Cancer plays no favourites. It can strike the young, the old, the poor, the rich. When three-year old Lukas Walton, the grandson of Walmart founder Sam Walton, was diagnosed in 1989 with Wilm’s tumour, a rare form of kidney cancer, his parents were distraught. They were somewhat comforted when told that chemotherapy with meds such as vincristine, dactinomycin, and doxorubicin had a high success rate, but understandably, they also looked into alternative and adjuvant therapies. When initial treatment did not wipe out the cancer, Christy, Lukas’ mother, embarked on a nutritional regimen with large amounts of fruits, herbs and vegetables that according to some alternative practitioners is the answer to stopping cancer in its tracks. Lukas recovered and that spurred John, his father, to look more deeply into the possibility of treating cancer by means of diet.
John Walton realized that folklore and anecdote cannot prove that dietary manipulation can cure cancer. Proof would require proper scientific evidence! So, he decided to fund a study to the tune of five million dollars that would examine the role of nutrition in preventing the progression of cancer. Being the son of Walmart patriarch Sam Walton, John was worth billions, so money was not a problem. The idea was to enroll breast cancer patients in a long-term study that would involve a change in their nutritional status. The “Women’s Healthy Eating and Living (WHEL) Study was designed to see whether increasing fruit, vegetable and fiber intake, while lowering fat consumption, would have an impact on the progress of the disease. Breast cancer was selected because a large population of women who had been diagnosed with breast cancer and had received treatment was available for follow-up.
Just over 3000 breast cancer patients were divided into two groups. Half were given detailed, continuous advice on how to increase their fruit and vegetable servings to about twelve a day while cutting down on fat. The other half was given standard dietary advice about healthy eating with the usual Five-A-Day motto for fruits and vegetables. The women kept food diaries over a seven-year span and also had blood drawn periodically to measure carotenoid levels which are indicative of fruit and vegetable consumption. Expectations were that the dramatic increase in fruit and vegetable consumption in the experimental group should have a protective effect against cancer recurrence given that a number of observational studies had previously indicated that populations with a higher intake of fruits and vegetables have a lower incidence of cancer. Alas, this did not prove to be the case.
Although as shown by blood tests and the food diaries, fruit and vegetable intake in the experimental group was significantly increased, both groups showed the same frequency of breast cancer recurrence and mortality. How do we interpret this finding? Should breast cancer patients be told that diet is not important? Not at all. The data indicate that at the beginning of the study the women were already consuming an average of about seven fruits and vegetables a day. This of course is way above the North American average. Apparently, increasing this to twelve does not afford any added benefit. The implication is that breast cancer patients should make sure they are getting at least seven servings of fruits and veggies a day, but there is no need to go to extremes. As with so many things in life, if some is good, it doesn’t mean that more is better.
It would be interesting to have a study of women who had a very low intake of fruits and vegetables before a cancer diagnosis and then dramatically increased consumption, but no such study is available. John Walton unfortunately was not around to learn about the results of the study he funded. He was killed in 2005, piloting a plane he had built. Lukas Walton is doing just fine and has himself funded a number of studies on sustainable agriculture and access to nutritious food. Did his vegetarian diet make a difference in his recovery? Impossible to say since no single case can prove a cause-and-effect relationship.
My original statement about cancer playing no favourites is not totally correct. Lifestyle factors do make a difference. While increasing fruit, vegetable and fiber intake may not affect the progress of cancer, it can reduce its incidence. Obesity, smoking, alcohol consumption, certain infections, a high intake of processed and red meat as well as certain occupations such as miners, roofers, asphalt pavers, woodworkers and diesel-exposed workers have been linked with a higher incidence of cancer. Affluence can also be a risk factor. Women in developed countries have a higher incidence of breast cancer because having their first child later in life increases risk due to hormonal factors. So does less adherence to breast-feeding. Early menstruation, as more likely to occur in developed countries, increases risk possibly due to more years of cycling estrogen and progesterone. In contrast, many full-term pregnancies, more likely in low-income countries, decrease risk.
As more and more studies of cancer come to light, the “knowns” about the disease increase and the “unknowns” decrease.
