Salad Science

November 14, 2011 Written by JP    [Font too small?]

I rarely eat salads at home or at restaurants. I have all kinds of excuses as to why this is so. I tell myself that salad dressings are usually loaded with preservatives, sugar and other undesirable ingredients. When dining out, I convince myself that the ubiquitous iceberg lettuce isn’t nutritious enough to merit several minutes of chewing. I even worry about getting tiny pieces of salad stuck in my front teeth and not knowing it until dinner, often with clients, colleagues or friends, is over! But, recently a friend who happens to be a salad fanatic inspired me to take another look at the science behind salads. What I found has, at long last, convinced me that salad lovers may have been right all along.

One of the most appealing reasons to eat more salad is that it’s one of the few effective and healthy dieting techniques around. Researchers at Pennsylvania State University report that adding a salad to a meal reduces total meal calories by 11% and increases total meal vegetable consumption by 23%. Previous research indicated that eating a low-calorie salad at the beginning of meals accomplishes this by enhancing satiety. Eating salads is also an excellent way of ensuring nutrient density and mitigating oxidative stress. For instance, a paper appearing in the Journal of the American Dietetic Association reports that salad eaters are 119% to 165% more likely to meet the recommended dietary allowance for Vitamin C than infrequent salad eaters. In addition, if you add fresh herbs and spices such as ginger, lemon balm or marjoram and healthy dressing ingredients such as apple cider vinegar and olive oil in your dressing, you can substantially increase the salad’s overall antioxidant capacity.

Avocados and low-sodium soy sauce are two other additives worth including. Putting a modest 150 gram serving of avocado slices on a salad has been shown to increase the absorption of protective carotenoids (beta-carotene, lutein, lycopene). Dark soy sauce is yet another source of potent antioxidants. Research further indicates that low-sodium soy sauce is a health promoting and palatable alternative to common table salt in salad dressing. When putting this all together, here’s what we find in real world terms. Children who eat a “health conscious” diet containing regular salads may benefit from a cognitive standpoint as attested by higher IQ scores. Men and women with the highest salad intake carry a lower odds ratio (-17% to -24%) of developing cardiovascular disease. One study revealed an even more dramatic finding. Frequent salad consumption reduced the incidence of new cases of diabetes by approximately 84% in an examination involving over 1,110 middle-aged adults living in the UK. To my mind, the evidence in favor of salads is now overwhelming. Let’s all keep that in mind the next time we go out for dinner or shop at the local farmer’s market.

Note: Please check out the “Comments & Updates” section of this blog – at the bottom of the page. You can find the latest research about this topic there!

To learn more about the studies referenced in today’s column, please click on the following links:

Study 1 – Salad and Satiety. The Effect of Timing of Salad Consumption on Meal (link)

Study 2 – Salad and Satiety: Energy Density and Portion Size of a First-Course (link)

Study 3 – Salad and Raw Vegetable Consumption and Nutritional Status (link)

Study 4 – Antioxidant Capacity of Vegetables, Spices and Dressings Relevant (link)

Study 5 – Carotenoid Absorption from Salad and Salsa by Humans … (link)

Study 6 – Salt Reduction in Foods Using Naturally Brewed Soy Sauce (link)

Study 7 – The Identification of Antioxidants in Dark Soy Sauce (link)

Study 8 – Are Dietary Patterns in Childhood Associated with IQ (link)

Study 9 – Seasonal Consumption of Salad Vegetables and Fresh Fruit (link)

Study 10 – Frequent Salad Vegetable Consumption Is Associated with (link)

Low Sodium Soy Sauce Can Replace Salt in Salad Dressing

Source: J Food Sci. 2009 Aug;74(6):S255-62. (link)

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Posted in Diet and Weight Loss, Food and Drink, Nutrition

11 Comments & Updates to “Salad Science”

  1. Sylvia Stewart Says:

    Thanks for that great post Healthy Fellow! I personally love salads and mine always include a homemade olive oil dressing and avocado. I love your tip about using low sodium soy sauce in place of salt however! Your post is encouraging me to toss more salads as the winter months ensue to help fight the ‘battle of the bulge’.

  2. JP Says:

    Thank you, Sylvia. Here’s to more salad eating! 🙂

    Be well!


  3. MiaB. Says:

    So glad to hear this {from a fellow current salad enthusiast!}
    I often use avocadoes also, & will try the dark soy sauce…(sounds like it would be especially tasty with ginger~!)
    Thanks for the great info on your blog ; )

  4. joanna Says:

    When I was in the US, I found that asking for a salad without dressing confused waitresses for some reason and so I took to asking for a slice of lemon instead, which made a lovely addition to the salad.

  5. JP Says:

    Thank you, MiaB! Much appreciated! 🙂

    Be well!


  6. JP Says:

    Hi, Joanna.

    I’ve become a bit of a pro at ordering (and usually receiving) exactly what I want when dining out. I frequently make special requests or ask for substitutions in order to make meals healthier. I’ve found that if I ask in a clear, kind way, my wishes are usually granted. The way I look at it, we’re paying customers and we ought to be able to enjoy the food we’re buying.

