Skip to: Site menu | Main content

Professional Health Studies

  • The Medical Literature
  • Coronary heart disease
  • Stroke
    		•
  • Cancer
  • High blood pressure (Hypertension)
  • Cataracts
    		•
  • Multivitamin supplements delay the progression of HIV disease
    		•

    Health Studies, The Medical Literature

    I have often heard the it argued that there is no proof, research, or clinical health studies that vitamins and minerals are anything more than a useless waste of money. I question how hard they have looked.

    "people who take nutritional supplements can greatly lower the risk of developing disease"

    The medical literature contains many articles in some of the worlds top medical journals which confirm that people who take nutritional supplements can greatly lower the risk of developing disease, and also aid recovery from illness. listed below is a selection of some of these papers, each paper contains a brief synopsis and its reference.

    Many of the papers come from the USA Nurses Study. This is perhaps the largest and most reliable preventative of all health studies of disease in the history of medicine.

    "The researchers looked at their diet and lifestyle and observed the effects on the development of disease"

    88,000 healthy female nurses were followed carefully for 26 years. The researchers looked at their diet and lifestyle and observed the effects on the development of disease in these nurses.

    In addition to looking at what they ate and drank, they also documented their supplement use. Eight percent of those participating of those participating in the study were taking a multivitamin tablet, 23% vitamin C, 15% vitamin E and 4% took vitamin A.

    (Am J Clin 1981 Jun; 1121)

    The researchers used a technique called "multivariate analysis" which enabled them to separate the effect of each of the different lifestyles and intakes.

    What is interesting is how many completely unrelated conditions are helped by similar nutritional advice.

    These trials have shown that:

    Antioxidant Vitamins - benefits coronary heart disease, cancer, cataracts.

    Multivitamins - can reduce heart attacks and cancer.

    Fish Oils - can reduce heart attacks, cardiac arrest, stroke, cancer.

    Minerals - can help high blood pressure, heart disease and stroke.

    Considering that all our cells need similar nutrition, and that nutritional deficiency and free radicals cause or aggravate many diseases, then it is not surprising that the same regimen is beneficial for many different diseases.

    [ Back to top ]

    Coronary heart disease

    Coronary heart disease includes angina, heart attacks, and cardiac arrest. Many nutrients have been shown to reduce these including: Vitamin E, alpha-linolenic acid, folic acid, vitamins B6 and B12, unsaturated fats, fruit & vegetables, dietary fibre, whole grains, nuts, alcohol, fish oils and magnesium

    As you will read, some of the reductions in disease are truly remarkable. These results suggest that relatively simple and cheap changes in nutrient intake could dramatically reduce the risk of this disease which continues to kill almost l/3rd of the population of most Western countries.

    "48% of people who have a heart attack, die within 30 days. Half of those who die have NO prior warning - especially young people"

    (R.M. Norris UK Heart Attack Study, British Heart Foundation publication 1999)

    Sudden unexpected death is very common with heart disease. Many people know of friends who simply drop dead and never reach the high tech facilities in our hospitals. Because of these horrific figures prevention is far more effective than waiting until symptoms appear and then starting treatment.

    Here are some of the studies showing how coronary heart disease is affected by nutrition:

    1. Vitamin E

    Women in the Nurses Study who took vitamin E for short periods showed almost no benefit, however when they took it for more than 2 years, the risk of coronary disease was reduced by 41% (NEJM 1993, May 20; 1444)

    2. Alpha linolenic acid

    This is one of the few fats our bodies cannot manufacture. This is an omega 3 fatty acid found in oily fish and flax seed oils, it seems to be beneficial for the function of blood vessels, nerves, skin and joints.

    3. Folic acid and vitamin B6

    These B vitamins lower the blood homocysteine. High blood homocysteine level is an important risk factor for heart disease

    4. Dietary fat intake

    There are 4 types of fat we can eat - saturated fats (animal fats), poly-unsaturated fats (vegetable & fish oils), mono-unsaturated (olive oil) and trans fatty acids (found in margarines). It appears that the trans fats which have only been recently introduced into our diet are by far the worst. Transfats are found in cookies and margarines or are produced when fat is heated.

