
Fish
Is fish a health food? The question is, compared to what? Compared to some of the healthiest foods—for example, fruits, vegetables, beans, and whole grains—fish are low in antioxidants and phytonutrients, lacking fiber, and do contain some cholesterol and saturated animal fat. While the consumption of whole plant foods has been associated with longer protective telomeres, the tips on each of our chromosomes that keep our DNA from unraveling and fraying, in contrast, consuming refined grains, soda, dairy, and meat, including fish, has been linked to shortened telomeres, a sign of cellular aging.
Unless one can access a time machine and teleport back to the days before the Industrial Revolution, fish will remain the leading source of many toxic pollutants. In 2012, researchers published an analysis of the diets of kids aged two to seven. (Children are thought to be especially vulnerable to chemicals in the diet because they are still growing and thus have a comparatively greater intake of food and fluids relative to their weight.) Chemicals and heavy metals in kids’ bodies from the foods they ate were indeed found to exceed safety levels by a larger margin than in adults. Cancer risk ratios, for instance, were exceeded by a factor of up to 100 or more. For every child studied, benchmark levels were surpassed for arsenic, the banned pesticide dieldrin, and potentially highly toxic industrial by-products called dioxins. They were also too high for DDE, a by-product of DDT.
Which foods contributed the most heavy metals? The number-one food source of arsenic was poultry among preschoolers and, for their parents, tuna. The top source for lead? Dairy. For mercury? Seafood. Eating just a single serving of fish each week during pregnancy, for example, can lead to more mercury in their infant’s body than injecting them directly with about a dozen mercury-containing vaccines.
Where in the food supply are these pollutants found? Today, most DDT comes from meat, particularly fish. The oceans seem to have become, essentially, humanity’s sewer: Everything eventually flows into the sea. The same is true when it comes to dietary exposure to PCBs—another set of banned chemicals. A study of more than 12,000 food and feed samples across 18 countries found that the highest PCB contamination was found in fish and fish oil, followed by eggs, dairy, and then other meats. The lowest contamination was found at the bottom of the food chain, in plants.
Hexachlorobenzene, another pesticide banned nearly a half century ago, today may be found mainly in dairy and meat, including fish. Perfluorochemicals, or PFCs? Overwhelmingly found in fish and other meats. The contaminants in fish may help explain studies showing an association between fish consumption and diabetes. To lower our pollutant exposure, we should try to eat as low on the food chain as possible.
The information on this page has been compiled from Dr. Greger’s research. Sources for each video listed can be found by going to the video’s page and clicking on the Sources Cited tab. References may also be found at the back of his books.
Popular Videos for Fish


Fish Consumption and Suicide
The mercury content in fish may help explain links found between fish intake and mental...
ALS (Lou Gehrig’s Disease): Fishing for Answers
The neurotoxin BMAA is found in seafood and the brains of Alzheimer’s and ALS victims....
Dioxins in U.S. Farm-Raised Catfish
Feed contaminated with toxic pollutants thought to originate from sewer sludge fed to chickens and...
Fish and Diabetes
The relationship between fish consumption and diabetes risk may be due to toxic pollutants that...
California Children Are Contaminated
The levels of arsenic, banned pesticides, and dioxins exceeded cancer benchmarks in each of the...
Is Fish Oil Just Snake Oil?
Advice to eat oily fish, or take fish oil, to lower risk of heart disease,...
How Long to Detox from Fish Before Pregnancy?
How many months does it take to clear 99% of the mercury and other industrial...
Omega 3s and the Eskimo Fish Tale
The concept that heart disease was rare among the Eskimos appears to be a myth.
Is Fish “Brain Food” for Older Adults?
Why has fish consumption been associated with cognitive impairment and loss of executive function?All Videos for Fish
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Plant-Based Pregnancy Outcomes and Breast Milk
The composition of breast milk is compared between vegetarian and nonvegetarian women.
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Antibiotic Resistance Genes in the Guts of Vegetarians vs. Meat-Eaters
Those eating plant-based have a reduced load of antibiotic resistance genes in their gut.
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The Best Diet for Healthy Aging
Swapping just 1 percent of plant protein in place of animal protein was associated with significantly less age-related deficit accumulation.
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The Best Diet for Treating Atrial Fibrillation
What foods should we eat and avoid to reduce our risk of Afib?
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How to Treat H. Pylori Naturally with Diet
What food can eradicate H. pylori in the majority of patients?
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Are the Health Benefits of Nuts Limited to Those Eating Bad Diets?
Do nut eaters live longer simply because they swap in protein from plants in place of animal protein?
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Supplements for Hair Growth
Might biotin or zinc supplements prevent hair loss in men and women?
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Animal Protein vs. Plant-Based Protein
I discuss a public health case for modernizing the definition of protein quality.
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Pesticides (DDT) and Alzheimer’s Disease
How can we avoid the breakdown product of pesticides that may increase the risk of Alzheimer’s disease as much as if you carried APOE e4, the so-called Alzheimer’s gene?
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Which Foods Are Anti-Inflammatory?
Foods that reduce inflammation. What does an anti-inflammatory diet look like?