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

Discussion in 'Food and nutrition' started by Curly Sue, Feb 19, 2005.

  1. Curly Sue

    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!
     
    Tags:


  2. MMu

    MMu Guest

    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!
     
  3. Juhana Harju

    Juhana Harju Guest

    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
     
  4. John Que

    John Que Guest

    > 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
     
  5. Juhana Harju

    Juhana Harju Guest

    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
     
  6. John Que

    John Que Guest

    "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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