    5. Refined Sugars

    Sugars which are rapidly absorbed into the blood stream cause peaks in blood glucose and insulin. These are called high glycemic sugars, and have been blamed for obesity, diabetes and also can aggravate heart disease. (e.g. bread, potato, white rice, sweets).

    • Women in the Nurses Study who ate high glycemic foods had more than 2 1/2 times the risk of developing coronary heart disease. (Am J Clin Nutrition June 2000; 1455)

    6. Fruit and Vegetables

    Fruit and vegetables contain many antioxidants and other protective nutrients. The Nurses study did show some benefit, but it was small when compared with the vitamin studies shown above.

    • Women in the Nurses Study who had a high intake of fruit and vegetables had 20% fewer heart attacks than those on low intakes (Ann lnt Med 2001, June 19,1106)

    7. Dietary fibre

    Fibre in the diet keeps the bowels moving, this helps absorb some of the toxins in our food and can also lower the cholesterol. Fibre is made up of soluble and insoluble carbohydrates which are not absorbed from the bowel. Unrefined grain fibre appears to be the best source. When grains are refined, the outer layer, or husk, is removed. Most of the nutrients and fibre are in this outer husk)

    • Women in the Nurses Study who had a high intake of fibre in their diet had less coronary artery disease (19%). But cereal fibre was the most strongly associated with reduced events, with a 37% reduction in coronary heart disease. (JAMA 1999 2 Jun ; 1998)

    8. Whole grain

    In addition to fibre, whole grains also contain many vitamins and other nutrients which are lost when the grain is processed and refined.

    • Women in the Nurses Study regularly eating whole grain foods had 25% less coronary disease than those eating few or no whole grain foods. (Am J Clin Nutr 1999 Sep; 412)

    9. Nut consumption

    Nuts provide all the necessary nutrients for the growing plant and are a rich source of many beneficial fats, oils, proteins and vitamins.

    • Women in the Nurses Study who ate more than 5oz of nuts per week had 45% fewer heart attacks than those who ate no nuts (BMJ 1998 Nov 14;317)

    10. Alcohol

    Alcohol raises the level of the good HDL cholesterol, and wine, especially red, also contains many beneficial antioxidants. It appears to have a substantial benefit - but probably not enough to make a non-drinker start drinking! However it does mean that one does not need to stop the pleasurable 1 or 2 evening drinks - BUT no more!

    • Women in the Nurses Study who were light to moderate drinkers 1/2 - 4 drinks per day had fewer deaths (18%) - mainly due to reduced coronary artery disease. Heavier drinkers had more breast cancer & cirrhosis deaths. (N Engl J Med 1995 May 11; 1245)

    • In a number of studies, 2 drinks per day reduced the risk of heart attacks by 30-50%. (Am J Cardiol 1990; 1966:1237 and Lancet 1991;339:1523)

    11. Fish oils

    Fish contain omega 3 oils - very long chained polyunsaturated fatty acids derived from the plankton at the bottom of the food chain. These appear to have many beneficial actions within the body. From the heart point of view, fish oils appear to reduce the incidence of heart attacks, but most excitingly, they have a major effect upon sudden death (cardiac arrest is the cause of many, if not most deaths from heart attacks)

    12. Magnesium

    This mineral appears to be important in the function of muscles, and also in the control of heart rhythm. A number of studies have shown magnesium to be beneficial:


    [ Back to top ]

    STROKE

    Most strokes develop from blockages in the arteries feeding the brain or from pieces of these blockages breaking off (emboli). This process is very similar to coronary artery disease and the prevention is similar. In addition:

    [ Back to top ]

    CANCER

    There are many causes of cancer, and the body has a number of protective defences against cancer -especially the immune system. These systems all require good nutrition to function optimally. We do not know how many of these nutrients help reduce cancer, but as shown below there are a number of simple dietary steps which will greatly reduce the risk, including multi-vitamins, antioxidant vitamins, selenium and other minerals, fruit & vegetables and fish oil.

    1. MULTI-VITAMINS AND FOLIC ACID

    Folic acid and other B vitamins appear to be very important in cancer protection. Note the length of time needed to demonstrate a real benefit in the Nurses Study, but after that time, the effect was huge.

    2. Vitamin E

    It is believed that free radicals and oxidation may play a part in causing many cancers and Vitamin E is a powerful antioxidant.

