Re: 2 Questions: Healthiest vegetables? & Risk of vitamin A overdose?



C

Curly Sue

Guest
On 19 Feb 2005 17:30:48 -0800, [email protected] (chris) wrote:

>2 questions for the experts out there...
>
>1. I'm sure many of you would agree that an ideal diet should include
>a wide variety of vegetables everyday, but if for some reason you had
>to eat the same, say, 4 or 5 vegetables each day, which would be the
>healthiest to consume?
>
>
>2. If my daily diet includes a big bowl of raw spinach, steamed
>broccoli, carrots, tomatoes, and other vegetables, am I at risk of
>overdosing on vitamin A, which I understand has high concentrations in
>spinach and other vegetables? If so, how do you recommend I change my
>diet?
>
the vegetables have beta-carotene, which is a sort of precursor of
vitamin A. beta-carotene is not as toxic as vitamin A. But don't eat
the same ones every day; you should get some crucifera vegetables
(cabbage, brussels sprouts, cauliflower, broccoli) among others.

Sue(tm)
Lead me not into temptation... I can find it myself!
 
1) eating the same vegetables (or anything else for that matter) is never
recommendable.
variety is the key to a balanced diet.

2) you can't overdose on beta carotene when thinking of vitamin a toxicity
because it's only split to vitamin a on demand.

problems with very high beta carotene (probably not possible to reach this
level with food) however may arise if you are smoking. (see the finland
study on smokers and beta carotene)


"Curly Sue" <[email protected]> schrieb im Newsbeitrag
news:[email protected]...
> On 19 Feb 2005 17:30:48 -0800, [email protected] (chris) wrote:
>
>>2 questions for the experts out there...
>>
>>1. I'm sure many of you would agree that an ideal diet should include
>>a wide variety of vegetables everyday, but if for some reason you had
>>to eat the same, say, 4 or 5 vegetables each day, which would be the
>>healthiest to consume?
>>
>>
>>2. If my daily diet includes a big bowl of raw spinach, steamed
>>broccoli, carrots, tomatoes, and other vegetables, am I at risk of
>>overdosing on vitamin A, which I understand has high concentrations in
>>spinach and other vegetables? If so, how do you recommend I change my
>>diet?
>>
> the vegetables have beta-carotene, which is a sort of precursor of
> vitamin A. beta-carotene is not as toxic as vitamin A. But don't eat
> the same ones every day; you should get some crucifera vegetables
> (cabbage, brussels sprouts, cauliflower, broccoli) among others.
>
> Sue(tm)
> Lead me not into temptation... I can find it myself!
 
MMu wrote:
::: On 19 Feb 2005 17:30:48 -0800, [email protected] (chris) wrote:

:::: [...]If my daily diet includes a big bowl of raw spinach, steamed
:::: broccoli, carrots, tomatoes, and other vegetables, am I at risk of
:::: overdosing on vitamin A, which I understand has high
:::: concentrations in spinach and other vegetables? If so, how do you
:::: recommend I change my diet?
::::
:: problems with very high beta carotene (probably not possible to
:: reach this level with food) however may arise if you are smoking.
:: (see the finland study on smokers and beta carotene)
::
The Finnish study was done with isolated beta carotene supplements and
the beta carotene was not in its natural form. Beta carotene from food
sources is perfectly alright.

--
Juhana,
Finland
 
> The Finnish study was done with isolated beta carotene supplements and
> the beta carotene was not in its natural form. Beta carotene from food
> sources is perfectly alright.
>
all trans-beta carotene.

natural would be a mix of trans and cis
 
John Que wrote:
::: The Finnish study was done with isolated beta carotene supplements
::: and the beta carotene was not in its natural form. Beta carotene
::: from food sources is perfectly alright.
:::
:: all trans-beta carotene.
::
:: natural would be a mix of trans and cis

That's right. This is the Finnish Study:

The effect of vitamin E and beta carotene on the incidence of lung
cancer and other cancers in male smokers. The Alpha-Tocopherol, Beta
Carotene Cancer Prevention Study Group. N Engl J Med. 1994 Apr
14;330(15):1029-35. PMID: 8127329

"Unexpectedly, we observed a higher incidence of lung cancer among the
men who received beta carotene than among those who did not."

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8127329

But there are also studies where an *inverse* relationship between beta
carotene and lung cancer was found, so the situation is not so clear:

Connett JE, Kuller LH, Kjelsberg MO, Polk BF, Collins G, Rider A, Hulley
SB. Relationship between carotenoids and cancer. The Multiple Risk
Factor Intervention Trial (MRFIT) Study. Cancer. 1989 Jul
1;64(1):126-34. PMID: 2731108

"The results of this study provide further evidence for a possible
protective effect of beta carotene against lung cancer among cigarette
smokers."

Menkes MS, Comstock GW, Vuilleumier JP, Helsing KJ, Rider AA, Brookmeyer
R. Serum beta-carotene, vitamins A and E, selenium, and the risk of lung
cancer. N Engl J Med. 1986 Nov 13;315(20):1250-4. PMID: 3773937

--
Juhana
 
"Juhana Harju" <[email protected]> wrote in message
news:[email protected]...
> John Que wrote:
> ::: The Finnish study was done with isolated beta carotene supplements
> ::: and the beta carotene was not in its natural form. Beta carotene
> ::: from food sources is perfectly alright.
> :::
> :: all trans-beta carotene.
> ::
> :: natural would be a mix of trans and cis
>
> That's right. This is the Finnish Study:
>
> The effect of vitamin E and beta carotene on the incidence of lung
> cancer and other cancers in male smokers. The Alpha-Tocopherol, Beta
> Carotene Cancer Prevention Study Group. N Engl J Med. 1994 Apr
> 14;330(15):1029-35. PMID: 8127329
>
> "Unexpectedly, we observed a higher incidence of lung cancer among the
> men who received beta carotene than among those who did not."
>
>
http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=8127329
>
> But there are also studies where an *inverse* relationship between beta
> carotene and lung cancer was found, so the situation is not so clear:
>
> Connett JE, Kuller LH, Kjelsberg MO, Polk BF, Collins G, Rider A, Hulley
> SB. Relationship between carotenoids and cancer. The Multiple Risk
> Factor Intervention Trial (MRFIT) Study. Cancer. 1989 Jul
> 1;64(1):126-34. PMID: 2731108
>
> "The results of this study provide further evidence for a possible
> protective effect of beta carotene against lung cancer among cigarette
> smokers."
>
> Menkes MS, Comstock GW, Vuilleumier JP, Helsing KJ, Rider AA, Brookmeyer
> R. Serum beta-carotene, vitamins A and E, selenium, and the risk of lung
> cancer. N Engl J Med. 1986 Nov 13;315(20):1250-4. PMID: 3773937
>
> --
> Juhana

The positive reports are based on correlation.
The old saying goes " correlation doesn't prove causation."
Now that I've said that, I state the obvious which you
are aware. The 1986 and 1989 studies are based
the dietary source apparently. The involved beta carotenoid
would be both trans and cis. There would likely be
a great mix of carotenoids especially in the diets of
the healthier subjects.
>
 
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