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Turmeric: Ancient spice may offer osteoarthritis relief in dogs, cats

Turmeric could be the next new joint health additive for pet food if the necessary research were conducted.

Turmeric has been finding its way into pet foods with increasing frequency in the past few years. There are dozens of websites and online news outlets describing many positive attributes of turmeric for pets. It is purported to have a wide variety of health benefits.

In folk medicine, turmeric has been prescribed for rheumatism, pain, fatigue, arthritis, gastritis, dermatitis and liver issues. It has been described as preventive and adjunctive treatment for cancer and may even have anti-bacterial and anti-fungal properties. Almost too good to be true.

Interestingly, there are a fair number of studies published in the alternative and mainstream medical journals in human and laboratory animals that validate some of these effects. There are a few short-term studies with dogs showing either limited effects or small improvements in markers of reduced osteoarthritis. However, longer-term and larger studies are lacking. Little information is available regarding efficacy, safety or proper preparation and dosage for dogs and cats. Perhaps digging a bit deeper will help determine whether turmeric belongs in pet food and how it might best be used.

Spice for human food, color for pet food

Turmeric (Curcuma longa) is a flowering perennial plant that grows to approximately 1 meter. It is related to ginger and is native to India and Asia, with some cultivated in Central America as well. It requires warm growing conditions with plenty of rainfall. Turmeric rhizomes (roots) are harvested and the “fingers” are removed from the “mother” root. The mother root is saved for seed and the separated fingers are cured in hot water, then dried; and the outer layer is cleaned in a process called “polishing” before being milled into a powder.

Turmeric is commonly considered a spice and is permitted in pet food for use as a coloring additive. It provides a rich orange-yellow color that we commonly associate with French’s mustard. It has also been used to color cheese, salad dressing, butter and margarine. But it’s probably best known as the key component in curry powder, a spice palate used in Indian and Asian cuisine. In this capacity, it has been used in food preparation for centuries. Estimates for consumption by humans in these regions puts daily intake at 2,000-2,500 mg/day without signs of toxicity or adverse effect.

The active component in turmeric is composed of a variety of phenolic compounds and terpenoids. The most active are described as the curcuminoids, which include curcumin, demethoxycurcumin and bisdemethoxycurcumin. Curcumin contains antioxidant activity. It comprises about 2-8% of the turmeric and is responsible for the yellow color and flavor. For pharmacological purposes, curcumin is prepared by solvent extraction of the milled turmeric with acetone or methanol, and then solids are filtered off and solvent is removed under vacuum. The resulting oleoresin is crystallized and then ground into a powder.

Turmeric powder more effective for pets?

There are several nutraceutical studies with curcumin and modifications that have demonstrated a pharmacological response in dogs, so the active element seems to have an effect. However, the bigger question for pet food relates to turmeric powder rather than purified curcumin extract.

Interestingly, in some animal studies, turmeric powder has been more effective than the extracts; but bioavailability of the active element can be low. In human foods and supplements, it is recommended that turmeric be taken with pepper (piperine) to aid bioavailability. Emulsifiers (e.g., lecithin) and (or) vegetable oils may improve absorption. Further, preparation of turmeric powder can be modified to enhance potency through enzymatic hydrolysis and (or) fermentation.

Digestibility, palatability or other acceptability measures for pet foods supplemented with turmeric have not been reported. Generally, pet food manufacturers are adding small amounts (0.05 to 0.25%) to the food as part of an antioxidant or anti-inflammatory package to imply a health benefit. Details regarding optimal dose that might impart benefit to osteoarthritis in senior-type diets have not been described.

An interesting side note regarding turmeric relates to its potential as a preservative for fats to retard oxidation. In one study with a blend of fish oil and flaxseed oil treated with curcumin (0.1 and 0.2% food dry basis) and applied to a pet food, the turmeric-treated foods performed equal to or better than BHA in a short-term oxidation study (12 weeks).

Supply chain shared with human food and supplements

The supply chain for turmeric is the same as that for the human food ingredient and supplements market. There is no separate pet supply channel for this ingredient. Thus, prices may be much higher than for standard commodity ingredients typically encountered in the pet food trade. Therein lies the challenge of determining the amount to include in the formula – finding that right mix between effective dose, palatability effects (if any), impact on color of the finished product and cost relative to the expectations of the pet food purchaser.

Given turmeric will likely be used at relatively small amounts, it may benefit from being delivered to the diet in a premix along with other small inclusion additives (e.g., vitamins, trace minerals, antioxidant blends). Further, sequencing in the manufacturing plant may be necessary as the yellow color has the potential to bleed over into foods that follow in the production schedule.

While the anecdotal information regarding the uses and benefits of turmeric seem very interesting, especially considering the increasing population of aging animals, the reality is that we don’t have enough information about this ingredient in dogs and cats to responsibly use it at doses beyond what is permitted today for a food color additive. Future work should focus on documenting any adverse reactions, measurement of active compounds, markers of osteoarthritis and other anti-inflammatory intermediates. Further, the area of antioxidant capacity and anti-microbial potential should be explored to provide a better picture of where turmeric might play a role in pet foods.