The unique combination of nutrients in sardines makes the tiny fish a great choice if you’re looking to manage blood sugar. In fact, eating them regularly could even lower your risk of developing type 2 diabetes and protect your heart health.
Blood sugar spikes are primarily driven by simple carbohydrates (or simple sugars). Sardines have no carbohydrates at all, so they won’t raise your blood sugar after you eat them.
In addition, sardines may help modulate blood sugar spikes when you do eat carbohydrate-rich foods. That’s because sardines contain other beneficial nutrients, including:
- Protein: A can of sardines contains 22.6 grams of protein. This can slow gastric emptying, meaning that it takes more time for food to leave your stomach. Slower digestion is good for blood sugar, as any sugar you consume during a meal is released into the bloodstream more gradually.
- Healthy fats: Sardines are one of the best sources of omega-3 fatty acids. These healthy, unsaturated fats can reduce inflammation, which otherwise interferes with the function of insulin. Insulin is a hormone that helps move glucose out of the bloodstream and into cells, keeping blood sugar levels where they should be. Plus, like protein, foods with healthy fats can slow digestion.
- Magnesium and vitamin D: Sardines are a decent source of both magnesium and vitamin D. Evidence suggests these two micronutrients work together to help keep blood sugar levels steady, though most research has been done in supplements.
- Taurine: This amino acid found in sardines helps improve how your body responds to insulin, which may lead to better blood sugar control.
Keeping your blood sugar stable over time may help prevent type 2 diabetes. And research suggests sardines’ blood sugar benefits could help people lower their risk of type 2 diabetes.
In a 2021 study, researchers followed 152 older adults with prediabetes, a condition where blood sugar levels are elevated but don’t yet qualify as diabetes. For one year, half of the participants followed a diabetes-prevention diet, while the other half followed the same diet and also ate 200 grams (just over two cans) of sardines each week.
The sardine group saw major improvements—37% were at very high risk of diabetes when the study began, but that number dropped to 8% after a year. In the control group, the percentage of those at very high risk for diabetes fell from 27% to 22%.
The researchers concluded that sardines may be able to improve the body’s response to insulin, suggesting that regular consumption of sardines can lower diabetes risk for those with prediabetes.
It’s important to avoid diabetes and maintain healthy blood sugar if you want to protect your heart. But sardines can boost your heart health in other ways, too.
For one, sardines contain omega-3 fatty acids, which improve heart health by:
- Lowering triglycerides: Omega-3s help manage high levels of triglycerides, which are fats in the body. Depending on your cholesterol levels, high triglycerides can contribute to fatty buildups in the arteries which raise stroke and heart attack risk.
- Tamping down inflammation: Over time, inflammation damages your blood vessels, allowing plaque—waxy deposits made of cholesterol, fat, and calcium—to build up in the arteries. This can restrict blood flow and raise the risk of a heart attack. Omega-3s may help prevent this with their anti-inflammatory properties.
In addition to omega-3s, sardines contain other nutrients that play various roles in supporting healthy heart function, including potassium, magnesium, zinc, calcium, and iron.
Because of these benefits, the American Heart Association recommends that people eat two servings of non-fried fish (which can include sardines) each week to lower their risk of heart disease.
A standard, 3.75-ounce serving of canned sardines in oil provides the following:
- Calories: 191
- Protein: 22.6 grams
- Fat: 10.5 grams
- Carbohydrates: 0 grams
- Calcium: 351 milligrams
- Iron: 2.69 milligrams
- Potassium: 365 milligrams
- Magnesium: 35.9 milligrams
- Selenium: 48.5 micrograms
- Zinc: 1.2 milligrams
- Vitamin B12: 8.22 micrograms
- Vitamin D: 4.42 micrograms
- Vitamin E: 1.88 milligrams
- Sodium: 282 milligrams
Sardines are generally a healthy choice. However, there are a few things you should watch for if you’re making them a regular part of your diet:
- Sodium content: In canned varieties of sardines, sodium levels can be high—a standard can contains 282 milligrams of sodium. Adults should limit their sodium intake to 2,300 milligrams per day, so a can of sardines provides about 10% of that daily amount. Maintaining healthy sodium intake is particularly important if you’re managing high blood pressure.
- Heavy metals: Lead and mercury are sometimes found in fish. These metals accumulate gradually, so older, larger fish like sharks and swordfish have the highest levels. Sardines and other smaller options are much safer because they sit lower on the food chain. However, it can also depend on where they were caught, as some sardines from specific regions around the world have tested above safety limits.
