Features May 2014 Issue

Vitamin C’s Impact on Arthritis

Despite claims about its potential benefits, vitamin C’s role in joint health isn’t entirely clear.

When it comes to the possible role vitamin C plays in protecting joints from the development and progression of arthritis, one word is commonly used: conflicting.
The contradictory evidence about vitamin C’s effects on joint health began over a decade ago when an animal study published in Arthritis & Rheumatism (June 2004) showed that long-term use of vitamin C may worsen the severity of osteoarthritis of the knee. Later, researchers suggested that vitamin C supplementation may indeed be beneficial in preventing knee OA (Public Health Nutrition, April 2011).

Now, a recent study published in Osteoarthritis and Cartilage (Feb. 2014) reports not only that higher levels of circulating vitamin C and E offered no protection against knee OA, they also may be associated with an increased risk of the condition.
It’s not just about ascorbic acid

One reason that vitamin C, or ascorbic acid, is being singled out is due to its status as an antioxidant, substances known to promote good health and disease prevention. While research has shown that dietary patterns rich in antioxidants, such as the Mediterranean diet, may confer health benefits, it’s difficult to isolate one nutrient as being responsible for the overall impact, according to Cleveland Clinic registered clinical dietitian Maxine Smith, RD, LD.

“We want to find these magic golden nuggets that can provide good health, but diet is so much more complex than that,” says Smith. “Although vitamin C is necessary for healthy bones and connective tissue, such as its role in collagen formation, research is showing that it’s likely a combination of compounds that promote overall health improvement and decrease in disease risk.”

It’s not clear as to vitamin C’s role in the prevention of arthritis, but it is known that the water-soluble vitamin is a positive component of an anti-inflammatory diet. Currently, the recommended dietary allowance (RDA) for vitamin C for those 19 years and older is 90 mg for males and 75 mg for a female. “This is very easy to achieve from diet,” Smith says.

Don’t discount deficiency
There are some groups that are at greater risk of missing out on vitamin C’s anti-inflammatory benefits, including smokers, those with severe malabsorption and those whose diets eliminate total food groups. One common symptom of an initial vitamin C deficiency is inflamed or bleeding gums.

“The Western diet also tends to be very inflammatory due to being high in red meat, refined grains, sugars, processed foods and limited fruits and vegetables,” says Smith.

“Instead, we recommend a more plant-based diet, fewer processed foods and more fish.

“Vitamin C likely works synergistically with other phytochemicals to protect your cells from oxidation,” Smith explains. “This may slow the progression of disease. Eating a lower inflammatory diet may also reduce joint pain.”

Unlikely sources
When you think about vitamin C, you more than likely conjure a juicy orange. But for those who can’t tolerate acidity in their diet, the anti-inflammatory benefits of vitamin C are available through numerous other sources.

“The number one source of vitamin C is sweet red peppers,” Smith says. “Just one-half cup gives you over 100 percent of the daily allowance.”
Additional easily accessible sources include dark, green vegetables. Surprisingly, a medium baked potato offers about a third of the daily vitamin C requirement. When looking at fruits, a one-half cup of sweet strawberries provides close to 100 percent of the daily allowance.

“Many studies suggest benefits of nutrients are based on the totality of the diet,” says Smith. “It’s not known if vitamin supplements would have the same effect.”