What Happens if You Eat Fish Every Day

What is mercury poisoning?

The biggest concern with eating a lot of fish is mercury poisoning. Mercury is a naturally occurring substance and is not problematic in small amounts. However, too much can lead to troubling symptoms that affect children (born and unborn) most significantly. Acute mercury poisoning can lead to permanent neurological deficits, including developmental delays in children.

There is no cure, but further progression can usually be halted by removing the source of the mercury. Really bad levels of exposure might require chelation therapy to remove the mercury from your system. Unfortunately, neurological disorders in children from mercury are typically permanent. Adults are likely to find their symptoms temporary.

Highest and lowest risk fish

In general, larger, predatory fish have higher levels of mercury because they feed many on smaller fish who each have a lower level. They also live longer, during which time the mercury continues to accumulate. This is the same way that humans can end up with too much mercury if they eat a lot of fish.

But, stresses Eric Rimm, professor of epidemiology and nutrition at the Harvard School of Public Health, “For most individuals it’s fine to eat fish every day.” With the exception of pregnant women and children, you can safely eat fish every day without worry of mercury poisoning as long as you limit the amount of high mercury fish to two servings per week.

Low mercury fish: salmon, shrimp, catfish, tilapia, scallops, oysters, herring, sardines, and trout

High mercury fish: swordfish, king mackerel, shark, tilefish, orange roughy, marlin, ahi and bigeye tuna

Benefits of daily fish consumption

Eating fish affords many positive health benefits, including improved metabolism, sleep quality, skin quality, and concentration as well as lower inflammation. But that’s not all. Read on for six great reasons to eat more fish.

1. Get good fat

When it comes to red meat, it is always best to choose the leanest cuts possible. But with fish, it is actually the fattiest kinds that are most healthful. That’s because the fat in fish is in the form of omega-3 fatty acids, or “good” fats. Omega-3s contribute to the optimal function of the brain for starters, but also play a critical role in cardiovascular health.

Regular consumption of omega-3 fatty acids can help lower the risk of heart disease or stroke, and slows the growth of plaque in the arteries. It also lowers triglycerides (i.e., “bad” fat) and reduces blood pressure.

2. Maintain a healthy heart

Swapping fish for other forms of protein like red meat, chicken, pork, and lamb can be a smart choice for heart health. The omega-3s largely deserve the thanks, but recent studies indicate that it may be the combination of omega-3 fatty acids and other nutrients in fish that cause the lower incidence of heart attack or death from heart disease among people who eat a lot of fish.

3. Get enough vitamin D

Fish is a natural source of vitamin D, which is otherwise only synthesized from sun exposure. But many people are nevertheless deficient in D because we spend so much time inside. Because vitamin D plays a crucial role in allowing the body to absorb a lot of other nutrients, without it we may experience deficiencies despite adequate intake.

Think of your daily serving of fish as a booster for everything else you eat throughout the day.

4. Fight depression

Scientists are still trying to determine why, but it’s clear that people who eat the most fish have lower than average incidence of depression. It may be that an overall healthy diet is associated with better mood, but we also know that omega-3 fatty acids can affect the level of feel-good chemicals dopamine and serotonin in the brain.

Finally, as fish is naturally able to reduce inflammation, eating a lot of it improves blood flow. That can also help improve brain function and smooth out mood swings.

5. Reduce risk of autoimmune disorders

An autoimmune disorder is when the body’s immune system gets confused and attacks and destroys healthy body tissue. One of the most common examples is type 1 diabetes, in which an immune system attacks insulin-producing cells in the pancreas.

There have been multiple studies that indicate lower incidence of type 1 diabetes in people who consume omega-3s or fish oil regularly. Early information seems to point to lower risk for other autoimmune diseases like rheumatoid arthritis and multiple sclerosis as well.

6. Stay mentally sharp

As we age, mental function often declines. Response times to stimuli become longer and short term memory is compromised. This is called age-related cognitive decline, and in severe cases, it can progress into Alzheimer’s. For some reason we don’t fully understand yet, people who eat a lot of fish have slower rates of cognitive decline. It may be related to the amount of grey matter found in our brains.

Grey matter is the major functional tissue that contains neurons to process information and store memories. The more the better, and people who eat fish regularly seem to have more grey matter in the areas of the brain that regulate memory and emotion.

If you like fish, there’s really no reason not to eat it every day. Well, there are two reasons – pregnancy or childhood. And one further concern is environmental. If every non-pregnant adult ate fish every day, we would quickly cause the extinction of the world’s edible fish population. However, fish has a distinctive taste that not everyone likes, so as long as fish lovers stick to sustainably harvested products, extinction should not be a concern.

If you are one of those people who don’t care for food with fins, you can still reap some of the benefits of fish by taking a fish oil supplement. The oil in these supplements is typically processed to remove mercury. Food sources of anything are always better absorbed than extracts or supplements, but it is still better than nothing. Eating fish clearly offers many health benefits.