introduction to tuna sashimi

Tuna was once considered by the samurai unfit to eat, and is now one of the most popular fish in Japan. It was in 1903 that a sardine shortage led to a cannery filling the cans with albacore, a species of tuna which had no commercial value.

The canned tuna soon became popular, and the tuna industry came into being. Dolphins became a bycatch of tuna, and in 1972 Congress enacted the Marine Mammal Protection Act (MMPA) to protect dolphins from harmful fishing methods.

These efforts to protect dolphins have paid off, with dolphin deaths in the eastern tropical Pacific Ocean tuna fishery decreasing by 97%. Various dolphin safe labels are now being used to verify that dolphins are not being harmed in the tuna fishing process. However, the US Consumers Union has explained that this is no guarantee as there is no third party and independent verification of the dolphin friendly claims.

Health benefits of tuna:

Reduced Risk of Alzheimer’s Disease and Dementia

Data collected in a study on the dietary intake of EPA and DHA fatty acids from fish concluded thatmoderate fish consumption could postpone cognitive decline in the elderly. Another study demonstrated that a diet high in fish is associated with better cognitive performance in the elderly.

In the Cardiovascular Health Cognition Study, consumption of fatty fish more than twice per week was associated with a reduction in risk of dementia by 28%, and Alzheimer’s Disease by 41% in comparison to those who ate fish less than once per month.

Cancer Prevention

In a prospective study of 61,433 women it was suggested that consumption of fatty fish such astuna could reduce the occurrence of renal cell carcinoma (kidney cancer).

Preliminary studies have shown that fatty acids present in fish inhibit the growth of breast cancer, and the Oncology Department at St Thomas' Hospital in London has proposed that premenopausal women over the age of 40 years who are shown to be at increased breast cancer risk supplement their diet with omega-3 fatty acid rich fish.

Blood Pressure Control

An international study of 4680 men and women ages indicated that omega-3 fatty acid intake (largely from fish) could be beneficial in preventing adverse blood pressure levels.

Eyesight Health

The results of a study have demonstrated that omega-3 fatty acid intake and fish consumption is associated with a reduced risk of age-related macular degeneration.

A high dietary intake of Omega-3 fatty acids is also associated with a decrease in dry eye syndrome.

Heart Health

Several studies and clinical trials have provided strong evidence that modest consumption of fish or fish oil (1-2 servings/wk of oily fish, or approximately 250 mg/d of EPA+DHA) substantiallyreduces the risk of coronary heart disease death.

Arthritis

There is evidence from double blind, placebo-controlled clinical trials that the increase of dietary omega-3 fatty acids supplied as fish oil can have beneficial effects in rheumatoid arthritis.

Nutrients

Tuna is an excellent source of the omega-3 fatty acids EPA and DHA, protein, potassium, selenium, and vitamin B12. It's a very good source of niacin and phosphorus.

Glycemic Index (GI)

In a study to determine the estimated GI of various foods, it was concluded that tuna has a GI of 0.

Protein

Tuna is an excellent source of protein, and while some vitamin and mineral losses occur during canned tuna processing, the protein nutritive values are not dramatically changed.

Nutrient Values of Fresh Yellowfin Tuna per 100g
Calories 139kcal	Energy Value 582kj	Total Fat 1.22g	Carbohydrates 0.00g	Sugars g
Dietary Fiber 0.0g	Protein 29.97g	Sodium 47mg	Zinc 0.67mg	Potassium 569mg
Iron 0.94mg	Magnesium 64mg	Copper 0.082mg	Calcium 21mg	Vitamin C 1.0mg
Vitamin E mg	Vit. B3 (Niacin) 11.936mg	Vitamin B6 1.038mg	Vit. B1 (Thiamin) 0.501mg	Vit. B2 (Riboflavin) 0.057mg

1. Large predatory fish such as tuna have the highest levels of mercury contamination, which is a known developmental neurotoxicant.

2. A guide to mercury levels in tuna and other fish can be downloaded here:Mercury Wallet Card

3. In government food safety tests, canned albacore or white tuna, in addition to fresh or frozen tuna steaks, was found to have significantly more mercury than the canned chunk light tuna.

4. Pregnant women, women of childbearing age, nursing mothers and young children should avoid fish with high levels of mercury.

5. Bluefin tuna, which is prized for its use in Sushi, is facing extinction due to over fishing, and for this reason alone should be avoided.

6. Although most manufacturers display a “dolphin friendly” label on their cans, long line tuna fishing is undiscriminating, and the bycatch includes sharks, turtles and albatrosses.

7. Some canned tuna contains MSG, and is best avoided.

Reference/Source:

elements4health.com