Pickled herring can be a reasonable choice for people with diabetes, but it comes with trade-offs that matter. The fish itself is rich in omega-3 fatty acids and protein, both beneficial for blood sugar management and heart health. The pickling process, however, often adds significant sodium and sugar that can work against you. The answer depends largely on which type of pickled herring you choose and how much you eat.
How Pickled Herring Affects Blood Sugar
Herring on its own is very low in carbohydrates, which means it has minimal direct impact on blood sugar. A typical serving of pickled herring scores well on blood sugar indexes because the protein and fat content far outweigh the carbohydrates. The concern is what gets added during pickling.
A study of overweight Swedish men compared meals containing 150 grams of pickled herring, baked herring, and baked beef. The pickled herring meal produced a higher insulin response than either the baked herring or the beef. The reason wasn’t the fish itself. It was the higher carbohydrate load in the pickled herring meal (81 grams versus 47 grams in the other meals), which came from sugar in the pickling brine. So the fish is fine for blood sugar; the sweetened brine is the problem.
There’s an interesting counterpoint here. The vinegar used in pickling may actually help with blood sugar control. A review of the evidence found that roughly 2 to 6 tablespoons of vinegar taken with a carbohydrate-rich meal can improve the body’s glycemic response. Pickled herring contains acetic acid from the vinegar brine, which could partially offset the sugar added during preparation. That said, relying on pickled herring as a vinegar delivery system isn’t practical when you can simply dress a salad with vinegar instead.
The Omega-3 Advantage
Where herring truly shines for people with diabetes is its omega-3 fatty acid content. Herring is one of the richest dietary sources of EPA and DHA, the long-chain omega-3 fats that your body uses most readily. These fats reduce chronic inflammation, which is considered a hallmark of insulin resistance. They also influence how cell membranes function, improving the way cells respond to signaling from insulin and other hormones.
Animal research has shown that metabolites produced from omega-3 fats can improve both peripheral and liver-based insulin action, and may help suppress excess glucose production by the liver. While translating animal findings to humans is never straightforward, the anti-inflammatory properties of omega-3s are well established and relevant to the kind of low-grade inflammation that drives type 2 diabetes progression.
The cardiovascular benefit is even more clear-cut, and that matters because heart disease is the leading cause of death among people with diabetes. A large study of diabetic women found that those who ate fish five or more times per week had a 64% lower risk of coronary heart disease compared to women who ate fish less than once a month. Higher intake of long-chain omega-3 fats was also linked to lower overall mortality. Herring, whether pickled, baked, or smoked, delivers these fats in abundance.
The Sodium Problem
Sodium is the biggest nutritional concern with pickled herring. While a 3-ounce serving of plain grilled or baked herring contains about 98 milligrams of sodium, the same amount of pickled herring can contain several times that. The exact number varies by brand and recipe, but “high in sodium” is the consistent label from nutrition databases.
This matters because many people with type 2 diabetes also have high blood pressure or are at elevated risk for it. Excess sodium raises blood pressure, which in turn increases the risk of heart attack, stroke, and kidney damage. If you already manage hypertension alongside diabetes, pickled herring in large amounts could undermine that effort. Smoked herring contains considerably less sodium than the pickled version, and fresh herring contains the least of all.
Hidden Sugar in Commercial Brands
Check the ingredient list on any jar of commercial pickled herring and you’ll almost always find sugar listed near the top. A typical product lists herring, sugar, onions, water, distilled vinegar, salt, and spices. Some varieties, like herring in wine sauce or cream sauce, can contain even more added sugar. The amount per serving varies, but it’s enough to raise the carbohydrate content of what would otherwise be a very low-carb food.
If you enjoy pickled herring and want to keep it in your diet, look for brands that minimize added sugar, or consider making your own at home where you control the brine. A simple brine of vinegar, water, salt, and spices without sugar produces a tangier product but one that’s far more compatible with blood sugar management. You can also rinse commercial pickled herring before eating it to remove some of the sugary brine coating the fillets.
Best Ways to Include Herring
For someone managing diabetes, the ideal approach is to get herring’s benefits while minimizing its risks. Fresh or baked herring gives you all the omega-3s, protein, and micronutrients with minimal sodium and zero added sugar. A 3-ounce serving delivers substantial protein with almost no carbohydrates, making it one of the most blood-sugar-friendly protein sources available.
If pickled herring is what you prefer, treat it as an occasional food rather than a staple. Keep portions moderate, choose low-sugar varieties, and balance the sodium by keeping the rest of your meal lower in salt. Pairing pickled herring with whole-grain crackers and vegetables, rather than white bread, helps manage the overall glycemic impact of the meal.
Smoked herring offers a middle ground: more flavor than plain baked herring, less sodium than pickled, and no added sugar. It retains the full omega-3 profile and pairs well with the same foods you’d eat with pickled herring. For someone who wants the taste of cured fish without the blood sugar and blood pressure trade-offs, it’s the most practical option.