Monday, August 03, 2015
Tommy Danielson believes that the positive sample was from a contaminated supplement he was taking . (Let's assume that this former doper, who rode with Lance Armstrong, has reformed as is not lying. I tend to believe him.) Why was he taking a supplement? He likely was taking something that someone recommended as a legal way to improve his performance.
However, there is little evidence that any sports supplements actually improve performance. I haven't reviewed the literature recently. But the last time I checked, the only two supplements that had some minor evidence were: Vitamin C for prevention of colds in endurance athletes and creatine for some body builders and vegetarians who did not get it from their diet.
The supplement industry is basically unregulated. It is a multi-billion dollar industry, but a law in the United States (DSHEA) prevents the Food and Drug Administration from regulating it. Basically, the supplement companies can make any claims they want, as long as they do not say it prevents a disease. Additionally, they are not subject to inspections or quality controls, so contaminants can get into them. (I'm not clear how synthetic testosterone gets into them, but maybe it was made in the same facility as testosterone.)
So why risk taking a supplement that is not going to help you? It might get you disqualified from a race, affect your career, and could even harm you. If you have to take one, and there is solid randomized controlled evidence for it, get it tested or use one certified by USP.
What if you are not an athlete? Maybe you just hear you should take glucosamine, Vitamin D, or Vitamin C to be healthy? As I've said before, multivitamins are not helpful, and may even cause harm. The evidence is clear. STOP taking them.
One of the last hopes of the Vitamin industry was Vitamin D. There was controversy for many years with many recommending its use, despite an National Academy of Medicine report advising against. Now we finally have a good study that supplementing with Vitamin D does not help women with mild "deficiency".
Many people tell me that eating healthy is too expensive. Yet Americans spend billions of dollars a year on supplements that do little to nothing. Let's put that money into buying healthy food. Until the supplement industry can produce high quality randomized controlled trials showing that a product works, I suggest staying away from them.
Monday, June 29, 2015
- Education and advice are unlikely to be effective. Environmental change and more advanced behavior modification are more effective.
- Beverages: eliminate sugary beverages. Limit juice and encourage fruit instead. Water is the ideal beverage for kids to drink.
- Limit foods with high caloric density. (I think they got this terminology slightly wrong. Nuts, for instance, are highly caloric, but are also highly healthy. I think they should have said "limit processed food".)
- Children less than 2 years of age should not have any interaction with electronic entertainment/communication (including tablets, phones, TVs). Those older than 2 should be limited to 2 hours. (My thought: Parents might consider doing the same for themselves!)
- Kids should be active for 60 or more per day.
- Prevention should start before birth by focusing on healthy weight gain and other practices in pregnancy. (My comment: it is hard to work on "healthy habits" once women are pregnant. It is much more effective to get healthy before getting pregnant.)
Friday, June 19, 2015
One of the major studies we relied on was a Cochrane review. Cochrane reviews are the "gold standard" of evidence-based medicine. They take all the of the studies on a topic and use a standardized method to compile the evidence. The Cochrane review we relied on was just updated with new data. The results are the same. The plain language summary is:
"The review found that cutting down on saturated fat led to a 17% reduction in the risk of cardiovascular disease (including heart disease and strokes), but no effects on the risk of dying."
Let's break this down. If you replace saturated fats with other fats (but not with carbs), you will not reduce your risk of death. However, you will reduce your risk of a cardiovascular event. But here are what the numbers look like.
In the regular saturated fat group 83 people out of 1000 had Cardiovascular Events over 4.7 years, compared to 70 (95% CI 61 to 80) out of 1000 for the reduced saturated fat group.
Here is the visual for the regular group:
Saturday, February 28, 2015
I was just at the Partnership for a Healthier America conference, where lots of nutrition experts mingled with lots of food company executives. There was a lot of confusion and snickering amongst the group. Some decried the Committee for stating that how much cholesterol you eat is not that important. Others asked why saturated fat and salt were still emphasized, even though the best evidence does not support reducing these food ingredients to improve health.
The non-scientists asked the scientists why nutrition is so confusing. They made it sound like the science was constantly changing, but the guidelines committees ignored the science. I listened to this segment of NPR's Science Friday, where the host asks why the nutritionists, "have known that eggs are ok to eat, but the rest of us didn't."
Who is at fault here? I'm not sure. But I recently skimmed through my nutrition courses from when I was an undergraduate at Cornell. I went through my notes where I indicated that we were taught that is very difficult to find an association between salt and hypertension within a population. I also had copious notes stating that the connection between calcium intake and bone health was weak. (Thanks to Charles McCormick for this great class!)
I then went to my intro course table of contents and found our lecture titles: "Diet and serum cholesterol: environment or biology?", implicating that cholesterol in the diet doesn't matter that much. Another was, "Ambiguous connections: salt and hypertension". Thank you Dr. Levitsky for teaching us how to think about the facts without the hype.
The "new" news that we do not have great evidence dietary cholesterol, salt, and other nutrients are critical for health, is really not that new. I was learning it back in 1997.
