Clearly the best foods to fight ageing are the ones you share at meals with your over 90 year old parents or over 100 year old grandparents. Genetics determines when most people die and how fast they age. Specifically somatic genes called telomeres which are built in to our cells. There are also genetic propensities, and learned-from-parents behaviors, that have a huge impact on how long we can expect to live. Eating fatty foods, sugars, alcohol etc., with little exercise are things many of us learn from our parental ancestors. We see, we do, and we die at about the same age they did, and for the same reasons.
That said, here are some food ingredients that can make a difference. Docosahexanoic acid, which can be refined from fish oils, and which can be eaten in foods such as salmon or cod may be helpful in prolonging active brain function. Folic acid, which is a miracle vitamin, seems to protect against a vast array of bad things including breakdown of cells due to oxidation. Red wine contains resveratrol, which a very large study in Japan has confirmed may play a role in soaking up free radicals (O-two-minus) in the body. Finally, for the brain, there is a supplement called PS, (phosphatidylserine) which is a derivative of soy lecithin. My own experience with this material is that it makes me less absent minded, and I can think a bit faster.
Moving on from brain benefit foods to heart benefit foods. Aspirin is the main heart helper. It's not really a food, unless you want to chew a certain tree bark which contains it. But a little aspirin every day, before going to bed, gives your heart a better rest at night. Then to keep the fat off and the muscles toned, you may want to try conjugated linolenic acid, which you can get as a supplement, or which is also contained is safflower oil in high concentrations. One part of heart health is easy sleep and anger management. Both of these are helped by Kava Kava (root), which is a food in Hawai'i, and a beverage. Finally for the heart, red wine, in moderate amounts one to three small glasses per day. It's good to cook with wine. Sometimes you can even put it in the food! The resveratrol appears to be the active ingredient, but there are also other antioxidants. Skim milk, or 2% milk is much better for your heart than whole milk. It also lets the flavor of good coffee or good tea come through much better. Cholesterol is no joke. It build up over the course of a lifetime, and doesn't hurt at all until the moment it kills you.
Try to limit sugar intake and caffeine intake to one helping per day. I take these both together in my one cup of morning coffee. After that, no sugar whatsoever, and no chocolate, or caffeine drinks. If you want a long life, you can't kick your heart with chemicals all day. It's like burning the candle at both ends. People who live that way, wind up old before their time. I realize that with long commutes the problem is falling asleep at the wheel, and of course this also tends to shorten lifespan, so feel free to break my rule on coffee or tea or coke, or sugar when the effect of drinking it will be to save your life - keep you from dozing off at the wheel.
Potassium is a key metal needed in fairly significant amounts by the body for general good health. Bananas and Brocolli are great sources of potassium. The beta carotenes have a good reputation as antioxidants and carrots are an excellent source. In fact most red vegetables are very good for you - carrots, tomatoes, red bell peppers, pumpkins, etc. Tomatoes are of particular value to men because the lycopene they contain may keep the prostate in check. I can't eat enough tomatoes to make a difference in this respect so I take a lycopene supplement (made from concentrating the lycopene from many tomatoes).
Oranges, lemons and limes are excellent sources of vitamin C. If you drink orange juice in the morning, try to get the no sugar added kind - all natural, and don't drink a huge glass of it - be moderate - think sugar minimization. You can take a vitamin C pill as a supplement to your orange juice. This vitamin is crucial to strong bones and teeth. Also to your peridontal health - your gums. The health of your teeth and gums is very closely related to your heart health - as most modern trained dentists will confirm for you if you inquire.
The B vitamins, especially B-6 and B-12 are found in most red meats. You want to be real careful with red meat. I use it almost as a spice in my food rather than as the center of the meal. I add pieces to rice, or macaroni, or potatoes. I remove the fat in three ways: 1. by selecting it off at the store when I pick up the particular package of meat I will buy 2. By cutting it off when I get home before the meat is cooked and 3 by cooking it off and throwing away the fatty liquid in the pan. If you lightly (but adequately) cook the meat, it can be made tender by marination rather than leaving streaks of fat in it. Marination helps the fat the be removed by the cooking process because it loosens up the grain of the meat and lets the heat get in to melt away the fat. Animal fat is the worst thing for you next to excess sugar.
Keep in mind that none of the supplements, or even the foods, mentioned above are particularly cheap, and that poverty causes more early death than any disease. Epidemiologists know this truth and will confirm it. So, the key is to eat as healthy as you can reasonably afford to. Take supplements or neutraceuticals as appropriate for your budget. Stay away from excess sugar and animal fat. Eat more fish and chicken. Don't eat the chicken skin. Chicken wings are terrible for you. Fish skin, it's just the opposite, the layer of fishfat just under the skin is extremely good for you - especially salmon, or any cold water fish like cod.
Many people need to limit their salt intake for a variety of health reasons. That area is technical enough that I'm not including it here, except to say that if you are on a limited salt diet it's best to respect your doctor's orders. You can marinate meat in walnut oil and potassium chloride salt substitute, and comes out just fine. Throw in a bit of garlic juice and a bit of jalapeno pepper sauce, and a bit of black pepper, and you have a perfectly delightful marinade, with very low salt content. There is a new lemon crystal ingredient made from real lemons which I use to spice up marinades as well. It costs about 9 cents per little paper bag. People use it for ice tea.
It's not always just what you eat that makes a difference. You can shorten your life perfectly well by eating in a hurry, or in a place or with people that make you angry or anxious. Meals are special times. They should be moments of relaxation, not hurried, not harried, not fulminating, not furious. If necessary, take your meals alone, or skip them entirely rather that bolting down food in a foul temper. Give your body a chance to accept the food gracefully into itself. Try to be a bit quite for 10 minutes or so right after you eat. That way, you can have a longer and more serene life. Peace.