So, let's take a step back and try to define things, because I think there's some confusion here.
- Supplements can be bad for you (we agree).
- Soylent contains supplements (we disagree).
- Therefore, point one applies to Soylent (we disagree).
The problem here is obviously point two. In an abstract sense, the definition of a fortified food is that it's a food that contains supplements. So point two is obviously correct, right?
Well, not in the way you seem to be implying. To quote your article:
Through his analysis, Byers found that people who took high doses beta carotene supplements had an increased risk for lung cancer. Selenium supplements were associated with skin cancer. Men who took vitamin E had an elevated risk for prostate cancer. Folic acid, a B vitamin, taken in excess could lead to an increased risk for colon cancer.
These are dietary supplements in the common definition of the term: (loosely) vitamins/minerals/etc. taken in addition to the food you eat. The article doesn't mention any studies about eating a diet devoid of a nutrient and instead supplementing it (which isn't exactly Soylent but closer) or eating a diet of fortified foods (which Soylent essentially is). Soylent is a meal replacement (a food), not a dietary supplement. Until you prove that the studies somehow apply to Soylent as well as dietary supplements, we will continue to disagree, no matter the terminology we use.
I'll make one more example to hopefully clarify things. Soylent 1.6 contains 60 mg of vitamin C, according to the spreadsheet. The entirety of the vitamin C is from the vitamin & mineral premix. Are you "supplementing" vitamin C if you subsist on 100% Soylent 1.6? Of course not, it's an essential vitamin. Regardless of whether or not you call it a supplement, it's obviously healthier to not die of scurvy. To be what Soylent is (a nutritionally complete food), it needs to be, you know, nutritionally complete.
Are there other options? Sure, you could eat an orange, or make a Soylent-type product from whole foods, or take a dietary supplement (ahem), or eat "normal" foods instead. But my point is that, whatever we call Soylent, you're making a connection to studies that don't apply to Soylent.
One last quote from your article:
A person who has a known deficiency of a certain vitamin or mineral -- either due to diet or health condition that prevents proper absorption -- can take a supplement, preferably a multivitamin that provides levels in line with recommended daily allowances. But in every case, Byers cautions consumers to acknowledge that there may be "harm in excess."
Taking a supplement is better than a known deficiency, according to your article. Soylent checks out.
Levels of vitamins and minerals in line with recommended daily allowances are preferable, according to your article. Soylent checks out.
There may be harm in excess, according to your article. Soylent checks out.