“Functional Foods & Natural Supplements” - Food can do more than provide calories

“Functional Foods & Natural Supplements”

Food can do more than provide calories

By Dr. Aamir Javed, DVM, MSc Animal Nutrition, PhD Scholar (Animal Nutrition)

Introduction: When Food Does More Than Feed

Walk into any pet store today and you'll find an impressive selection of supplements promising healthier joints, better digestion, stronger immunity, shinier coats, and even longer lives. Many are marketed as "natural," "functional," or "holistic."

But as a veterinarian and animal nutritionist, I always encourage pet parents to ask one important question:

Does my pet actually need it?

Food is much more than a source of calories. Nutrients and bioactive compounds in foods can influence inflammation, immunity, gut health, skin, joints, metabolism, and other physiological processes. These foods or ingredients are often described as functional foods when they provide benefits beyond basic nutrition.

Supplements can also have a legitimate role in veterinary care. Omega-3 fatty acids may support dogs with osteoarthritis, certain joint nutraceuticals can complement mobility programs, and specific supplements may be useful when a diagnosed deficiency or medical condition requires targeted nutritional support.

However, "natural" does not automatically mean "safe," and more is not always better.

A supplement can interact with medications, provide excessive amounts of certain nutrients, contain contaminants, or simply offer no meaningful benefit. Some products also make impressive claims based on laboratory studies rather than controlled studies in dogs and cats.

The goal should therefore be evidence-based supplementation: use the right ingredient, at an appropriate dose, for a clearly defined purpose.

Let's look at some of the most commonly discussed functional foods and supplements and separate genuine potential benefits from exaggerated claims.

Omega-3 Fatty Acids

Omega-3 fatty acids are among the best-researched functional nutrients in companion animal nutrition.

The most important long-chain omega-3 fatty acids for dogs and cats are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).

They are particularly important because they can influence inflammatory pathways and cell membrane function.

Potential Benefits

Appropriate amounts of EPA and DHA may support:

• Joint health 
• Skin and coat health 
• Cardiovascular function 
• Brain development and function 
• Normal immune regulation 

Marine sources such as salmon, sardines, anchovies, and purified fish oil are particularly rich in EPA and DHA. Algal oil is another source, particularly of DHA.

One important point: not all omega-3 supplements are equivalent.

Flaxseed, for example, primarily provides alpha-linolenic acid (ALA). Dogs can convert some ALA to longer-chain omega-3s, but the conversion is limited. Cats have an especially limited ability to convert ALA into EPA and DHA.

Therefore, when the goal is specifically to provide EPA and DHA, marine or algal sources are generally more reliable.

Fish oil should also be selected carefully. Look for reputable products with clear information about EPA and DHA content, appropriate storage instructions, and quality-control testing.

Because fish oil provides calories and can affect dietary fat intake, dosing should be considered as part of the overall diet.

Mushrooms

Medicinal mushrooms have attracted considerable interest in veterinary and human nutrition.

Species such as:

• Reishi 
• Turkey tail 
• Shiitake 
• Maitake 
• Lion's mane 

contain compounds including beta-glucans and other bioactive molecules that have been studied for their potential effects on immune function and cellular processes.

What Does the Evidence Say?

The evidence is promising in some areas, but it is important not to overstate it.

For example, turkey tail mushroom (Trametes versicolor) has been investigated in canine oncology, including research into compounds that may influence immune responses. However, this does not mean mushrooms can cure cancer or replace conventional cancer treatment.

Research in dogs and cats remains more limited than marketing claims often suggest.

If considering a mushroom supplement, use a product specifically intended for pets and discuss it with your veterinarian particularly if your pet has cancer, liver disease, immune-mediated disease, or is taking medication.

And never assume that every mushroom found in nature is safe. Wild mushroom ingestion can be dangerous, and some species are highly toxic.

Colostrum

Colostrum is the first milk produced by mammals after giving birth. It is naturally rich in immunoglobulins, proteins, growth factors, and other bioactive components.

Bovine colostrum supplements are sometimes marketed for digestive and immune support in companion animals.

The theoretical benefits are related to components such as immunoglobulins and bioactive proteins that may interact with the intestinal environment.

However, evidence for routine supplementation in healthy adult dogs and cats is still developing.

Colostrum should therefore be considered a potentially useful functional ingredient, rather than a universal requirement.

