about asparagus, l-asparagine and cancer

I wanted to post this as a note on Facebook but it seems there is no such option for a non-personal page, so I am posting it here. I read this in a newsletter that I subscribe to, written by a pair of naturopaths based in Denver, CO. I find their newsletters very informative and well-researched. However, it seems this current newsletter is not updated on their website yet, but since I have been talking about asparagus and posted a couple of related recipes, I thought I would reproduce the information below, also useful for future reference. Original article written by Jacob Schor ND, FABNO.

Excerpted from April 2011's newsletter:

If you have cancer, you have probably already read that asparagus will cure your cancer.  A letter making this claim has gone viral on the internet.  I doubt that there are more than a handful of people with cancer who have not received a copy forwarded to them by some well meaning friend or relative.

Let me start by saying there is little reason to believe the claim that asparagus will cure cancer.  Instead it may actually make a few specific cancers worse.

Let me summarize what we do know about these claims in the hope that information may antidote this long, standing urban myth.

The “Asparagus Cure for Cancer” first appeared in print in the February 1974 issue of Prevention magazine.      This article was followed by a similar article in the December 1979 issue of Cancer News Journal, a magazine once distributed in health food stores. Both articles claim that a dentist named Richard R. Vensal discovered that eating asparagus could cure cancer.

According to the letter, a cure can be achieved by consuming 4 tablespoons of pureed cooked asparagus twice a day.  Improvement is supposedly seen in two to four weeks.

Unfortunately there is little reason why we should believe this information.  The dentist Richard Vensal never published anything in either a scientific journal or book that can be found.


It is certainly possible that some chemical found in asparagus might be beneficial against cancer.

There is a single study suggesting this that was published in 2009.   Chinese researchers report that a chemical, which they named asparanen A, showed an anticancer effect when tested on liver cancer cells.    [1]

There are no studies that describe the results of feeding asparagus to animals with cancer.  Nor are there any published clinical trials on giving asparagus to human cancer patients.  Nor are is there any epidemiological data that hints that asparagus farmers have less cancer.

While there is a wealth of research that diets high in vegetables are anti-cancer, there is no evidence that singles out asparagus in particular suggesting it has an anti-cancer effect.  So while there may be some health benefits from eating asparagus because it is a vegetable, at this point, there is little reason to think that asparagus are exceptional.

In contrast there is substantial published data on the anticancer effect of other specific vegetables.  For example, a current search of the National Institute of Health’s National Library of Medicine, lists 597 published articles in the medical and scientific literature related to the anticancer effect of broccoli.   [2]  A search for published papers on garlic and cancer yields 648 references.   [3]

There are only two clinical trials involving asparagus in humans. One paper published in 2009, describes a study in which patients with high blood pressure were given a combination of parsley and asparagus extracts in the hope that their blood pressure would improve. Unfortunately, no benefit was seen.     [4]  An earlier study published in 2008, reported that a combination of asparagus and elderberry extracts helped patients lose weight.    [5]

Losing weight is not the same as curing cancer.

Thus at this point there is little reason to think that asparagus will cure cancer.


Ironically though there is a long established link between asparagus and a particular form of cancer.  Unfortunately, asparagus may, instead of curing this cancer, make it worse. Let me explain:

In 1953 a pathologist named John G. Kidd discovered that blood serum taken from healthy guinea pigs, when injected into mice, killed leukemia cancer cells.  [6] Ten years later John D. Broome MD explained why this happened.  Guinea pig blood contains an enzyme called l-asparaginase that breaks down an amino acid called l-asparagine.  Healthy cells make l-asparagine, but certain types of leukemia cells are not able to.  These leukemia cells rely on nearby healthy cells to supply them with l-asparagine.  The enzyme in the guinea pig blood breaks down the needed l-asparagine and so deprives the nearby cancer cells of this amino acid they require for their growth.  [7]

L-asparaginase enzyme is now available as a drug (Elspar) and is part of the standard treatment for acute lymphoblastic leukemia (ALL).  The drug, by decreasing l-asparagine, starves the cancer cells.  Most types of cancer do make l-asparagine, so Elspar is useful in treating only a few specific types of cancer.

As the names hints, asparagus contain large quantities of l-asparagine.  Eating asparagus would seem ill-advised for people who have cancers treated with Elspar or l-asparaginase.  Eating asparagus may stimulate growth in these cancers, most especially in ALL.  Eating a lot of asparagus may have an undesirable impact on other types of leukemia and possibly lymphomas as well.

People diagnosed with cancer are often desperate to do everything in their power to fight the disease.  They grasp onto every story and rumor about anything that might possibly help them.  The myth that asparagus cures cancer is a good example of this.


