Herbs & Spices: Tiny Powerhouses for Immune Support and Cancer Prevention

Keto, Mediterranean, low-carb, and balanced diets walk into a bar and for once, they all agree on something: herbs and spices are good for you!

In fact, I think herbs and spices deserve their own food group. They’re inexpensive, concentrated, and instantly elevate both the flavor and nutrient potency of your meals. You don’t have to eat a lot of them to get the best bang for your calorie dollar. 

Small but mighty, herbs and spices are packed with phytonutrients — plant compounds that play a vital role in immune support, inflammation control, and disease prevention including cancer. 

As an oncology nutrition consultant, I see herbs and spices as the easiest and most delicious way to upgrade your meals while supporting your body’s own healing systems.

Herbs and spices are one of my favourite subjects to talk about and I am super excited to share my love for them in the next couple of blog posts. 

This first post of the two-part series we will will explore:

• What herbs and spices are

• Why they are good for cancer prevention and for overall longevity

• The top 10 herbs and spices richest in polyphenols

• How to choose organic, heavy-metal-tested products

In the follow-up post, I will share with you some practical tips on how to choose herbs and spices, whether dried or fresh are best, how to store them and so much more!

Without further ado, let’s dive in!

What Are Herbs & Spices?

There is no one definition of culinary herbs and spices but generally:

• Spices come from the bark, roots, seeds, buds, or stems of plants (think cinnamon, cloves, cumin, or turmeric). They’re usually used dry and pack intense flavor.

• Herbs are the leafy parts of plants like parsley, basil, cilantro, and mint. They can be used fresh or dried.

Both are rich in bioactive compounds - natural chemicals that give plants their aroma, color, and protective power. These active properties of herbs and spices are actually their natural protection mechanisms to deter environmental stressors such herbivorous insects and animals, fungi, pathogens, and parasites.

You can think of them as “medicinal dust” that brings both food and immune system to life. 

A Brief History

Long before we had antibiotics or pharmaceuticals, ancient civilizations relied on herbs and spices for healing and prevention.

They were used to treat wounds, improve digestion, and even preserve food naturally.

In fact, spices were once worth more than gold. Wars were fought and trade routes were discovered in pursuit of them. Egyptians used cinnamon in embalming rituals, and Ayurvedic and Traditional Chinese Medicine systems integrated herbs for thousands of years to promote longevity and immune resilience.

Today, modern functional nutrition confirms what ancient wisdom knew: herbs and spices are nature’s pharmacy, brimming with antioxidant-rich compounds that support optimal health.

The “Antis”: Nature’s Functional Pharmacy

Herbs and spices are loaded with natural compounds that act as immune modulators and disease fighters. I like to call them “the Antis” because they do so much good work behind the scenes:

• Anti-inflammatory – calm chronic low-grade inflammation linked to cancer, diabetes, and heart disease.

• Antioxidant – neutralize free radicals that damage cells’ DNA

• Anti-bacterial, anti-viral, and anti-fungal – support the body’s defenses against infections.

• Anti-cancer – may slow tumor growth and prevent cancer cell development.

• Anti-glycemic and anti-lipid – help balance blood sugar and cholesterol.

These properties make herbs and spices central to an anti-inflammatory diet and cancer-preventive nutrition plan. When we regularly include them, our immune system doesn’t have to do all the work on its own.

One large Harvard study even found that people who ate spicy foods almost every day had a 14% lower risk of death than those who ate them once a week!

Polyphenols: The Secret Behind the Power of Herbs and Spices

Among the many phytonutrients in herbs and spices, polyphenols stand out as the most powerful.

Polyphenols are potent antioxidants that support  regulate inflammatory pathways and enhance immune resilience - all critical for cancer prevention. Recent research is also showing that the beneficial gut bacteria loves polyphenols which act as prebiotic (food) for the healthy microbiome.

It’s not a surprise that by weight, Herbs and Spices contain the highest amount of polyphenols out of all the foods on the planet! Lentils are also up there but we will focus on that another day. 

Fun fact: Dried peppermint has about 134 times more polyphenols per 100 g than green tea leaves. 

