Omega-3s have been studied for other conditions, with either inconclusive or negative results. These conditions include allergies, atopic eczema (an allergic skin condition), cystic fibrosis, diabetes, inflammatory bowel diseases (Crohn’s disease or ulcerative colitis), intermittent claudication (a circulatory problem), nonalcoholic fatty liver disease, and osteoporosis.
The randomized trials assessing the efficacy of fish oil supplementation on secondary prevention of CAD lend further evidence to the findings that fish oil may protect from sudden cardiac death.36 The Diet and Reinfarction Trial (DART),37 one of the first randomized trials of fish oil in CAD, has been interpreted as potential support for fish oil’s role in sudden death reduction because the primary outcome of all-cause mortality occurred within 2 months of the trial’s onset.38 After such a short time span, it was believed that atherosclerosis would not be altered and therefore another mechanism was reducing mortality. This was further supported by the fact that nonfatal MIs were not reduced. Although the actual modes of death other than CAD-related deaths were not documented, it has been postulated to be secondary to a reduction in sudden death.39 The Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico-Prevenzione40 (GISSI-Prevenzione) trial, a larger randomized trial of fish oil in CAD, has also been interpreted as evidence for fish oil’s protection against sudden death. Sudden death, however, was not a primary end point. Rather, the reduction in fatal events was driven by a reduction in cardiovascular death, which included coronary death, cardiac death, and sudden death.
The deficiency of EPA and DHA in diet contributes to skin conditions, such as dandruff, thinning hair, eczema and psoriasis, as well as age spots and sun spots. Without the essential fatty acids, too much moisture leaves the skin. The truth is your internal health can appear on your skin, and taking fish oil internally as a supplement may be as good as or better than applying conventional moisturizers.
Walnuts are chock full of healthy fats — including omega-3s — and also contain a slew of other nutrients like magnesium, biotin, and vitamin E. Some studies even suggest that eating walnuts improves memory, learning ability, and motor development.1 Walnuts are versatile, too — try them with fresh or dried fruit, in salads, or baked into desserts. Get started with these banana walnut waffles — made with coconut sugar and unsweetened almond milk.
Fish oil is also commonly used to treat conditions such as Rheumatoid arthritis, high blood pressure, ADHD, menstrual pain, hardening of the arteries or kidney problems. These conditions can be improved by improving blood flow, which omega-3 fatty acids in the blood stream. There is also some evidence that fish oil may help with conditions such as chest pain, liver disease, migraine prevention, gum infections, breast pain, and muscle soreness due to exercise, skin rashes and stomach ulcers.
The most widely available dietary source of EPA and DHA is oily fish, such as salmon, herring, mackerel, anchovies, menhaden, and sardines. Oils from these fish have a profile of around seven times as much omega−3 as omega−6. Other oily fish, such as tuna, also contain n-3 in somewhat lesser amounts. Consumers of oily fish should be aware of the potential presence of heavy metals and fat-soluble pollutants like PCBs and dioxins, which are known to accumulate up the food chain. After extensive review, researchers from Harvard's School of Public Health in the Journal of the American Medical Association (2006)  reported that the benefits of fish intake generally far outweigh the potential risks. Although fish are a dietary source of omega−3 fatty acids, fish do not synthesize them; they obtain them from the algae (microalgae in particular) or plankton in their diets. In the case of farmed fish, omega-3 fatty acids is provided by fish oil; In 2009, 81% of the global fish oil production is used by aquaculture.
Heavy metal poisoning by the body's accumulation of traces of heavy metals, in particular mercury, lead, nickel, arsenic, and cadmium, is a possible risk from consuming fish oil supplements.[medical citation needed] Also, other contaminants (PCBs, furans, dioxins, and PBDEs) might be found, especially in less-refined fish oil supplements. However, heavy metal toxicity from consuming fish oil supplements is highly unlikely, because heavy metals selectively bind with protein in the fish flesh rather than accumulate in the oil. An independent test in 2005 of 44 fish oils on the US market found all of the products passed safety standards for potential contaminants.[unreliable source?]
Jump up ^ Abdelhamid, Asmaa S; Brown, Tracey J; Brainard, Julii S; Biswas, Priti; Thorpe, Gabrielle C; Moore, Helen J; Deane, Katherine HO; AlAbdulghafoor, Fai K; Summerbell, Carolyn D; Worthington, Helen V; Song, Fujian; Hooper, Lee (18 July 2018). "Omega-3 fatty acids for the primary and secondary prevention of cardiovascular disease". Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD003177.pub3.