Recipe:

Broiling asparagus is so simple that one hardly needs a recipe.  This is how I do it.

Line a cookie sheet with foil.  Wash the asparagus, break off the bottoms.  Oil them lightly with olive oil.  Sprinkle them lightly with Kosher or sea salt.  Broil them until they taste done.  Serve either warm of cold.



References:

1. Liu W, Huang XF, Qi Q, Dai QS, Yang L, Nie FF, Lu N, Gong DD, Kong LY, Guo QL. Asparanin A induces G(2)/M cell cycle arrest and apoptosis in human hepatocellular carcinoma HepG2 cells. Biochem Biophys Res Commun. 2009 Apr 17;381(4):700-5. Epub 2009 Feb 28.

2. To search yourself, go to: http://www.ncbi.nlm.nih.gov/pubmed?term=broccoli%20and%20cancer

3. http://www.ncbi.nlm.nih.gov/pubmed?term=garlic%20and%20cancer

4. Chrubasik S, Droste C, Black A. Asparagus P(R) cannot compete with first-line diuretics in lowering the blood pressure in treatment-requiring antihypertensives. Phytother Res. 2009 Sep;23(9):1345-6.

5. Chrubasik C, Maier T, Dawid C, Torda T, Schieber A, Hofmann T, Chrubasik S. An observational study and quantification of the actives in a supplement with Sambucus nigra and Asparagus officinalis used for weight reduction. Phytother Res. 2008 Jul;22(7):913-8.

6. H. D. Moon Presentation of the Gold Headed Cane to John G. Kidd. February 24, 1973. Am J Pathol. 1973 October; 73(1): 1–6. PMCID: PMC1904051
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1904051/pdf/amjpathol00248-0005.pdf

7.  BROOME JD. Evidence that the L-asparaginase of guinea pig serum is responsible for its antilymphoma effects. I. Properties of the L-asparaginase of guinea pig serum in relation to those of the antilymphoma substance.
J Exp Med. 1963 Jul;118:99-120.

garlicky shrimps with asparagus & lemon

For some reason, I am coming across a lot of recipes with lemons in it, and I have been trying quite a few! I wouldn't call myself a big lemon fan but I must say some of these recipes are definitely keepers. This one I wanted to post while we can still enjoy asparagus. I found this recipe on Fine Cooking, where it was titled "Hot Garlicky Shrimp with Asparagus & Lemon" but it really is not that "hot" despite the use of crushed red pepper flakes, and I would say my pepper flakes are still pretty fresh. Well, I am not complaining as I can always sprinkle over some cayenne pepper if I wish to up the heat in my meal; I am only happy that I do not need to prepare a separate dish for the girls, so we can all enjoy this delicious dish! We find this one goes really well with rice, because the sauce is so drinkable-good, we pour them over the rice, dig in, and lick our plates squeaky clean.

(And honestly, I did not weigh the asparagus, I just used a bunch of what they sold me as a "bundle" at the stores, and then a few more because I felt like it. Some days it just drives me a bit bananas if I have to always measure and weigh... ...)

Green,orange and mellow yellow: so pleasing to the eyes!

Garlicky Shrimps with  Asparagus & Lemon
Recipe from Fine Cooking

• 1 lb shrimp (21 to 25 per lb.), peeled, deveined, rinsed, and patted dry  
• 3/4 tsp kosher salt; more as needed  
• Freshly ground black pepper  
• 1 lemon  
• 6 Tbsp extra-virgin olive oil (I used expeller-pressed coconut oil) 
• 4 medium cloves garlic, thinly sliced (I minced them instead) 
• 3/4 lb asparagus, bottoms snapped off, halved lengthwise if thick, and cut into 2-inch lengths (2 cups) 
• 1/8 to 1/4 tsp crushed red pepper flakes (add more if you like it hot) 
• 2/3 cup low-salt chicken broth  
• 1/2 tsp cornstarch  

