Benefits associated with fish consumption and omega-3 fatty acids continue to grow in number. Omega-3 fatty acids can have a positive effect also on gallstones, osteoporosis, weight loss and eye sight.
Data gathered in the Health Professional Follow-up Study in the US provides an indication that there is a long-term relationship in an energy-balanced diet between the consumption of unsaturated fats (both mono- and polyunsaturated, which includes the omega-3 fatty acids) and a reduced risk of gallstones. The data is drawn from a 14-year follow-up of 45,756 men aged 40 to 75 in 1986 and free of gallstones. In that time 2,323 new cases were diagnosed.
With respect to osteoporosis, a condition related to reduced bone mass, studies suggest that omega-3 fatty acids such as EPA help increase levels of calcium in the body, deposition of calcium in the bones, and improvement in bone strength. In addition, studies also show that people who are deficient in certain essential fatty acids (particularly EPA and gamma-linolenic acid [GLA], an omega-6 fatty acid) are more likely to suffer from bone loss than those with normal levels of these fatty acids. In a study of women aged over 65 and with osteoporosis, those who given EPA and GLA supplements experienced significantly less bone loss over three years than those who were given a placebo. Many of these women also experienced an increase in bone density.
Research using animal models at the Charles University in Prague indicates that omega-3 fatty acids of marine origin and rich in DHA increase the oxidation of fat in the body and reduce the number of fat cells. This approach to aiding weight loss was tested in a pilot study that was presented at the North American Association for Study of Obesity annual meeting in November 2004. Twenty women with severe obesity, body mass index (BMI) over 40, and already on a very low calorie diet were given the same DHA-rich omega-3 supplement used in Prague or placebo. After three weeks the group given the supplement had lost 20 percent more weight than those in the control group and BMIs were down by as much as 15%.
A more recent study, published in 2007, shows seafood helping young men lose weight. The study is part of the European Union SEAFOODplus programme, which is a large multi-centre research project into the health benefits of seafood. Young adult men on a low calorie diet with seafood lost more weight than those on a diet with similar calorie count but no seafood.
Two studies published in 2006 indicate benefits for eyesight, notably macular degeneration. This begins as blurring in the centre of what the eye sees and progresses eventually to blindness. One study looked at 681 elderly American men. Those who ate fish twice a week had a 36% lower risk of macular degeneration. The other followed 2,335 Australian men and women over five years. Here the results indicated that those who ate fish at least once a week reduced their risk of macular degeneration by 40%.