Disappointment 

Last week, eagerly anticipated results from the Women's Healthy Eating and Living (WHEL) study were published in the Journal of the American Medical Association (JAMA). The WHEL study is a randomized trial designed to determine possible benefits of a diet rich in vegetables and fruit, low in fat, and high in fiber for women with a history of early stage breast cancer (stages I-IIIA).

The researchers studied over 3,000 women, half of whom were instructed to eat the high vegetable and fruit, high fiber, low fat diet. The goal of this intervention diet was to have the women eat a minimum of 3 servings of fruit, 5 servings of vegetables, and 30 grams of fiber per day, and no more than 20% of total calories from fat. The other half of the women in this study were instructed to follow the control diet - a general healthy eating plan based on the "5-A-Day" program, the goal of which is to eat a minimum of 5 servings of vegetables and fruit per day.

Hopes and expectations, mine included, were that the women following the ultra-healthy intervention diet would have fewer recurrences of breast cancer and fewer new cancers than the women following the control diet. Unfortunately, the results were not what we expected. By "we", I am referring to anyone who follows these large cancer nutrition diet trials and others in the cancer nutrition community with interest and expertise in this area of research.

After 7.3 years of follow up, the women in the intervention group had no better outcomes than the women in the control group who were following the 5-A-Day diet. In other words, the number of breast cancer recurrences, new breast cancers, and deaths due to any cause were about the same in the two groups of women in this study. 

I would be lying if I said I wasn't disappointed with these results. This was a well designed study that failed to show a clear cut benefit, in women with a history of early stage breast cancer, of eating a very healthy, vegetable and fruit-rich diet. However, before you throw up your hands and say, "Forget it, why bother to eat a healthy diet, it doesn't even matter..." it may be helpful to look at the big picture of what these results may mean and why it is not a good idea to give up on healthy eating.

Confusion

When interpreting the results of the WHEL study that were published in JAMA, one of the first things to consider is a study that was published just one week earlier. The week before the JAMA article hit the press, other results from the WHEL study were published in the Journal of Clinical Oncology (JCO), another prestigious medical journal. This is quite common.

When researchers conduct a large, expensive study with many participants, they try to get as much information out of it as they can. They compare different sub-groups within the larger study. They analyze the data in different ways. Basically, they want to get as much "bang for their buck" as they can.

So, the week before the JAMA study appeared, the Journal of Clinical Oncology (JCO) study was published. The JCO study found that a combination of eating 5 or more servings of vegetables and fruit per day and exercising for the equivalent of walking 30 minutes per day, 6 days per week significantly reduced the risk of death after early stage breast cancer by nearly 50%! The combination of eating well and exercising resulted in a 44% reduced risk of death and this was true regardless of whether the women were overweight, obese, or at a healthy body weight.

Of note, the JCO study supports the findings from the larger study that were published in JAMA: In early stage breast cancer survivors, a healthy diet alone may not provide measurable protection against breast cancer recurrence, new breast cancers, and death due to any cause. Additionally, it showed that exercise alone probably doesn't provide much benefit either.

So, on the one hand, you have results from the WHEL study saying that an ultra-healthy diet doesn't provide benefit for breast cancer survivors. On the other hand, you have results from the WHEL study saying that if you follow a reasonably healthy diet (5-A-Day) and combine it with regular physical activity, you do see benefit.

Who To Believe

At this point, no one would blame you for being confused. Just consider the conclusions of the two editorials that accompanied the two studies I've been discussing.

1. The JAMA editorial that accompanied the study showing no benefit from the ultra-healthy diet states, "Unfortunately, available data do not support best practice dietary recommendations to improve long-term prognosis for early stage breast cancer survivors."
2. Meanwhile, the JCO editorial that accompanied the study showing a great benefit from a combination of healthy eating and regular exercise states, "In summary, the data from the WHEL control cohort add to the growing body of literature that lifestyle does matter in breast cancer prognosis. Increasing physical activity to 30 to 60 minutes per day is a recommendation for the general population and these data suggest that this recommendation should be extended to breast cancer patients and survivors. Similarly, increasing intake of vegetables and fruit is recommended for risk for several diseases, and now seems to aid in improving breast cancer prognosis."

