Eating Fish for Heart Health: Guide for Canadians

Eating fish for heart health is one of the most well-supported nutrition recommendations in Canada, backed by decades of research showing that just one or two fish meals per week may reduce your risk of dying from a heart attack by up to one third. Whether you are trying to protect your cardiovascular system or manage an existing heart condition, adding fish to your weekly meals is a simple and proven step that most Canadian health experts agree on.

Why Eating Fish for Heart Health Makes a Real Difference

The key reason fish is so beneficial comes down to omega-3 fatty acids and their role in heart disease prevention. These essential unsaturated fats help lower blood pressure, reduce chronic inflammation, and improve cholesterol levels — all major risk factors that contribute to cardiovascular events. Despite these well-known benefits, most Canadians still fall short of the recommended intake, making it more important than ever to understand how fish fits into a heart-healthy diet.

Why Eating Fish for Heart Health Makes a Difference

Common Fish Options for Eating Fish for Heart Health in Canada

Fish Type	Omega-3 Content (per 85g serving)	Heart Health Benefits	Canadian Availability & Considerations
Atlantic Salmon (Wild)	1,500–2,000 mg	Reduces triglycerides, lowers blood pressure, decreases inflammation	Widely available across Canada; choose wild-caught Pacific or Atlantic varieties when possible
Mackerel	2,200–2,600 mg	Strongly reduces LDL cholesterol, supports healthy heart rhythm	Affordable and accessible; avoid King Mackerel due to higher mercury levels
Sardines	1,300–1,800 mg	Lowers cardiovascular disease risk, reduces arterial inflammation	Canned varieties widely available; low mercury, safe for frequent consumption
Rainbow Trout	900–1,200 mg	Supports healthy blood pressure and reduces risk of arrhythmia	Farmed in Ontario and British Columbia; low contaminant levels, excellent domestic option
Herring	1,700–2,100 mg	Reduces triglycerides and supports overall cardiovascular function	Common in Atlantic Canada; available pickled or fresh; low mercury risk
Albacore Tuna (Canned)	700–900 mg	Provides moderate omega-3 benefits, supports healthy cholesterol levels	Health Canada recommends limiting to 150g per week for adults due to moderate mercury content

Fish contains omega-3 fatty acids, a type of unsaturated fat that is good for your heart. When you replace saturated fats — like those found in red meat — with the unsaturated fats in fish, your cholesterol levels can improve. Lower cholesterol means less plaque building up in your arteries.

Omega-3 fatty acids also help reduce inflammation throughout your body. Inflammation plays a big role in heart disease, stroke, and other serious conditions. In addition, omega-3s have been linked to lower blood pressure and better immune system function.

For many years, Health Canada has encouraged Canadians to eat fish at least twice a week as part of a heart-healthy diet. Most Canadians do not get enough omega-3s from their daily meals, making fish an important food to include regularly.

What Omega-3 Fatty Acids Do for Your Body

Omega-3 fatty acids do much more than protect your heart. Here is a quick look at the key benefits researchers have identified:

• Reduce triglycerides (a type of fat in your blood)
• Lower blood pressure
• Reduce blood clotting risk
• Support a healthy immune system
• Help ease symptoms of arthritis
• Support brain development and learning in children

However, not all omega-3 benefits are equal. Studies show the greatest heart benefits come from eating whole fish rather than taking supplements alone. The combination of nutrients in real fish seems to work better together than any single ingredient in a pill.

Which Fish Are Best for Heart Health?

Fatty fish contain the highest levels of omega-3 fatty acids. These are your best choices for eating fish for heart health. Good options include:

• Salmon — widely available across Canada, fresh or frozen
• Herring — affordable and commonly found in Canadian grocery stores
• Mackerel — high in omega-3s, though larger mackerel have more mercury (see below)
• Trout — especially rainbow trout, which is popular in Canadian lakes and fish markets
• Sardines — small, affordable, and low in contaminants
• Tuna — a decent source of omega-3s, though lower than salmon or herring

Most freshwater fish have lower omega-3 levels than ocean fish. However, some trout varieties — including Canadian lake trout — contain relatively high amounts of omega-3s. These are a great local option for many Canadians.

Fish to Limit or Avoid

Some fish are low in omega-3s and high in a less helpful fat called arachidonic acid, a type of omega-6 fatty acid. Tilapia and catfish fall into this category. Too much arachidonic acid may increase inflammation in your body, which can raise your risk of heart disease.

Furthermore, large predatory fish tend to carry higher levels of mercury and other contaminants. It is a good idea to limit how often you eat shark, swordfish, and large mackerel. These fish sit at the top of the food chain, so they accumulate more toxins over their longer lifespans.