Human diet has changed rapidly in recent centuries resulting in a reported increased diet of omega−6 in comparison to omega−3. The rapid evolution of human diet away from a 1:1 omega−3 and omega−6 ratio, such as during the Neolithic Agricultural Revolution, has presumably been too fast for humans to have adapted to biological profiles adept at balancing omega−3 and omega−6 ratios of 1:1. This is commonly believed to be the reason why modern diets are correlated with many inflammatory disorders. While omega−3 polyunsaturated fatty acids may be beneficial in preventing heart disease in humans, the level of omega−6 polyunsaturated fatty acids (and, therefore, the ratio) does not matter.
Hamazaki, K., Syafruddin, D., Tunru, I. S., Azwir, M. F., Asih, P. B., Sawazaki, S., and Hamazaki, T. The effects of docosahexaenoic acid-rich fish oil on behavior, school attendance rate and malaria infection in school children--a double-blind, randomized, placebo-controlled trial in Lampung, Indonesia. Asia Pac.J Clin Nutr 2008;17(2):258-263. View abstract.
Today, the average American has a 20:1 ratio of omega-6 to omega-3 fats, when a healthy ratio is more ideally around 2:1. Put in other numerical terms, the typical American diet tends to contain 14 to 25 times more omega-6 fatty acids than omega-3 fatty acids. (35) This shows just how deficient most of us are and why supplementing with fish oil is so beneficial.
From the time of your pregnancy through your child's later life, omega-3 fats DHA and EPA have a radically important role in her brain health and other functions. I recommend supplementing with krill oil before and during pregnancy, and while you breastfeed. Babies receive DHA through your breast milk, so continuing breastfeeding through the first year will give your child a great headstart for health and success.
Human studies also confirm cognition and memory improvement with omega-3 supplementation. For example, a study showed that both fish oil and krill oil enhanced cognitive function in a group of older men by increasing oxygen delivery to their brains. Interestingly, for those taking krill oil this effect was more prominent than those taking fish oil, though both groups were significantly better than placebo.30 As we pointed out earlier, because the omega-3 DHA is bound to phospholipids in krill it may be more effectively incorporated into the critical cell membrane in brain cells.
Healthy cells require a delicate balance of EPA and DHA and the body employs clever mechanisms to support this natural equilibrium. DHA levels are self-regulated through inhibiting the activity of the enzyme delta-6 desaturase – the very enzyme that supports the conversion of EPA into DHA – to ensure levels of DHA do not become too high. It is therefore possible to have too much preformed DHA, if our supplement intake exceeds the body’s needs.
The effect of fish oil on incident atrial fibrillation has not been studied in large randomized trials, and observational population-based trials show mixed results. The Danish Diet, Cancer and Health Study, and the Rotterdam Study followed 47,000 and 5100 middle-aged adults, respectively.45,46 Neither study found that the consumption of fish oil affected the incidence of atrial fibrillation. Similar findings were seen in the Women’s Health Initiative where there was no association between fish and omega-3 FA intake regarding incident atrial fibrillation.47 However, in a 12-year prospective, observational study of 4815 adults over the age of 65, daily fish consumption was associated with a 31% risk reduction in incident atrial fibrillation.48
What's more, ALA is just a precursor to EPA and DHA. You need certain enzymes to elongate and desaturate ALA so it can become long-chained omega-3s. Unfortunately, this does not work in some people, particularly those who are deficient in certain vitamins and minerals, leading to very low conversion rates – only 1 percent of ALA is converted to EPA/DHA. In some, the conversion can even dip as low as 0.1 to 0.5 percent!
Fish oils seem to decrease blood pressure. Taking fish oils along with medications for high blood pressure might cause your blood pressure to go too low.
Some medications for high blood pressure include captopril (Capoten), enalapril (Vasotec), losartan (Cozaar), valsartan (Diovan), diltiazem (Cardizem), Amlodipine (Norvasc), hydrochlorothiazide (HydroDiuril), furosemide (Lasix), and many others.
