There’s no question that maintaining a nutritious diet can help keep your body healthy. But when it comes to which foods can specifically benefit which body parts, science remains surprisingly sketchy. For all the hype about the health benefits of, say, antioxidants and probiotics, a scan of the scientific literature reveals how much we don’t know. Here’s a guide to foods whose benefits to the body are supported, to varying degrees, by reputable research.

Eyes

Food: Egg yolks, yellow corn

Benefit: Lutein, one of the brightly colored (yellow, in this case) compounds called carotenoids that give fruits and vegetables their color, may help ward off age-related macular degeneration, probably by acting as a cell-damage-fighting antioxidant.

Brain

Food: Salmon, tuna, sardines

Benefits: The omega-3 fatty acid docosahexaenoic acid (DHA) found in cold-water, fatty fish is thought to play a role in protecting against dementia; one study found that people who ate lots of fatty fish had a reduced risk of Alzheimer’s disease. The 2010 Dietary Guidelines for Americans call for eating four ounces of fish, twice a week.

Bones

Food: Milk, fortified soy beverages

Benefit: The calcium in dairy products (and added to some soy beverages) is a building block of bone tissue early in life; later, it helps fight osteoporosis. The Dietary Guidelines recommend three cups of low-fat or nonfat milk daily.

Heart

Food: Baked potato, prune juice Benefits: Research has found that potassium, found in many fruits and vegetables, lowers the risk of dying from cardiovascular disease, especially when consumption of sodium is reduced. Most of us should have about 4,700 mg of potassium daily; a small baked potato has 738, a cup of prune juice 707.

Lungs

Food: Broccoli, Brussels sprouts, bok choy

Benefits: Vegetables (the Dietary Guidelines call for three cups a day) are associated with reduced cancer risk. And research suggests that the glucosinolate in cruciferous vegetables (those in the same family as cabbage, whose name means “cross-bearing” and refers to the shape of the petals) might be especially useful in keeping carcinogens from damaging DNA, thwarting cancer’s development.

Stomach

Food: Ginger

Benefits: There’s evidence that eating ginger can battle motion sickness and perhaps nausea associated with pregnancy. As little as a gram of powdered ginger might tame nausea or vomiting, though medications appear to work better at fighting those ills.

Colon

Food: Beans and peas

Benefits: Beans and peas are excellent sources of fiber, whose health benefits include keeping you regular. The dietary guidelines say women should consume 25 grams of fiber daily; men need 38.

Prostate

Food: Green tea

Benefits: Although studies have been scant, promising research suggests that green tea’s antioxidant polyphenols may help prevent cancer of the prostate and other organs. Green tea is generally considered safe to consume in abundance.

Ovaries

Food: Ice cream

Benefits: A 2007 Harvard study found that women who consumed high-fat dairy products such as ice cream reduced their risk of infertility. It’s not clear why; the authors surmised that the fat might somehow improve ovarian function when women are trying to conceive.

SOURCES: Molecular Vision, Nov. 17, 2010; Archives of Neurology, November 2006; Institute of Medicine; Archives of Internal Medicine, July 11, 2011; Linus Pauling Institute; University of Maryland Medical Center; “Report of the Dietary Guidelines Advisory Committee on the Dietary Guidelines for Americans, 2010”; National Cancer Institute; Human Reproduction, Feb. 28, 2007