In the landmark Global Burden of Disease examine, researchers compiled the highest 20 causes of dying and incapacity. Number one on the record was hypertension, two and three was smoke, and the fourth main trigger of loss of life and health was not eating sufficient fruit. Lack of exercise was quantity 10, adopted by an excessive amount of sodium, not sufficient nuts and seeds, not sufficient entire grains, after which not sufficient greens. Number 18 on the highest 20 record was not getting sufficient long-chain omega-3 fatty acids like DHA and EPA present in seafood, attributable to their purported protecting impact towards coronary heart illness. As I focus on in my video Is Fish “Brain Food” for Older Adults?, even years in the past when the examine was printed, researchers had been already questioning the advantages of these fish fat, as increasingly randomized managed trials put them to the take a look at and so they failed, culminating within the meta-analysis I profiled in my video Is Fish Oil Just Snake Oil? that appeared to place the problem to relaxation.
Consumption of fish and fish oil wasn’t solely hyped for cardiovascular safety, although. Omega-3s have additionally been touted to deal with depression. However, after bearing in mind all of the unfavorable outcomes that went unpublished, there seems to be no profit for main depression or for stopping suicide, as I explored in my video Fish Consumption and Suicide.
What about omega-3s for the prevention of cognitive decline or dementia? The obtainable randomized managed trials present no profit for cognitive operate with omega-3 supplementation in research lasting from 6 to 40 months amongst healthy older adults.
It might typically even make issues worse. “Higher current fish consumption predicted worse performance on several cognitive speed constructs. Greater fish consumption in childhood predicted slower perceptual speed and simple/choice reaction time.” This could also be attributable to neurotoxic contaminants, corresponding to mercury, in seafood. We’ve recognized that the creating mind is especially delicate to the damaging results of mercury, however perhaps the getting old mind is as effectively.
This would clarify outcomes which have proven greater omega-3 ranges to be related to excessive ranges of cognitive impairment and dementia. More EPA (eicosapentanoic acid) was discovered within the cognitively impaired, and extra DHA (docosahexanoic acid) was discovered within the demented, presumably as a result of of pollution like mercury and polychlorinated biphenyls (PCBs) in seafood which were associated to cognitive impairment and Alzheimer’s illness.
The identical cognitive “functions disrupted in adults, namely attention, fine-motor function and verbal memory, are similar to some of those previously reported in children with prenatal exposures,” that’s, uncovered within the womb. And, the adults uncovered to mercury by way of fish consumption didn’t have solely delicate EEG mind wave adjustments, however “observable deficits in neurobehavioral performance measures,” corresponding to poorer efficiency on checks of wonderful motor pace and dexterity, in addition to focus, for instance. “Some aspects of verbal learning and memory were also disrupted by mercury exposure,” and the better the mercury ranges, the more serious they did.
That examine, nonetheless, was performed downstream of a gold mining operation, which makes use of a course of that makes use of heaps of mercury. Other such research had been performed on folks eating fish subsequent to chemical vegetation or poisonous spills, or eating whale meat. What a couple of extra mainstream inhabitants? An “elite group of well-educated participants”—most had been company executives like CEOs and CFOs––all dwelling in Florida and rich sufficient to afford a lot seafood that no less than 43 p.c exceeded the U.S. Environmental Protection Agency’s security restrict for mercury had been studied. Researchers discovered that extreme seafood consumption, which they outlined as greater than three to 4 servings per thirty days of large-mouth fish like tuna, snapper, and bass, elevates mercury ranges and causes cognitive dysfunction, leading to a couple of 5 p.c drop in cognitive efficiency. This might not seem to be a lot, but it surely’s “a decrement that no one, let alone a health-conscious and achievement-oriented person, is likely to welcome.”
“It is worth noting the irony in the situation; that is, the fact that corporate executives who chose to overconsume seafood for health reasons sustained a drop in their executive functions. Yet, if a 4.8% drop in executive function due to excessive seafood intake occurs in highly functioning, healthy adults with ample cognitive reserve, the major concern for further study is whether similar [mercury] level elevations in individuals already suffering from cognitive decline might result in substantially greater declines,” notably with cognitive decline, dementia, and seafood consumption on the rise.
Fruit deficiency is the number-one dietary danger issue? For extra, see Inhibiting Platelet Aggregation with Berries.
But what about th Inuit? See Omega-3s and the Eskimo Fish Tale.
For extra on the shift of the proof on fish and coronary heart illness, see my Is Fish Oil Just Snake Oil? video.
The biggest hazard of mercury publicity could also be for kids, as I focus on in Mercury vs. Omega-3s for Brain Development and How Long to Detox from Fish Before Pregnancy?.
Other movies on the impact of fish contaminants and health amongst adults embrace Fish and Diabetes and Fish Consumption and Suicide.
Mercury will not be the one neurotoxic contaminant of seafood, although. See Diet and Amyotrophic Lateral Sclerosis (ALS) and ALS (Lou Gehrig’s Disease): Fishing for Answers.
Michael Greger, M.D.
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