Jump up ^ Miller M, Stone NJ, Ballantyne C, Bittner V, Criqui MH, Ginsberg HN, Goldberg AC, Howard WJ, Jacobson MS, Kris-Etherton PM, Lennie TA, Levi M, Mazzone T, Pennathur S (May 2011). "Triglycerides and cardiovascular disease: a scientific statement from the American Heart Association". Circulation. 123 (20): 2292–333. doi:10.1161/CIR.0b013e3182160726. PMID 21502576.
AD is a devastating disease for which there are limited treatment options and no cure. Memory loss is an early indicator of the disease, which is progressive, and leads to the inability of the patient to care for him- or herself and eventually to death (47). Currently, the number of individuals with AD is estimated to be 26.6 million and is expected to increase to 106.2 million by 2050 (48). There have been many studies conducted regarding the use of omega-3 fatty acid supplementation and AD (Table 2). DHA is present in large amounts in neuron membrane phospholipids, where it is involved in proper function of the nervous system, which is why it is thought to play a role in AD (49). A case-control study consisting of 148 patients with cognitive impairment [Mini-Mental State Examination (MMSE) score <24] and 45 control patients (MMSE score ≥24) showed that serum cholesteryl ester-EPA and -DHA levels were significantly lower (P < 0.05 and P < 0.001, respectively) in all MMSE score quartiles of patients with AD compared with control values (49). Another study found that a diet characterized by higher intakes of foods high in omega-3 fatty acids (salad dressing, nuts, fish, tomatoes, poultry, cruciferous vegetables, fruits, dark and green leafy vegetables), and a lower intake of foods low in omega-3 fatty acids (high-fat dairy products, red meat, organ meat, butter) was strongly associated with a lower AD risk (50). Image analysis of brain sections of an aged AD mouse model showed that overall plaque burden was significantly reduced by 40.3% in mice with a diet enriched with DHA (P < 0.05) compared with placebo. The largest reductions (40–50%) were seen in brain regions that are thought to be involved with AD, the hippocampus and parietal cortex (51). A central event in AD is thought to be the activation of multiple inflammatory cells in the brain. Release of IL-1B, IL-6, and TNF α from microglia cells may lead to dysfunction of the neurons in the brain (52). In 1 study, AD patients treated with EPA+DHA supplementation increased their plasma concentrations of EPA and DHA, which were associated with reduced release of inflammatory factors IL-1B, IL-6, and granulocyte colony–stimulating factor from peripheral blood mononuclear cells (53).
Growing up, Joe was plagued with a myriad of health issues such as gut problems, autoimmune issues, chronic fatigue, brain fog, insomnia, and general inflammation. Both conventional and alternative doctors weren’t able to help him, so he decided to fix himself. With lots of health questions and few satisfying answers, Joe decided to read every research paper he could get his hands on and conduct thousands of experiments on his own body in order to fix his health issues. Joe started SelfHacked in late 2013 when he successfully fixed all of his issues, and now it gets millions of readers a month looking to educate themselves about how they can improve their health. Joe is now a thriving author, speaker, and serial entrepreneur, founding SelfDecode & LabTestAnalyzer.
There’s evidence that points to the mechanism behind the effects of fish oil on body composition, showing that fat burning at rest is increased with 6 grams/day of fish oil supplementation, and additional research suggests that higher omega-3 levels may be helpful for enhancing satiety during weight loss efforts. Other evidence suggests that fat loss may be a side-effect of the reduction in inflammation that fish oil can help with. Any way you look at it, supporting your dietary habits with 4 or more grams of fish oil per day is probably a good idea!
“This systematic review did find moderate evidence that ALA, found in plant oils (such as rapeseed or canola oil) and nuts (particularly walnuts) may be slightly protective of some diseases of the heart and circulation. However, the effect is very small, 143 people would need to increase their ALA intake to prevent one person developing arrhythmia. One thousand people would need to increase their ALA intake to prevent one person dying of coronary heart disease or experiencing a cardiovascular event. ALA is an essential fatty acid, an important part of a balanced diet, and increasing intakes may be slightly beneficial for prevention or treatment of cardiovascular disease."
