Breast Cancer Awareness Month — Boosting Survival

We are often asked if there are specific foods that can
boost cancer survival. For Breast Cancer
Awareness Month, we thought we’d address this question as it relates to breast
cancer. 

Existing research doesn’t support the notion that specific
foods that can increase survival. However,
there is considerable evidence that dietary
patterns can make a significant difference for women fighting breast
cancer. Let’s take a look at some of these
dietary patterns.  

Dietary Fat Intake

In the Women’s Intervention Nutrition Study (WINS), R.T.
Chlebowski and colleagues demonstrated that when women reduced their fat intake
to 20% or less, they reduced their risk of breast cancer recurrence by an average
of 24% (http://jnci.oxfordjournals.org/content/98/24/1767.long). 

One currently popular diet hyped as being good for all of us
is a diet rich in animal proteins and low in carbohydrates, because the
assumption is that all carbohydrates
are unhealthy.  However—and, contrary
to popular opinion—these diets are not good for any of us and, in fact, can
be the recipe for a bad outcome for breast cancer patients! Why? Because all carbohydrates are NOT created equal. Simple and refined carbs can lead to glycemia
and insulinemia, both of which can drive cancer growth! On the other hand, complex carbs do not raise
blood glucose and insulin. In fact, the
research demonstrates that controlling glycemia and insulin levels through the
use of complex carbohydrates not only reduces the risk of recurrence, but also
reduces mortality. (http://www.ncbi.nlm.nih.gov/pubmed/11773152).

Vegetables and Fruits

Vegetables and fruits are fundamental to any healthy diet,
and are part of healthy dietary recommendations for the prevention of cancer as
well as other diseases. As it relates to
breast cancer, Cheryl Rock and colleagues assessed carotenoid levels of
patients in a breast cancer diet trial and found that those in the top 2/3 of
carotenoid levels over the course of the study were 33% less likely to have a
breast cancer recurrence or new breast cancer. (http://www.ncbi.nlm.nih.gov/pubmed/19190138).  Carotenoids are found in both vegetables and
fruits; yellow and orange fruits and vegetables and dark green leafy vegetables
are particularly good sources. Dark
green vegetables, which also contain lutein, include kale, collards, spinach
and Swiss chard. Other high carotenoid
vegetables and fruits include carrots, sweet potatoes, pumpkins, winter squash,
apricots, mangoes, cantaloupe, and tomatoes. As far as fruit juices, while it’s OK to occasionally enjoy some of
these fruits as juices, we generally recommend eating them as whole fruits. However, if you choose to drink juices, you
might consider diluting them with water by 25%-50% in order to reduce the
sugar load. Eating whole fruit provides extra fiber and helps control calories as well as
excess fructose consumption. A high
fiber intake is associated with lower overall mortality in breast cancer
patients (including both breast cancer deaths and deaths from other
causes).  http://www.ncbi.nlm.nih.gov/pubmed/?term=fiber+breast+cancer+belle;
http://www.ncbi.nlm.nih.gov/pubmed/17044767. Foods high in fiber include raspberries,
pears, barley, whole wheat spaghetti, brown rice (as opposed to white rice),
beans (all types, e.g. split peas, lentils, kidney beans, black beans), green
peas, broccoli, cauliflower, and turnip greens.

Dairy

A recent study found that high-fat dairy intake was
significantly related to higher breast cancer mortality as well as mortality
from other diseases. Low fat dairy did not demonstrate a direct correlation to
breast cancer mortality. http://www.ncbi.nlm.nih.gov/pubmed/?term=kroenke+dairy+breast+cancer. So, if you’re going to use dairy products,
choose low-fat varieties of milk, yogurt, or cheese. Or, better still—and what we recommend to
our patients at the Block Center—consider some of the dairy alternatives
available today, including soy milk, almond milk (available in low-fat and
unsweetened), and rice or oat milk. 