Top 10 polyphenol-rich herbs and spices

Source: PMID: 21045839 DOI: 10.1038/ejcn.2010.221

🌿Herb or Spice	Polyphenol Content (mg/100 g)	Key Benefits
Cloves	~15,188	Highest known source of polyphenols; strong antioxidant and antimicrobial properties
Dried Peppermint	~11,960	Calming, supports digestion, and rich in flavonoids
Star Anise	~5,460	Potent anti-viral and aromatic compound anethole
Oregano (dried)	~2,300	Broad-spectrum antimicrobial; supports gut health
Celery Seed	~2,094	Anti-inflammatory and circulation-supportive
Sage (dried)	~1,200	Cognitive support and anti-microbial activity
Rosemary (dried)	~1,000	Enhances detoxification enzymes; anti-cancer potential
Thyme (dried)	~878	Anti-bacterial and antioxidant
Spearmint (dried)	~956	Digestive support and breath freshener
Cinnamon	~710	Blood sugar balance and insulin-sensitizing

Even small amounts like ½ teaspoon of cloves (≈158 mg polyphenols) can make a meaningful contribution to your polyphenol intake.

These compounds are being studied for their potential role in cancer prevention, immune modulation, and longevity. However, the critical mass of data available seem to strongly suggest the protective effect of a polyphenol-rich dietary pattern.

Choose Organic & Tested Products

Because herbs and spices are grown in soil and often imported from around the world, they can contain pesticide residues or heavy metals if not properly sourced.

When possible, choose:

• Certified organic herbs and spices

• Brands that provide heavy-metal testing*

This simple choice protects your health and ensures the herbs you use truly support, rather than burden, your immune system.

*Even if heavy metal testing is done, it’s important to review lab reports and ensure heavy metal levels stay well below recommended limits. For those following a highly anti-inflammatory diet and consuming at least two teaspoons of herbs and spices daily, lower limits are advisable. While the American Spice Trade Association (ASTA), reflecting EU standards, sets the upper limit for lead (Pb) at 2.0 ppm, I recommend a stricter threshold of ≤0.5 ppm is more appropriate for higher spice consumption - especially for individuals with cancer or inflammation-related concerns.

Recipe: Chimichurri — A Polyphenol-Rich Power Sauce

A simple, flavorful way to bring herbs into your meals every day. I love to put it on my salads in a form of a salad dressing. 

Ingredients

• ½ cup fresh parsley, finely chopped

• ¼ cup fresh cilantro, finely chopped

• 2 tbsp fresh oregano (or 1 tbsp dried)

• 3 garlic cloves, minced

• 1 shallot, minced

• ½ red chili or pinch of chili flakes

• Juice of 1 lemon (or 2 tbsp red wine vinegar)

• ¼ cup extra-virgin olive oil

• Sea salt and pepper, to taste

Instructions

1. Combine all ingredients in a small bowl.

2. Let rest for 10–15 minutes to allow flavors to meld.

3. Serve over grilled vegetables, fish, or tofu—or use as a salad dressing.

The Takeaway

If you want to strengthen your immune system, reduce inflammation, and support cancer prevention through diet, start with your spice rack.

Herbs and spices are tiny but mighty, offering concentrated sources of polyphenols and antioxidants that fit beautifully within a plant-based or anti-inflammatory diet.

So go ahead — crack a bit more black pepper, mix mint and green tea together, sprinkle cinnamon on your latte, or make an Italian-spiced dressing to boost your salad’s flavor. Your body will thank you. 

Coming Next:

Part 2 — “Incorporating Herbs & Spices into Everyday Cooking”We’ll cover:

• How to choose high-quality herbs and spices

• Best-known cancer-fighting herbs and spices

• Storage and cooking tips to preserve potency

• The best ways to combine them for flavor and function

• More functional nutrition recipes for immune health

Reach out for a free 15-minute consult whenever you are ready to create a nutrition plan that works for you: https://my.practicebetter.io/#/616e32cc39803305784d2110/bookings?s=63d33de5fc4918f149d4b901&step=date.

In abundant health, 

Valerie