How Much Fish Should You Eat Each Week?

For most healthy adults, the recommendation is at least two servings of omega-3-rich fish per week. A standard serving is about 85 grams (roughly 3 ounces), which is about the size of a deck of cards. This is consistent with guidance from both Health Canada and major heart health organisations.

Two servings per week gives your body a steady supply of omega-3 fatty acids without overloading on any potential contaminants. You can spread these meals throughout the week — for example, salmon on Tuesday and a tuna salad on Friday.

Special Recommendations for Children and Pregnant Women

Pregnant women, women planning to become pregnant, breastfeeding mothers, and children under 12 need to be more careful. Their bodies are more sensitive to mercury and other toxins found in some fish. However, fish is still a healthy choice for these groups when chosen carefully.

Recommended limits for these groups include:

• No more than 340 grams of low-mercury fish per week (such as salmon, trout, or sardines)
• No more than 170 grams of canned tuna per week
• Avoid entirely: shark, swordfish, and large mackerel due to high mercury levels

These guidelines help protect developing brains and nervous systems while still allowing families to benefit from omega-3 fatty acids. For more details, you can review the Health Canada guidance on mercury in fish.

Does Mercury in Fish Cancel Out the Heart Health Benefits?

This is one of the most common concerns Canadians have about eating fish. The short answer is: for most healthy adults, the heart health benefits of eating fish outweigh the risks from mercury and other contaminants.

Mercury occurs naturally in the environment in small amounts. However, industrial pollution adds more mercury to lakes, rivers, and oceans. Tiny microorganisms in the water convert this mercury into a highly toxic form called methylmercury. Fish absorb methylmercury as they feed, and larger fish accumulate more of it over time.

If a person eats large amounts of high-mercury fish, the toxin can build up in the body. It may take weeks, months, or even a year for the body to clear it out. Methylmercury is especially harmful to the developing brains of foetuses and young children. For the average healthy adult, however, methylmercury is unlikely to cause serious problems when fish is eaten in reasonable amounts.

Other Contaminants to Know About

Beyond mercury, some fish can carry dioxins and polychlorinated biphenyls (PCBs). These are industrial chemicals that can accumulate in fatty fish tissue. The risks depend on where the fish was caught and its species. Farmed fish and wild-caught fish may have different contaminant profiles depending on their feed and environment.

Therefore, it is a smart habit to vary the types of fish you eat rather than relying on one species every week. Eating a variety of fish helps limit your exposure to any single contaminant while giving you a broad range of nutrients. The Mayo Clinic’s guide to omega-3 fatty acids and heart health offers a helpful overview of these benefits and risks.

Can Omega-3 Supplements Replace Fish?

Many Canadians wonder whether they can skip the fish and just take an omega-3 supplement instead. Supplements are convenient, but research consistently shows that eating whole fish provides more heart health benefits than supplements alone.

Whole fish contains a combination of nutrients — including protein, vitamins D and B12, and selenium — that work together in ways a supplement cannot fully replicate. However, omega-3 supplements can still be helpful for people who already have heart disease or who cannot eat fish for dietary reasons.

If you are considering omega-3 supplements, it is best to speak with your family doctor first. They can advise on dosage and whether supplements are appropriate alongside any medications you may be taking. Some omega-3 supplements can interact with blood thinners, so professional guidance is important.

When to See a Doctor

If you have concerns about your heart health, do not wait to get them checked. Book an appointment with your family doctor or visit a walk-in clinic if you do not have a regular doctor. Most provincial health plans in Canada cover routine heart health assessments, including cholesterol and blood pressure checks.

You should also speak to a healthcare provider before making major changes to your diet if you are pregnant, have kidney disease, or take prescription medications. A registered dietitian — often available through your provincial health plan — can also help you build a heart-healthy eating plan that works for your lifestyle and budget.

Always consult your doctor or a qualified healthcare professional before making significant dietary changes, especially if you have an existing health condition.

Frequently Asked Questions

Key Takeaways

• Eating fish for heart health is one of the most effective dietary changes you can make.
• Aim for at least two servings of fatty fish per week, each about 85 grams.
• The best choices are salmon, herring, trout, and sardines — all widely available in Canada.
• For most healthy adults, the benefits of omega-3 fatty acids outweigh the risks from mercury and other contaminants.
• Pregnant women, breastfeeding mothers, and children under 12 should choose low-mercury fish and follow portion limits.
• Whole fish is more beneficial than omega-3 supplements, though supplements may help people with existing heart disease.
• Talk to your family doctor or walk-in clinic if you have concerns about your heart health or diet. Most provincial health plans cover these consultations.