ƽÌØÎå²»ÖÐ

A quick search of Amazon for hyaluronic acid turns up thousands of products, from liquid serums to pills to creams that make a variety of claims.  seem to focus on hyaluronic acid’s ability to ease skin redness and reduce wrinkles while  focus on the benefits of hyaluronic acid on the joints. Some products, like , make claims about hyaluronic acid’s benefits to both the skin and joints.

How can one substance have so many effects? And is there any truth to the ‘’ or ’ declarations?

Within the body, hyaluronic acid plays an important, albeit diverse, role. It is a major component of epithelial tissue, and seems to play a role in cell division and movement. It is also a chief component of synovial fluid- the fluid found inside a synovial joint (like a human’s hips or wrists)- and acts as a lubricating agent. Hyaluronic acid is also found in joint cartilage, where it coats all the cells, and it even plays a role in the body’s innate immune system (high hyaluronic acid levels can be used as a marker for prostate and breast cancers). The average person has ~15 g of hyaluronic acid in their body, and about 1/3 of it is degraded each day.

In short, hyaluronic acid does a lot of things, from skin repair to joint lubrication, so it makes sense that promoters hype it as a possible treatment for a wide variety of health problems ranging from osteoarthritis to sun burns. But what does the science say about its efficacy?

Studies have shown intra-articular injections (injections into the joint) of hyaluronic acid to be just as effective, and sometimes more effective, at managing pain Ìý´Ç°ùÌý, often with , for patients with osteoarthritis. Likewise,  looking at artificial tears containing hyaluronic acid, used to treat chronic dry eyes, have found it to be a safe and effective option. . The thing that begs investigation however, is the oral administration of hyaluronic acid.

There have been a  on oral treatments of hyaluronic acid, and they all seem to have quite positive results.  found that daily supplementation with oral hyaluronic acid enhanced several markers of quality of life in adults with osteoarthritis of the knee, and  concluded that oral intake of high purity hyaluronic acid is effective in the treatment of American patients of knee osteoarthritis. Some studies,  partnered oral hyaluronic acid supplements with exercise and also had positive results.

These results seem promising, and I’d be right on board the hype train with everyone else, if I hadn’t spent some time reading the methods sections of these studies. Each study used a daily amount of hyaluronic acid ranging from 60-200 mg. Most supplements recommend hyaluronic in the 100-200 mg range, but , perhaps one of the best known supplements, contains only 17 mg of hyaluronic acid in its once a day packets. 

There is  that orally administered hyaluronic acid is absorbed in the digestive tract and that it does migrate to the relevant connective tissues. There is also  that it can have a biological effect without even being absorbed. These functions however, depend on there being enough hyaluronic acid molecules present to interact with the relevant receptors, and in a 17 mg dose, this likely just isn’t the case.

So by all means, ask your doctor about hyaluronic acid for your osteoarthritis or chronic dry eyes, but make sure to read the package before you buy the pills. As Dr Joe always says, it’s all about the dose!