    Be well!


  7. Michael at Alternative Health News Says:

    Salads with more variety and with many healthy ingredients make the taste buds happy and make the whole experience much more enjoyable. Salads do not have to be dull they can be as creative as you want to make them.

  8. JP Says:

    Agreed, Michael!

    Be well!


  9. JP Says:

    Updated 08/12/15:

    J Epidemiol Community Health. 2014 Sep;68(9):856-62.

    Fruit and vegetable consumption and all-cause, cancer and CVD mortality: analysis of Health Survey for England data.

    BACKGROUND: Governments worldwide recommend daily consumption of fruit and vegetables. We examine whether this benefits health in the general population of England.

    METHODS: Cox regression was used to estimate HRs and 95% CI for an association between fruit and vegetable consumption and all-cause, cancer and cardiovascular mortality, adjusting for age, sex, social class, education, BMI, alcohol consumption and physical activity, in 65 226 participants aged 35+ years in the 2001-2008 Health Surveys for England, annual surveys of nationally representative random samples of the non-institutionalised population of England linked to mortality data (median follow-up: 7.7 years).

    RESULTS: Fruit and vegetable consumption was associated with decreased all-cause mortality (adjusted HR for 7+ portions 0.67 (95% CI 0.58 to 0.78), reference category <1 portion). This association was more pronounced when excluding deaths within a year of baseline (0.58 (0.46 to 0.71)). Fruit and vegetable consumption was associated with reduced cancer (0.75 (0.59-0.96)) and cardiovascular mortality (0.69 (0.53 to 0.88)). Vegetables may have a stronger association with mortality than fruit (HR for 2 to 3 portions 0.81 (0.73 to 0.89) and 0.90 (0.82 to 0.98), respectively). Consumption of vegetables (0.85 (0.81 to 0.89) per portion) or salad (0.87 (0.82 to 0.92) per portion) were most protective, while frozen/canned fruit consumption was apparently associated with increased mortality (1.17 (1.07 to 1.28) per portion).

    CONCLUSIONS: A robust inverse association exists between fruit and vegetable consumption and mortality, with benefits seen in up to 7+ portions daily. Further investigations into the effects of different types of fruit and vegetables are warranted.

    Be well!


  10. JP Says:

    Updated 08/12/15:

    Eur J Nutr. 2015 Jun;54(4):557-68.

    Dietary glycaemic load associated with cognitive performance in elderly subjects.

    PURPOSE: Ageing is associated with loss of cognitive function and an increased risk of dementia which is expected to place growing demands on health and long-term care providers. Among multiple causative factors, evidence suggests that cognitive impairment in older subjects may be influenced by diet. The objective of this study was to examine the association between dietary patterns, dietary glycaemic load (GL) and cognition in older Irish adults.

    METHODS: Community-dwelling subjects (n 208; 94 males and 114 females; aged 64-93 years) were analysed. Dietary intake was assessed using a validated semi-quantitative food frequency questionnaire. Cognitive capacity was tested using the Mini-Mental State Examination (MMSE). The data were clustered to derive patterns of dietary intake. Multivariable-adjusted logistic and Poisson regression models were used to examine the relationship between dietary GL and MMSE score.

    RESULTS: Elderly subjects consuming ‘prudent’ dietary patterns (high in fruit, vegetables, fish, low-fat dairy and salad dressings and low in red meat and white bread) had higher MMSE scores (better cognitive function) than those consuming ‘Western’ dietary pattern (high in red meat and white bread and low in fruit and vegetables; P < 0.05). Logistic and Poisson regression analyses both indicated that the MMSE score was inversely associated with the GL of the diet (P < 0.05) even after adjusting for age, gender, diabetes, hypertension, healthy food diversity, nutritional status, residential property price, cardiovascular medications and energy intake. CONCLUSION: In this community-dwelling elderly Irish cohort, consumption of a high glycaemic diet is associated with poorer cognitive performance as assessed by the MMSE. Be well! JP

  11. JP Says:

    Updated 12/21/16:

    Food Chem. 2017 Apr 15;221:521-534.

    Changes in rocket salad phytochemicals within the commercial supply chain: Glucosinolates, isothiocyanates, amino acids and bacterial load increase significantly after processing.

    Five cultivars of Eruca sativa and a commercial variety of Diplotaxis tenuifolia were grown in the UK (summer) and subjected to commercial growth, harvesting and processing, with subsequent shelf life storage. Glucosinolates (GSL), isothiocyanates (ITC), amino acids (AA), free sugars, and bacterial loads were analysed throughout the supply chain to determine the effects on phytochemical compositions. Bacterial load of leaves increased significantly over time and peaked during shelf life storage. Significant correlations were observed with GSL and AA concentrations, suggesting a previously unknown relationship between plants and endemic leaf bacteria. GSLs, ITCs and AAs increased significantly after processing and during shelf life. The supply chain did not significantly affect glucoraphanin concentrations, and its ITC sulforaphane significantly increased during shelf life in E. sativa cultivars. We hypothesise that commercial processing may increase the nutritional value of the crop, and have added health benefits for the consumer.

    Be well!


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