Eating to prevent heart disease and cancer.
Karen, an expert on how our diet affects risk for cancer, heart disease and diabetes, talks about how AICR's evidence-based dietary recommendations for cancer prevention compare to eating for heart health.
Q: We've talked with you about risk factors shared between cancer and type 2 diabetes. What about with cancer and heart disease?
A: We used to think about these as separate diseases, we've always known that smoking causes heart disease and some types of cancer; physical inactivity was always associated with heart disease, now we know it also relates to cancer. Other shared risk factors are excess weight and abdominal fat.
Q: What is new in terms of understanding heart disease risk related to diet?
A: It used to be all about dietary fat and total cholesterol for heart disease, now we see it's much more than your blood cholesterol; it's the whole environment within the blood vessels.... For people focused on a cholesterol number, this is a huge paradigm shift.
We now know there's several kinds of LDL [low density lipoproteins]; some pose risk and others don't. The ones associated with risk are small and can get in the blood vessel walls. It's these small ones associated with this whole metabolic environment that is familiar for increased cancer risk: elevated insulin levels, insulin resistance and inflammation. They are the same connections to diabetes risk.
Q: When comparing the diets, there seem to be a few differences in recommendations for each disease. For example, how does dietary fat relate to cancer prevention and heart health?
A: In terms of cancer risk, the primary thing we know is that it's a concentrated source of calories, so overdoing on dietary fat makes it easy to take in too many calories. Studies of calorie density have shown that if you have enough vegetables in your diet, there is no percent fat associated with weight gain. And the type of fat is not associated with cancer risk at this point.
For heart disease: the dogma and the official line is that the type of fat that leads to small LDLs is saturated and trans fats. But it's clear not all saturated fat is the same: chocolate has saturated fat but that's not the fat that leads to heart disease. We are getting beyond dietary fat as the sole definition of heart-healthy eating though.
Q: In what way?
A: For heart disease, some people thought that as long as you ate less saturated fat it didn't matter if you ate fiber or vegetables or cookies. But now we're seeing that it's the overall healthy diet with all its phytochemicals, antioxidants and everything else that brings down inflammation, insulin resistance, and reduces metabolic syndrome--that's the key.
Q: What about red wine and its effects on heart disease and cancer risk?
A: Moderate alcohol intake is associated with lower risk of heart disease but with breast cancer, any amount links to increased risk. This is a place where women need to look at their personal history. There are many things you can do to lower your risk of heart disease, drinking alcohol is not the only one. The American Heart Association does not recommend consuming alcohol to lower risk. If you drink alcohol, drink because you want to--and in moderation. Alcohol beyond moderate amounts links to higher blood pressure and increased risk.
Q: Eating too much red and processed meats increases risk of colorectal cancer: how does that align with heart health?
A: Here, the heart disease message can get you off track by focusing so much on saturated fat it can group lean red meat with poultry and chicken. In the past, the message has been that if you want to eat red meat then go ahead and choose lean meat ... some cuts might be so lean you could eat it [all day] and you wouldn't be going over on your saturated fat limit.
But we know in terms of cancer, overdoing on red meat is clearly a risk. And when meat is the major part of your plate, you don't have room for the vegetables, fruits, whole grain and beans that provide inflammation-fighting nutrients and phytochemicals as well as fiber.
Q: What about fiber?
A: Foods with dietary fiber link to lower colorectal cancer risk and they also help to lower LDL cholesterol. Not all fiber lowers blood cholesterol but again, the emphasis is on looking beyond that. Each fiber [type] may add different pieces to the puzzle in terms of decreasing inflammation and insulin resistance.
Q: For the person who wants to eat for overall health, what's the best advice?
A: For me, the bottom line is that you don't have to eat one way for your heart and another to lower cancer risk--or diabetes. Instead of putting each disease in a box, it looks like the diet developed for cancer protection extends to the others because all these boxes are connected through the metabolic environment.
Focus on the good foods, getting enough fruits, vegetables, whole grains and fiber--that will allow you to fill up and reduce excess body fat. And no matter how "healthy" the food, eat amounts that help you reach and maintain a healthy weight. Doing this will lower inflammation and reduce insulin resistance. It's not about fat or sugar as the focus; it's about having an overall healthy eating pattern.
Published on March 6, 2013
This article appears in the March issue of AICR's Cancer Research Update.
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|Publication:||African Journal of Food, Agriculture, Nutrition and Development|
|Date:||Apr 1, 2013|
|Previous Article:||Cutting cancer risk with heart health.|
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