In a survey, participants who took fish oil, and took moderate exercise for 45 minutes three times per week, but did not change their normal eating habits, lost an average of 4.5lb over three months.
Lead researcher Alison Hill, an honours student in the School of Health Sciences at the University of South Australia, observed 68 overweight and obese study participants with high blood pressure and high cholesterol and divided them into four separate groups for a period of 3 months:
Group 1 - Small doses of tuna fish oil (omega-3 fatty acids) Group 2 - Sunflower oil (much lower in omega-3 fatty acids) Group 3 - Small doses of tuna fish oil, PLUS 3 x 45 mins. exercise a week Group 4 - Sunflower oil, PLUS 3 x 45 mins. exercise a week
Hill said she wanted to see how well the omega-3's found in the fish oil would help the study participants lose weight. She noted:
"The omega-3 found in fish oil increases fat-burning ability by improving the flow of blood to muscles during exercise."
She discovered that Group 3, who took fish oil and exercised 45-minutes by walking or running three days a week, lost an average of 4.5 pounds over the three-month study, while Groups 1, 2, and 4 did not lose any weight at all. The results of this study made Hill "very surprised" because the study participants "were still eating whatever they wanted."
"It's pretty exciting because this implies the results would be even better if you did control diet and exercised more heavily," Hill concluded.
So what is it about fish oils that is bringing about the weight loss?
This is not yet clear, but scientists believe that omega-3 oils help people who are insulin-resistant. This condition, which affects many overweight people, means they cannot convert their blood glucose into energy and therefore they eat more sugary or carbohydrate foods in an effort to have more energy. This often goes undiagnosed for some years. Fatty acids such as omega-3 increase the ability of cell membranes to use up blood glucose, meaning there is less left over to turn into excess fat.
Alison Hill states:
"We suspect that they improve blood flow to exercising muscles and stimulate key enzymes to transport fat that needs to be used as fuel. In overweight people this ability is almost always impaired."
Although scientists believe the omega-3 fatty acids help reverse insulin problems found in overweight people which slows down the speed at which they burn up glucose, it's not yet known whether the same effect would be seen in people of normal weight.
Omega-3 has also been shown in many studies to be helpful in reducing high blood pressure, heart disease, arthritis, Alzheimers disease, attention deficit hyperactivity disorder, and many other conditions.
Not surprisingly, Hill is already working on more long-term studies to see what happens with varying levels of fish oil and exercise. She presented these findings at the Congress of the International Society for the Study of Fatty Acids and Lipids (ISSFAL) in Cairns, Queensland, Australia.