To improve the health of your heart, brain, skin, hair, body and much, much more, consider adding fish oil to your daily supplement regime or consume wild-caught fish daily. If you’re adverse to fish oil pills, make sure to get at least two servings of fatty fish each week to fulfill your omega-3 needs and provide your body with fish oil benefits. This is a recommendation also encouraged by the American Heart Association. (38)
There was a significantly greater association of treatment with reduced anxiety symptoms in participants receiving omega-3 PUFAs than in those not receiving omega-3 PUFAs in the subgroup with an EPA percentage less than 60% (k, 11; Hedges g, 0.485; 95% CI, 0.017-0.954; P = .04; Figure 4)35,49,52,54-61 but no significant difference in the association of treatment with reduced anxiety symptoms between participants receiving omega-3 PUFAs and those not receiving omega-3 PUFAs in the subgroup with an EPA percentage of at least 60% (k, 9; Hedges g, 0.092; 95% CI, –0.102 to 0.285; P = .35) (Figure 4).33,34,36,47,48,50,51,53,60 There were no significantly different estimated effect sizes between these 2 subgroups by the interaction test (P = .13).
Krauss-Etschmann et al. (26) Double-blind, placebo-controlled, randomized 311 DHA+EPA daily with either fish oil with DHA (0.5 g) and EPA (0.15 g) or with methyltetrahydrofolic acid (400 μg), both, or placebo, from gestation week 22 Fish-oil supplementation was associated with decreased levels of maternal inflammatory/TH1 cytokines and a decrease of fetal Th2-related cytokines
The three types of omega-3s are APA, EPA and DHA. The first is a medium-chain fatty acid and must be converted into EPA before being synthesized by the body, and only about 1 percent of the APA consumed is able to be converted. EPA and DHA are already in a form ready to be synthesized (and are the subject of most scientific research regarding omega-3s).
Schilling, J., Vranjes, N., Fierz, W., Joller, H., Gyurech, D., Ludwig, E., Marathias, K., and Geroulanos, S. Clinical outcome and immunology of postoperative arginine, omega-3 fatty acids, and nucleotide-enriched enteral feeding: a randomized prospective comparison with standard enteral and low calorie/low fat i.v. solutions. Nutrition 1996;12(6):423-429. View abstract.
The use of DHA by persons with epilepsy could decrease the frequency of their seizures. Studies have shown that children with epilepsy had a major improvement, i.e. decrease in the frequency of their seizures, but another study showed mixed results with 57 adults taking DHA supplementation. The 57 subjects demonstrated a decreased frequency of seizures for the first six weeks of the study, but for some, it was just a temporary improvement (R).
Irish AB, Viecelli AK, Hawley CM, et al; Omega-3 Fatty Acids (Fish Oils) and Aspirin in Vascular Access Outcomes in Renal Disease (FAVOURED) Study Collaborative Group. Effect of fish oil supplementation and aspirin use on arteriovenous fistula failure in patients requiring hemodialysis: A randomized clinical trial. JAMA Intern Med. 2017;177(2):184-193. View abstract.
Basil — a flavorful and easy-to-find herb — is a strong source of omega-3 fatty acids. Since basil is used primarily as a seasoning, however, you likely won’t get a full day’s supply of omega-3 from a standard serving. For best results, use whole basil leaves, and add them toward the end of your meal’s cooking time to preserve the plant’s nutrients. In addition to delivering omega-3s, basil teas like Buddha Tea’s Organic Holy Basil Tea also promote calm and reduce cell inflammation.
Stiefel, P., Ruiz-Gutierrez, V., Gajon, E., Acosta, D., Garcia-Donas, M. A., Madrazo, J., Villar, J., and Carneado, J. Sodium transport kinetics, cell membrane lipid composition, neural conduction and metabolic control in type 1 diabetic patients. Changes after a low-dose n-3 fatty acid dietary intervention. Ann Nutr Metab 1999;43(2):113-120. View abstract.
So back to fish oil in general. The major fish oil benefits include decreasing the risk of heart disease and stroke while also helping reduce symptoms of depression, hypertension, attention deficit hyperactivity disorder (ADHD), joint pain, arthritis and chronic skin ailments like eczema. (2) Fish oil intake has also been associated with aiding the body in weight loss, fertility, pregnancy and increased energy. Prescription fish oil has even been approved by the FDA to lower unhealthy high triglyceride levels. (3)
Fish oils rich in omega 3 fatty acids help improve fertility and cell division. Preliminary research conducted on animals has shown that when males are fed a diet containing fish oil, the quality of the sperm is enhanced. After ejaculation, the sperm has increased survival against lipid peroxidative attacks in the female genital tract, thereby increasing the chances of conception. On the other hand, similar animal studies have shown inhibition in the synthesis of prostaglandin E and prostaglandin F, which are produced in large quantities by human seminal vesicles. The research, however, found no impact on the count and mobility of sperm.
