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Why Japanese fishermen always smile
Should you consider stepping up your omega-3 intake to improve your mental state? One way to boost omega-3 in your diet would be to eat more fish, and it's interesting to note that fish-eating people have considerably lower rates of depression, compared to beef- and pork-eating ones. For example, the incidence of depression in North America and Europe is about 10 times greater than the rate in Taiwan, where the people eat large amounts of fish. Studies carried out in the United States reveal that about 4.4 per cent of males and 8.7 per cent of females in New Haven, Connecticut suffer from depression. The rates of depression are 2.3 per cent for males and 4.9 per cent for females in Baltimore, and 2.5 per cent and 8.1 per cent in St. Louis. In contrast, rates of depression in Hong Kong, where people eat huge quantities of fish are about .71 per cent and 1.30 per cent for males and females, respectively. In Japan, where fish consumption is even higher, depression rates are .35 per cent for males and .46 per cent for females, and in some Japanese fishing villages rates of depression have been pegged at zero!

If low omega-3 consumption contributes to both depression and coronary artery disease, then depression and atherosclerosis should be positively correlated, the exact reverse of the hypothesis that depression, as a consequence of low cholesterol, protects against heart disease. In fact, 30 years of research have shown that depression is a good PREDICTOR of heart disease AND poor survival after a heart attack (depression as a REACTION to heart disease was separated from the analysis)

There has not been a lot of experimental work looking at the direct effects of omega-3 fats on depression, but the work that has been done has been favourable. In one study carried out with 494 elderly people, treatment with 'bovine cortex', or cow brains, which are a rich source of omega-3s, significantly improved mood and reduced symptoms of withdrawal and apathy, compared to treatment with corn oil (forget about the current scare over BSE)

A digression on breast-feeding
Since omega-3s are so critical for brain function, it's not surprising that the quantity of omega-3s in infants' diets can have a significant impact on brain development. In an important study which com-menced in Cambridge, Ipswich, Kings Lynn, Norwich, and Sheffield in 1982 and 1983, investigators kept track of 210 babies who received mother's milk and 90 babies who were fed only formula. Mother's milk is an excellent source of omega-3 fat, while formula contains none

At the age of 18 months, developmental scores were obtained for all 300 toddlers, and at the ages of seven to eight, IQ was assessed in the children using the Weschler Intelligence Scale for Children. Developmental scores were higher at 18 months, and IQ was greater at seven to eight years in the children fed breast milk. In fact, IQ scores were eight to 10 points higher in the breast milk-fed kids!

The research team, a group of distinguished British paediatricians, was able to remove most of the problems associated with this kind of research. For example, the breast-fed children received mother's milk through a tube, eliminating the likelihood that the close bond between mother and child associated with suckling had provided the IQ bonus. And even when the higher social status and educational backgrounds of the mothers who chose to breast feed were adjusted for statistically, the intelligence advantage associated with breast-milk intake remained

Critics have contended that choosing to provide breast milk is an indicator of the tenaciousness of a mother, and that this tenaciousness carries over into the nurturing provided to the child, boosting IQ. However, mothers who chose to furnish breast milk but were then unable to produce milk had kids with IQs similar to those of kids whose mothers chose to dish out formula. There was simply something special in mother's milk! Overall, getting breast milk raised IQ by about eight points, while higher educational status for the mother nudged IQ up by just two points. Being female rather than male lifted IQ by four points, so mother's milk was easily the most important IQ-raising factor detected in the study. The researchers also unearthed a 'dose-response' relationship between mother's milk and IQ. Those children who had received more maternal milk were sharper than kids who had imbibed less, particularly with regard to verbal measures of intelligence

What exactly was so good about mother's milk? The researchers pointed the finger at our old friend DHA, which is not present in infant formula but which occurs in decent concentrations in human breast milk. As the investigators pointed out, DHA is accumulated in large quantities in the developing brain and retina and is crucial for overall mental development

What is the practical meaning of all of this? The addition of fish to your diet several times weekly may decrease your risk of cardiovascular disease and depression. Research suggests that a dietary intake of .5 to 1.0 grams of omega-3 fat per day reduces the risk of cardiovascular death in middle-age men by about 40 per cent, but current actual intake in the United States is only .05 grams daily. If you want to use supplements to obtain more omega-3 fats, experts contend that the supplement should contain high amounts of EPA and DHA but little or no cholesterol or vitamins A and D. Vitamin E should be added to prevent the omega-3s from being oxidized

