Veggies, fruits, and fish reduce asthma
Tooth loss associated with dementia
Broccoli and skin cancer protection
Exercise helps balance
Diet aids fertility
Whole grains, diet, stop heart disease
Saturated fats harm blood vessels
A diet that is largely based on fruits, vegetables, and fish reduces the risk that a child will develop allergies and asthma. A study of 460 children in Spain showed that the children with the highest fish consumption compared to those with the lowest had a 57 percent reduced risk of developing allergies in the first 6 years of life.
Vegetables, such as tomatoes, eggplants, cucumbers, string beans, and zucchini were even better at reducing asthma symptoms, such as wheezing, cutting the risk by 62 percent. (Chatzi L, et al., Diet, wheeze, and atopy in school children in Menorca, Spain. Pediatr Allergy Immunol. 2007 Sep;18(6):480-5.)
A previous study by the same group on children in Crete also showed that fruits and vegetables reduced the risk of allergic rhinitis and asthma. This study of 690 children revealed that 80 percent of the children ate fruits at least twice a day, and 68 percent of them ate vegetables at least twice per day. Fruits (grapes, apples, oranges, and tomatoes) were not associated with abnormal skin testing, but increasing consumption of these was associated with a reduced risk of wheezing and allergic rhinitis. (Chatzi L, et al., Protective effect of fruits, vegetables and the Mediterranean diet on asthma and allergies among children in Crete. Thorax. 2007 Aug;62(8):677-83.)
In addition, the study found that eating nuts was associated with reduced asthma and rhinitis, while margarine increased the risks. The closer the children stayed to the Mediterranean diet the more protection they had from asthma. (To me, one of the striking features of the research is the high percentage of kids in Crete who eat lots of fruits and vegetables! It appears that being a “picky eater” is not an ingrained genetic trait in children.)
Information derived from the Nun Study, research on aging among sisters of the School Sisters of Notre Dame between 75 and 90 years old, shows that tooth loss is associated with an increased risk of Alzheimer’s disease. (Stein PS, et al., Tooth loss, dementia and neuropathology in the Nun study. J Am Dent Assoc. 2007 Oct; 138(10):1314-22.)
Researchers followed 144 subjects who had no signs of dementia at the start of the study for 12 years, and found that those with 10 or more teeth were half as likely to develop dementia during the course of the study as those with 0-9 teeth. The association has been noted before, but it was not clear whether tooth loss was a result of dementia, but these subjects had already lost teeth before there were signs of dementia. Tooth loss is often the result of gingivitis, inflammation that is a possible contributor to both heart and brain diseases.
Broccoli contains a number of phytochemicals and vitamin C, all known to be protective against cancer. One of the phytochemicals, sulforaphane, appears to protect the skin from UV damage, reducing the risk of skin cancer. (Talalay P, et al., Sulforaphane mobilizes cellular defenses that protect skin against damage by UV radiation. Proc Natl Acad Sci U S A. 2007 Oct 30;104(44):17500-17505.)
The sulforaphane does not act as a sunscreen, but it enhances the cells’ resistance to the effects of UV light. UV light initiates oxidative cell damage, interferes with membrane function by damaging lipids, and it causes inflammation, suppresses immunity, and leads to skin cancer. (It also helps the body by stimulating vitamin D production in the skin.)
The protective effect of sulforaphane has previously been shown in animals and in cell lines. This new study shows that it is also helpful in human subjects. Six volunteers were pretreated with sulforaphane before exposure to various doses of UV radiation. The treatment reduced the subsequent redness of the skin by an average of 38 percent. Redness of the skin, or erythema, is a biomarker for UV-induced damage. It is easily quantified, and it is non-invasive, making it an easy tool for research. Sulforaphane increases the production of phase-2 enzymes that help to detoxify carcinogens.
Exercise helps elderly people to maintain their balance. Balance is something that declines with age, leading to more falls, greater risk of fractures, disability, and death. You can check yourself by standing on one leg to see how difficult it is. Then, try closing your eyes and stay upright – it can be quite difficult. Sometimes it helps to take vitamin B12, which is important for peripheral nerve health.