It is particularly important to distinguish nutritional support from treatment. Colostrum should not replace appropriate veterinary diagnosis or treatment for chronic gastrointestinal disease, infection, or immune disorders.

Pets with known dairy sensitivities may also require additional consideration.

Bone Broth

Bone broth has become a popular addition to homemade pet diets.

It can provide:

• Water 
• Protein-derived compounds 
• Gelatin 
• Some minerals 
• Palatability 

It can also be useful for encouraging fluid intake or making meals more appealing.

However, there is a common misconception that bone broth is automatically a nutritionally complete food or a concentrated source of every mineral found in bones.

It isn't.

The nutrient composition varies enormously depending on the ingredients, cooking method, cooking time, and dilution. Bone broth should therefore be considered a supplementary food, not a replacement for a complete and balanced diet.

When preparing or purchasing bone broth for pets:

• Avoid onion and garlic. 
• Avoid excessive salt. 
• Avoid seasonings that aren't pet-safe. 
• Remove cooked bones completely. 
• Avoid excessive fat, particularly for pets prone to pancreatitis. 
• Introduce it gradually. 

For pets with specific medical conditions, even seemingly harmless additions can affect calorie, sodium, phosphorus, or fat intake.

Green-Lipped Mussel

Green-lipped mussel (Perna canaliculus), native to New Zealand, is one of the better-known marine joint-support ingredients.

It naturally contains omega-3 fatty acids and other bioactive compounds.

Research in dogs suggests that green-lipped mussel products may provide supportive benefits for osteoarthritis and mobility, although results vary depending on the product and study design.

It is often used alongside:

• Weight management 
• Controlled exercise 
• Physical rehabilitation 
• Veterinary pain management 

The important distinction is that a joint supplement supports joint health; it does not rebuild severely damaged cartilage or reverse established arthritis.

Product quality also matters because processing can influence the concentration and activity of beneficial compounds.

Pets with shellfish allergies should not receive green-lipped mussel without veterinary advice.

Turmeric and Curcumin

Turmeric (Curcuma longa) contains several bioactive compounds, with curcumin being the best studied.

Curcumin has demonstrated antioxidant and anti-inflammatory activity in laboratory research, which has generated considerable interest in its potential use in companion animals.

However, there is an important limitation: bioavailability.

Curcumin is poorly absorbed when administered alone. Various formulations have therefore been developed to improve absorption.

Some studies in dogs have investigated curcumin-containing products for joint health and inflammatory conditions, but the evidence is still developing.

Should You Add Turmeric to Your Pet's Food?

A small amount of culinary turmeric is very different from administering a concentrated curcumin supplement.

High-dose supplements may interact with medications or cause gastrointestinal problems in some animals.

If your pet is taking anticoagulants, has gallbladder disease, gastrointestinal disease, or is undergoing surgery, consult your veterinarian before using concentrated curcumin products.

Most importantly, turmeric should never replace proven treatment for arthritis or other inflammatory disease.

Milk Thistle

Milk thistle (Silybum marianum) contains a group of compounds collectively known as silymarin.

It is primarily discussed as a liver-support supplement because laboratory and experimental research suggests antioxidant and hepatoprotective properties.

Veterinarians sometimes use milk thistle-containing products as an adjunct in cases involving liver disease or exposure to certain toxins.

But "liver support" is not the same as "liver detox."

A pet with liver disease requires diagnosis and management of the underlying problem. Depending on the condition, treatment may involve dietary modification, medication, monitoring, or other interventions.

Milk thistle should therefore be viewed as a potential adjunct, not a standalone treatment.

Product standardization is also important because the concentration of active compounds can vary considerably among supplements.

Spirulina

Spirulina is a type of cyanobacteria commonly marketed as a nutritional supplement.

It contains:

• Protein 
• Pigments such as phycocyanin 
• Certain vitamins and minerals 
• Bioactive compounds 

Its antioxidant and immune-modulating properties have generated interest in animal nutrition.

However, evidence demonstrating major clinical benefits in healthy dogs and cats remains limited.

One of the biggest concerns with algae-based supplements is quality control. Poorly manufactured products can potentially contain contaminants such as heavy metals or harmful cyanotoxins.

If you use spirulina, select a reputable product with appropriate contaminant testing.

And remember: spirulina is not a substitute for high-quality animal protein or a complete vitamin-mineral formulation.

