Dietary Supplements

September 24, 2013 by  
Filed under Consumer awareness, Supplements

I hope that you enjoyed Jamie’s post about protein supplementation last week. As a follow up, I thought it would be helpful to share some information about dietary supplements in general. Do some dietary supplements work? Yes. Are some dietary supplements dangerous? Yes. How should you proceed? Well, it depends. Here’s some food for thought.

Dietary supplements vs. drugs

Dietary supplements include vitamins, minerals, amino acids, enzymes, herbs, animal extracts, and probiotics. Similar to drugs, they come in the form of pills, gel capsules, liquids, and powders. But unlike drugs, dietary supplements are NOT regulated for safety or effectiveness by the Food and Drug Administration (FDA) before they go to market. Thanks to the Dietary Supplement Health and Safety Education Act (DSHEA) passed in 1994, the FDA is only responsible for taking action against unsafe dietary supplements after they reach the market.1

Remember Fen-Phen? Ever heard of Metablolife 356, Lipokinetix, or Hydroxycut?  These are all dietary supplements that were banned by the FDA because they contained dangerous ingredients. Banned, yes, but only after confirmed cases of liver failure, seizures, cardiovascular problems, and deaths.

How can I find a safe dietary supplement?

The first step is to look for the United States Pharmacopoeial Convention (USP) seal of approval. The USP is a non-government organization that tests dietary supplements for authenticity, strength, dissolvability, weight, and packaging. USP verification is a voluntary process for supplement manufactures, but may provide peace of mind for concerned consumers.

Consumer Labs is another organization to consider. They test dietary supplements similar to the USP, then post their results to a subscription-based website:

Figure 1. USP and Consumer Labs labels.

USP and CL jpeg

The second step regarding safe dietary supplement usage is to limit your expectations. If a supplement claim sounds too good to be true, it likely is. Don’t expect a magic pill to make you faster, stronger, bigger, smaller, longer, thinner, smarter, etc.  A daily multivitamin/mineral supplement can never replace the benefits of a healthy diet and lifestyle.

The third step is to dismiss the well-known adage “If one pill is good, then two are better, and three must great”. Look for vitamin and mineral supplements that provide no more than 100-200% of the Recommended Dietary Allowance (RDA). It’s an indisputable fact that chronic nutrient deficiencies negatively affect health, but 5000% of the RDA of a given nutrient will not make you 5000% healthier.  Besides, if you eat any amount of real food you are bound to consume some percentage of the RDA.  Combine this with a daily multivitamin/mineral supplement containing 100% of the RDA and you are assured of getting your needs met. Another idea to take a multivitamin/mineral supplement only every other day.

Take home message

First, ask yourself if you truly need a dietary supplement. What does it depend on for you (diet, lifestyle, finances, etc.)? If you do decide that a supplement is in your best interest, then the take home message  is “buyer beware”. Or at least be aware. Look for the USP seal of approval and avoid supplements containing more than 200% of the RDA. Also, if you are pregnant, lactating, or taking prescription medications, please consult with your physician before consuming any type of dietary supplement.


Does Protein Supplementation Build Muscle?

September 18, 2013 by  
Filed under Protein

Many personal trainers and exercise gurus recommend protein supplementation to build muscle. Their recommendations usually suggest ingesting a bolus of protein (perhaps 25-40 g) after a workout. They will cite anecdotal reports of enhanced muscle building and increased strength following this regime. Some noted health authorities, famous athletes and celebrities may also endorse protein supplementation and be employed by companies that make protein-enriched food products. As scientists however, we need to know what properly controlled, peer-reviewed research has to say about this topic.

Some basic considerations are useful to clarify the issue of protein supplementation. First, do most people get enough protein in their diets? If not, then protein supplementation would seem to be promising. Second, do athletes need more protein in their diets than the RDA and if so, do most athletes consume enough protein from regular foods to support activity and muscle building? Third, does increasing protein intake support muscle growth, and if so, when should extra protein be consumed, before, during or after a workout? And lastly, if one consumes more protein, do the amino acids produced from protein breakdown preferentially travel to muscle and improve muscle physiology?

Nutrition scientists have considered these issues in detailed investigations using animal models and in human clinical trials. It turns out that most individuals in the U.S consume more protein than the RDA. Studies have shown that athletes have higher demands (up to 2-2.5 times higher) for dietary proteins, especially strength and endurance athletes, but since they consume more calories each day, they can usually meet protein needs by consuming a normal, varied diet. Concerning protein increasing muscle mass and strength, studies have shown that exercising (i.e. using) muscles increases these parameters and that increasing protein intake alone will not have the desired effects. There is evidence however, that a modest amount of protein consumed during or after a vigorous workout (as part of a long term resistance-type training program) will enhance muscle repair and could have some effect on muscle mass and strength (Am. J. Clin. Nutr. 96(6): 1454-64, 2012). It is however important to keep in mind that if protein is consumed in excess of energy need, it will ultimately be metabolically converted into triglycerides and stored in adipose tissue.

Given these facts, do you think consuming excess protein is going to have a positive influence on your athletic abilities? Could consuming excess protein before or after a workout have a placebo effect? What about if one is a vegan? Do vegans have higher protein requirements? Are vegan diets typically lower in protein content? Does decreasing carbohydrate intake and substituting protein sound like a sound strategy to improve athletic performance? Why or why not? These are all important issues that should be considered as one develops a diet that supports athletic performance and maximizes muscle strength and endurance.

It Depends

September 16, 2013 by  
Filed under General

“What should I eat?”

This is, without a doubt, the most common question that I hear as a college nutrition professor. It’s a wonderfully simple question with a surprisingly simple answer. In fact, over the years I’ve taken to offering students in my class an automatic “A” if they can answer this question in just two words or less. Think about it! Any takers?

The answer is… it depends. That’s it. No fancy jargon, no expensive advertising campaigns, and no proprietary formulas. Most importantly, no false assumptions that what works for a Hollywood celebrity or your best friend’s second cousin will work for you. “It depends” recognizes that everybody’s body and needs are different. There are of course good general nutrition guidelines to consider, like the food guide pyramid or, but ultimately what you should eat is unique to you.

What does it depend on?

For starters, it depends on who you are and what your needs are. Are you young or old, male or female, active or sedentary? For example, a young child’s needs are quite different from an older adult, just as an elite athlete’s needs are different from a couch potato.

What you should eat also depends somewhat on your family history. If your genes are prone to chronic diseases like heart disease, diabetes, or cancer, you may want to consider how certain foods increase or decrease your risk. For example, alcohol in moderation may help decrease heart disease risk for some individuals, but it may increase cancer risk for others. It’s up to you (and your doctor) to weigh the pros and cons of various dietary interventions. And even then there is unlikely to be just one “right” diet.

Lastly (but certainly not least), be sure to factor in life factors like your financial status, religious and moral beliefs, geographical location, season, time of day, habits, personal desires, etc. What can you afford to eat? What do you have access to eat? What do you like to eat? How do school, work, and/or family responsibilities influence your eating decisions? No diet in the world will be successful long term if it’s not realistically aligned with these factors.

Think critically

Sorry, it turns out that the answer to “What should I eat?” is not so simple after all! Take heart though, this blog isn’t meant to confuse you. Rather it’s meant to encourage and empower you. Encourage you to think critically about the latest nutrition fad or discovery, and empower you to make smart food choices based on your own needs and desires. Over the course of the next month/term/year I hope that you will learn a lot from this blog. I also hope that after each post you will pause and reflect about how the information relates directly to you… What does it depend on for you?