Eating too much of oily fish can actually increase the risk of developing type 2 diabetes by up to a quarter, a new study has found.
The study conducted by French scientists found that those who ate a portion a day had a 26% higher rate of type 2 diabetes.
The researchers, according to the report published on Daily Mail studied the eating habits of more than 70,000 women, after which they came up with their findings on the consumption of oily fish for different set of people.
Previous studies to this have indicated that oily fish contain Omega-3, which has been found to help stave off cancer and heart diseases. However, experts have suggested that people consume no more than 4 portions a week.
While experts recommend eating up to four portions of oily fish such as mackerel and salmon a week, those who eat more than that could be doing themselves harm.
Oily fish is rich in omega-3 polyunsaturated fatty acids (PUFAs) which are said to boost brain power, keep hearts healthy and reduce inflammation of the brain, cardiovascular system and other cells.
HOW MUCH OILY FISH SHOULD YOU EAT?
Health experts recommend eating at least one portion – around 140g when cooked – of oily fish a week.
Oily fish can contain low levels of pollutants that can build up in the body.
For this reason, there are maximum recommendations for the number of portions we should be eating each week. These recommendations are different for different groups of people.
The general population is advised to have no more than four portions of oily fish a week.Women who are planning a pregnancy or who are currently pregnant or breastfeeding should eat no more than two portions of oily fish a week.
This is because pollutants found in oily fish may affect the future development of a baby in the womb.Children, pregnant women and women who are trying to get pregnant should not eat swordfish, as it contains more mercury than other fish. Other adults are advised to eat no more than one portion of swordfish per week.
They found those who ate the most omega-3 -which is also found in red meat – increased the risk of developing diabetes by more than a quarter, compared to those who ate the least.
The participants were from a 1990 study initiated investigating the risk factors associated with cancer and other major non-communicable diseases in women.
Women in the top third, who ate roughly 1.6g of polyunsaturated fatty acid – the equivalent of a portion of sardines or salmon a day – had a 26 per cent increased risk of developing type 2 diabetes.
This was when compared to those who consumed less than 1.3g per day and after other factors like BMI were taken into account.
Meanwhile, high omega-3 consumption was associated with a 19 per cent increased risk of diabetes among overweight women.
Closer examination also showed eating an omega-3 fatty acid called DPA (docosapentaenoic acid), which is also found in red meat, increased the risk of diabetes in non-overweight and overweight women by 45 per cent and 54 per cent, respectively.
The same occurred with the omega-6 faty acid, arachidonic acid (AA), which is also abundant in oily fish and meat.
A high level of this was associated with a 50 per cent increased risk of diabetes in people of a healthy weight and a 74 per cent increased risk for overweight women.
Dr Guy Fagherazzi, of University Paris-Saclay, Villejuif, France, said: ‘Different polyunsaturated fatty acids appear to have different effects regarding the risk of developing type 2 diabetes.
A high consumption of docosapentaenoic acid and arachidonic acid may contribute to the development of type 2 diabetes.’
He added: ‘We wouldn’t necessarily recommend cutting these sources out of our diet, but perhaps diminishing meat intake, as it is often consumed in quantities much greater than our nutritional requirements.’
The findings were presented at the European Association for the Study of Diabetes (EASD) meeting in Munich.