Collagen

Collagen is the primary structural protein found in connective tissues, including skin, cartilage, tendons, and ligaments.

As pets age, maintaining healthy connective tissue becomes increasingly important.

Collagen supplements may provide peptides and amino acids involved in connective-tissue metabolism.

Potential Applications

Collagen is commonly used to support:

• Joint health 
• Skin health 
• Coat quality 
• Tendon and ligament function 

Undenatured type II collagen (UC-II) is a specialized form that has been studied for joint support in dogs.

Hydrolyzed collagen peptides are another form used in nutritional supplements.

However, collagen should not be viewed as a replacement for dietary protein. Collagen has an incomplete amino acid profile and should complement not replace high-quality complete protein sources.

When Supplements Help and When They Don't

This is perhaps the most important section of the entire article.

Supplements can be extremely useful when there is a clear nutritional or therapeutic objective.

They may help when:

1. There Is a Specific Nutritional Need

A diagnosed deficiency may require targeted supplementation.

For example, an animal with a confirmed nutritional deficiency may need additional amounts of a specific vitamin or mineral.

2. There Is Evidence for a Particular Condition

Certain nutraceuticals have evidence supporting their use alongside conventional treatment.

For example, appropriately dosed EPA and DHA can be incorporated into nutritional management plans for osteoarthritis.

3. The Diet Has a Specific Functional Goal

A diet formulated for a particular life stage or health objective may benefit from carefully selected functional ingredients.

4. A Veterinarian Recommends Them

This is particularly important when a pet has a medical condition or is receiving medication.

When Supplements May Not Help

Supplements are often unnecessary when:

The diet is already complete and balanced.

Adding multiple vitamin and mineral supplements can actually create nutritional imbalances.

There is no demonstrated benefit.

An ingredient being popular online does not automatically mean it works in dogs or cats.

The supplement is being used instead of veterinary treatment.

A supplement cannot replace antibiotics for a bacterial infection, insulin for diabetes, surgery for an obstruction, or appropriate cancer treatment.

The dose is unknown.

"Natural" ingredients can still produce adverse effects when administered at inappropriate doses.

Too many supplements are being combined.

Stacking several products can unnecessarily increase calorie intake and create overlapping ingredients or interactions.

A Better Approach to Supplementation

Before giving your pet any supplement, ask five questions:

1. What am I trying to achieve?

Joint support? Skin health? Digestive function? A diagnosed deficiency?

2. Is there scientific evidence?

Look for controlled studies in dogs or cats—not just human studies or laboratory research.

3. What is the appropriate dose?

The amount matters. "A little" is not a scientifically meaningful dosing strategy.

4. Is the product trustworthy?

Choose manufacturers that provide clear ingredient quantities, quality-control information, batch testing where appropriate, and species-specific instructions.

5. Could it interact with my pet's medications or disease?

Always check with your veterinarian when your pet has a medical condition or takes medication.

Food First, Supplements Second

One of the most important principles in animal nutrition is food first.

A complete and balanced diet should provide the foundation of your pet's nutritional programme. Functional foods and supplements should complement that foundation rather than compensate for an inadequate diet.

For example, adding fish oil to an otherwise nutritionally deficient homemade diet does not make that diet complete.

Similarly, adding collagen, turmeric, mushrooms, or spirulina cannot correct deficiencies in essential amino acids, calcium, vitamins, or trace minerals.

Nutrition works as a system. Individual ingredients matter, but overall dietary balance matters more.

Final Thoughts

Functional foods and natural supplements can be valuable tools in veterinary nutrition but they should be used thoughtfully.

Omega-3 fatty acids, green-lipped mussel, collagen, and certain other ingredients have promising or useful evidence for specific applications. Others, such as medicinal mushrooms, colostrum, turmeric, milk thistle, and spirulina, continue to attract scientific interest, but their benefits should not be exaggerated beyond the available evidence.

As a veterinarian and animal nutritionist, my recommendation is simple:

“Don't supplement because a product is trendy. Supplement because there is a reason”

Start with a complete and balanced diet, maintain a healthy body weight, provide regular exercise, and address any underlying medical problems. Then, if a particular supplement has a clear purpose and reasonable evidence behind it, it can become a useful part of your pet's overall wellness plan.

The best supplement is not the one with the longest ingredient list. It's the one that your pet actually needs, at the right dose, for the right reason.

And sometimes, the healthiest supplement decision you can make is not giving one at all.