Yes, you can eat tuna while nursing; light tuna (2–3 servings per week) is safe when following FDA advice, but albacore should be limited to one serving per week to manage mercury intake.
You probably know tuna is packed with protein and DHA — great for your baby’s brain development. But then you hear warnings about mercury, and suddenly that can of tuna feels like a minefield.
The good news is that nursing parents don’t have to avoid tuna entirely. Federal agencies like the FDA and CDC have spelled out clear, safe limits based on decades of research. This article breaks down what those limits are, why they matter, and how to keep tuna in your rotation without stress.
What the Guidelines Actually Say for Nursing Parents
The FDA and EPA recommend that people who are breastfeeding eat between 8 and 12 ounces of low-mercury seafood per week. That’s roughly two to three servings. Canned light tuna is listed as a “Best Choice” — meaning you can eat it at that rate without concern.
Albacore (white) tuna is a different story. Because it comes from larger, older fish that accumulate more mercury, the FDA places it in the “Good Choices” category. That means you stick to one serving per week. A serving is about 4 ounces before cooking (about half a full-size can).
The NHS in the UK uses slightly different language but reaches a compatible recommendation: nursing mothers should not eat more than two portions of oily fish per week, which includes fresh tuna (but not canned light tuna, which is not considered oily fish). So if you’re following UK guidelines, you can have canned light tuna plus up to two portions of fresh tuna or other oily fish, as long as total mercury load stays low.
Why Mercury in Tuna Is a Concern for Nursing Moms
Most of us have heard that mercury is bad for a baby’s developing nervous system. That’s true — but it’s also why agencies have created such specific limits. The goal isn’t to scare you off fish; it’s to help you enjoy the benefits (omega‑3s, protein, B vitamins) while avoiding the risks of excessive methylmercury.
Here’s what the science says about how mercury enters the food chain and why tuna gets singled out:
- Mercury accumulates in larger fish. Methylmercury builds up in the muscle of predatory fish that live longer and eat other fish. Bigeye tuna and shark top the list of fish to avoid during breastfeeding.
- Smaller tuna species carry less mercury. Canned light tuna typically comes from skipjack tuna, which are smaller and accumulate far less mercury than the larger albacore or bigeye varieties.
- Mercury passes into breast milk in small amounts. The amount that transfers is low — the CDC notes that following fish advice keeps baby’s exposure well below safety thresholds. Your body also filters some mercury before it reaches milk.
- The benefits of fish outweigh the risks for most families. A review in PMC concluded that eating fish 2–3 times per week during pregnancy and breastfeeding provides DHA that supports infant brain development, and the mercury risk is minimal when lower‑mercury choices are selected.
The takeaway: mercury is real, but the limits are designed so you don’t have to stress. The key is choosing the right type of tuna and keeping track of portions.
Making Sense of Canned Light vs. Albacore Tuna
The easiest way to follow the guidelines is to know which label to grab at the grocery store. Canned light tuna — usually from skipjack — is your go‑to for multiple servings per week. Albacore (white) tuna is fine in moderation, but you count it as your one “Good Choice” serving. Fresh tuna steaks fall into the same category as albacore: good but limited.
The table below summarizes the mercury risk categories and recommended weekly servings for the most common types of tuna, as outlined by the FDA fish advice breastfeeding.
| Tuna Type | Mercury Level | FDA Category | Max Servings/Week |
|---|---|---|---|
| Canned light (skipjack) | Lower | Best Choices | 2–3 |
| Canned albacore (white) | Moderate–higher | Good Choices | 1 |
| Fresh tuna (yellowfin, ahi) | Moderate | Good Choices | 1 |
| Fresh tuna (bluefin) | High | Choices to Avoid | Avoid |
| Bigeye tuna | Highest | Choices to Avoid | Avoid |
To put that in practical terms: if you eat two cans of light tuna in a week, you still have room for other lower‑mercury seafood like salmon, sardines, or cod. And if you have one can of albacore, skip the fresh tuna steak that week — it counts toward the same mercury budget.
3 Steps to Safely Include Tuna While Nursing
You don’t need a spreadsheet to manage your seafood. These three steps align with the FDA and CDC recommendations and keep things simple.
- Choose light tuna most of the time. When you buy cans, check the label for “light” or “skipjack.” That’s your best choice for multiple weekly servings. Reserve albacore for occasional use — like once a week or less.
- Keep one serving at about 4 ounces. A standard can of tuna is about 5 ounces drained, so that counts as roughly one serving. If you’re eating a fresh tuna steak, aim for a piece the size and thickness of the palm of your hand.
- Mix up your seafood sources. The guidelines encourage eating a variety of fish — not just tuna. Salmon, sardines, trout, and cod all provide omega‑3s with very low mercury. Rotating keeps you well within safety limits and gives you a wider nutrient profile.
Following these steps means you can enjoy tuna sandwiches, tuna salad, or tuna melts several times a week without second‑guessing the mercury numbers.
Mercury in Breast Milk: What the Research Shows
It’s natural to worry about what passes into your milk. The CDC explains that methylmercury from fish does transfer to breast milk, but the amount depends on how much high‑mercury fish you eat. For mothers following the FDA/EPA advice, the levels in milk are well below any established safety concern.
Per the CDC mercury fish advice, nursing parents are encouraged to eat mostly small fish such as sardines and scallops, which have the lowest mercury levels. Tuna — even light tuna — is a step up in mercury, which is exactly why the serving limits exist. The idea is to balance your omega‑3 intake across a range of fish rather than relying heavily on any one species.
The table below shows how tuna compares to a few common low‑mercury options that can round out your weekly seafood total.
| Fish | Typical Mercury Level | FDA Category |
|---|---|---|
| Sardines (canned) | Very low | Best Choices |
| Salmon (wild or farmed) | Very low | Best Choices |
| Canned light tuna | Lower | Best Choices |
| Albacore tuna (canned) | Moderate–higher | Good Choices |
Notice that you can eat unlimited amounts of sardines and salmon within the 8–12‑ounce weekly total because they’re Best Choices with very low mercury. They’re excellent ways to get your omega‑3s without counting servings as carefully as you would with tuna.
The Bottom Line
Tuna is safe and beneficial during breastfeeding when you stick to the serving guidelines: up to 2–3 servings of light tuna per week, or 1 serving of albacore. The agencies that set these limits did so based on decades of data showing that the nutritional upside of fish — especially DHA — outweighs the mercury risk for most nursing mothers. Keep variety on your plate, and you won’t have to worry.
If you have specific concerns about your mercury exposure or your baby’s development, your pediatrician or a lactation consultant can review your seafood habits and help tailor suggestions to your family’s needs — no need to guess.