One study concludes that healthy diet doesn't matter. The other concludes that diet does matter.

Important Considerations

What is one to make of this confusing picture? I believe it is important to keep the following points in mind when you think about the two sets of results recently published from the WHEL study.

• This study was conducted in early stage breast cancer patients. It does not tell us anything about whether a diet very high in vegetables and fruit, low in fat, and high in fiber provides benefit to people with other types of cancer. All cancers are different and how factors like diet affect risk of recurrence is likely to be different as well.
• The women in the intervention group in the WHEL study never reached the low fat target. They were counseled and coached to eat no more than 20% of total calories from fat, yet by year 4 of the study, fat intake averaged more than 27% of total calorie intake in both the intervention and the control groups. We cannot say whether the low fat component of this diet worked, because most women weren't able to reach the target of no more than 20% of calories from fat.
• All of the women in the WHEL study (intervention and control groups) gained some weight. Nearly a dozen studies suggest that weight gain after a diagnosis of breast cancer increases risk of breast cancer recurrence. It may be that if a woman does not maintain a healthy body weight, no amount of vegetables and fruit will provide benefit. Furthermore, published results from the Women's Intervention Nutrition Study (WINS) suggest that when women truly follow a very low-fat diet (and in this case, they also lost weight), it may reduce risk of recurrence significantly.
• Despite a reported 180 calorie per day decrease in intake, on average, in both the intervention and control groups in the WHEL study, the women gained weight over time. This raises important questions about how accurately the women in this study reported what they were eating. With such a significant decrease in calorie intake, weight loss, not weight gain, would be expected, yet this is not what happened. This points to one of the biggest problems in conducting diet research - it is very difficult to accurately measure what people are actually doing!
• At this point, the follow up time for the WHEL study is about 7 years. It may be that as researchers continue to follow these women for many years into the future, the positive benefits of the ultra-healthy intervention diet will become clear and measurable. Perhaps enough time has not elapsed to demonstrate benefit.
• The WHEL study results that were published in the Journal of Clinical Oncology  (JCO) suggests that a combination of healthy eating and regular exercise can reduce risk of death after early stage breast cancer, possibly by as much as 50%.

Moving Forward

The recently published results from the WHEL study can be confusing; however, this doesn't mean you should give up entirely on making healthy lifestyle choices after a diagnosis of breast or any other type of cancer. I firmly believe that it makes sense to "hedge your bets": 

• Focus on a variety of manageable lifestyle changes that can improve health.
• Maintain a healthy body weight. Consult a dietitian and/or join a weight loss support program for help with this. Research shows that these approaches, particularly when used together, can help with weight management in breast cancer survivors.
• Don't "put all of your eggs in one basket". Don't put so much energy into eating a healthy diet that you fail to keep yourself physically active. Likewise, don't spend so much time exercising that you don't have time to prepare and enjoy healthy meals and snacks.
• Focus on eating plenty of vegetables and fruit everyday, but don't place unnecessary guilt on yourself if you aren't "perfect" in your eating habits. Moderation is key!
• Focus on a low fat diet. Try to keep your fat intake as low as you can, because it is likely that you are eating more fat than you think. Don't feel badly - we all have this problem, me included!
• When you do eat fat, go for the healthy kinds - flaxseeds, other nuts and seeds, olive oil, fish.
• Exercise some every day. Don't feel like you have to run a marathon; remember that the WHEL study results published in JCO show that just 30 minutes of brisk walking each day is enough to provide health benefit. Make the time for yourself and view this as your time to take care of you.
• Work with your healthcare team to take all of the steps you can to keep yourself healthy after a cancer diagnosis.
• Don't feel guilty about what you "could have, should have, would have" done with your diet and exercise routines to prevent cancer. Take this opportunity to make the best choices you can from here on out. The goal is to keep yourself as healthy as you can by eating well, exercising moderately, enjoying the support of family and friends, and figuring out what hobbies or activities you enjoy doing that help you relax, manage stress, and feel good.

Nutritionist Suzanne