This research analysis of 34 clinical trials with 2883 participants older than 75 shows the value of strength training, balance exercises, and even simply walking in maintaining balance as you age. (Howe T, Exercise for improving balance in older people. Cochrane Database Syst Rev. 2007 Oct 17;(4):CD004963.) Balance exercises such as tai chi can be particularly helpful according to the studies included in this analysis.
It is possible to enhance fertility through dietary choices. A new eight-year study of 17,544 women showed that infertility due to ovulation problems (the main cause of infertility) could be reduced by 66 percent, and that due to other causes by 27 percent. (Chavarro JE, Diet and lifestyle in the prevention of ovulatory disorder infertility. Obstet Gynecol. 2007 Nov;110(5):1050-1058.)
The diet that helps according to this research is low in trans fats (from partially hydrogenated oils), replacing them with monounsaturated oils (such as are found in olive oil and avocados), and it is rich in plant-based protein sources instead of animal protein. Proteins are found in many plant sources, such as beans and tofu, nuts, seeds, whole grains, and even green vegetables.
The diet is also low in refined carbohydrates and high in complex carbohydrates (whole grains and beans) and other low-glycemic foods, and it has a moderate amount of whole-milk dairy product. (The researchers cautioned against continuing to consume such dairy for the long term due to other risks.) It also appears helpful to take a multivitamin and iron derived from plant sources or supplements. Fertility was also improved by exercise and weight control.
A research report on 21,376 subjects, followed for over 20 years in the Physicians’ Health Study, shows that the consumption of breakfast cereals is associated with a reduction of the risk of congestive heart failure, the most common cause of hospitalization in the elderly. (Djoussé L, Gaziano JM, Breakfast cereals and risk of heart failure in the physicians' health study I. Arch Intern Med. 2007 Oct 22; 167(19):2080-5.)
However, the association was only significant for the consumption of whole grains, not refined grains. (Whole grains include whole wheat, oatmeal, brown rice, millet, barley, quinoa, corn, and several others, but not white flour or white rice.) Previous studies have shown that whole grains reduce the risk of heart attacks and hypertension, both of which can lead to congestive heart failure.
In another study in the same journal (Akesson A, et al., Combined effect of low-risk dietary and lifestyle behaviors in primary prevention of myocardial infarction in women. Arch Intern Med. 2007 Oct 22;167(19):2122-7.) of 24,444 post-menopausal women, a diet consisting of fruits, vegetables, whole grains, beans, and fish, along with several healthy lifestyle habits (including a small amount of alcohol), led to a 92 percent reduction in the risk of heart attacks compared to a diet including red and processed meat, poultry, rice, pasta, eggs, and fried potatoes (the “Western diet”).
What is important about these studies is the unavoidable conclusion that heart disease is something that you can prevent by lifestyle choices. It is not genetic, but is under your control. Choosing to eat properly, exercise, and not to smoke will virtually eliminate the problem.
In research from Australia, a group of 14 subjects were given a single meal containing either a large amount of saturated fat or one with the same amount of calories but much less fat that was derived from safflower oil, which contains polyunsaturated fats. The result was a striking difference in the ability of their HDL molecules to control inflammation.
The high saturated fat meal increased the markers associated with inflammation, while the diet with polyunsaturated fat decreased those markers (this meal was also low in overall fat content, so that may have played some role).
In addition, the saturated fat meal (equivalent to a cheeseburger, fries and a shake) decreased the blood flow in small blood vessels by impairing endothelial function (endothelium produces relaxing factors that open up blood vessels). The polyunsaturated fat meal increased blood flow and endothelial function. (Nicholls SJ, et al., Consumption of saturated fat impairs the anti-inflammatory properties of high-density lipoproteins and endothelial function. J Am Coll Cardiol. 2006 Aug 15;48(4):715-20.)
These effects were seen at 3 and 6 hours after the meals were eaten. What the study shows is that dietary choices can have an immediate effect on heart risks, and repeated exposure to such meals can have long-term deleterious effects. To achieve the benefits suggested by all these studies, a mostly vegetarian diet fits quite well as part of the healthy lifestyle.