Our lifetime risk of developing an invasive cancer,

not like some superficial skin cancer or like ductal carcinoma

of the breast, but serious cancer is about 40%.

Two in five of us are going to get a cancer diagnosis in our lifetimes.

What can we do to reduce our risk?

Only about 5% of cancers are caused

by problem genes we inherited from our parents.

The other 95% are caused by mutations

in our DNA we acquire in our lifetimes.

For example, based on a genetic analysis of lung cancer,

smokers may acquire an average of one DNA mutation

for every 15 cigarettes smoked.

Smoking is bad, but the number one cause of these mutations is our diet,

and that's not even including the cancers attributed to obesity.

I've got tons of videos on dietary approaches to prevent cancer,

but what if you already have it?

Well-meaning professionals sometimes counsel cancer patients

to “Eat whatever you want.“

Given the time constraints that doctors face, it may be understandable

that the treating oncologist, the treating cancer doctor,

may be reluctant to engage in a conversation about nutrition,

but given the critical role that diet may play,

perhaps it should be a critical part of their job to be able

to answer patients' questions about nutrition before and

after cancer treatment and not default to the unhelpful

“it doesn't really matter, eat whatever you want”

which may not be in the best interest of the patient.

The official recommendation

of the American Institute for Cancer Research,

a leading authority on diet and cancer,

is that those with cancer should follow the same diet

that helps prevent cancer from taking root in the first place.

That means more whole grains, vegetables, fruits, and beans,

while limiting fast food, processed food, meat, soda and alcohol.

Similar recommendations have been

put forth by other cancer authorities:

more fruit, vegetables, whole grains, and beans,

and less salt, sugar, meat, and alcohol.

Cancer survivors adhering to these guidelines do seem

to live significantly longer, or at least older female cancer survivors,

the only group in which it's been looked at so far.

They add that there are certain foods that may be beneficial

in cancer care including: beans, berries, cruciferous vegetables,

flaxseed, garlic, green tea, tomatoes, and others,

but emphasizes it's not about a single magic bullet food or component,

but the combination of foods in a predominantly plant-based diet.

Here's how some popular diets used by cancer patients stack up.

The so-called alkaline diet gets high marks for being

vegetable-focused and encouraging people to cut down on animal foods.

The keto diet does the worst, though they get points for keeping

people away from refined grains, alcohol and soft drinks.

Macrobiotic diets win the day, being closest to a whole food,

plant-based diet, centered around whole grains, vegetables,

and beans though may not be advising enough fruit.

Paleo diets are a mixed bag with insufficient whole grains and beans

and too much meat, and the vegan diet starts out strong,

but doesn't necessarily preclude all manner of vegan junk food.

Have any of these diets been put to the test?

I've done a video on the abject failure of the keto diet.

The alkaline diet was tried on eleven lung cancer patients.

They lived an average of 28 and a half months,

which is about 40% longer than most patients have

historically lived, but there was no direct control group.

The only diet proven in a randomized controlled trial

to reverse the progression of cancer was Dr. Dean Ornish's whole food

plant-based lifestyle program, which I've covered before.

Most randomized controlled trials to date on diet and cancer

are like this, feasibility studies just to see if we can get

cancer patients to eat healthier. Period.

Otherwise what's the point of even running the study?

Here they did find they could get patients with head and neck cancer

to ramp up green leafy and cruciferous vegetable intake

up to 9 cups a week, so it's at least something you could test,

but we don't yet have outcomes data, but why wait?

What's the downside of trying to eat healthier?

It may even save your life, another way.

Cardiovascular disease competes with breast cancer as the leading cause

of death for older women diagnosed with breast cancer.

Researchers followed more than 60,000 women

diagnosed with breast cancer over the age of 65 for

an average of nine years, by which time half had died.

And the number one cause of death was actually cardiovascular disease,

edging out the breast cancer, and so choosing a healthy diet

centered around whole plant foods, the only diet ever proven

to reverse heart disease in the majority of patients,

may save your life, whether you have cancer or not.