What Is Squid Ink?

Reviewed by Dan Brennan, MD on November 27, 2021

‌Squid ink is a dark, usually bluish-black fluid that’s made by squids. Squids and other cephalopods like cuttlefish and octopuses store this ink in an ink sac. When they’re in danger, they release it to conceal them so they can get away from predators.‌

Squid ink, also called cephalopod ink, has been used in traditional medicine for centuries. It’s also used as a pigment, writing ink, dye, and black food coloring. If you’ve eaten black burgers, waffles, pasta, or ice cream, you may be familiar with squid ink. 

Why Do Squids Make Cephalopod Ink?

‌Squids use ink as a defense tool. When squids are threatened or attacked, they release the dark ink from their ink sac. It makes a dark cloud that makes the water murky. This blocks the predator’s view and confuses it, allowing the cephalopod to escape.  

Squids and octopuses produce black or bluish-black ink, while some cephalopods produce brown or red ink. But not all cephalopods can produce this ink. 

What Does Squid Ink Contain?

‌Squid ink is made up of many compounds and nutrients. It gets its dark color from a natural pigment called melanin, the same thing that gives color to your hair and skin.

Squid ink also contains:‌

  • Enzymes that help in making melanin
  • Peptidoglycans, complex compounds made of sugar and proteins
  • Catecholamines, protein hormones
  • Amino acids, building blocks of proteins
  • Metals like cadmium, lead, and copper, which may help in making melanin
  • Toxins like tetrodotoxin

Uses of Squid Ink

Humans have used squid ink for centuries for things like:‌

Medicines. Squid ink has some antibacterial, anticancer, anti-inflammatory, antioxidant, and other healing properties.  

Writing, art, and painting. Sepia ink or blackish-brown squid ink was used by artists and painters to create long-lasting paintings. Modern artists still use the sepia pigment to create different shades and effects.  

Cosmetics. Squid ink is used in hair color and mascara because of its distinct black color.

Food. Squid ink is often used in Japanese and Greek cuisines. With its rich umami or savory flavor and black color, squid ink can be added to many of your favorite foods.

Foods that use squid ink may include:

  • Black pasta 
  • Black rice or risotto
  • Ink soup
  • Sauce
  • Bread and burger buns
  • Black tacos
  • Black waffles
  • Black ice cream and other desserts
  • Cookies and crackers

Health Benefits of Squid Ink

‌Squid ink is used in food and medicine for many health benefits, including: 

It has antimicrobial properties. Research has shown that squid ink is effective against pathogens like bacteria, fungus, and viruses. It also has antibiotic effects against some infectious bacteria.

It may have anti-cancer effects. Studies have found that squid ink can promote antitumor activity and fight cancer. It may be used in anti-cancer drugs and chemotherapy to treat cancer in humans.

It can boost your immunity. Some compounds in cephalopod ink can help protect your immune cells and boost your immune response. 

It can reduce hypertension or high blood pressure.  Squid ink has enzymes that can lower your blood pressure and prevent hypertension.   

It may have effects against retroviruses. The ink from some cephalopod species can help fight retroviruses like HIV, the virus that causes AIDS.

It may treat ulcers. Squid ink has been found to reduce ulcers in rats. This may be promising for the treatment of ulcers in humans.

It can reduce pain and inflammation. Squid ink has anti-inflammatory properties, so it might have potential in treating chronic health issues like heart disease.‌

It has antioxidant properties. Squid ink has antioxidant effects, which can protect your cells from free radical damage and oxidation. This is why squid ink may be used in anti-aging products. 

Risks of Squid Ink

‌Although squid ink isn’t poisonous, it may carry some risks.

Eating food made with squid ink can cause an allergic reaction similar to seafood allergy. If you have a shellfish or squid allergy, avoid any foods with squid ink.

Show Sources

African Journal of Pharmacy and Pharmacology: “In vitro antioxidant, analgesic and cytotoxic activities of Sepia officinalis ink and Coelatura aegyptiaca extracts.”
Food Research: “Medicinal and therapeutic properties of cephalopod ink: a short review.”
Marine Drugs: “A Potential Adjuvant Agent of Chemotherapy: Sepia Ink Polysaccharides,” “Cephalopod Ink: Production, Chemistry, Functions and Applications.”
Dietitian/Nutritionists from the Nutrition Education Materials Online: My Nutrition: “Diet and shellfish allergy.”
Pharmacognosy Research: “Therapeutic Significance of Loligo vulgaris (Lamarck, 1798) ink Extract: A Biomedical Approach.”

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