ODS seeks to strengthen knowledge and understanding of dietary supplements by evaluating scientific information, supporting research, sharing research results, and educating the public. Its resources include publications (such as Dietary Supplements: What You Need to Know), fact sheets on a variety of specific supplement ingredients and products (such as vitamin D and multivitamin/mineral supplements), and the PubMed Dietary Supplement Subset
Three omega−3 fatty acids are important in human physiology, α-linolenic acid (18:3, n-3; ALA), eicosapentaenoic acid (20:5, n-3; EPA), and docosahexaenoic acid (22:6, n-3; DHA). These three polyunsaturates have either 3, 5, or 6 double bonds in a carbon chain of 18, 20, or 22 carbon atoms, respectively. As with most naturally-produced fatty acids, all double bonds are in the cis-configuration, in other words, the two hydrogen atoms are on the same side of the double bond; and the double bonds are interrupted by methylene bridges (-CH
Sala-Vila A, Díaz-López A, Valls-Pedret C, et al.; Prevención con Dieta Mediterránea (PREDIMED) Investigators. Dietary marine ?-3 fatty acids and incident sight-threatening retinopathy in middle-aged and older individuals with type 2 diabetes: Prospective investigation from the PREDIMED trial. JAMA Ophthalmol. 2016;134(10):1142-1149. View abstract.
42. Cawood AL, Ding R, Napper FL, Young RH, Williams JA, Ward MJ, Gudmundsen O, Vige R, Payne SP, Ye S, et al. Eicosapentaenoic acid (EPA) from highly concentrated n-3 fatty acid ethyl esters is incorporated into advanced atherosclerotic plaques and higher plaque EPA is associated with decreased plaque inflammation and increased stability. Atherosclerosis. 2010;212:252–9. [PubMed]
After the age of five, the development of the brain and CNS starts to reduce and the body’s need for DHA reduces. This is a good time to increase EPA in the diet, as studies show that EPA can help with childhood behaviour and academic performance, as well as focus, attention and reducing aggression. Dry skin conditions, asthma and allergies are also common in children and good levels of EPA at this time can help reduce the inflammation associated with these issues.
Fish oil’s most potent effect on atherosclerosis may be related to its potential to alter plaque inflammation, thereby stabilizing vulnerable plaques. In recent years there has been a growing body of evidence that is shifting the paradigm of how inflammation is contained and dissipated.4 In this new model, inflammation resolution is an active process mediated by lipid-derived compounds. Newly discovered families of chemical mediators, resolvins, and protectins5,6 are directly involved in blocking neutrophil migration, infiltration, and recruitment, as well as in blocking T-cell migration and promoting T-cell apoptosis.7–12 In addition, protectins can reduce tumor necrosis factor and interferon secretion.13 Interestingly, both protectins and resolvins are strictly derived from omega-3 FA. EPA is the substrate of the resolvins family and DHA can be converted to both resolvins and protectins.7 It may be that the effects of fish oil on inflammatory mediators underlie the positive findings demonstrated in several trials assessing fish oil and plaque stability.14–16
According to the Cardiovascular Research Institute in Maastricht in Netherlands, “Epidemiological studies show that replacing fat with carbohydrates may even be worse [than the Western-type high-fat diet] and that various polyunsaturated fatty acids (FA) have beneficial rather than detrimental effects on CVD (cardiovascular disease) outcome.” This includes fish-oil fatty acids with anti-inflammatory properties, which can help prevent and reverse a plethora of cardiovascular diseases. (19)
A healthy balance of dietary omega 6 and omega 3 fatty acids is a prerequisite for normal immune function, cognitive health, and cardiovascular health. Among other factors, sufficient dietary levels of EPA, DHA or other omega 3 fatty acids are also important in the regulation of normal blood lipoprotein and healthy cholesterol metabolism. Fish oil supplements can also lower elevated triglyceride levels, improving cardiovascular health and reducing the risk of heart disease.†
Jatoi, A., Rowland, K., Loprinzi, C. L., Sloan, J. A., Dakhil, S. R., MacDonald, N., Gagnon, B., Novotny, P. J., Mailliard, J. A., Bushey, T. I., Nair, S., and Christensen, B. An eicosapentaenoic acid supplement versus megestrol acetate versus both for patients with cancer-associated wasting: a North Central Cancer Treatment Group and National Cancer Institute of Canada collaborative effort. J.Clin.Oncol. 6-15-2004;22(12):2469-2476. View abstract.
