Tuna boasts many health benefits. But how much fatty fish, such as tuna, should you consume in a week, and how does canned tuna compare with fresh tuna? Dietitian Lock Poh Leng from SingHealth Community Hospitals (SCH) answers this and more.
Health benefits of tuna
"Besides being a good source of protein, iodine, selenium, zinc, calcium,vitamins A and B12,tuna is a type of fatty fish which contains Vitamin D and Omega-3 fats (EPA & DHA) that offer many health benefits", shares Dietitian Lock Poh Leng from Sengkang Community Hospital (SKCH), under SingHealth Community Hospitals (SCH). SCH is a member of the SingHealth group.
1. Essential for a child’s developing brain, nervous system and vision
Omega-3 fats in fish suchas tuna, salmon, sardine, mackerel and tenggiri are important to children’s health. It’s essential for fetus and child’s developing brain, nervous system and vision.
Studies have shown that consuming fish early in life may help prevent asthma, eczema, and other allergic diseases.
How much fatty fish, including tuna should you consume in a week?
The US, Food and Drug Administration advises parents to offer fish to their children one to two times per week from a variety of low-mercury options.
The recommended portion size each time based on age and calorie needs are as follows:
2 to3 years old | 30g |
4 to 7 years old | 60g |
8 to 10 years old | 90g |
11 years old and above | 120g |
2. Decrease one’s risk of cardiovascular disease
For adults, consuming 240g of seafood each week provides average consumption of 250mg of EPA and DHA daily. This amount has been shown to protect against cardiac deaths and reduced cardiovascular risks.
3. Reduce cognitive declineduring old age
A 2018 study in American Journal of Epidemiology found that older adults who ate fish four or more times per week had memory scores equivalent to being 4 years younger compared to older adults who rarely ate fish. Fish with high amounts of omega-3 fats may reduce cognitive decline in the elderly.
Omega-3 fats found in fatty fish (EPA & DHA) are essential fats that are required in the human diet as our body can’t produce them internally and hence must be obtained from food.
Fatty fish such as tuna, salmon, mackerel, sardines and tenggiri contain vitamin D and the omega-3 fats (EPA & DHA) that offer health benefits, primarily decreased cardiovascular disease risk.
Omega-3 fats are essential for a child’s developing brain, nervous system and vision.Fatty fish tend to have more omega -3 fats than do other leaner ocean fish. But no one fatty fish is healthier than others e.g. although salmon contains higher omega-3 fats (2.3-3.6g per 120g than tuna (0.4g-1g per 120g),the key is to eat a variety of fish as different types of fish offer a different range of nutrients that together contribute to positive health outcomes.
It isnot recommended to eat tuna on a daily basis, as eating a variety of foods is important to ensure a wide range of different nutrients for good health.
Use My Healthy Plate by Singapore Health Promotion Board as a guide for healthful eating by incorporating all the essential food groups i.e. wholegrains, protein & calcium-rich foods, fruits and vegetables in your diet every day.
Mercury in seafood: How much is safe?
The American College of Obstetrics and Gynecologists advises women who are pregnant, may become pregnant, orare breast-feeding to eat a total of 240g – 360g of low- mercuryseafood weekly.
Common fish and seafood choices that are higher in omega-3 fats (EPA and DHA) but lower in mercury content include salmon, sardines, Atlantic/Pacific mackerel (not king mackerel)and oysters.
For adults, consuming 240g of seafood each week provides average consumption of 250mg of EPA and DHA daily. This amount has been shown to protect against cardiac deaths and reduced cardiovascular diseaserisks.
How harmful is mercury in fish?
Mercury can be harmful if consumed in excess. Mercury binds with the mineral selenium from performing its role in the brain and the immune system. But, the selenium found in fish and seafood helps counter the potential adverse effects of mercury.
All fish contain some mercury due to industrial pollution in lakes, rivers and oceans. However, large predatory fish or larger fish with longer lifespan such as tuna and salmon have more mercury accumulated in their muscles from the other smaller fish they eat.
Fish can accumulate mercury through absorption from the surrounding polluted water from environmental contaminants. Women who are pregnant or breast feeding or who may become pregnant to have at least 240g per week to support fetal growth and development as well as maternal health.
Pregnant women to avoid four-types of fish that are high in mercury content i.e. tilefish, shark, swordfish and king mackerel. But most people are not eating those types of fish.
Difference between fresh tuna and canned tuna
Fresh tuna can last only about a week after leaving the water whereas canned tuna is available all year round. Fresh and canned tuna provide the same good omega-3 fats.
However, canned tuna can be higher in sodium, fat and calories if it is packed in brine or oil. So be sure to choose canned tuna in water to minimise the sodium and fat content.
What to look out for when buying canned tuna
Look for tuna flakes or tuna chunks in water with a natural source of Omega-3 and with no preservatives or added MSG. You should check labels for omega-3 fats content or DHA (docosahexaenoic acid) and EPA (eicosapentaenoic acid) content.
Compare and choose canned tuna with higher omega-3 fats content based on per 100g serving.
Nutritional analysisof tuna
Nutrient composition for tuna based on 120g portion.
| Nutrient | Amount |
|---|---|
Protein | 23g |
Iodine | 12mcg |
Selenium | 81.4mcg |
Zinc | 0.8mg |
Calcium | 22mg |
Vitamin A | 20mcg |
Vitamin B12 | 3.1mcg |
Vitamin D | 1.44mcg |
Omega-3 | 0.4g |
Tuna and apple sandwich recipe
Try our tasty and easy-to-prepare sandwich!
Ingredients (for 2 servings)
150g Tuna flakes in water, well-drained | 2 teaspoons of Extra Virgin Olive Oil |
100g julienned carrot | ¼ teaspoon of salt |
50g (1 small) chopped red onion | A pinch of pepper |
150g (1 medium) chopped green apple | 4 crisp lettuce leaves |
2 teaspoons of Canola Oil | 4 slices of whole-wheat or whole-meal breads |
Steps
1. Heat the pan to medium low heat.
2. Use 2 teaspoons of Canola oil for sautéing. Sautee chopped red onion and julienned carrot.
3. Add in tuna flakes, salt and pepper. Stir the tuna well.
4. Add in chopped green apple last to keep it crunchy. Stir till thoroughly incorporated.
5. Set the tuna mixture aside. Add 2 teaspoons of extra virgin Olive oil to the tuna mixture and stir well, before dishing out to enhance the flavors.
6. Place a lettuce leave on each side of 2 slices of bread. The lettuce will keep the whole-meal bread from becoming soggy. Add the tuna mixture.
7. Cover with the second slice of whole-meal bread and cut in half.
8. Serve immediately.
Check out more tuna recipes:
Nasi Kuning (Yellow Rice) with Tuna Flakes
Tuna and Corn Sandwich
Tuna Salad with Plum Dressing by Pietro Ristorante Italiano
Tuna, Ikura, Broccoli and Quinoa Bowl
Ref: H24
Plus, other articles on food tips:
Health Benefits of Sardines
Health Benefits of Salmon
Kai-lan: Tasty, Easy, Healthy!
Health Benefits of Spinach
How Healthy is Coconut?
How Healthy is Mango?
Tea, Is It Healthier Than Coffee?
