Oily Fish: A ‘Game Changer’ in Fight Against Heart Disease

Summary key points:

• Heart disease is the number one leading cause of death worldwide
• Fatty fish is a rich source for omega 3.
• Omega 3 plays an important role in preventing heart disease and reducing inflammation.
• Servings of 2 portions a week is the recommended amount of omega 3 in your diet
• Salmon, Tuna, Mackerel, Sardines are all examples of omega 3 food sources
• Some pollutants can threaten the effectiveness of omega 3 consumption
• Supplements, plant-based food, eggs are alternatives to fatty fish

Are you a cardiovascular disease patient? Do you know someone who suffers from heart disease? Chances are, yes you do! According to the Center for Disease Control And Prevention (CDC) Cardiovascular disease is the number one leading cause of death worldwide, in effect, this has become a rising problem so much that in an effort to raise awareness they started the Every heart Counts movement.

Fortunately, Oily fish has now been exposed as being a fierce protector when it comes to cardiovascular health. In fact, it’s considered to be so favorable that the American Heart Association (AHA) recommends including at least 2 portions of fatty fish per week in its guidelines for a healthy diet. ¹

You might be wondering right now what’s so special about oily fish, right? Well, let’s break it down together. Fatty fish contains eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) also known as omega-3 fatty acids. ²

What is Omega-3 fatty acids?

Omega-3 fatty acids is the secret sauce of heart-healthy unsaturated fats, they play a critical role in reducing inflammation which in turns protects the blood vessels, lowering the risk for heart disease and strokes. ³ Besides their anti-inflammatory effect, omega 3 benefits the heart by performing these functions:

• Reducing triglycerides and cholesterol risk
• Preventing high blood pressure
• Reducing blood coagulation
• Controlling abnormal heartbeats ⁴

To explain more on the function of omega 3 for the heart and its beneficial effect.

Now that we know the benefits, it’s only natural to ask ourselves:

Which kind of oily fatty fish rich in omega-3 fatty acids?

Here is a fatty fish list for you rich in omega 3: ^3,4

• Herring
• Salmon
• Oyster
• Trout
• Tuna
• Cod
• Mackerel
• Sardine

On average, you shouldn’t consume more than 8 ounces a week of fatty fish rich in omega 3. ⁵ Or 20g/day for the best results.⁶ Though, if you’re interested in nutrition or on a special diet, take a look at this reference which shows the rough estimates of omega 3 fatty acids and their content. ⁷ However, be careful not to take too much, excess consumption of oily fish can cause bleeding.⁸

This is all great news, so basically what we know so far is that fatty fish contains omega 3, which is very good for our heart health, but has this been tried before? Let’s talk NUMBERS!

This topic has been very popular for the past couple of years that there have been numerous trials, and studies about it. Fortunately for us this means reliable data from extremely trusted sources.

The first finding we have agrees with current guidelines that promote the use of marine-derived omega-3 fatty acids for the prevention of coronary heart disease and major vascular events, this is according to a study published in the American Journal of Clinical Nutrition where the result proved to be substantially effective for lowering the risk of Cardiovascular disease, with collective analysis signifying 36% lower risk of heart disease death with moderate consumption of fatty fish compared with no consumption. ⁹

In another large research study done by Khan and his fellow scientists that was published in EClinicalMedicine journal, they found out after analyzing 38 randomized controlled trials, that omega-3 Fatty acids were linked with reducing cardiovascular death and other cardiovascular outcomes. In addition, they also identified EPA as better than DHA in reducing bad heart disease outcomes. ¹⁰

In another study, researchers evaluated previously published work on the association between omega 3 fatty fish and heart disease, they wanted to figure out if it will be beneficial among those who are healthy and prevent any risk for developing heart disease in the first place or is it for those who are already CVD patients and prevent further complications? They examined the data from 4 studies in 21 countries among 191, 558 participants from both groups, those who are patients and those who are healthy. They used a questionnaire to search for heart disease outcome and identify those who experienced cardiac disease events like myocardial infarction, stroke, congestive heart failure, or sudden death. As a result, they concluded that consumption of oily fish is effective in decreasing heart disease symptoms, but it didn’t show much effect in the case of healthy participants. ¹¹

“This study has important implications for guidelines on fish intake globally. It indicates that increasing fish consumption and particularly oily fish in vascular patients may produce a modest cardiovascular benefit.” said lead co-author Andrew Mente, associate professor of research methods, evidence, and impact at McMaster and a principal investigator at the Population Health Research Institute of McMaster University and Hamilton Health Sciences. And he conducted this study from data pooled over 25 years, so he knows what he’s talking about!