A Pregnancy Prerequisite: Omega-3 fatty acids directly affect brain development, making it crucial for expectant mothers. Additionally, research indicates they decrease a mother's risk of depression. When the mother doesn't have enough of these essential fatty acids, the baby borrows from her. Some prenatal vitamins now include omega-3s, so be sure to check the label or grab a handful of walnuts each day.
Increased consumption of omega 3 fats is widely promoted globally because of a common belief that that it will protect against heart disease. There is more than one possible mechanism for how they might help prevent heart disease, including reducing blood pressure or reducing cholesterol. Omega 3 fats are readily available as over-the-counter supplements and they are widely bought and used.
Many studies documenting the benefits of omega-3s have been conducted with supplemental daily dosages between 2 and 5 grams of EPA and DHA, more than you could get in 2 servings of fish a week. But that doesn't mean eating fish is an exercise in futility. Many studies document its benefits. For example, a 2003 National Eye Institute study showed that 60- to 80-year-olds eating fish more than twice a week were half as likely to develop macular degeneration as those who ate no fish at all.
Could you be deficient in omega-3s? The University of Maryland Medical Center says that the symptoms “include fatigue, poor memory, dry skin, heart problems, mood swings or depression, and poor circulation.” They also warn against a poor omega-3 to omega-6 ratio, cautioning readers that it may be “associated with worsening inflammation over time.” (6)
Like its other leafy green counterparts, broccoli is a powerful source of ALA, one of the omega-3 fatty acids your body needs (but can’t make on its own). Broccoli is also high in fiber, zinc, and — surprisingly — protein, a must for any ADHD brain. If you or your child doesn’t like broccoli, try pairing it with a cheesy sauce or baking it into tots — try this simple recipe to get started.
Capanni, M., Calella, F., Biagini, M. R., Genise, S., Raimondi, L., Bedogni, G., Svegliati-Baroni, G., Sofi, F., Milani, S., Abbate, R., Surrenti, C., and Casini, A. Prolonged n-3 polyunsaturated fatty acid supplementation ameliorates hepatic steatosis in patients with non-alcoholic fatty liver disease: a pilot study. Aliment.Pharmacol.Ther. 4-15-2006;23(8):1143-1151. View abstract.
Age-related macular degeneration (AMD) is an eye disease that can cause vision loss in older people. Two major National Institutes of Health (NIH)-sponsored studies, called Age-Related Eye Disease Study (AREDS) and Age-Related Eye Disease Study 2 (AREDS2), showed that dietary supplements containing specific combinations of vitamins, antioxidants, and zinc helped slow the progression of AMD in people who were at high risk of developing the advanced stage of this disease. AREDS2, which had more than 4,000 participants and was completed in 2013, also tested EPA and DHA. The results showed that adding these omega-3s to the supplement formulation didn’t provide any additional benefits. Other, smaller studies of omega-3 supplements also haven’t shown them to have a beneficial effect on the progression of AMD.
Omega-3 fatty acids are frequently in the news regarding their health benefits (or doubts in some cases). Two types of omega-3s in particular - eicosapentaenoic acid (EPA) and docohexaenoic acid (DHA) – are known to be essential fatty acids. “Essential” refers to the fact that our cells need these fatty acids in order to function normally. But the body cannot make them from other fats, which means it’s “essential” we supply them in our diet or through supplementation.
Cancer. Research on the effects of fish oil in preventing cancer has produced conflicting results. Some population research suggests that eating fish or having higher blood levels of omega-3 fatty acids from fish oil is linked to a lower risk of different cancers, including oral cancer, pharyngeal cancer, esophageal cancer, colon cancer, rectal cancer, breast cancer, ovarian cancer, and prostate cancer. But other research suggests that eating fish does not reduce the risk of cancer.