Significant amounts of omega-3 fatty acids--compounds thought to improve cardiovascular functions--are present in some canned tuna products, according to a recent Massachusetts Institute of Technology study.
The research, conducted at MIT's Sea Grant Program, found that canned, solid white albacore is among the best sources of omega-3 in the seafood world. Only salmon and sardines, fresh or canned, contain higher concentrations.
Omega-3, according to growing amounts of medical literature, acts in several beneficial ways to increase the flow of blood to the heart. The substance lowers blood fat levels in arteries and also works as an anti-clotting agent.
An account of the MIT report was carried recently in the UC Berkeley School of Public Health's Wellness Letter under a "Tuna Vindicated" headline.
The results were certainly good news for the tuna industry and consumers. The development comes at a time when canned fish has lost much of its luster as interest in and sales of fresh and frozen fish have increased.
The research project was designed to address fears that tuna processing destroyed the omega-3 levels in the fish.
"The canning process doesn't significantly reduce the omega-3 content," according to the Wellness Letter article. "Thus canned white (albacore) tuna contains more than double the amount of omega-3s found in fresh cod or haddock, though less than (in) salmon or sardines."
Not all canned tuna was similarly praised.
Chunk light tuna, for instance, has only half the omega-3 levels of the more costly solid white albacore.
Packing methods also play a role. Tuna canned in water, for instance, loses a mere 3% of the omega-3s present when the liquid is drained.
But when the fish is canned in oil, between 15% and 25% of the substance is lost when the oil is removed. The higher depletion rate is attributed to the fact that omega-3s are oil-soluble, the research indicated.
Tuna packed in oil was also called to task, in the Wellness Letter, for its calorie content.
"The added oil is vegetable oil, not fish oil, and it more than doubles the calorie content of the tuna and increases its fat content fifteenfold," the article stated. "That's another good reason to choose water-pack tuna."
Light-Damaged Milk--The long-running battle between the paper and plastic industries is heating up again. At issue in the latest skirmish is the decade-old dispute of whether milk looses nutrients when packaged in plastic containers.
The Paperboard Packaging Council announced recently in a grocers trade journal that it will launch a national advertising campaign in February and March stating that milk in paper cartons provides "more vitamins."
The basis for the claim is research that shows measurable nutrient loss when milk--packaged in plastic containers--is exposed to fluorescent light for extended periods. This type of illumination is the kind most frequently used in supermarket dairy cases.
The soon-to-be-published ad, meant to appeal to parents, states, "There's a way to make sure your children's milk is better protected: buy it in paper cartons. Paper cartons block almost all harmful light."
The original work on nutrient loss was conducted in 1981 by Cornell University and demonstrated that the ultraviolet rays, given off by fluorescent light, destroyed Vitamin A and riboflavin present in plastic-containerized milk. The loss was particularly acute in low-fat milk where 20% of the vitamin A was lost in just two hours of light exposure.
However, a 1983 UC Davis study on the phenomena seems to contradict the findings. Milk in plastic containers pulled from California supermarket shelves showed negligible loss of nutrients.
Even so, the stakes are high in the milk carton battles. Industry estimates place the value of milk packaging alone in excess of $1 billion annually. For now, plastic containers hold a large market share--more than 60%. Much of plastic's success is attributed to easier handling containers, most of which have easy-to-crasp handles and resealable pouring spouts.
Hoping to make up ground lost to the plastics industry, the recent trade journal announcement by the paperboard council informed grocers that a consumer preference change could be in the making.
It stated, "We're going national . . . with this campaign that tells people how paper cartons protect the nourishment in milk. In the individual markets where it's run already, it's consistently sold more milk in paper cartons . . . "
But while the paper and plastics industries continue to wage their marketing war, dairymen can find little solace in ads that call into question milk's nutritive value.
A Food-Policy Campaign--A Washington-based consumer group is urging both the Democratic and Republican presidential candidates to adopt a series of food-related resolutions in their campaign platforms.