One favourite way of getting an answer to a nutrition and health question is to gather all the most recent published studies, put them in a data melting pot, and see if you can extract a "truth". One review did this recently and found pretty much what you might expect, depending on your personal nutrition mantra or affiliation. They compared various foods groups and types to the risk of common diet-related disease such as heart disease, cancers, gut disease, bone and organ diseases and even mental illness.
Very simply put, they found that:
Drinking tea may reduce the risk of type 2 diabetes, heart disease, Parkinson's disease and some cancers eg breast and stomach cancer.
Coffee drinking wasn't quite as powerful as tea, yet seemed to drop the risk of type 2 diabetes, mental illness, heart disease and colon cancer.
Milk pretty well had a neutral effect on long-term health, although it did a good job on maintaining good bone density
Wine helped lower the risk of heart disease and many cancers (yoo-hoo!), but there was a warning: every glass bumped up the chance of getting breast cancer by 5%. Usual message - respect alcohol.
Sweetened drinks increased the chance of overweight and diabetes, but only when consumed in unhealthy amounts.
Fruit and veg, as expected, are wonderful for your health, especially for heart disease and cancer, as well as helping keep your weight in check.
Wholegrains look good on all fronts, but white rice was associated with an increase in type 2 diabetes risk. The authors say that wholegrains are more health protective than fruit and veg.
Legumes are another food that looks great for health, especially with a lower risk of most cancers.
Nuts and seeds are great for keeping heart disease away, with nut lovers at 37% lower risk of heart problems. I guess they mean the unsalted type.
Meat never seems to get good press, but the negatives are usually associated with a high consumption of red meat (see my comment below).
Any food over-consumed, be it meat, soft drink/sodas, wine or coffee, will always be associated with poor health, because if you over-eat something you are likely to be under-eating something else, usually something wholesome. Drink two litres of cola a day and you aren't likely to be drinking milk for calcium and protein. Drink a bottle of wine each night and I doubt if you are eating much fruit. Eat lots of takeaways and your vegetable intake will suffer. Nutrition is just as much about "too little" as "too much".
So whenever you see nutrition research being sold as the truth then always reflect on your own diet and ask:
Is it varied?
Is it nutrient-dense?
Is it minimally processed?
Is the emphasis on plant-based foods?
Answer yes to all four and there is a good chance you are eating well without having (boring) discussions about whether you should fuss about carbs or fat or the type of fat, or if there is a teaspoon of sugar in the house. We sadly forget that health is about the quality and nutrient density of food, the sentiment of which was captured in a recent article by Rosemary Stanton.