But what about those who are healthy and do not suffer from heart disease? Should they ignore the previous recommendations for eating fatty fish and loading on omega 3?

‘People at low risk for cardiovascular disease can still enjoy modest protection from CVD by eating fish rich in omega-3, but the health benefits were less pronounced than those high-risk individuals.’ – Mente exclaimed ¹²

After hearing all the positive benefits, you will get from including fatty fish into your diet, there’s one downside you need to be on the lookout for which is Fish Pollutants!

Recent data from the Food Standards Agency warns about methyl mercury and PCB also known as polychlorinated biphenyl which is short for toxic waste found in industrial compounds – a really bad guy – while methylmercury is a naturally occurring pollutant found in air and can be precipitated in water as well. Both are toxic pollutants in oily fish which is why they recommend the following: ¹³

• Eat a variety of fish – don’t stick to just one kind
• Limit weekly consumption of fish to the portion agreed as safe by experts
• Pregnant women and children should completely avoid ‘marlins, swordfish and sharks’ – As they contain methyl mercury which after building up in the body can cause harm
• Restriction of tuna fish for young girls and women in childbearing age – to avoid methyl mercury buildup in their bodies

So how can you spot safe choices when you shop for fish to eat?

Let’s start with the general rule and go into specifics:

• Make sure to choose young fish rather than old fish
• Visit: Seafood Watch – Sustainable Seafood list which is updated periodically factoring environmental sustainability and methyl mercury/PCB toxins that can be very harmful for you.

Despite their toxic effect, the surprising thing about mercury is that it’s not only harmful but when it’s built up it can actually cause heart disease! This is what a study conducted by Hu and his fellow researchers. They gathered data from 14 studies and the results were collected from more than 34,000 participants only to find out that long term exposure to mercury was a great risk factor and the sole responsible culprit in many bad cardiovascular outcomes. ¹⁴

The previous finding shouldn’t necessarily give you trust issues yet, because even though we’ve presented you with both the benefits and the drawbacks of fatty fish consumption. We also presented you with the solutions. There’s only one question left to ask, which is:

Allergic to fish or a vegan/vegetarian?

Fear not our fellow readers, we still have some alternatives up our sleeve, and they are: 13,15

• Omega 3 plant foods
• Omega 3 eggs
• Omega 3 supplements

Omega 3 plant foods:

Alpha-linolenic acid (ALA) is the most common omega-3 fatty acid. The human body generally uses ALA for energy, and conversion into EPA and DHA is very limited. There are many rich plant foods with high amount of omega 3, but here are some examples with rich omega 3 source: flax seeds, walnuts, chia seeds, soybean/soybean oil, tofu, canola oil, or margarines made with these oils.

Omega 3 eggs:

Omega 3 eggs are produced by chicken put on a diet with flax seed. The hen’s body converts the omega 3 fat from the flax seed they are fed into omega 3 fats that our bodies can use, and they should be restricted to 2 per week.

Omega 3 supplements:

Although the verdict on supplements efficacy still swings between yes and no, it’s recommended to take omega 3 from natural sources, however, supplements are sold and can be integrated into. A daily intake of 500mg of EPA and DHA combined is roughly the equivalent of one portion of oily fish per week. Nevertheless, if you are taking “blood thinning” medications such as aspirin, warfarin or heparin, always consult your doctor before switching to any kind of fish oil supplements as these also have a “blood thinning effect”.

Here are some more examples for you of more foods important for heart health.