Fish and Fish Oil

High intake of omega-3 fatty acids from fish in the diet has
been correlated with reduced breast cancer events (recurrences, new breast
cancers) and reduced overall deaths from breast cancer and other causes. http://www.ncbi.nlm.nih.gov/pubmed/?term=patterson+epa+breast+cancer)

Fish that are high in omega-3 fats include salmon, sardines,
anchovies, tuna, cod, haddock, Atlantic mackerel, halibut, and other fish from
northern oceans. We recommend reducing
or avoiding tropical fish, like tilapia, or farmed catfish, which are not high
in omega-3s. 

Soy

Back in the 80s and 90s there was controversy as to
whether an estrogen-sensitive breast cancer patient might worsen their disease
by consuming soy products. In fact,
there were a few leading breast cancer specialists that railed against the
consumption of soy, raising worries of its safety. At the same time, breast cancer
research at the Block Center demonstrated enhanced outcomes among patients
consuming increased levels of soy. And now, emerging science from both the
laboratory and from large scale epidemiological studies have confirmed what our
early data suggested. Bottom line, soy
is not harmful for breast cancer patients, and may, in fact, be quite helpful. (http://www.ncbi.nlm.nih.gov/pubmed/20426596). 

A particularly interesting 2013 study pooled the results
from three large American studies and one Chinese study of the diets of breast cancer
patients after diagnosis. This combined
study found that soy foods turned out to be associated with better survival
with an impressive 15% reduction in risk of death for all breast cancer
patients regardless of menopausal status or presence of estrogen receptors. They also found that soy foods were
associated with lower recurrence rates in postmenopausal women whose tumors
lacked estrogen receptors, as well as those who had both estrogen and
progesterone receptors. (http://www.ncbi.nlm.nih.gov/pubmed/?term=chi+post-diagnosis+soy).

When you add soy foods to your diet, emphasize the
relatively un-processed types of soy, such as tofu, edamame, miso and
tempeh. These are healthier and less
caloric than highly processed soy meat substitutes. Additionally, when used as a substitute for
meat, soy may be helpful in controlling weight, since it’s lower in calories. 

Insulin Levels

A 2002 study found that breast cancer patients with high
insulin levels, which are correlated with high body mass index, had elevated
risks of breast cancer mortality and recurrence.(http://www.ncbi.nlm.nih.gov/pubmed/11773152). Several studies since then have implicated
elevated insulin, and elevated blood glucose and related variables to breast
cancer. To reduce elevated insulin and
blood glucose, we suggest consuming low-glycemic index foods, which have been
found to only minimally raise blood glucose levels. Avoiding refined flours, refined sugar and
related products (white and brown sugar, molasses, honey, cane juice, and
others), and eating nuts such as almonds or walnuts can help. In one study, almonds reduced C-peptide, a
marker for insulin production, more effectively than whole-wheat muffins: (http://www.ncbi.nlm.nih.gov/pubmed/?term=jenkins+almonds+whole+wheat+c-peptide). Alternatives to refined sugars include
sweeteners such as stevia and limited quantities of other natural sweeteners
such as agave or brown rice syrup. And,
a sweet piece of nutritious fruit can make a delicious dessert!    

Our general dietary recommendations

At the Block Center, we recommend a diet low in saturated
fats and high in fiber, plant-based sources of protein, cold water fish rich in
omega-3 fatty acids, complex carbohydrates, fruits and berries rich in
antioxidants, and nuts, seeds and cruciferous vegetables, foods containing
other substances such as allium compounds, dithiolthiones, flavonoids,
glucosinolates, indoles, isothiocyanates, phenols, and d-limonene. This
nutritional strategy is intended to do several things, including:

• Help curtail inflammation,
  which is essential for combating recurrence and progression. In fact, elevated inflammatory markers
  increase risk and mortality by 2 to 3 fold, whereas countering this can be
  the difference in proliferation and dissemination of breast cancer cells,
  or never seeing the cancer again!
• Reduce free-radical damage.
• Minimize platelet
  activation (which can lead to dangerous blood clotting).
• Manage blood sugar surges.
• Reduce serum levels of
  insulin-like growth factor 1, or IGF-1 (which stimulates cell
  multiplication and inhibits cell death).

Evidence shows that reducing glycemia, insulinemia,
inflammation, and oxidation makes a huge difference in every challenge a breast
cancer patient faces, including improving the biological integrity needed to
counter growth and reducing the risk of
recurrence.