People often ask me, “If you could list some “super” foods, what would you tell people to consume more often?” My answer is usually something like, “Try to consume more of a Mediterranean-type diet; include more whole grains, nuts, vegetables, fruit, and fish in your diet.” However, people always want me to be more specific. Therefore, in this Nutritionist’s View article, I will discuss a few of those “powerful functional” foods that have been shown to be great for one’s health. By no means is this list exhaustive, and I may come back to this again in another column with other foods; however, the foods presented here should be a good start.
BERRIES (BLUEBERRIES, STRAWBERRIES, BLACKBERRIES, RASPBERRIES, ETC.)
Berries are packed with antioxidants, which can help decrease free radical production in the body. The production of free radicals occurs daily, but consuming food that can help decrease the amount of free radicals may help stave off cancer and heart disease.
I often tell people, “If you can consume a bowl of mixed berries every day, that is the best supplement.”
One can incorporate mixed berries into his/her diet through eating them as a side for breakfast, putting them on cereal, making smoothies, and/or putting them in salads. Berries are sweet, and, during the winter, frozen berries can be purchased and used in smoothies or put into plain yogurt.
Plenty of research has been conducted on the amount of antioxidants in berries (blueberries have among the highest antioxidants among all berries); however, I came across a study where the researchers studied the effect of New Zealand blueberry consumption on recovery from eccentric exercise-induced muscle damage. McLeay et al. (6) conducted a randomized crossover study to evaluate if a blueberry smoothie would elicit greater antioxidant and antiinflammatory capabilities compared with placebo. They studied 10 women who consumed the blueberry smoothie or a placebo, with similar antioxidant capacity, 5 and 10 hours before and 12 and 36 hours after exercise-induced muscle damage. Exercise-induced muscle damage was elicited by having the women perform 300 eccentric contractions of the quadriceps. The researchers reported a faster rate of recovery and faster rate of decrease in oxidative stress in the blueberry smoothie group. They also reported that the women in the blueberry smoothie group regained their strength faster compared with those in the placebo group. Thus, blueberries might help in recovery from eccentric exercise and certainly are beneficial to overall health.
Avocados are another excellent food. Although high in fat, most of the fat in an avocado is monounsaturated, which is a “good fat,” and can help to decrease low-density lipoprotein (LDL) cholesterol in the blood. Avocados are an excellent source of potassium and vitamins B, C, E, and K. Furthermore, although avocados are a fruit, they have a low amount of sugar and provide 4 g of protein and 11 g of fiber (medium-sized avocado) (7).
Avocados have been shown to protect against prostate, breast, and oral cancers. Furthermore, avocados have more lutein than other fruits. Lutein is an antioxidant that has been shown to protect the eye from macular degeneration and cataracts (7).
Interestingly, avocados have been shown to improve nutrient absorption when consumed with other food compared with when those food are consumed alone.
Li et al. (4) also reported that consumption of an avocado with a hamburger decreased vasoconstriction compared with when participants consumed a hamburger alone. The antiinflammatory effects of an avocado could have a significant impact on vascular health on individuals.
This does not mean that people can consume pounds of hamburger, however, if avocados are added; they can help stave off the inflammatory effects.
Fulgoni et al. (2) evaluated the relationship between avocado intake, diet quality, and overall risk of the metabolic syndrome. They used the National Health and Nutrition Examination Survey database to evaluate their aim. They found that those who consumed avocados had significantly better dietary quality; significantly greater intakes of fruit, vegetables, total fat, monounsaturated and polyunsaturated fats, dietary fiber, vitamins E and K, magnesium, and potassium; and significantly lower intakes of added sugars. They also reported that body weight was significantly lower, and blood levels of high-density lipoprotein (HDL) cholesterol were significantly higher in those who consumed avocados. Fulgoni et al. (2) also reported that the odds ratio for metabolic syndrome was 50% lower in those who consumed avocados compared with those who did not. Although these data are strong for avocado consumers, one also must be aware of the fact that perhaps those who consumed more avocados also had overall healthier diets for other reasons. Nonetheless, because of the antiinflammatory and antioxidant effects of avocados, adding them to the diet could help with overall health.
Nuts (e.g., almonds, walnuts, hazelnuts) can help decrease LDL cholesterol in the blood, as well as reduce the risk of blood clots. Nuts also may improve the lining of arteries in the body. Nuts not only are a good source of protein but also contain monounsaturated and polyunsaturated fats, in particular, omega-3 fatty acids, which also are found in fish, and can help decrease the risk of heart disease. Nuts also contain fiber and vitamin E (5).
In addition to their heart-health benefits, nuts may help with weight loss. Abazarfard et al. (1) studied the effects of almonds on body composition and lipid profile in overweight and obese women on a weight loss program. There were 100 overweight and obese women who participated in a 3-month randomized controlled trial. Participants were assigned randomly to a balanced hypoenergetic almond-enriched diet (almond group) or to a balanced hypoenergetic nut-free diet (nut-free group). Thus, the groups consumed the same amount of calories, but the only difference was that those in the almond group consumed 50 g (450 kcals) of almonds per day during the 3-month trial.
Abazarfard et al. (1) reported that body weight, body mass index, waist circumference, waist-to-hip ratio, diastolic blood pressure; blood concentrations of total cholesterol, HDL cholesterol, triglyceride; and fasting blood glucose all significantly decreased in the almond group. They reported a greater decrease in LDL cholesterol levels and systolic blood pressure, with a greater increase in HDL cholesterol concentrations in the nut-free group. Despite these better changes in lipid concentrations and systolic blood pressure, the overall change in body weight and other cardiovascular markers establish that there may be a benefit to including almonds as part of a weight loss plan and as part of an overall diet, even if weight loss is not a goal, for improvement in cardiovascular health.
Fish is a high-protein food that provides vitamins D and B2 (riboflavin), as well as iron, zinc, calcium, phosphorus, magnesium, and potassium. Although low in fat, fish is an excellent source of omega-3 fatty acids (docosahexaenoic [DHA] and eicosapentaenoic [EPA]), which can help prevent cardiovascular disease, help with healthy brain function, and may decrease the pain of arthritis. Although all fish have DHA and EPA, these fats are found at especially high levels in salmon, sardines, anchovies, tuna, trout, herring, and mackerel. It is recommended that individuals consume fish at least two times per week (8).
Hansen et al. (3) evaluated the effect of fatty fish consumption on sleep, heart rate variability, and serum levels of DHA and EPA, as well as serum levels of 25-hydroxyvitamin D (25OHD), the usual measure of vitamin D status within individuals. Ninety-five men, who were in an inpatient facility, were assigned randomly to the fish group or the control group. The fish group consumed salmon three times per week from September through February, whereas the control group was given an alternative meal (e.g., chicken, pork, beef). The fish group had better sleep (measured via sleep latency) than the control group, and heart rate variability at rest was affected positively by fish consumption. Serum concentrations of DHA and EPA were significantly higher in the fish group. At the end of the study, vitamin D status was closer to optimal concentrations in the fish group compared with that in the control group. In this study, consumption of salmon three times per week had a positive impact on sleep and heart rate variability.
In this article, I discussed some functional food that have been shown to improve health and even act as an ergogenic aid for muscle soreness (berries). Berries, avocados, nuts, and fish all have established and favorable effects on health, in particular, cardiovascular health. Incorporating these food into one’s regular food pattern can lead to health benefits and perhaps exercise performance benefits as well.