How omega-3s can affect performance
What about fat type and performance? If you're already involved in regular training, the effects of omega-3 fats may not be so direct and immediate that ingesting increased quantities of them for six weeks would improve your race times or lift your VO2max.. However, it's obvious that the less depressed you are, the higher will be your motivation and drive to succeed as an athlete, so inclusion of omega-3 fats in your diet may be favourable to performance from a mental standpoint

It's also possible that omega-3s might improve performance by upgrading blood flow to the muscles. In one study, blood flow to leg muscles of human subjects was restricted by the application of tourniquets. Some subjects then received a placebo, while others received an infusion of 'prostaglandin E1', a chemical which is produced by omega-3 fatty acids. Blood flow was 2.5 times greater in individuals who received E1. Increased blood flow would help endurance athletes by transporting increased oxygen and fuel to muscles and perhaps by improving the buffering of acids produced during intense exercise. The extra oxygen might raise VO2max, and there's also some evidence that omega-3 fats could reduce muscle inflammation following overly strenuous workouts

Only one peer-reviewed piece of research has actually looked at whether omega-3 fats can bolster exercise capacity. In that study, carried out at Western Washington University, 32 healthy young males were divided into four groups. One group acted as controls, a second group ingested four grams of omega-3 fat per day, a third group undertook a vigorous aerobic exercise programme, and a fourth group participated in the same exercise programme while taking the omega-3 supplements

After 10 weeks, the non-exercising group which consumed omega-3s was better off than the non-exercised control group without the omegas. Their average VO2max had risen by 11 per cent, against just 4.5 per cent for the controls. In other words, starting to supplement one's diet with omega-3s is a bit like going on a moderate exercise programme; one's ability to utilize oxygen seems to increase

However, both exercising groups, the one with omega-3s and the one without, broadened VO2max by about the same amount, 20 per cent, indicating no additional benefit of omega-3 fats when an exercise programme is undertaken. It would be interesting to see this same study carried out for a longer period of time or with a more experienced group of athletes. Perhaps under those conditions, omega-3s could induce some subtle, positive effects

What about medium-chain fats?
Broadening our focus from omega-3 fatty acids to fats in general, there has been some indication that 'medium-chain' fats are better for performance than the usual 'long-chain' lipids (medium-chain fats have only 10 to 14 carbons in their fatty-acid chains, while long-chain lipids have about 18 to 22). The advantage of medium-chains may be due to several factors: medium-chain triglycerides (MCTs) are absorbed from the digestive system more quickly than regular lipids, and scientific studies have linked MCTs with an increased metabolism of body fat, preservation of muscle tissue, and significant increases in metabolic rate. To make themselves look more attractive to finicky humans, MCTs don't allow themselves to be stored very easily as body fat, and some research has indicated that MCTs are not likely to end up in the fatty deposits which tend to clog the inside walls of your coronary arteries

To make matters even more interesting, exercise scientists have long speculated that MCTs might promote improved endurance performances, primarily because MCTs can slip into the 'mitochondria' inside muscle cells much more readily than regular fats. Since muscles create most of the energy they need by breaking down fat and carbohydrate inside their mitochondria, MCTs' ability to enter the mitochondria quickly should increase energy production and help to conserve muscles' most precious fuel - glycogen

Until now, however, MCTs' capacity to enhance exercise was speculative, but a recent study at the University of Cape Town demonstrates that MCTs can indeed improve performances - in certain situations. In the South African study, six experienced cyclists performed the same exercise test on three separate days. The test consisted of two hours of easy pedalling at just 60% VO2max (about 73 per cent of maximal heart rate), closely followed by a 40-kilometre time trial completed as quickly as possible. During the three tests, the athletes consumed either a 10 per cent carbohydrate solution, a 4.3 per cent MCT beverage, or a drink which contained both 10 per cent carbos AND 4.3 percent MCTs. In all cases, the subjects consumed 400 ml (14 ounces) of drink at the beginning of the test and then 100 ml (3.4 ounces, or three to four normal swallows) every 10 minutes thereafter

The carbohydrate PLUS MCT drink produced the best performances during the 40-K time trial. With carbo plus MCT, cyclists needed just 65 minutes to complete the ride, versus 66:45 with carbohydrate alone and a sluggish 72:08 with only MCTs

Why did adding MCT to the carbohydrate sports drink enhance performance? Basically, MCTs decreased glycogen depletion in the cyclists' leg muscles during the first two hours of the tests; the MCTs simply replaced glycogen as an energy source during those first two hours. As a result, when the cyclists pedalled along furiously during the 40-K trial, carbo-MCT athletes had more glycogen available to sustain their intense efforts

Why MCTs alone don't work
It's important to bear in mind that the MCTs had to be ADDED to carbohydrate in order to shore up performance; the MCT-only drink produced terrible results. Owen Anderson

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