1. Sprinkle the shrimp with a scant 1/4 tsp. salt and a few generous grinds of black pepper. Using a peeler, gently shave the zest in strips from the lemon, taking care not to get any of the bitter white pith. Squeeze the lemon to get 1 Tbs. juice.
2. Put a 12-inch skillet (not nonstick) over medium-high heat for 1-1/2 minutes. Add 2 Tbsp of the oil and once it’s shimmering hot, add the shrimp in a single layer. Cook undisturbed until the shrimp browns nicely, about 2 minutes. Flip the shrimp and brown the second side, about 1-1/2 minutes. (I find tongs work really well when doing this.) Transfer to a large plate. The shrimp should be a little undercooked.
3. Reduce the heat to medium, add the remaining 4 Tbsp oil and the garlic and cook, tossing, until the garlic starts to sizzle steadily, about 30 seconds. Add the asparagus, lemon zest, and red pepper flakes, sprinkle with 1/2 tsp salt and cook, tossing often, until the garlic is golden brown and the asparagus looks blistery in places, 2 to 3 minutes. Add the chicken broth, cover, with the lid ajar, and cook until the asparagus is just tender, 1 to 2 minutes.
4. In a small dish, whisk together the cornstarch with 1 Tbsp water, stir into the asparagus mixture, and bring to a boil. Stir in the shrimp, reduce the heat to low, and cook, tossing, until the shrimp is opaque throughout (cut one in half to check), 1 to 2 minutes. Stir in the 1 Tbsp lemon juice and then add salt, pepper, and additional lemon juice to taste. Serve immediately.

veggies in the oven

Growing up and watching my mother and my grandma prepare food, nothing was ever prepared in the oven. Vegetables were steamed, sauted, stir-fried, deep-fried, braised, cooked in a broth, but never in the oven. The oven was used by my aunts for baking cookies, fruit cakes, pineapple tarts (that people die for) and the most delectable chicken pot-pies.

What I have now, this kitchen that I cook and bake in, is the second kitchen I can call my own. Prior to this house in the United States, R and I lived in a tiny apartment in Hong Kong. It was a tiny little place we rented near to the university where we studied and worked (and met). The so-called kitchen was a very small room plunked right in the middle of our teensy apartment. It was about 40-square foot, and now that I think about it, our bathroom was even bigger than the kitchen, which contained the sink, a small fridge, the cooking range (no oven), two small cabinets for storage, and a washing machine too. Usually I am the lone person in there, cooking up a sweat; it had an accordion folding door that afforded me all the privacy (and focus!) I needed while I struggled to balance colanders of washed vegetables on barely-existing counter-tops (usually I used the top of the closed washing machine as my counter-top when cooking), stirring the other simmering pot (there were only two burners), reaching for condiments and all that. It had a small square window that allowed me to look out over to what was happening in the pet store next door. Mostly I see (and hear) dogs yelping while being manicured and shampooed.

Which makes me very grateful for the oven I have right now. It is nothing fancy or top of the line. In fact, since it's the same thing the previous (and first) owners of this house had installed, it should be about 20 years right now. But it still works, thank goodness! I love how it helps me prepare delicious vegetables without too much time and effort involved. No splattering oil, no skillets to scrub. No need to stand and flip, or stir. And honestly, I don't think any vegetables that came out of the oven, nicely roasted and served onto a platter with steam still billowing all around, had been rejected by any of my children. Never ever. I love how roasting vegetables in the oven intensify its flavor and free up hands and space for other components of the meal.

And really, there is no recipe, and therefore no limits. And I am not the only one who loves preparing veggies in the oven. This week I got some really good-looking asparagus from Trader Joe's and while checking out, we got talking about how to prepare the asparagus (oven-roasted) and how we also roast potatoes, carrots, broccoli, cauliflower and Brussels sprouts in the oven, and how people fight over their yummy goodness.

Of course, variety is key, so not every meal in our house ends up with an oven-roasted veggie. There are many ways to cook, but today I am here to sing the praises of oven-cooked vegetables. I think when my children grow up they are definitely going to remember how their vegetables came out from the oven, hot and alluring.

The greatest virtue of veggies in the oven is its simplicity. Wash the vegetables, cut into chunks if necessary, toss with olive oil, salt and pepper, and whatever seasoning you fancy. (Sometimes I roast garlic cloves with the vegetables, which becomes really sweet, and we then eat the garlic with the vegetables.) Pop into the oven and roast to how you like your vegetables. Usually we like to see a few brown spots on our sprouts and cauliflower. For the asparagus I made last night, it only took about 12 minutes in a 350F oven. After it came out, I shaved some pecorino cheese over it.

Oven-roasted asparagus

Sometimes I cut up a few strips of bacon and toss it with the vegetables, leaving the saltiness and smokiness of the bacon to flavor the vegetables, making them even more irresistible. I have also roasted Brussels with lemon zest and black pepper, and sometimes I toss the vegetables with some chopped roasted nuts. I've also experimented with green beans roasted with a bit of sesame oil, and sprinkled with sesame seeds.

Thankfully, my children do not say "yuck" to vegetables, and we endeavor to eat them in various ways, but veggies in the oven? -- they rock.