrition, Health and Wellness, intervention research, nutrition, parenting, research translation, social trends