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Seafood and Mediterranean Diet Linked with Better Brain Health in Aging

To see how the Mediterranean diet relates to brain health, researchers analyzed the diets and health of 7,756 older adults. Those most closely following a Mediterranean diet had a significantly lower risk of cognitive impairment but did not have a significantly slower decline in cognitive function. However, those eating the most fish had both a significantly lower risk of cognitive impairment and a significantly slower decline in cognitive function.
Alzheimers Dement. 2020 Jun;16(6):831-842. doi: 10.1002/alz.12077. Epub 2020 Apr 13. (Keenan TD et al.)

Mediterranean Diet Linked with Healthier Vitamin D Levels

A traditional Mediterranean diet includes frequent seafood and frequent but small portions of dairy foods, leaving some to wonder how a Mediterranean diet relates to markers of bone health. In this study, researchers analyzed the diets and vitamin D levels (using 25(OH)D blood levels) of 284 overweight and obese adults in Italy. Vitamin D levels in the blood are important to study, as they can indicate whether someone’s bones are strong or at risk of osteoporosis. Those most closely following a Mediterranean diet were significantly more likely to have higher vitamin D levels, as well as to have healthier BMI, waist size, insulin levels, and triglycerides (a type of fat in the blood). Seafood, which is abundant in the Mediterranean diet, is an important source of vitamin D, and the authors suggest that vitamin D may partially explain the Mediterranean diet’s protective effect on osteoporosis.
Int J Food Sci Nutr. 2020 Mar 29;1-7. doi: 10.1080/09637486.2020.1744533. Online ahead of print. (Zupo R et al.)

Seafood During Pregnancy Linked with Improved Brain Development in Children

Seafood is well-recognized for its brain health benefits, but researchers wonder if these benefits outweigh the risks of mercury exposure. In this study, scientists analyzed 44 papers on 102,944 mother-child pairs and 25,031 children. They found consistent evidence of brain health benefits for children when mothers ate seafood while pregnant, and that benefits began even at the lowest amounts of seafood (about 4 oz /week). No negative impacts on neurocognitive development were noted even at the highest levels of seafood consumption (more than 12 ounces per week).
Prostaglandins Leukotrienes, and Essential Fatty Acids. 2019 Oct 11;151:14-36. doi: 10.1016/j.plefa.2019.10.002. (Hibbeln CJR et al.)

Eating Omega-3 Fatty Acids While Pregnant May Reduce Pre-Term Births

Not many women eat fish frequently during pregnancy, but perhaps they should. In a rigorous Cochrane review of 70 randomized controlled trials (involving 19,927 women), scientists found that getting more omega-3 fatty acids (from food, like seafood, or supplements) may reduce the incidence of pre-term birth and low birthweight in babies.
The Cochrane Database of Systematic Reviews. 2018 Nov 15;11:CD003402. doi: 10.1002/14651858.CD003402.pub3. (Middleton P et al.)

Traditional Mediterranean and Japanese Diets Linked with Lower Risk of Death from Heart Disease

At first glance, Japanese and Mediterranean cuisines might seem worlds apart. However, the overall eating patterns share more similarities than one might think. Researchers analyzed the diets and long-term (50-year) data on death from heart disease in 12,763 men in the Seven Countries Study from the 1960s. The researchers noted a very similar eating pattern between the Mediterranean group and the Japanese group, with lots of seafood and vegetables, and low amounts of animal foods and animal fat. They also found that eating more vegetables and starch, and more closely following a “Mediterranean” diet (as the Mediterranean and Japanese groups did) were linked with significantly lower risks of death from heart disease. Sweets, animal foods, and hard fats (like butter or lard) were linked with increased risk.
European Journal of Clinical Nutrition. 2018 May 17. (Kromhout D et al.) [Epub ahead of print.]

Mediterranean-Based Diets Associated with Better Cognitive Function

Dementia is a serious neurological disease, so preventive measures are an important area of research.  In a study of 5,907 adults, researchers analyzed whether the Mediterranean diet and/or the MIND diet  (a diet similar to the Mediterranean diet, full of “brain-healthy” foods like leafy greens, nuts, berries, beans, whole grains, seafood, poultry, olive oil, and wine) have an effect on cognitive performance. Researchers found that those most closely following the Mediterranean Diet had 35% lower odds of having poor cognitive performance (assessed through tests of memory and attention), when compared to those not following a Mediterranean Diet. Results were similar for the MIND diet, probably because there is so much overlap in these two eating patterns.
Journal of the American Geriatrics Society. 25 April 2017. [Epub ahead of print.]  (McEvoy CT, et al.)

Healthy Diets (Such as Mediterranean Diet) Linked with Better Sperm Quality

For couples trying to get pregnant, a healthy diet may help tilt the odds in their favor. To see what types of foods are associated with better male fertility and healthy sperm quality, researchers analyzed data on eating patterns and male fertility in 35 observational studies from around the world. They found that a healthy diet (e.g. a Mediterranean diet) with lots of seafood, poultry, vegetables, fruits, low fat dairy, and grains is associated with better sperm quality. They also found that in some studies, processed meat, soy foods,  potatoes, full fat dairy, coffee, alcohol, sugary drinks, and sweets were linked with poor sperm quality and male infertility.
Human Reproduction Update. 2017 Mar 10:1-19. (Salas-Huetos A et al.)

Low Level Mercury Exposure from Fish Appears Safe During Pregnancy

Seafood is a staple in many traditional diets, but many wonder if the health benefits of fish consumption outweigh the risk of mercury exposure. In a study of 334 infants in Ohio, researchers assessed the neurobehavior of infants and the fish intake and blood mercury levels in mothers and cord blood. The researchers “found minimal evidence of mercury associated detrimental effects” on the infants, with no statistically significant problems related to level of mercury consumption when other lifestyle and dietary factors were controlled for. In fact, the researchers also observed that the infants with higher (but still safe) blood mercury levels had better attention and less need for special handling, suggesting that the benefits of fish consumption may outweigh the risks of low-level mercury exposure.
Neurotoxicology and Teratology. 2016 Feb 12. Pii: S0892-0362(13)30007-1. (Xu Y et al.)