Friends by now we have established that 40s are little different . We are some years away from of ageing . The hormones , metabolism are changing .  This time calls for some staples in diet which will help this transition to go smooth . Here is a list of some foods which will help you .( take in consideration your current health status .)
Oats –  Oats are high fibre  but complex carbs so it takes long to convert it to simple sugars thus it is very beneficial to diabetic people too . It has high level of Magnesium which is helpful  to body. It helps reduce risk of cardiac problems as it removes bad cholesterol . The Beta Glucan fibre in it is beneficial to cholesterol levels and improves immunity according  to some research.
Red grapes -Resveratrol which is present in red grapes is most important anti ageing, anti cancer , heart healthy antioxidant . It helps reduce the risks of cancers n cardiac issues .
Tomatoes- The lycopene from tomatoes have antioxidant properties which are shown to help against prostate cancers .tomatoes are rich source of potassium , vit C , vit A  which is helpful to eyes by reducing Macular degeneration . Also they are strong blood purifiers and reduce urinary track infections . It’s one of the most beneficial foods ever . But you should be careful about pre-existing conditions like tomato allergy , kidney stones in which case you may need to avoid it .
Soy products – Benefits of soy are still argued but one should always take in consideration the pre-existing conditions . Soy improves lipid profile ratio .Studies have shown that regular intake of soy can significantly lower you blood concentrations of triglyceride and low density lipoproteins (LDL) and raise the level of high density lipoproteins (HDL)
The omega-3 and omega-6 fatty acids as well as the powerful phyto-antioxidants in soy  protect your blood vessels from lesions and hemorrhage. The phytoestrogens in soy help prevent prostrate cancer in males n reduce post menopausal symptoms in females . It’s also a very important source of proteins for vegetarians .
Garlic -This is a good source of vit B6 which helps in building of good immune system .It has anti cancer properties so helps prevent cancers , it has good anti bacterial properties too . It also has properties which helps against cardiac problems .
Milk The most important source of protein and calcium , it gives adequate proteins in a vegetarian diet . Its calcium content helps in preventing Osteoporosis n Osteomyelitis  which is quite common post menopause .
Olive oil -The polyphenols in olive oil have amazing antioxidant , anti ageing properties . The monosaturated fats in it also help against cardiac issues

Almonds- Almonds are also known for lowering bad cholesterol, protect artery walls, reduce heart attack risks. they have riboflavins and L-carnitine which boost brain activity n prevents Alzeimers..

Coloured Vegetables and Fruits- The phytonutrients found in these coloured vegetables and fruits  are all helpful  to the body as antioxidents which helps in preventing ageing.
These are some essential foods which will help to keep age n age related problems at bay . It will improve life quality n keep you away from age related problems . But I will again recommend to keep your pre existing conditions in mind in which case you may need to avoid few things .If used in moderation and right quantities  these will benefit you surely for happy and Healthy 30s to 50s.