It's hard to ignore the ads about dietary supplements for diabetes. The promises sound so appealing that you may start to ask yourself:
Does chromium really amplify insulin response in people with type 2 diabetes?
Will alpha lipoic acid relieve the burning, tingling, and numbness of my neuropathy?
Can fish oil protect my heart?
You'd prefer not to waste money on the equivalent of Lucille Ball's Vitameatavegamin, but you want to improve your health. It's difficult to know, however, whether dietary supplements really help because there are insufficient clinical studies to validate the claims.
Let's start with the recommendations of two major diabetes organizations:
The American Diabetes Association, in its Standards of Care 2009, states: "There is no clear evidence of benefit from vitamin or mineral supplementation in people with diabetes (compared with the general population) who do not have underlying deficiencies." If a supplement is recommended for the general population -- for example, folic acid for pregnant women -- it is also recommended for people with diabetes.
The Canadian Diabetes Association Clinical Practice Guidelines state that people with diabetes "should be encouraged to meet their nutritional needs by consuming a well-balanced diet. Routine vitamin and mineral supplementation is generally not recommended."
These organizations aren't necessarily against supplements. They are, however, saying there have not been enough well-designed studies showing benefits.
But Do Supplements Work?
In developing guidelines, medical organizations give more weight to studies that are long-term and involve large numbers of people at different sites. The studies must be placebo-controlled -- some people get the supplement, and some people take look-alike pills (placebos) that contain no supplement. The studies must have reproducible results -- do other groups doing similar studies get similar results?
This type of research is ongoing with many supplements. As more data come in, health organizations may change their recommendations on some supplements -- shifting to either positive or negative.