One of the largest studies (1) to date on keto and breast cancer recently came out and showed clearly: NO you should not forego fruit, potatoes, legumes, and whole grains in order to load up on fat and more fat on the current keto-craze, if you want to have the best survival rate when it comes to breast cancer.

Now why might that be?

The keto diet has bored me out of my mind already when the craze first started a couple years ago, so much so, that I simply haven’t bothered to even write a blot about it. The diet is boring. The science behind it is terribly lacking and poorly translated into relevant scenarios.

Frankly, I find it pretty obvious how ridiculous the keto diet trend is: eating approx. 80% of fat daily while cutting out all fruit, potatoes, whole grains and being scared of eating too many carrots.

Yet followers of this diet will still be supplementing happily with fiber, antioxidants, polyphenols, vitamin C and beta-glucans, all documented substances which fight cancer, but oh-no, let’s avoid eating the naturally occuring sources, where these things are found: fruit, legumes and whole-grains. Sigh. If this doesn’t make you want to bang your head against the wall, I don’t know what will. Well, maybe if peanutbutter cups from Trader Joe’s suddenly go out of stock, which is also a totally legit reason for complete and utter despair admittedly. Darn those dark-chocolate peanutbutter cups from Trader Joe’s.

But what about all the doctors and health gurus saying keto is the way to go?

Yes, sure, we have studies that show this diet is fine if we are losing weight on it and if we are very overweight to start with (2). The weightloss still happens mainly due to energy restriction though: it’s not so much fun to eat broccoli with fat and meat all day long. You really reach a point where a banana and peanutbutter sandwich sounds soooo good. And christ almighty, it’s not like we are craving a shot of heroin, it’s just a banana and peanutbutter sandwich - that should be allowed on a healthy eating plan.

Sometimes we make healthy eating so complicated it is ridiculous - as if we win a prize for making something simple as complicated as possible.

Perhaps so we know that most of us are just gonna give up already - and eat the entire double-stuffed oreo cookie cabinet now we are at it, and just we wanted that darn banana, but we weren’t “allowed”. Anybody who says you have to be afraid of bananas - well they are just bananas.

The thing is, too much weight just creates a cascade of biochemical parameters to go awry.

So while such nutritional weightloss studies done on severely obese (2), might seem as if the keto diet is a great diet, we need to consider the fact, that for severely overweight people, anything that can get them to lose the weight will benefit their overall markers - until they reach normal fat%.

Once we are within a fairly normal range, you see the burden on the liver taking a toll from having to metabolize a high-fat diet and the inflammatory markers get negatively affected from following the keto diet (3).

When we look at tendency to be estrogen dominant and risk for breast cancer, we find a link to liver health.

If our liver is not functioning up to par and overloaded metabolizing a high fat diet along with toxic blackages, then estrogen gets accumulated rather than metabolized by our body - that is why we do not want to follow a keto diet if we have hormone cancer.

Now there are scenarios where keto can be relevant and useful - especially if used during radiation or chemotherapy.

Eating keto while doing chemo or radiology can make the cancer cells more susceptible to the treatment while to a certain degree saving the healthy cells from the damaging side-effects of such treatments. (4)

So what’s the take away here?

If you are severe overweight, whatever way that works for you to lose the extra pounds will benefit you. But once you’re just dealing with the vanity extra pounds: your liver, inflammatory markers and your hormones, especially if you are female, will take a blow, if you follow keto-diet for longer than 3 months time. Women’s hormone estrogen is involved in regulating serotonin and these two measurements affect women’s fertility, mood/depression and tendency to suffer from disordered eating patterns/binge-starvation cycles etc.

References:

1) JAMA Oncol. 2018 Oct 1;4(10): Association of Low-Fat Dietary Pattern With Breast Cancer Overall Survival: A Secondary Analysis of the Women's Health Initiative Randomized Clinical Trial. Chlebowski RT et al.

2) Exp Clin Cardiol. 2004 Fall; 9(3): 200–205. Clinical Cardiology. Long-term effects of a ketogenic diet in obese patients. Hussein M Dashti et al.

3) JAMA. 2003 Aug 20;290(7):912-20. Effect of a high-fat ketogenic diet on plasma levels of lipids, lipoproteins, and apolipoproteins in children. Kwiterovich PO et al.

4) Radiological Society of North America