It has long been known that eating oily fish (e.g. salmon, sardines) has health benefits for the heart. But it also looks like regularly eating sardines may be a good way to lower the risk of getting type 2 diabetes, as well as improving heart health.
In a study (conducted in Spain) 152 persons at risk for developing type 2 diabetes ("pre-diabetes") were randomly assigned to one of 2 groups for 1 year: Group 1 regularly ate sardines + followed a diabetes preventive diet, or Group 2 ate the same diabetes preventive diet, but without sardines. All participants were 65 years or older.
They found that after 1 year, the sardine group had greater health improvements than the non-sardine group. Fewer in the sardine group were still in the prediabetes group, and fewer had developed type 2 diabetes. The sardine group also had decreased triglycerides (good), greater increases in healthy HDL cholesterol, reduced insulin resistance, and lower blood pressure, as compared to the non-sardine group.
The sardine group also had higher taurine levels in the blood, as well as increases in nutrients linked to health benefits, including omega-3 EPA and DHA, vitamin D, and fluorine. Taurine has antioxidant and anti-inflammatory benefits.
What was their weekly consumption of sardines? They consumed 200 g of canned sardines in olive oil per week - eaten as 100 g servings twice per week. Which is a little less than eating two of the little 125 g cans of sardines in olive oil available at the grocery store. It was recommended that they eat the entire sardine, including bones, due to their rich content of calcium and vitamin D. [By the way, while the researchers don't discuss this - increased extra virgin olive oil consumption also has health benefits.]
Medscape article: Sardines Linked to Reduced Type 2 Diabetes Risk
Excerpts from Medical Xpress: Eating sardines regularly helps prevent type 2 diabetes
The health benefits of sardines and oily fish are widely known: their high levels of unsaturated fats help to regulate cholesterol levels and prevent the onset of cardiovascular diseases. However, the benefits don't end there.
A study led by Diana Diaz Rizzolo, lecturer and researcher of the Universitat Oberta de Catalunya's (UOC) Faculty of Health Sciences and the August Pi i Sunyer Biomedical Research Institute (IDIBAPS), has discovered that the regular consumption of sardines helps to prevent the onset of type 2 diabetes.
The study enrolled 152 patients aged 65 years and older who had been diagnosed with prediabetes (blood glucose levels between 100-124 mg/dl) from three different Primary Care centers. All of these patients were put on a nutritional program that sought to reduce the risk of them developing the disease, but only the intervention group added 200 grams of sardines to their diet every week (two cans of sardines in olive oil).
Of the group that did not include sardines in their diet, 27% of the members were at a high risk of suffering from diabetes (measured via the FINDRISC questionnaire). After one year, 22% found themselves in the same category. Of the group that included sardines in their diet, 37% of the members were at a high risk of suffering from diabetes at the start of the study. After one year, only 8% remained at a very high risk. Improvements were also seen in other important biochemical parameters, such as a reduced insulin resistance index (HOMA-IR), increased "good" cholesterol (HDL), increased hormones that accelerate the breakdown of glucose (adiponectin) and decreased triglycerides and blood pressure, amongst others.
The fact that foods such as sardines—which are rich in taurine, omega 3, calcium and vitamin D—have a clear protective effect against the onset of diabetes does not mean that taking these supplements in isolation will have the same effect. "Nutrients can play an essential role in the prevention and treatment of many different pathologies, but their effect is usually caused by the synergy that exists between them and the food that they are contained in. Sardines will therefore have a protective element because they are rich in the aforementioned nutrients, whereas nutrients taken in isolation in the form of supplements won't work to the same extent," claimed Rizzolo.