So now people are telling us nutrition is confusing and that we said salt, cholesterol, and fat are bad and then good. I'm not sure where the confusion comes from. Is it from nutrition researchers who devote their careers to studying the role of one nutrient and its effect on health? Is it from journalists who love to sensationalize the latest food craze based on one study? Or is it from food companies who make so many claims about food and health, that we end up just buying whatever sounds good at the time?
I'm not going to blame one group. We are all part of the problem. But, one thing has been consistent throughout the years. This fact is summed up in this line in the new dietary guidelines report:
"Vegetables and fruit are the only characteristics of the diet that were consistently identified in every conclusion statement across the health outcomes."So just follow the simple advice to eat more (whole) fruits and vegetables. (Sorry smoothies and vegetable juices don't count.) Avoid the processed junk. That advice is probably a few generations old.
Monday, November 10, 2014
One of the most interesting measures that passed was the soda tax in Berkeley. San Francisco voters also voted in favor of the tax, but did not reach the 2/3rds majority needed to pass. (The 2/3rds threshold has to do with California law on new taxes.) Others have tried institute a soda tax. The two most notable examples were New York City and Richmond, CA. Both resulted in the American Beverage Association (ABA), an industry trade group, spending millions of dollars to defeat the measures. The ABA spent a few more million in the recent ballot initiative in Berkeley. By law, companies have a fiduciary responsibility to maintain profits for their shareholders. Thus, my conclusion is that they had to spend this money. They feared profits would decline if these measures passed.
Friday, February 28, 2014
Remember that game where you guess how many jelly beans are in a jar? Well, if I guess once, I'll probably be wrong. But if I'm allowed to guess 500 times, I might get it right once. But that doesn't mean I'm a good guesser of jelly beans numbers.
The same concept applies to research studies. The more times you test a question, the more likely you are to get a postive result. That doesn't mean that the answer to the question is "yes". It just means you guessed so many times that your were bound to get a correct answer.
The New York Times Missed this point in their article when they wrote the headline:
"Obesity Rate for Young Children Plummets 43% in a Decade"
Sounds like a huge drop. I wish it was. But the researchers tested many age groups to see if there was a decline over 10 years. They checked the age ranges 2-5, 6-11, 12-19, 20-39, 40-59, and >60. When you "guess" if there is a decrease in obesity in all of these age groups, you are likely to find one "yes".
The researchers admit this and even caution interpreting their results this way:
"When multiple statistical tests are undertaken, by chance some tests will be statistically significant (eg, 5% of the time using α of .05). "
And they conclude:
"Overall, there have been no significant changes in obesity prevalence in youth or adults between 2003-2004 and 2011-2012. "
Yet some how the New York Times missed this, and focused their headline on a minor result. While we might have made small gains against childhood obesity, we haven't really begun to change the trajectory of the epidemic.
Friday, January 24, 2014
When I saw Mrs. Obama speak last year at the PHA conference, she was really starting to emphasize that marketing is a big cause of overeating. You can provide all the "health choices" you want, but if you price the unhealthy ones lower, and have ads all over the television for them, they are going to sell more.
The new PHA agreement with Subway takes a step in the right direction. As part of the agreement, Subway will form a policy on advertising to children. (Hopefully PHA will have to approve this policy.) In addition, they will spend $41 million to advertise fruits and veggies to children. This type of advertising is badly needed to compete with the billions of dollars that advertise junk foods to kids.
So the real question is: will this get kids to eat healthier at Subway? In our study of what teenagers buy at Subway and McDonald's, we found they were eating a lot of processed food, few veggies, and a lot of calories.
My view is that the change in marketing is a positive step. But, there is still a problem with much of the food at Subway. We found that teens ate 2,149 mg of sodium in a Subway meal. That's more than 3 times what the National School Lunch Program recommends. Now, in truth, salt amounts are not very important for young kids. But the amount of salt tells us that the food at Subway is highly processed. For instance, the meat and bread have a lot of salt because they are highly processed. And we know that processed food leads to many of the problems of obesity. Notably, in the agreement they were only able to agree to 935mg of sodium in kids meals. That is more than our panel of experts and RAND recommended (700mg).
How else could we know if kids are eating healthier at Subway? I would want to know if they are eating more vegetables. I do not see any specifics in this agreement about Subway reporting how many servings of veggies they are selling to kids. PHA often does require these types of reports, but I do not see it in the press release. The best way to study this is doing what I did: collect receipts from kids and calculate what they are eating. But, it would be much easier if Subway would give vegetable sales out, so that researchers (like me) could analyze it.
What happens if they do get kids to eat more veggies, and somehow less meat and refined grains? What happens when the kids get to the cash register? For those of you who frequent Subway, you know there is a giant display of cookies. The sales clerk almost always asks, "Would you like a cookie and a drink with your sub?" Having cookies at the cash register is a risk factor for disease. So the easiest thing Subway could have done to improve health is to move the cookies to a place kids are less likely to ask for them, and parents are less likely to buy them.
I congratulate Subway and PHA for the agreement, but would like to see some objective and public research/analysis. Without this analysis, the public will not know if this is another Subway marketing scheme or an improvement in what kids are eating.