A sustainable diet for the future - Macroalgae and Mollusks

Monikandon Sukumaran* and Kesavan Devarayan College of Fisheries Engineering Tamil Nadu Dr.J.Jayalalithaa Fisheries University, Nagapattinam

2021-01-19 07:42:53

Credit: pixabay.com

Credit: pixabay.com

Omega-3 fatty acids and omega-6 fatty acids are essential fatty acids, in addition to other essential micronutrients, like iodine, iron, copper, zinc, and selenium, that are required for building of neural systems in the brain and development of body weight in humans. These essential fatty acids cannot be synthesized by our body and it has to be acquired through the food which we eat. Our ancestors were able to acquire these essential fatty acids and micronutrients in sufficient quantities through marine foods.  Imbalance of these fatty acids and micronutrients can cause neural related diseases such as depression, bipolar disorders and other mental diseases that are now skyrocketing which also require very costly treatment and termed as global burden of human ill health.

Modern diet

Modern diet is simply related to junk food that contains high calorie or rich calorie food which is insufficient with or lack of micronutrients, vitamins, proteins, amino acids, minerals, fiber and carbohydrates. These foods do not posses the nutrients that are essential for our body. Modern diet is perceived to have less or no nutritional value and is considered as unhealthy food.

If a food contains high levels of refined sugar, white flour, salt, polyunsaturated fat, transfat and other food additives but at the same if it is lacking with micronutrients, essential minerals, fiber and proteins which is required for health it is known as junk food. The present generations and their preferred modern diet are junk food that has high fat content, sodium, sugar and has high calories but useless in terms nutritional value. These foods are very attractive with flavour, texture and colours, food additives are usually added in these foods to enhance the appearance or shelf life of the food.

Traditional diet

Traditional diets are the basic foods that are consumed by major people of the country in every day’s food. These traditional diets are plant, marine based foods, grains, fruit, vegetables, and fiber. However, the eating behaviours in particular areas may vary on marine food sources than meat. Unlike the other meats, marine foods are not high in saturated fats, but it is rich in source of omega-3 fats which protects against heart diseases and stroke. It helps in lowering triglycerides and increases the good cholesterol or HDL.

Source of essential fatty acids for humans in their diet

Now the question is that how do these super unsaturated fatty acids come from. These are synthesized by the micro algae and macro algae at the bottom of food web. These organisms possess enzyme systems to produce the super-unsaturated fatty acids from other fatty acids. These super-unsaturated fatty acids produce by the micro and macro organisms, find its way from the food web and get accumulated in the marine organisms, such as fish, shellfish, and some mammals. This is the source where humans usually tap their essential fatty acids like DHA and EPA from marine sources.

Eating marine food sources sustainably

In the context of eating the marine food sources, eating close to the bottom of the food web may be optimum way to use the resources globally.  Why eating from the bottom of the food web in the sea is considered as wise way of eating because, at each trophic level in the ecosystem about 90 percent of the nutrients are lost. Eating marine food sources sustainably means eating the marine species which are not used or used little by the consumers or the marine species which are not exploited or not traditionally used as food.

Future sustainable diet- Algae and mollusks

A sustainable diet is one which is produced with less environmental impacts to the biodiversity and ecosystems and also it should contain rich nutrients, safe, and culturally accepted food at an affordable cost. While considering a new sustainable food for the future, that is enriched with essential nutrients, algae and mollusks can be considered.

Macroalgae like marine seaweeds are commonly found in all climatic belts and which can be harvested wild or farmed in aquaculture. In general, most of the seaweeds are edible, tasty and forms an important part of diet in many Eastern countries as they are rich in macro, micro nutrients as well as vitamins and unsaturated fatty acids. But it is rarely used in Western world and it is not exploited. Out of 1000 species of sea weeds in worldwide at present about 500 species are used as food or food ingredients.

Mollusks are eaten in some parts of the world even though they are abundant in local waters they are not preferred. Cephalopods like squid, cuttlefish, and octopus are example of mollusks. Cephalopods are rich in protein, minerals, vitamin B12 and little amount of fatty acids. There are about 800 species of Cephalopods out of them only 30 species are used as human food and the annual marine catch reports to about 5%. The annual catch data witnesses that Cephalopods are unexploited marine crop.

Reasons preventing eating strange things like seaweeds and cephalopods

          Even though the seaweeds and cephalopods are rich in protein, macro, micro nutrients as well as vitamins and unsaturated fatty acids. There are number of good reasons to eat seaweed and Cephalopods but Why do we not eat more of them, what are the obstacles behind eating them.  There are some factors and reasons like sensory factors, physiological factors, social and physcological factors preventing one from eating the seaweeds and cephalopods.

The key factor behind this is the tradition, language and culture. The word weed is used for some thing like thrown away rotten smelling etc and it does not give good connotations to food. In Western countries seaweeds are given positive images in the food cultures by proposing terms like “sea vegetables,” “sea greens,” or “ocean greens” and to further boost them by using words like “superfood” or “future food.”

Due to the globalization of the food the Eastern food cultures are influencing on the focus of good health and benefits of eating seaweeds and there is interest in consumption of eating seaweeds in North America and Europe.


The awareness about the richness in protein, macro, micro nutrients as well as vitamins and unsaturated fatty acids has made the people of some parts of eastern and western world to consume the seaweeds. Despite of the nutritional values it has also led a way to the sustainable eating of the marine sources. Even though there are number of good reasons for consuming cephalopods still it is being underutilized.

The sensory, traditional and cultural factors are the important barriers for the consumption of seaweeds and cephalopods it may require little time to the people to think about the sustainable and healthy eating.