NPR Story: Fruits and Veggies Prevent Cancer?
NPR ran an article today, Fruits and Veggies Prevent Cancer? Not So Much, It Turns Out…
Excerpts:
“A huge nine-year study of diet and cancer, involving nearly a half-million Europeans in 10 countries, finds only a very weak association between intake of fruits and vegetables and cancer incidence. The study is in the current issue of the Journal of the National Cancer Institute. Those who get an extra two servings of fruits and veggies a day lower their cancer risk by only four percent.”
Not the best news, but at least it cuts the risk by 4%. I’m inclined to think this study is correct, that fruits and vegetables help prevent cancer, but not by a lot. Good news is later in the article:
“But meanwhile, there’s a pretty strong reason for everybody to continue eating lots of fruits and vegetables. It’s called cardiovascular disease. A 2004 study in the JNCI found that eating five servings of fruits and vegetables a day is associated with a 28 percent lower risk of heart disease and stroke, compared to people who eat fewer than 1.5 servings a day.”
April 7th, 2010 at 5:49 pm
[…] benefits of veganism—which is a point I’ve been making ever since Meat Market came out. Link. Spread the […]
April 8th, 2010 at 6:26 am
Okay, but what about the idea that meat and other animal products are correlated with higher incidences of some types of cancers – like red meat and bowel cancer or dairy and prostate cancer. If fruits and veggies don’t strongly defend against cancer, is it still accurate to say that a vegan diet is a good defense against many forms of cancer?
April 8th, 2010 at 10:02 am
In the case of animal products being linked to higher risks of cancer, it is usually large amounts of animal products vs. smaller amounts of animal products. For example, in 2002 I did a careful analysis of all the studies that looked at dairy product intake and prostate cancer and found that 3 servings of dairy per day likely increased the risk of cancer versus 1 serving per day. It is probably reasonable to assume, therefore, that people eating no servings of dairy would also be protected compared to people eating 3 servings or more per day. But, if you compared no servings to 1 to 3 servings, there’s less of a chance of a protective effect of eating no dairy.
The only study that has looked at vegan’s rates of type 2 diabetes found that vegans had much lower rates. The study was cross-sectional, so it doesn’t mean that being vegan caused the lower rates – it could mean that people who have type 2 diabetes are less likely to go vegan; I would guess it’s a combination of the two. And it could be that type 2 diabetes increases the risk of cancer. And, if so, then perhaps being vegan lowers the risk of cancer.
There is also the theory that vegans’ lower levels of IGF-1 might decrease our risk of cancer.
This is all very theoretical. Hopefully we will be getting some data on the cancer rates of vegans in the coming decade, from EPIC-Oxford and Adventist Health Study-2 that can shed some light on this subject.