A friend contacted me the other day to tell me that she had been diagnosed with breast cancer, that she was going to need chemotherapy, and to ask if I had any advice on what she could do, nutrition-wise, to improve her chances of getting a successful result.
It’s a difficult question to answer, because while some of the evidence on nutrition and cancer is fairly well established (such as the benefits of eating a Mediterranean-style diet, see below), other approaches, such as intermittent fasting, are much more controversial.
But new research suggests that in the right patients this may also be helpful.
There are different types of intermittent fasting, ranging from time-restricted eating (in which food intake is limited to a certain number of hours per day) to the 5:2 diet, in which calories are reduced by two or more days a week. .
The first evidence of the possible benefits of the latter in preventing breast cancer emerged from a study carried out by the University of Manchester in 2013. The researchers took a group of 115 middle-aged women who had a family history of breast cancer, which placed them at greater risk of the disease.
There are different types of intermittent fasting, ranging from time-restricted eating (in which food intake is limited to a certain number of hours per day) to the 5:2 diet, in which calories are reduced by two or more days a week. (File image)
The women were randomly assigned to follow a standard low-calorie diet or, for two days a week, half were asked to eat only 650 calories of a Mediterranean-style low-carbohydrate diet (i.e., intermittent fasting).
After eight weeks of this regimen, the intermittent fasting group lost an average of 6kg, almost twice as much as those who dieted daily.
Significantly, they also saw much greater improvements in their insulin sensitivity, a measure of how much insulin your body has to produce to lower your blood sugar levels.
This is important because high insulin levels are thought to help promote cancer growth. The same researchers published a study in 2016 that showed that a month of intermittent fasting not only led to weight loss, but breast biopsies revealed that just over half of the women had changes in gene activity in their breast tissue. , which suggested that they were less likely to get cancer.
In addition to intermittent fasting’s impact on insulin levels, it may also help fight cancer by increasing the effectiveness of our T cells, a vital part of the immune system. This is suggested by a new study from the Van Andel Research Institute in Michigan, United States, published in the journal Immunity.
The research, which was based on mice, showed that ketones, a type of fuel our body produces in response to intermittent fasting, help supercharge T cells, making them more effective at neutralizing cancers. Therefore, there is evidence that intermittent fasting can boost your immune system and may help reduce the risk of developing certain cancers, including breast cancer. And if you have cancer, it can ease the effects of treatment.
While few studies have been conducted in humans, my attention was drawn to recent research presented at the European Society of Medical Oncology conference by the Charité University of Medicine in Berlin.
In addition to intermittent fasting’s impact on insulin levels, it may also help fight cancer by increasing the effectiveness of our T cells, a vital part of the immune system. This is suggested by a new study from the Van Andel Research Institute in Michigan, USA, published in the journal Immunity (File image)
The study involved 106 women who had been diagnosed with early breast cancer and were about to undergo chemotherapy.
Half were asked to follow a low-calorie diet, consisting mainly of vegetable juices and broths, for two days before chemotherapy and then for 24 hours afterward.
Surprisingly, despite consuming fewer calories than normal, women who followed the fasting regimen reported much less fatigue and a much greater sense of well-being after chemotherapy than the control group, and no side effects were reported.
In addition to increasing ketone levels, short-term fasting lowers blood glucose levels, which makes it harder for cancers to grow and can make them more vulnerable.
While encouraging, the study was too short to show whether short-term fasting has a positive impact on long-term survival.
This research is still in its infancy, and when it comes to chemotherapy, intermittent fasting is not something I would recommend trying to do outside of a proper clinical trial.
Instead, as I told my friend with breast cancer, I think a safer approach would be to adopt a Mediterranean-style diet, rich in oily fish, olive oil, nuts, fruits, vegetables and legumes. Not only has this been shown in trials to reduce the chances of getting cancer, but a recent study showed that it can also make chemotherapy more tolerable.
The research, conducted by the University of Rochester Medical Center in the United States, showed that cancer patients who followed a Mediterranean-style diet for a couple of months reported much less fatigue after chemotherapy than those who followed a program of “usual care.”
Interestingly, the beneficial impacts of the diet appeared to come, at least in part, from the increase in patients’ mitochondria, the little batteries in all of our cells that provide them with energy, particularly those that supply T cells.
At the moment, the Mediterranean-style diet is not routinely suggested to people who are about to undergo chemotherapy, but it is something I would recommend.