Monday, June 8, 2009

Why Dietary Supplements Fall Short

This weekend, I was talking to someone about dietary supplements. I usually say "most are a waste of your money." But still, they sell very well. People continue to think that they can make a difference in their health. Part of it is convincing marketing. The other part is the desire of the consumer to find something to help them.

My stance continues to be, eat whole foods, as unprocessed as possible (think of the perimeter of the grocery store). If the food or food-like item has a health claim, put it back. A supplement would only be justified if you suffered a deficiency due to a disease or genetic disorder. In which case, refer to your physician. Here are three reasons why you don't want to spend your money on supplements:

  1. Food is greater than the sum of its nutrients-Just about all supplements are one or a couple nutrients that have been researched in a test tube or a rat. However, when a population study (a good scientific study, which a lot are not) is conducted, there usually appears not to be any benefit. Or, sometimes there is the opposite effect. The issue is that our bodies have developed and functioned well on whole foods, filled with many, many nutrients, minerals, and compounds- maybe hundreds. It may not be just one nutrient that helps people, or the nutrients are absorbed better in their natural form. The bottom line is, whole foods offer so much more nutrition than a number of supplements. Also, high levels of a certain nutrient (like Vitamin E) may not help any more than simply adequate intake of that nutrient.
  2. Supplements are used as insurance- The typical American diet is pretty bad. I think we all are aware of that. Processed foods are everywhere. So, taking a supplement after eating a Twinkies, Kit Kat bar, Big Mac, fries, and a Coke is not really balancing the nutrition scale. You may view the supplement as a way of giving your body the nutrients that you didn't get from your food. But, you still ate the foods with chemicals, preservatives, sugar, and trans-fats. That stuff is in your body, causing problems (raising insulin levels and triglycerides, leaching out vitamin C, etc.). You are also replacing nutrient-rich foods with processed foods.
  3. Placebo Effect- I am amazed how dramatically some people claim to feel when they start taking a supplement. Once a client informed me that he started taking a popular antioxidant drink with Glucosamine in it. Glucosamine is a substance that your body uses to make cartilage. After two days, he raved about how much better his joints felt. I had to laugh because it takes many weeks for cartilage to regrow. Glucosamine doesn't speed up the process, it is used to make the cartilage- it is the 'raw material' used to build the cartilage. The placebo effect is extremely common with supplements. But, are they falsely leading you to believe that you are getting healthier?
Michael Pollan, author of In Defense of Food, summarizes his advice in this informative book with these words: "Eat food, not too much, mostly plants." I think that is safe and appropriate advice. So, take your supplement money and buy a cookbook to learn how to incorporate those plants into a tasty meal.


Janet said...

What about something like a calcium chew or a multi vitamin? Are those a waste too? I mean I think I get plenty of calcium throughout the day through veggies and dairy, but since I am almost 30 I want to stock up as much as possible..right?

Dan Hubbard, M.Ed. said...

You can get all of the vitamins and minerals in the mv and the calcium from eating a variety of plants. Calcium can be found in many places, including: almonds, broccoli, soy, turnip greens, milk, cheese, eggs,and other foods. Of course, getting adequate calcium is important, but regular, progressive strength training is key to stimulating the body to increase bone density. There are other factors contributing to bone density, too. Vitamin D, iron, and phosphoric acid intake all affect calcium balance.