Anchovies are often found in Japanese meals. (Source: Freeacresm)

The link between small fish and longevity

Nagoya University (Japan) Associate Professor Chinatsu Kasahara was interested in conducting this research because of her personal interest. Since she was a child, she has eaten these types of fish and now cooks them for her children.

To assess the relationship between fish intake and mortality, Associate Professor Kasahara and colleagues looked at data from 80,000 Japanese people aged 35 to 69 (about 34,000 men and 46,000 women).

They administered a food frequency questionnaire to analyze participants' diets, focusing on how often people ate small fish.

During the nine-year study period, nearly 2,500 participants died. Of those, nearly 1,500 were cancer-related.

After adjusting for factors such as age, body mass index (BMI), alcohol consumption and smoking frequency, the researchers found a significant correlation between regular consumption of small fish in women and reduced cancer-related mortality.

Women who ate small fish one to three times a month had a 32% lower risk of death from all causes and a 28% lower risk of death from cancer than those who rarely ate small fish. Those who ate small fish one to two times a week or three or more times a week had a 28% and 31% lower risk of death from all causes and a 29% and 36% lower risk of death from cancer, respectively. The data showed similar trends in men, but the association was less clear.

The researchers are not sure why this is the case, but they hypothesize that it may be due to the smaller sample size of men in the study and that some factors such as fish intake were not clearly accounted for.

Sardines are small but packed with important nutrients. (Source: Discouts)

Small fish, big benefits

Meanwhile, in Western countries, small fish are often undervalued. American nutritionist Sharon Palmer told Health : “We often underestimate these types of fish and prefer larger ones. Currently, a lot of the world's supply of small fish is being used as fishmeal for aquaculture.”

But small fish are rich in nutrients because people often eat them whole. The heads, bones and organs of small fish are rich in calcium, vitamin D and vitamin A. “Smaller fish like sardines and anchovies are rich sources of nutrients like omega-3 fatty acids and protein,” says American nutritionist Roxana Ehsani.

The micronutrients in small fish have been shown to support bone, immune, heart, muscle, skin, and metabolic health. They can also reduce inflammation in the body, which increases the risk of heart disease, diabetes, and asthma. “Plus, these fish are more plentiful and contain fewer environmental toxins,” Palmer adds.