The Bottom Line

Several clinical studies have proven the key role omega 3 from fatty fish plays in the preventing heart diseases and reducing inflammation which means that with ongoing further research, fatty fish can be utilized in targeted therapy in several other diseases as well. Albeit there’s the rising issue of contaminants but if everyone keeps in mind foretold recommendations and guidelines in this article, we can all enjoy the pros of fatty fish and stay away from the cons! You can also be on the safe side and lower the portion of oily fish, and follow these tips to boost your heart health.

“Fish should be part of a balanced diet, but two fish meals a week is not really a wise recommendation” Dr. Carpenter from the environmental health sciences at the State University of New York in Albany.

Stay tuned for more updates, and tell us how much will you incorporate of fatty fish in your week? 😊

References:

1.        Omega-3 Fatty Acids and Heart Health | Circulation [Internet]. [cited 2022 Jan 25]. Available from: https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.114.015176

2.        Omega-3 Fatty Acids and Coronary Heart Disease – Health Encyclopedia – University of Rochester Medical Center [Internet]. [cited 2022 Jan 25]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=1&contentid=3054

3.        Fish Help the Heart by Fighting Inflammation [Internet]. [cited 2022 Jan 25]. Available from: https://www.webmd.com/heart-disease/news/20050705/fish-help-heart-by-fighting-inflammation

4.        Omega-3 in fish: How eating fish helps your heart – Mayo Clinic [Internet]. [cited 2022 Jan 25]. Available from: https://www.mayoclinic.org/diseases-conditions/heart-disease/in-depth/omega-3/art-20045614

5.        2 Servings of Fish Per Week Helps Prevent Recurrent Heart Disease [Internet]. [cited 2022 Jan 25]. Available from: https://www.healthline.com/health-news/2-servings-of-fish-per-week-can-help-prevent-recurrent-heart-disease#Dietary-guidelines-for-fish-consumption

6.        Zhang B, Xiong K, Cai J, Ma A. Fish Consumption and Coronary Heart Disease: A Meta-Analysis. Available from: www.mdpi.com/journal/nutrients

7.        Chaddha A, Eagle KA. Omega-3 Fatty Acids and Heart Health. Circulation [Internet]. 2015 Dec 1 [cited 2022 Jan 25];132(22):e350–2. Available from: https://www.ahajournals.org/doi/abs/10.1161/CIRCULATIONAHA.114.015176

8.        Cleveland Clinic. Omega-3 Fatty Acids: Foods & Benefits [Internet]. 2019 [cited 2022 Jan 26]. Available from: https://my.clevelandclinic.org/health/articles/17290-omega-3-fatty-acids

9.        Mozaffarian D. Fish and n-3 fatty acids for the prevention of fatal coronary heart disease and sudden cardiac death. American Journal of Clinical Nutrition. 2008;87:1991S.

10.      Khan SU, Lone AN, Khan MS, Virani SS, Blumenthal RS, Nasir K, et al. Effect of omega-3 fatty acids on cardiovascular outcomes: A systematic review and meta-analysis. EClinicalMedicine. 2021 Aug;38:100997.

11.      Mohan D, Mente A, Dehghan M, Rangarajan S, O’Donnell M, Hu W, et al. Associations of Fish Consumption with Risk of Cardiovascular Disease and Mortality among Individuals with or without Vascular Disease from 58 Countries. JAMA Internal Medicine. 2021 May 1;181(5):631–49.

12.      McMaster University. Study finds two servings of fish per week can help prevent recurrent heart disease [Internet]. 2021 [cited 2022 Jan 26]. Available from: https://healthsci.mcmaster.ca/home/2021/03/08/study-finds-two-servings-of-fish-per-week-can-help-prevent-recurrent-heart-disease

13.      Heart UK – The Cholesterol Charity. Fish. 2015;

14.      Hu XF, Lowe M, Chan HM. Mercury exposure, cardiovascular disease, and mortality: A systematic review and dose-response meta-analysis. Environmental Research. 2021 Feb 1;193:110538. 15.       McMaster Children’s Hospital. Omega 3 fats. 2013.