Eating right in midlife may prevent dementia later on, according to a new doctoral thesis published by the University of Eastern Finland. Results indicated those who consistently consumed healthy foods at the average age of 50 had a nearly 90 per cent lower risk of dementia in a 14-year follow-up study compared to those who did not eat healthfully.

Researchers used a healthy diet index based on eating a variety of foods. "Healthy" foods included vegetables, berries/fruits, fish and unsaturated fats from milk products and spreads. "Unhealthy" foods included sausages, eggs, salty fish, sugary drinks, desserts/candy and saturated fats from milk products and spreads.

Participants were between 39 and 64 years old, and 65 to 79 years old at the study baseline and follow-up, respectively. While 2,000 participants were involved in the initial study, 1,449 completed the follow-up.

Eating a large amount of saturated fats was linked to decreased cognitive function and increased dementia risk. Those who eat a diet high in saturated fats and carry the epsilon 4 variant of the apolipoprotein E (ApoE) gene are also at risk. This gene is a risk factor for Alzheimer's disease.

"Even those who are genetically susceptible can at least delay the onset of the disease by favoring vegetable oils, oil-based spreads and fatty fish in their diet," says doctoral thesis author Margo Eskelinen, MSc. The thesis was based on the population-based Finnish Cardiovascular Risk Factors, Aging and Incidence of Dementia (CAIDE) study.

The Alzheimer's Association recommends increasing intake of "protective foods" to maintain a healthy brain. These include dark-skinned fruits and vegetables such as prunes, raisins, red grapes, plums, blueberries, cherries, broccoli, spinach, kale, onion, red bell pepper, beets and eggplant. Nuts such as almonds, walnuts and pecans are also recommended, as are cold-water fish such as trout, salmon, tuna, mackerel and halibut. Increasing intake of vitamins such as C, E, folate and B12 is also considered helpful.

Study results were published in the International Journal of Geriatric Psychiatry, Dementia and Geriatric Cognitive Disorders and Journal of Alzheimer's Disease.

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    Walnuts are chock-full of heart-healthy and anti-inflammatory nutrients, and are the only good nut source of alpha linolenic acid (ALA), <a href="http://www.huffingtonpost.com/2012/06/29/healthy-food-healthiest-list_n_1636409.html#slide=1162293">HuffPost Healthy Living earlier reported</a>. That means they help promote blood flow, which in turn allows for efficient delivery of oxygen to the brain. And <a href="Diseasehttp://alzheimers.org.uk/site/scripts/news_article.php?newsID=730">research presented at the 2010 International Conference on Alzheimer's</a> found that mice with the disease who were regularly fed walnuts had improved memory, learning and motor skill coordination, <a href="http://www.myhealthnewsdaily.com/758-best-foods-brain-health.html">according to MyHealthNewsDaily</a>.

  • Olive Oil

    Olive oil is a great source of monounsaturated fats, which have been shown to <a href="http://www.boston.com/dailydose/2012/05/18/tweaking-dietary-fat-intake-could-help-slow-brain-aging-study-suggests/OO7tmvxhB2E8V0algT7DlL/story.html">actually <em>slow</em> brain aging</a>.

  • Berries

    Animal studies have long indicated a link between berry consumption and brain health. But a recent study published in the <em>Annals of Neurology</em> found that a diet high in blueberries, strawberries and others were linked to a <a href="http://healthland.time.com/2012/04/26/brain-food-berries-can-slow-cognitive-decline/">slower mental decline in areas like memory and focus</a> in a large sample of middle-aged women, reported <em>TIME</em>'s Alice Park.

  • Sardines

    Fatty fish like sardines (<a href="http://www.webmd.com/add-adhd/slideshow-brain-foods-that-help-you-concentrate">and salmon!</a>) are a well-known brain booster, thanks to the omega-3 fatty acids, EPA and DHA, which <a href="http://www.hsph.harvard.edu/nutritionsource/questions/omega-3/index.html">have been linked to lower risk of dementia, improved focus and memory</a>.

  • Coffee

    Caffeine, the mild stimulant found in coffee, improves mental acuity, though the drink's enthusiasts -- <a href="http://www.bbc.co.uk/sn/humanbody/truthaboutfood/best/caffeinebrain.shtml">who guzzle 120,000 tons of the stuff each year</a> -- likely already know that. Aside from caffeine's brain boosting effects, coffee's antioxidant richness helps maintain brain health. And some research suggests that drinking coffee can actually <a href="http://www.huffingtonpost.com/2011/09/27/coffee-cuts-depression-women_n_982122.html">stave off depression in women</a>.

  • Spinach

    Spinach is rich in the antioxidant lutein, which is thought to help protect against cognitive decline, <a href="http://www.nutraconference.com/networknow/public/SessionDetails.aspx?SessionID=1004689&FromPage=nz_ALSessionSearch.aspx">according to researchers from Tufts University</a>. And <a href="http://www.shape.com/healthy-eating/diet-tips/11-best-foods-your-brain?page=11">a longitudinal study at Harvard Medical School</a> found that women who reported eating the most leafy green and cruciferous vegetables had a markedly lower rate of cognitive decline, compared to those who ate the least.

  • Dark Chocolate

    Antioxidant-rich dark chocolate is healthy for your whole body, but its <a href="http://www.huffingtonpost.com/2012/06/18/brain-health-foods_n_1593650.html#slide=1087860">caffeine content is thought to play a role</a> in maintaining mental acuity. What's more, chocolate is rich in flavonoids, a class of antioxidant that helps to improve blood flow (and thus brain health) by regulating cholesterol and lowering blood pressure.

  • Avocados

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  • Water

    When a person becomes dehydrated, their brain tissue actually shrinks. And several studies have shown that <a href="http://www.ncbi.nlm.nih.gov/pubmed/20336685">dehydration can affect cognitive function</a>. Dehydration can impair short-term memory, focus and decision making, <a href="http://www.psychologytoday.com/blog/you-illuminated/201010/why-your-brain-needs-water">according to <em>Psychology Today</em></a>.

  • Wheat Germ

    Wheat germ is a rich vegetarian source of choline -- a nutrient that is involved in the body's production of acetylcholine, a neurotransmitter that boosts memory, <a href="http://www.shape.com/healthy-eating/diet-tips/11-best-foods-your-brain" target="_hplink">according to <em>Shape</em></a>. Eggs are another good choline source.

  • Beets

    Beets are a good source of naturally-occurring nitrates, which help improve blood flow to the brain, <a href="http://www.shape.com/healthy-eating/diet-tips/11-best-foods-your-brain">according to <em>Shape</em></a>.

  • Garlic

    Garlic may help stave off some forms of brain cancer, according to research published in <em>Cancer</em>, the medical journal of the American Cancer Society. Investigators found that <a href="organo-sulfur compounds found in garlic have been identified as effective against glioblastoma">the organo-sulfur compounds in garlic actually worked to kill glioblastoma cells</a> -- a type of malignant tumor cell.