Fishing for the right tuna

Eating oily fish like tuna and salmon has many health benefits because of its omega-3 content. Some of which include; decreasing the risk of depression, heart disease, weight loss and cholesterol. We all know fish is very good for us, but is all tinned fish the same?

Just to keep this nice an simple, I am going to take an in depth look at different tinned tuna products, how they are fished and any nasties you should beware of. A problem in supermarkets in general is the variety of products to choose from. So when tuna is on the menu for lunch, what brand of tuna do you choose?

It turns out there are a number of variables to consider when choosing your tuna. For example, energy content varies from low fat/ lite, to flavoured and in oil versions. Another, is the consideration for environmental impact, namely how fish are caught. Are they fished in environmentally friendly ways, through pole and line methods or net fishing? Then there are consumer concerns, about BPA chemical content coming from canned food items. This is a pending issue that hasn’t been resolved. Last but not least the omega-3 content in terms of its EPD and DHA ratio is also important. There are a few topics in the above list that may be foreign to you, so bear with me while I explain.

Will eating tuna help me lose weight?

If you’re trying to lose weight it would make sense to choose the less calorific tuna can. Similarly, if you are trying to gain weight choosing a tinned tuna with the highest amount of calories would be the better choice or is it?

Most in tins of tuna in oil range from 110-135kcal per 95g. If you choose tuna in spring water you’re looking at anywhere between 70-90kcal per 95g tin. Both are pretty standard and would fit into either weight loss or bulking plans quite nicely.

However, choosing the “low fat or lite” tuna just because it’s low in calories may not be the best option for weight loss. Remember that omega-3 fatty acids aid with weight loss, it may help the body burn through fat faster and promote better hormone regulation. It’s probably best to choose the tuna with the highest content of omega-3 rather than the lowest in calories.

Is eating tuna environmentally sustainable?

Can you imagine if we fished out our oceans, so much so that there was no fish left? That would be pretty sad. In the Mediterranean ocean this has already happened to some extent. At least in Australia, we have a little foresight to what the future might hold if we did the same. We can help preserve our oceans by being conscious of our food choices. The Mediterranean diet is touted as the best diet for weight loss and longevity.

At the moment I am reading another called the Omega diet, which outlines the benefits of high omega-3 intakes. All the research supports this too, omega-3 is healthful, but does that doesn’t necessarily mean we need to eat fish environmentally unsustainable amounts of fish every day.

If everyone ate fish every day, we would have no fish left! Besides in the traditional Mediterranean diet they also eat other plant based varieties of omega-3 (ALA ). They consume whole grains, olive oil, flaxseed and walnuts on a daily basis. The recommendation to include fish on a weekly basis to 2-3x serves, will provide all the health benefits you need from eating fish. At this amount it is also sustainable and will save our oceans. To top up your “good fat” intake use olive oil and eat nuts as snacks.

Should you be worried about chemicals BPA and pollutants like mercury?

I am not an expert in this area, I’ve only been researching this a little bit myself and I don’t claim to be a toxicologist or food technician by any stretch of the imagination. It seems that BPA is under the microscope by scientists at the moment. It stands for Bisphenol A. It s chemical used in industrial items paint stripper, nail polish remover, break fluid and pesticides. It’s also used in plastics like some types of water bottle and lining of canned food. If you’re buying tinned food like tuna for example, this maybe something you need to consider.

BPA is a powerful endocrine disruptor which means it mimics oestrogen hormone. Researchers are now finding at low doses in rats, can cause developmental health problems. The effects of low dose BPA on humans is still speculative and food packaging is still being approved for use.

The jury is still out on this one. So far according to article produced by Bastyr university in the USA we have nothing to worry about with canned tuna. Although, I suspect the rabbit hole goes a little deep that this. I know I am fence sitting, but watch this space, no doubt theres a lot more research to be done on BPA and it’s effects on health. The good news is due to consumer demand there are now BPA free products. You will now find BPA free, tinned fish, drink bottles and other food products. Just look out for “BPA free” claim on the packaging of the food you are purchasing.

What about mercury in fish?

Seafood is renowned for containing mercury toxin that is harmful to your health. The NSW food authority however states that mercury in fish, caught in Australian waters are very low in mercury and is safe to eat 3x week, this includes canned tuna.

On a side note in general in other countries tuna steaks may contain higher amounts of mercury than canned tuna, because amounts accumulate higher in larger fish. Compared to smaller tunas used for canning. Canned and fresh tuna in Australia are safe to eat regularly.

How do they fish for tuna and is it an environmentally sustainable practice?

Tuna companies are now very aware of environmentally safe fishing methods. Traditionally fishing trawlers would use large nets that would catch all fish including tuna, turtles and dolphins. Troll fishing destroys oceans and puts certain ocean life in danger.

A method called “pole and line” fishing is a more environmentally safe way to fish, it also helps local communities. Fish are caught one by one ensuring that they are just catching tuna or fish and nothing else. Were you can, choose tuna brands that have been caught by pole and line methods (P&L). Thankfully P&L fishing is the most common type of fishing used for catching tuna with tuna brands that are available in Australian supermarkets.

Do all tuna brands contain the same amount of omega-3?

There is one more thing to consider, not all canned tunas contain the same amount of omega-3. Depending on the species of tuna caught, seasonal variation, cleaning and cooking process of the fish, will determine its omega-3 status. Interestingly enough, any oils that are lost during the cooking and cleaning process is harvested and used to make fish oil supplements. Use this table to see how standard supermarket tuna brands rank.

As you can see Greenseas and Johnwest tuna rank the highest, considering all criteria including environmental sustainability. As a dietitian and public health advocate I am sometimes torn between what is good for us and what is environmentally sustainable.The environmental stuff becomes an issue because there are too many people on the planet and we need to realise that if we don’t consider it now, we won’t have food to eat in the future.

In the Western world we eat too much. I think gluttony has a big role to play with food sustainability. It not only affects our body weight but also the planet. All the extra food people eat, that they don’t need, commercially we have to cater for that. That means more fishing to deplete our oceans.

What can you do to decrease your eco foot print when buying tuna?

If you are serious about being eco-friendly try to maintain a healthy body weight. Only eat what you need to be healthy. Extra body fat means more environmental strain to sustain that weight through food. You can also buy the right type of products. Products that go out of their way to be eco-friendly. Try to eat a wide variety of in season produce. Eating across the food chain will ensure you’re not just eating one type of food source to extinction. For example fish 2x week, meat 2x week, chicken 2x week and then a few vegetarian meals.

A lot of people discredit the Australian Guide to Healthy Eating, because of the recommendations, advocating too many grains etc. Whatever the debate, the reason the recommendations are made that way is to consider all variables, health and sustainability. We as health professionals can’t recommend that people eat fish all day long if we are going to kill off all of our marine life, that’s not ethical or responsible.

Think bigger picture. More and more I see that being vegetarian more often than not for the environment, food sustainability and health may be the way to go. Not every single day, but at least vegetarian 2-3 days a week. Give it a go it may not be as painful as you think, lentil patty anyone?

Please note, I am not a vegetarian purist. I do eat meat and chicken, infrequently throughout the week and I have done 2-3month stints completely vegetarian. I just naturally don’t enjoy eating too many animal products, I prefer legumes and do enjoy tofu. I am not about to try an convince a meat lover to convert, different diets for different people.

I hope this post gave you a lot more to think about when choosing tuna. A simple can of fish has a lot more riding on it than you think. Next time you’re shopping for tuna think bigger picture and help to support the environment and your health.

Happy fishing!