The Health Benefits of Wholefoods Part 3.
In Part 2, I wrote about how plant compounds behave differently in wholefoods compared to when they are isolated in a concentrated form, using the example of studies with antioxidant sports supplements and prostate cancer studies with whole ginger extract versus an artificial mix of isolated compounds from ginger. There are a growing number of studies like these to provide further examples, and the general consensus from the scientific community is that wholefoods deliver much greater health benefits than isolated constituents with known activity. Not only are wholefoods more effective, but they are also safer.
More studies are required on safe doses of purified phytochemicals
It isn’t just sports supplementation that we need to be cautious about. The long-term effects of many purified chemicals are unknown and there are also no RDAs (Recommended Daily Amounts) for phytochemicals. High doses of even “healthy things” can lead to toxicity. For example, the antioxidant Vitamin C when taken in high doses (500mg) can have a pro-oxidant effect in the body and set about damaging DNA, and green tea extract taken as a supplement in high doses has been linked to some cases of liver toxicity. In many cases, there just isn’t enough information yet. The cholesterol-reducing ability of plant sterols has been used with great success in a number of functional foods, but this subject area has been studied extensively since the 1950s and to a high degree of scientific rigor i.e. randomised double-blind clinical trials.
Plant compounds act together to increase their bioavailability
I also touched on bioavailability in Part 2. The phytochemicals present in plants change during passage through the digestive system and most phytochemicals are metabolically modified within the gut before entering the blood circulation. As more is understood about bioavailability, it is increasingly found that the synergistic effect of plant compounds is highly relevant when it comes to their absorption in the body.
I’m very aware of the power that spices have when they are combined with each other
It’s also worth mentioning that there is a synergistic effect between plant compounds from different foods, highlighting the importance of good quality meals with varied ingredients. From my own experience, I’m very aware of the power that spices have when they are combined with each other, and black pepper is a real hero in this respect. A major constituent of black pepper called Piperine is known to increase the bioavailability of other nutrients in food, by increasing the amount of time that nutrients stay in the body and by increasing the uptake of nutrients in the digestive tract. This means that Piperine can drastically improve the efficacy of a substance. Over the last few years, the spice turmeric has been held up there with other “superfoods” for its potent antioxidant and anti-inflammatory activity, a result of its high curcumin content. However, curcumin is notorious for its poor bioavailablity. In other words, it is poorly absorbed by the gut, rapidly metabolised and tends to be eliminated very quickly from the body. However, when curcumin is taken with piperine from black pepper, bioavailability dramatically increases – one study in humans found this to be by as much as 2,000%!
This synergistic effect between different combinations of wholefoods is not limited to bioavailability. For example, studies on fruit have shown that combinations of fruit result in greater antioxidant activity.
Supplements are a second choice to a diet rich in plant-based wholefoods
I’m not against supplements by any means. Living in the north of Scotland where good quality sunlight is in short supply during many months of the year, I don’t think I would manage well without taking my vitamin D supplements! There are certainly some very good supplements out there, especially for people who are unable to obtain what they need through diet. In my view, though, supplements are a second choice to a diet rich in plant-based wholefoods. The U.S. Preventative Services task force published results in 2013 from a study that looked at whether selected vitamin and mineral supplements prevent cancer and cardiovascular disease in people without nutritional deficiency. Despite reviewing 26 studies, (24 randomised, controlled trials and two cohort studies), researchers found little evidence that such supplements help prevent cardiovascular disease, cancer, or anything else if you are healthy and not nutrient-deficient! Taking nutritional supplements makes sense in principle but in clinical terms, they have been shown to do little to prevent disease in healthy people who are not nutrient deficient in the first place. Plant-based wholefoods, on the other hand, have been shown to prevent disease.
Claude Barnard introduced an interesting, yet simple and seemingly obvious concept back in the 19th Century; that of the body as a host for disease. A healthy body presents a lower risk than that of a body that is undernourished and immune-compromised, a concept I came face to face with at the leprosy colony in India. The modern phenomenon of over-eating and eating the “wrong” types of foods is also putting the body at risk of disease, with the rise in diabetes, heart disease and dementia a testament to this. How will these people fair in a world of antibiotic resistance? There is no one-size-fits-all solution, but as technology moves forward, DNA testing and biochemical/metabolic monitoring will pave the way for a future of more effective and personalised nutrition and exercise plans, optimised for greater health and performance of an individual.
As scientists work steadily to unlock the power of plants, we are shown the massive potential of phytochemicals to strengthen the body against disease. The debate on the use of wholefoods versus single isolated constituents has spurred numerous studies that have consistently hailed wholefoods and wholefood extracts as the winners, yet despite the popularity of plant-based wholefoods and the rise of “clean eating”, information about their absorption, distribution and metabolism in the body is still relatively thin on the ground. However, from a scientific point of view, this is a space worth watching.
Wholefood plant extracts, such as ginger, show great promise as dietary supplements to help manage specific health conditions. However, although it is tempting to reach for the pills, until more is known, supplements should be treated with caution and a balanced diet rich in plant-based foods is consistently being shown as the best way forward for overall health.
The recent development of biomarker technology at Glasgow University to allow “fingerprints” of specific health conditions to be determined using the proteomic analysis of urine will be a game-changer when it comes to analysing the direct effect of specific foods and supplements on disease of an individual. Over the next few years, it will become easier to test claims associated with bioactive foods and ingredients but I expect this technology will also enable the discovery of more “superfoods” and pave the way for a new generation of functional foods and personalised diets, backed up by sound scientific evidence.
I think we’ve reached a turning point. The consumer is increasingly questioning marketing claims and we are going into 2016 with a much more positive message than “detox” when it comes to healthy eating and drinking; plant-based whole foods that promote health and wellbeing, not only supplying us with essential vitamins and minerals but that provide a treasure-trove of phytochemicals able to heal, prevent chronic disease and promote longevity. Plant actives are team players. They have always worked together and always will.
Helen Saini, PhD.
Fortmann SP., et al. (2013). Vitamin and Mineral Supplements in the Primary Prevention of Cardiovascular Disease and Cancer: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force. Ann Intern Med. 2013;159:824-834. doi:10.7326/0003-4819-159-12-201312170-00729. http://annals.org/article.aspx?articleid=1767855
Liu RH. (2003). Health benefits of fruit and vegetables are from additive and synergistic combinations of phytochemicals. Am J Clin Nutr. Sep; 78(3 Suppl):517S-520S. http://www.ncbi.nlm.nih.gov/pubmed/12936943
Podmore ID. et al. (1998). Vitamin C exhibits pro-oxidant properties. Nature. Apr 9; 392(6676):559.
Shoba, G. et al. (1998). Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Med. May: 64(4): 353-6. http://www.ncbi.nlm.nih.gov/pubmed/9619120