Immune Function
The right diet is the key to managing many diseases and to improving general quality of life. For this condition, scientific research has found benefit in the following healthy eating tips.
Monounsaturated Fats
Opt for monounsaturated fats, such as olive oil, over other kinds of fats to ensure optimal immune function.Monounsaturated FatsThe effect of fats on the immune system is complex and only partially understood. Excessive intake of total dietary fat impairs immune response, but some types of fat may be neutral or even beneficial.126 For example, monounsaturated fats, as found in olive oil, appear to have no detrimental effect on the immune system in humans at reasonable dietary levels.127
Research on the effect of the omega-3 fatty acids that are abundant in some fish, fish oils, and flaxseed oil is conflicting. Liquid diets containing omega-3 fatty acids used in hospitals for critically ill people have been shown to improve immune function and reduce infections.128,129 However, in one controlled study in healthy people, a low-fat diet improved or maintained immune function, but when fish was added to increase omega-3 fatty acid intake, immune function was significantly inhibited.130
Supplementation with DHA (an omega-3 fatty acid found in fish oil) in healthy young men has been shown to decrease the activity of immune cells, such as natural killer (NK) cells, and to inhibit certain measures of inflammation in the test tube.131 The anti-inflammatory effects of DHA may be useful in the management of autoimmune disorders; however, such benefits need to be balanced with the potential for increased risk of infections. Other studies suggest that increased oxidative damage might be the reason for the negative effects on the immune system sometimes caused by fish oil, and that increased intake of antioxidants, such as vitamin E, could correct the problem.132
As with omega-3 fatty acids, omega-6 fatty acids (as found in vegetable oils) have also produced conflicting effects on the immune system. Enriching a low-fat diet with omega-6 fatty acids did not impair immunity.133 However, diets high in omega-6 fatty acids have suppressed immunity in other reports.134,135
In summary, low-fat diets with moderate levels of monounsaturated fat from olive oil appear least likely to compromise immune function and may provide small benefits. Conclusions about the desirability of diets high in either omega-3 or omega-6 fatty acid supplementation await further research.
Yogurt
Many studies have shown immune-stimulating effects from yogurt that contains live cultures, such as Lactobacillus acidophilus and other friendly bacteria (probiotics).YogurtMany studies, in both animals and humans, have demonstrated immune-stimulating effects from yogurt which contains live cultures, such as Lactobacillus acidophilus and other probiotics (friendly bacteria). The effects of probiotics observed in humans include increasing the activity of several types of white blood cells. In preliminary human studies, consumption of live probiotic-containing yogurt has been associated with a reduced incidence of several immune-related diseases, including cancer, infections of the stomach and intestines, and some allergic reactions.136
Low-Sugar
All forms of sugar (including honey) interfere with white blood cells’ ability to destroy bacteria, so cutting back is one way to give your immune system a boost.Low-SugarAll forms of sugar (including honey) interfere with the ability of white blood cells to destroy bacteria.137,138 Animal studies suggest diets high in sucrose (table sugar) impair some aspects of immune function.139,140 The importance of these effects in the prevention of infections in humans remains unclear.
Alcohol Consumption
Limit alcohol intake to avoid damaging effects to your immune system.Alcohol ConsumptionAlcohol intake, including single episodes of moderate consumption, interferes with a wide variety of immune defenses.141,142 Alcohol’s immune-suppressive effect may be one mechanism for the association between alcohol intake and certain cancers143 and infections.144,145 However, moderate alcohol consumption (up to three to four drinks per day) has been associated in preliminary studies with either no risk146 or a decreased risk for upper respiratory infections in young nonsmokers.147