    3. Selenium

    Selenium is a trace element and appears to take part in many of the body's functions. In some areas of the world the levels of selenium in the soil are low. (NZ is one of those places (NZMJ1992; 22 April: 139)). Selenium appears to have a protective action against some cancers:

    [ Back to top ]

    HIGH BLOOD PRESSURE (HYPERTENSION)

    There are many causes of high blood pressure. While drug treatment is frequently required, doctors stress the benefits of a healthy active lifestyle, stress reduction and a low salt diet. Calcium and magnesium also appear to have benefit, as, surprisingly, does a small amount of alcohol.

    1. Calcium and Magnesium

    Women in the Nurses Study who through their food or supplements took higher doses of calcium or magnesium, had less hypertension than those taking lower doses. Those taking 800mg of calcium/day had 22% less high blood pressure than those taking less than 400mg/day. Those taking magnesium more than 30Omg per day had 23% less, compared to those taking less than 200mg; and those taking higher doses of BOTH calcium and magnesium had 45% reduction in developing hypertension. (Circulation 1989 Nov 1320)

    2. Alcohol

    Women in the Nurses Study who drank a little alcohol had a modest reduction in hypertension, but higher intakes increased the risk. Half a drink per day reduced BP by 5%, 1 per day - by 8%. But those drinking more than 1 1/2 drinks daily had a 20% increase in hypertension. (Arch int Med 2002 11 March ; 569)

    The important feature with high blood pressure is not simply the pressure reading, but the fact that hypertension leads to the development of coronary heart disease and stroke. So in addition to lowering the blood pressure it is also important to reduce the risk of heart disease and stroke. This can be aided by nutritional means (see above).

    [ Back to top ]

    CATARACTS

    Cataracts are opacities which develop in the lens of the eye and are believed to be caused by the effects of sunlight which causes free radicals. Antioxidant vitamin C can reduce this, and caratenoids may provide additional protection:

    1. Vitamin C

    Women in the Nurses Study who took vitamin C for more than 10 years had 77% fewer early cataracts and 83% less severe cataract development, compared to women who did not take Vitamin C supplements. (Am J Clin Nutrition 1997 Oct;911)

    2. Lutein and Zeaxanthin

    These are caratenoids found in spinach and curly kale. They reduced cataracts by 22%. (Am J Clin Nutr 1999 Oct:509)

    [ Back to top ]

    Multivitamin supplements delay the progression of HIV disease

    Background Results from observational studies suggest that micronutrient status is a determinant of the progression of human immunodeficiency virus (HIV) disease.

    Methods We enrolled 1078 pregnant women infected with HIV in a double-blind, placebo-controlled trial in Dar es Salaam, Tanzania, to examine the effects of daily supplements of vitamin A (preformed vitamin A and beta carotene), multivitamins (vitamins B, C, and E), or both on progression of HIV disease, using survival models. The median follow-up with respect to survival was 71 months (interquartile range, 46 to 80).

    Results Of 271 women who received multivitamins, 67 had progression to World Health Organization (WHO) stage 4 disease or died — the primary outcome — as compared with 83 of 267 women who received placebo (24.7 percent vs. 31.1 percent; relative risk, 0.71; 95 percent confidence interval, 0.51 to 0.98; P=0.04). This regimen was also associated with reductions in the relative risk of death related to the acquired immunodeficiency syndrome (0.73; 95 percent confidence interval, 0.51 to 1.04; P=0.09), progression to WHO stage 4 (0.50; 95 percent confidence interval, 0.28 to 0.90; P=0.02), or progression to stage 3 or higher (0.72; 95 percent confidence interval, 0.58 to 0.90; P=0.003). Multivitamins also resulted in significantly higher CD4+ and CD8+ cell counts and significantly lower viral loads. The effects of receiving vitamin A alone were smaller and for the most part not significantly different from those produced by placebo. Adding vitamin A to the multivitamin regimen reduced the benefit with regard to some of the end points examined.

    Conclusions Multivitamin supplements delay the progression of HIV disease and provide an effective, low-cost means of delaying the initiation of antiretroviral therapy in HIV-infected women.

    (N Engl J Med 351 (1) 23-32 July 1, 2004.)

    [ Back to top ]

    Additional information: contact us | disclaimer