Functional foods have experienced fast growth in recent years, and supermarket shelves offer a wide array of products that claim to have health benefits beyond basic nutrition. Many of these foods are fortified with nutrients and additives that most people need a dictionary for, but they sure do sound medicinal and technologically advanced. These foods are marketed as disease-preventing and health-promoting.
There are drinks that claim they can make your skin younger (if you believe what’s written on the cosmetics’ package, I guess you can believe that, too), boost your brain function, make you loose weight without a diet and build super-immunity.
One of the product lines that I find most intriguing is the drinks aimed at joint health. Several companies make beverages laced with glucosamine and/or chondroitin aimed at maintaining healthy joint cartilage (see Joint Juice, Elations, Vitamin Water - Balance, Supple, Monavie). Since glucosamine and chondroitin are widely used dietary supplements, I’ve been asked by joint sufferers whether these drinks actually work.
A short introduction to these supplements:
Glucosamine is thought to promote the formation and repair of joint cartilage.
Chondroitin is a cartilage component thought to promote cartilage water retention and elasticity and to inhibit its breakdown. Both compounds are made by the body.
Glucosamine and chondroitin supplements are derived from animal sources (shellfish shells and animal cartilage), but glucosamine can also be derived from vegetarian sources. These supplements are promoted widely, especially by lay media, to treat osteoarthritis, the most common form of arthritis in the US, afflicting about 21 million people. They are hugely popular, with estimated sales of around $730 million in 2004.
So it would be nice to know if these supplements actually work.
There have been several studies that evaluated the efficacy of glucosamine and chondroitin, alone and in combination. Some have demonstrated efficacy, but other studies have shown no benefit. Many of these early studies had serious flaws. A recent meta-analysis in the British Medical Journal summing the results of ten randomised controlled trials concluded that compared with placebo, glucosamine, chondroitin, and their combination do not reduce joint pain or have an impact on narrowing of joint space, and therefore these supplements shouldn't be covered by medical insurers.
The largest, most comprehensive and best-designed clinical trial so far is the Glucosamine/chondroitin Arthritis Intervention Trial (GAIT), a multi-center, randomized, national clinical trial funded by the National Institutes of Health. This study produced two major outcomes so far:
• The first study was published in the New England Journal of Medicine in 2006. In it 1,583 patients with symptomatic knee osteoarthritis were randomly assigned glucosamine, chondroitin sulfate, both glucosamine and chondroitin sulfate, celecoxib (a non-steroidal anti-inflammatory drug) or placebo for 24 weeks. Glucosamine and chondroitin sulfate alone or in combination did not reduce pain effectively in the overall group of patients with osteoarthritis of the knee, although exploratory analyses did suggest that the combination of glucosamine and chondroitin sulfate may have some effect in the subgroup of patients with moderate-to-severe knee pain.• The study’s second outcome was published in the scientific journal Arthritis and Rheumatism. A subgroup of the original GAIT trial participants, consisting of about 570 patients continued the trial for a total of 24 months to see if there’s radiographic evidence that glucosamine and chondroitin, alone or in combination, can affect joint deterioration. And the result: the supplements did not appear to slow the loss of cartilage, taken either alone or together, and performed no better than placebo.
The only good news is that glucosamine and chondroitin have now been tried quite extensively, and while I don’t believe they work any better than placebo, they are generally safe, with only minor side effects reported.
As to the question of putting them into food:
Although many people eat food of very low quality, food that doesn’t offer the benefits of food (i.e., nutrition, taste, tradition, joy and community), they believe some new processed foods with added supplements can deliver wellness better than real food can, and practically act as medicine.
This kind of attitude enables manufacturers to invent new processed foods daily, adding the molecule du jour to the mix, and to market it as the new fountain of health.
Even if a supplement is proven effective (bear in mind that supplements are not required by the FDA to prove efficacy the way drugs do), why add it to a drink full of sugars and color? Why not take it as a pill, without the added junk?
But perhaps the most important question is: Why not go back to some sensibility about food?
- Food should be made from food, not from ingeniously created new additives. Rule of thumb: If you can’t pronounce an ingredient, it’s not real food.
- Foods providing innate nutrition, great taste and joy are really a refreshing change in today’s processed food landscape, and quite good enough. I don’t see how we can expect food to go beyond that and tackle all that ails.
- And above all, while seeking benefits beyond basic nutrition, we forgot basic nutrition. By eating well, keeping active, and maintaining a reasonable weight we can prevent many chronic diseases.
Eating well is good enough. No magic is needed, and if there’s any promise of magic—we should all demand strong proof.
Dr. Ayala
Full disclosure: I’m vice president of product development for Herbal Water, where we make organic herb-infused waters that have zero calories and no sugar or artificial ingredients. I’m also a pediatrician and have been promoting good nutrition and healthy lifestyle for many years.